Athlete’s foot is a frequent infection that millions of people suffer from annually. I once had it during my military service where we had to wear boots almost an entire day. Once during a noon intercession, I performed my ablutions to pray and I placed my feet under the sunlight to dry them. I was also hoping that ultraviolet rays from the sun would be good for the infection. Soon, flies swarmed in between my toes. When I could not bear the excessive itching, I tried to kill the flies until I was stopped by a friend who reminded me of the great sage Bediuzzaman’s comments where he called flies “cleaning workers.” At that time, I also remembered Prophet Muhammad’s (peace be upon him) words on flies. So, I patiently endured the nuisance, and repeated the same procedure for the next three or four days. Eventually, my feet were healed and there was no trace of the fungi.

In one of his very interesting hadiths, the Prophet, peace and blessings be upon him, is reported to have said the following about flies: “If a fly falls into your drink, dip it into your drink, then throw it away, for on one of its wings is a disease, and on the other is a cure. It dips the wing with the disease to protect itself” [1]. This hadith has been a reason for much controversy mainly due to germ disease theory.  According to Jonathan C. Brown, “even before modern medicine, the Hadith of the Fly was raising skeptical eyebrows and prompting Sunni defensiveness as early as the writings of Ibn Qutayba (d. 276/889)” [2]. Brown also mentions that this hadith “could be false or it could be true, since scientists used the flesh of a snake to help prepare antidotes to its poison” [3].

Before the microscope was invented it was impossible to define microbes or talk about the anatomy or microbiology of flies as we can today. However, the introduction of experimentation and observation as an important scientific method with the Renaissance served as a turning point in Western scientific revolution. Thus, the “proof-based medicine” conception that relies on experimentation and observation emerged as a precursor to today’s medicinal and scientific research. The importance of perceptions that rely on causes relating to the material world in persuading the human mind cannot be denied. It is harder to make people believe in something unless they are provided with concrete results that appeal to our five senses. We should not rush to deny any claim solely based upon our preconceptions and prior knowledge without doing any research about it; rather, we should pass our judgment on it after experimentation and observation.

Some people may automatically reject the idea that when a fly falls in our food or drink that we should immerse this microbe-carrying insect completely and they may say that this would not eliminate the microbes. Indeed, it may sound reasonable to assume that this disgusting insect that feeds on all sorts of dirt would cause only diseases. If you have an ample supply of food or water and if you do not have the stomach for it, you can of course refrain from eating or drinking such a food or drink. But, you can hardly advise someone who has very little water or food in a desert or at the time of famine to throw away what they have because of a fly.

We should examine different types of flies in laboratory settings using the method of experimentation and observation. First of all, it is very difficult to prove that someone can contract an illness from eating food in which a fly had fallen into although he or she had immersed that fly completely in that food. If it is proven that someone becomes ill due to a fly’s alighting in their food, then strong objections can be raised. If it is said that there many diseases caused by flies, no one will deny it. The point is not whether flies carry germs, but whether this advice for being protected from the germs carried by flies is correct or not. As a matter of fact, the advice by the Prophet seeks to protect us from diseases that may be caused by germs carried by flies. The great scholar Bediuzzaman’s words on flies also give us an alternative perspective to consider about these “tiny birds”:

“…Flies are dutiful about cleaning away noxious substances or germs that cause disease. By sucking up and absorbing harmful germs, they destroy them, and they cause noxious or poisonous substances to change into other harmless forms, thus preventing the spread of many contagious diseases. A sign that they are both laborers for health and cleansing operatives and chemists, serving many instances of wisdom, is the fact that they exist in extremely great numbers. For the things that are valuable and beneficial are multiplied.” [4]

The hadith of the Prophet and Bediuzzaman’s commentary encourage us to explore more about flies and whether they can be a source of healing in any way.

Flies are very ubiquitous on earth. There are approximately 125,000 species of flies, but only ten species live in our homes and are of concern to us. They feed on garbage and organic waste materials that act as a breeding ground for microbes such as bacteria, fungi, and viruses. The female fly lays down more than 100 eggs in the dung of some animals or in garbage. After one day, the larva emerges to feed on the surrounding organic materials. In two weeks, they become full-grown flies. In four generations, one female fly can lay 1.5 million eggs, but fortunately the majority die due to weather circumstances or become food for birds, reptiles, amphibians, and other insects. A fly can live for 60 days at most.

Given the ecological balance in nature, one comes to accept that there should be species that will remove all sorts of organic waste, garbage, dead animals or plants, and similar things by eating them. Houseflies feed on the rotting corpses of animals while female horseflies suck blood. How can flies, which act as health workers that are charged with the duty of cleaning the world, digest so many diverse amounts of garbage and waste?

Flies get their nourishment differently from other animals. What other animals do for digestion is done by flies outside their bodies. They do not have teeth-like structures in their mouths in order to chew solid, dry food and therefore have to turn such food into liquid form or split it into 0.45-mm or smaller pieces. In this liquid form, flies can easily suck up their food using their suitably shaped mouths. To do this, flies vomit a saliva-like liquid, containing enzymes and acids, and that disintegrates the solid food into something that can easily be digested in a couple of seconds. In this process, some of the microbes in that waste food can be disintegrated while the rest will be sent to the stomach.

These foods and microbes taken inside in the form of vomit are sent to a sac called a “crop” if they are not small enough to go through the digestive tract. Flies produce fresh saliva regularly during which the vomit moves between their mouths and crops. Eventually, the sufficiently liquefied food is sent to the stomach which contains enzymes and acidic content as well as partially disintegrated microorganisms.

What does scientific research tell us?

Based on the theory that flies must have remarkable antimicrobial defenses and resistance to survive the bacteria from rotting dung, meat, and fruit, a team at the department of biological sciences at Macquarie University in Australia set out to identify those antibacterial properties.

“Our research is a small part of a global research effort for new antibiotics, but we are looking where we believe no one has looked before,” said Joanne Clarke, who presented the group’s findings at the Australian Society for Microbiology Conference in Melbourne.

Clarke’s research showed that flies produce their own antibiotics, and this was tested on four different fly species. Such research may lead to better treatments for human infections from Escherichia coli and other virulent bacteria even, perhaps, Staphylococcus aureus (MRSA).

Upon preliminary results, a global pharmaceutical company decided to support the research over the next six months by trying to isolate antibiotic compounds from the material collected from the flies. The research team is trying to identify the specific antibacterial compounds. As antibiotics that will eventually be invented and chemically synthesized come from the body surface of flies, not from other fungi or bacteria, it is believed that any gene that gives resistance to microbes will not be easily transferred to pathogens and the new antibiotic form will have longer and more effective treatment duration [5].

Later, Russian doctors had developed interest in this topic and observed that flies contain many substances that can be more effective than traditional medications and certain fly larvae have very strong therapeutic effects [6].

Noting that flies should be kept away from hospitals, Professor Juan Alvarez Bravo at the University of Tokyo expressed his support for such research, saying, “But soon we will witness a rapid treatment for many diseases, which consists of extracts from flies” [7].

Some researchers at Auburn University of the United States discovered a protein in the fly’s saliva which can accelerate the lengthy process of healing wounds and chronic skin cracking. Entomologists Ed and Mary Cupp managed to isolate the protein which houseflies inject into their prey to increase blood flow in the skin of their prey. Mary Cupp and surgeon Steven Swaim demonstrated that surgical incisions, skin ulceration, and diabetic foot lesions treated with solutions that combine antibiotics and this protein heal faster and stronger than incisions treated with antibiotics alone [8, 9].

In another study, it was found that epithelial cells forming the inner layers of the front and back intestines of the fly protect it from the bacteria it swallows thanks to a special cuticular lining, and in this way, bacteria never directly touch the intestinal epithelium and cannot give any damage to it. In this study, it was noted that people nurtured a radical approach to flies and that fly control has been abused for the sake of human health, suggesting that flies may be the source of novel germicides that make use of their antimicrobial digestive enzymes, lysozyme, and antimicrobial peptides [10].

Viruses cause many diseases in cattle, sheep, and birds. These diseases include encephalitis, aphthous fever (foot and mouth diseases), and duck plague which can be transferred to people through infected animals. Some crops such as potatoes, tomatoes, bananas, and sugarcane can also be destroyed by viral infections.

Flies carry the viruses of many diseases which are consequently transferred to man’s food, drink, and body. Of these viral diseases are common flu, measles, mumps, chickenpox, warts, yellow fever, infectious liver diseases, some cases of paralysis, some types of cancer, and some chronic diseases of the central nervous system.

El-Naggar, Zaghloul, from Egypt, indicates that some of the disease-causing viruses may directly infect living beings and cause damage to their cells, while there is a type of virus which infects bacteria cells known as “bacteriophage.” These viruses, which can kill the bacteria they infect in a short time, are known as “virulent bacteriophage.” Those viruses that do not kill the bacteria they infect are called “temperate bacteriophage” [11].

After a bacteriophage infects a bacterium, more than 100 viruses are released from that bacterium and each of these viruses can infect new bacteria. The spreading of infection may continue until all vulnerable bacteria cells die. After it was discovered that bacteriophages are parasites of bacteria, they started to be used in treating the diseases caused by bacteria. However, their use in this manner declined after the discovery of antibiotics. Yet, the interest in phage treatment was revived after the emergence of bacterial resistance to antibiotics [12].

Researchers from Stanford University announced that they found a substance in flies that can improve the human immune system [13].

The work by Rehab Mohammed Atta from the Microbiology and Immunology Department, National Research Center, Cairo, Egypt, is quite remarkable [14]. In this research, the extracts taken separately from the left and right wings of flies were used against the bacteria and fungi calculated on nutrient “agar” media in the laboratory. It was demonstrated there was both bacterial and fungal growth for the left wing extract plates while no bacterial or fungal growth was reported for the right ones.

Given the fact that the garbage and rotting corpses on which flies feed from contain numerous dangerous bacteria, it is quite reasonable that it contains antibacterial materials necessary for its survival. In this case, the fly’s needs might be of service as sources of antibiotics that can prevent epidemics among human beings, and this may be the reason why they were created in the first place: not to be a source of nuisance but a source of healing for us.

Aj-Taili, et al., from the department of medical microbiology, Qassim University in Saudi Arabia, conducted an experiment using water, honey, and various fruit juices in different cups. They found no germ in the solution in which the whole body of fly was immersed while the solution in which only one wing of the fly was dipped indicated the presence of germs [15].

In sum, we can say that antibacterial materials produced in the bodies of flies protect them against the microbes in their environments and that these microbes can prevent epidemics among human beings. At the very least, this topic deserves in-depth research. Atta’s study confirms the virtue of the hadith that says, “The best way to release this vital antidote is to dip the fly in a liquid because these substances are concentrated on the outer surface of the fly body and wing.” Abduldaem al-Kaheel refers to this study in his website: “This is logical because the fly has a lot of harmful bacteria on the outside of her body and therefore in order to continue in her life, it should also carry anti-bacterial materials; these materials were furnished by God to protect it from viruses and diseases.” In the light of these studies, the need for conducting more research for obtaining antibiotics from the right wing of the fly is clear [16].

References

1. Abu Dawud, At’imah, 49. Also see Bukhari, Tib, 57, Bed’u al-Khalk 17; Ibn Majah, Tib, 31, Nasa’i, Far’, 11.
2. Brown, Jonathan A. C. 2009. Hadith: Muhammad’s Legacy in the Medieval and Modern World, p. 264.
3. Ibid. p. 255.
4. Nursi, Bediuzzaman Said. 2008. The Gleams. The Light, Inc. p. 376.
5. Danny Kingsley, ABC Science Online, 1 October 2002, The new buzz on antibiotics. Clarke, J., Gillings, M. and Beattie, A. (2002). Hypothesis-driven drug discovery. Microbiology Australia, pp. 8–10.
6. Petersburg State University, (2006). The fly effect: Russian Scientists Invent new medicine with the help of flies.
7. Bravo, J. A. (1994). The ointment in the fly: antibiotics. New antibiotic derived from a common fly. The Economist (US).
8. Ed and Mary Cupp (2005). Protein in Fly Saliva Speeds Healing of Incisions Wounds. Auburn University. R Am Ex Ars Medica, Inc., 7:23.
9. Protein in Fly Saliva Speeds Healing of Incisions, Wounds 20-Jan-2005. www.newswise.com/articles/protein-in-fly-saliva-speeds-healing-of-incisions-wounds
10. Nayduch, D. and Burrus, R.G. (2017). Flourishing in Filth: House Fly–Microbe Interactions Across Life History. Special Collection: Filth Fly–Microbe Interactions. Annals of the Entomological Society of America, 2017, Vol. 110, No. 1.
11. El-Naggar, Zaghloul, (2010). Housefly Falls into One’s Drink! 09 September 2010. www.quranandscience.com/quran-science/sunnah-science/204-housefly-falls-into-ones-drink-274
12. Aydogan, D.Y., Hadimli, H.H. (2016). Bakteriyofaj Tedavisi (Bacteriophage Treatment), Etlik Vet. Mikrobiyol. Derg.; 27 (1): 38–47.
13. Stanford University Medical Center, 2007. Fruit Fly Insight Could Lead to New Vaccines. Science Daily. www.sciencedaily.com/releases/2007/03/070308220904.htm
14. Atta, R. M. (2014): Microbiological Studies on Fly Wings (Musca domestica) Where Disease and Treat. World Journal of Medical Sciences 11 (4): 486–489.
15. Aj-Taili, S.I., A.A.R. Al-Misnid and K.D. Al-Uteybi, (2002). Wing One and the Other Disease Carrying the Cure. Qassim University. Danny Kingsley.
16. Abduldaem al-Kaheel, 1995. New facts: fly have a cure, www.kaheel7.com/eng.

The teeth of a tiny mollusk (Patella vulgata), which is a species of sea snails, have been found to be some of the strongest biomaterials in the world. Also known as limpets, these mollusks are a very small crustacean, often around 0.05-2 cm in size with a large cone shell and possess an incredibly complex system of teeth that dazzles the mind.

Research has revealed that the tensile strength of the sea snail’s teeth is higher than that of spider silk and is comparable to only the strongest commercial carbon fibers. It was found that the teeth of sea snails scraping algae off of rocks showed a tensile strength between 3 and 6.5 GPa (gigapascals). Spider silk roughly reaches a tensile strength of about only 1.3 Gpa. Scientists say that the snail’s teeth can even withstand the pressure that turns carbon into diamonds. Studies have determined that, to our current knowledge, there is no other material of this size (roughly 100 μm micrometers) with as much strength and durability.

This exceptional durability has led scientists to do research on the structure and functioning of these teeth, and the studies showed fascinating results.

The role of teeth in nutrition

Sea snails have a special tongue, called a radula, which they use to scrape off food from rocks. The most important feature of the radula is that it contains more than 100 rows of iron-mineral teeth. However, those used for food intake consist of only 10 rows on the outermost part of the teeth. During eating, a tremendous mechanism operates: the teeth are constantly repositioned according to their conditions of maturation and wear. Worn teeth are replaced by newly matured teeth over the course of 12 to 48 hours to ensure that fresh, sharp teeth are used instead of dulled ones.

This wonderful displacement system operates in a similar way to the movement mechanism on a conveyor belt where the teeth begin to grow primarily in the posterior part of the radula. Meanwhile, they are strengthened and matured by iron mineralization. When this mineralization is complete, they are moved towards the front of the radula. In this way, completely matured teeth are permanently retained at the far-front scraping area. During the scraping process, the matured teeth wear out at a rate equal to the growth rate. In the meantime, a new set of teeth begins to grow. By means of this magnificent cycle, new teeth are constantly created and matured so that there are no disruptions in nutrition.

Biomineralization

The structure of the sea snail’s teeth is also a masterpiece of material science. The dazzling durability of its structure provides optimum strength when scraping food off of rock surfaces.

Although the exact process of biomineralization of the teeth is not known, it is believed that it involves reactions of dissolution and re-precipitation. When the non-mineralized matrix is examined, well-arranged and densely packed chitin fibers are observed that are only a few nanometers apart. The matrix is a structure which keeps the reinforcing material together in layers that are composed of different materials. This organic matrix serves as a framework for crystallization in the structure of the teeth. In the mineralization system, the basic macromolecule α-chitin component is created first. The first mineral that then precipitates is the “goethite,” i.e. the aqueous iron-oxide mineral, which crystallizes parallel to the chitin fibers. These crystals are nucleated on the chitin fibers and formed between them by pushing and pulling the fibers. This way, crystals placed in order cause biomineralization of the structure.

It was found that 80% of the overall volume of the structure is composed of these crystals. The gap between the crystals and the chitin matrix is filled with amorphous silica (SiO₂). The iron contained in the aqueous iron-oxide mineral is the metal that constitutes the largest proportion of the composition. Other metals such as sodium, potassium, calcium, and copper are present in different proportions depending on the sea snail’s exact geographic location.

Critical factors in durability

The most important reason that the sea snail’s teeth have such high durability is because the fibers of the aqueous iron-oxide minerals in the teeth are nano-scale. This is due to the fact that materials of this size are not affected by the conditions that reduce strength.

Another critical durability factor is the small length of critical fibers. Critical fiber length is a parameter that defines the length of a material required to transfer strain from the matrix to the fibers at the time of external pressure. To achieve maximum strain, the length must be greater than the critical length. Materials with a large critical fiber length can hardly reinforce the matrix because most of the strain is not transferred to the fibers and remains on the matrix. On the contrary, materials with smaller critical lengths can transfer the strain on the matrix to the fibers. Therefore, they serve as an effective reinforcement for the matrix.

Fibers of aqueous iron-oxide minerals are of a critical length of 420 to 800 nanometers. This is much smaller than the length of the fibers in the teeth of about 3.1 µm (micrometers). This shows that nanofibers are an effective reinforcer for the matrix and contribute greatly to the ability of the teeth to bear loads.

Besides the structure and composition of the snail’s teeth, its morphological shape is also important in providing strength. It ensures that the strain is evenly distributed all over the tooth.

Modeling of biomaterials

All these studies indicate the presence of high-strength composites, which is when a material obtained by combining two or more materials with different physical characteristics, in nature.

Sea snail teeth, which have been created as a highly resistant and strong biomaterial, act as an inspiration for engineering and material science. Their characteristics, such as content and design, are expected to be modeled in areas that require durability and rigidity.

These marvelous systems found in the natural world, sometimes in creatures as tiny as a snail or mollusk, serve as a reminder that nature is filled with wonders for us to explore.

References

· Barber, Asa H., Dun Lu ve Nicola M. Pugno, Extreme Strength Observed in Limpet Teeth,  Journal of The Royal Society Interface, April 2015, DOI: 10.1098/rsif.2014.1326, PubMed.

· World’s Strongest Natural Material Discovered, How It Works, Imagine Publishing, No. 71, p. 11.

· en.wikipedia.org/wiki/Limpet
www.iflscience.com/plants-and-animals/worlds-strongest-natural-material-limpet-teeth/

· www.newworldencyclopedia.org/entry/Limpet

· Barber Asa H., Lu Dun and Pugno Nicola M. “Extreme strength observed in limpet teeth.” 12. J.R. Soc. Interface. http://doi.org/10.1098/rsif.2014.1326

{module Science Square (Issue 128)}

First miniature human heart printed

Noor N et al. 3D Printing of Personalized Thick and Perfusable Cardiac Patches and Hearts.  Advanced Science, April 2019.

In a major breakthrough, researchers have “printed” the world’s first 3D vascularized engineered heart using a patient’s own cells and biological materials. This could have huge repercussions for human health: the World Health Organization said that last year, ischemic heart disease and stroke were the world’s leading cause of death for both men and women. Heart transplantation is currently the only treatment available to patients with end-stage heart failure. Given the serious shortage of heart donors, scientists have been trying to develop new “3D organ printing” approaches to regenerate the diseased heart. Past studies were only able to print simple tissues without blood vessels. The new study showed for the first time that an entire heart with cells, blood vessels, ventricles, and chambers could be successfully engineered and printed. The researchers first took a biopsy of fatty tissue from patients and separated the cellular and a-cellular materials of the tissue. While the cells were reprogrammed to become pluripotent stem cells, the extracellular matrix – a 3D network of extracellular macromolecules such as collagen and glycoproteins – were processed into a personalized hydrogel that served as the printing “ink.” After being mixed with the hydrogel, the cells were then robustly differentiated to cardiac or endothelial cells to create patient-specific, immune-compatible cardiac patches with blood vessels and, subsequently, an entire heart. The heart was 3D-printed in about three hours and was too small for humans. It was the size of a rabbit’s heart (~ 2.5 centimeters). But it is completely biocompatible and, most importantly, matches the patient, which reduces the chances of organ rejection inside the body. A human-sized heart might take a whole day to print and would require billions of cells, compared to the millions used to print these mini-hearts. While it’s not clear if a printer can produce hearts that are equal or superior to human ones, perhaps by printing patches there will be a possibility to improve or take out diseased areas in the heart and replace them with something that works. Researchers hope that maybe in 10 years, there will be organ printers in the finest hospitals around the world, and these procedures will be conducted routinely.

Bacterial factories for spider silk

Zhang F et al. Synthetic Biology for Microbial Production of Protein-based Materials, the American Chemical Society (ACS) National Meeting & Exposition, Spring 2019.

Spider silk has always fascinated researchers due to its lightweight and superior strength and numerous applications in areas such as drug delivery, smart textiles, and artificial muscles. It is one of the strongest natural materials in the world. It is thinner than a human hair, but its strength is more than that of steel, pound for pound. Since farming spiders is incredibly inefficient, scientists have been trying for decades to find a way to mass produce the material from genetically modified bacteria, yeast, and even goat milk, but these efforts have always fallen short. The biggest challenge was that the genetic information for dragline silk is a long string of repeating DNA, and, in previously tested organisms, cellular machinery arbitrarily alters or chops up such DNA sequences. To circumvent this problem, researchers precisely separated the repeating DNA into bits and inserted each repeating piece separately into bacterial genome. These smaller DNA pieces produced small peptides that ended up combining in bacteria and formed a strand of silk. The researchers also added to the end of each strand a chemical tag that glued the individual fibers together. This method was able to produce 2 grams of spider silk for each liter of bacteria and the resulting material behaved exactly like dragline silk. Its tensile strength was measured at 1.03 gigapascals, about the same as for naturally produced dragline silk. The engineered silk’s toughness measured 114 megajoules per cubic meter, compared with around 100 megajoules for silk made by spiders. And the engineered silk strands could stretch 18 percent before breaking, the same as natural dragline silk. The new silk was developed in part with NASA funding for applications such as giving astronauts a means of producing tough materials while on Mars. But the substance could be used in designing stronger materials for robotic, medical, or textile applications.

Electricity from falling snow

Ahmet A et al. All printable snow-based triboelectric nanogenerator. Nano Energy, April 2019.

Researchers have designed a new device with which we can now obtain electricity from falling snow. This new energy conversion method could become a new source of electricity in the future, especially in remote areas, as it does not need batteries. Researchers called it a Snow-based TriboElectric NanoGenerator, or Snow TENG. It is inexpensive, small, thin, and flexible like a sheet of plastic. After starting a charge from static electricity, energy is generated from the exchange of electrons. Snow is already positively charged by giving up its electrons, while silicone, a rubber-like material which consists of silicon atoms and oxygen atoms, is combined with carbon, hydrogen, and other elements to be negatively charged. When the positive-charged snow falls onto the surface of the silicone, the charges interact, and the Snow TENG captures the charge, which allows it to turn snowfall into electricity. 30% of Earth’s surface is covered by snow each winter, which is also the time when solar panels, one of the most reliable renewable sources of energy, aren’t very effective. Snow accumulation reduces the amount of sunlight that reaches the solar array, which makes them unable to operate. Snow TENG could be integrated into solar panels and provide a continuous power supply, even at a time when it’s snowing. Researchers used 3D printing to design the small device. It consists of a layer of silicone and an electrode which can capture the electric charge. Given that silicone is widely used in the industry, this method could dramatically reduce the global costs of producing electricity.

After the discovery of using steel to reinforce concrete, reinforced concrete buildings became extremely popular and presented a significant solution to the housing needs of urban populations.

The composition of concrete

Concrete is a structural material formed via blending sand, gravel, cement, and water. The specifications and ratios of the materials present in the mix directly determine the quality of the concrete. Generally, this ratio is 31 sand, 46 gravel, 15 cement, and 8 water. These ratios may vary depending on the construction needs.

The mixture of sand and gravel is described as an aggregate. Usually, aggregates up to 7 mm are called sand, and aggregates between 7-70 mm are called gravel. The most important role of the aggregate as a fill material is to reduce the volumetric changes of the concrete. The dough composed of water and cement displays great changes in volume. The introduction of sand and gravel into the cement helps to lessen these changes and also saves resources, since it is cheaper than cement. In order to obtain a concrete of good quality and applicable texture, the sand and gravel grains should be as round as possible and have similar diameters to each other.

Cement is produced from grinding a mixture of clay stones and limestone (CaCO3) that are cured at high temperatures. Cement is very important; when combined with water, it helps concrete to quickly solidify. The time the mix takes to solidify is called the setting time, and it is usually between an hour and an hour and a half, depending on environmental conditions. This time is shorter on warmer days and longer on colder days. Concrete begins to gain endurance (hardening) as it solidifies. It takes 28 days for the concrete to reach an endurance of 60-90 , and a much longer time to reach 100, depending on conditions. The cement amount in a cubic meter of concrete is called the dosage. One common and incorrect perception is that concrete endurance changes with the dosage. However in a mixture of a well adjusted sand and gravel ratio, concrete endurance depends on the water-cement ratio.

The water that can be used in the concrete mixture should be drinkable water that does not contain acids and salts. It is important that the water has a pH value higher than 7 and is free of carbonic acid, manganese compounds, ammonium salts, free chlorine, mineral oils, and industrial waste. Therefore, it should not be forgotten that sea water must not be used in the concrete mixture because of the salt it contains.

The properties of steel

Iron alloys that can be processed mechanically – either through pressing or rolling – are called steel. Iron is the most abundant metal in the Earth’s crust, making up nearly 4.5 of it. The most important element that specifies the property of steel is carbon. The role of carbon in steel’s structure is to harden the iron alloy and prevent the shifting of iron atoms. By adjusting the amount of carbon in the alloy, steel’s hardness, ductility, and endurance can be changed. Both the endurance and hardness of steel increases as the amount of carbon is enriched. However, this application increases steel’s fragility, reducing some of its features, such as ductility. Therefore, a 5 carbon level in the raw iron obtained through the melting of iron ore is decreased to 0.1 0.2, enabling steel to be processed. Iron alloys (steel) composed of elements such as carbon, silicon, manganese, chromium, copper, nickel and molybdenum are utilized in building structures.

The conformity of concrete and steel as reinforced concrete

Reinforced concrete materials are used in the construction of buildings, bridges, dams, and tunnels. The use of reinforced concrete became common at the end of the nineteenth century. For the best final product, the concrete and steel should be well integrated, and both should be of high quality.

Concrete and steel are two substances with very different characteristics. However, an inseparable coupling forms by balancing one’s disadvantages with the other’s advantages. Concrete is a material of high pressure endurance. And even though steel also has high pressure endurance, it still faces the risk of bending. The tensile strength of concrete is weak, but it is high in steel. Concrete is fire resistant; steel is vulnerable. Concrete is durable against external impacts, whereas steel is vulnerable, with a high risk of corrosion. Concrete has a brittle, breakable structure; steel, however, has a higher level of ductility. Even though concrete and steel generally behave the opposite of each other, they compensate for each other when they are together. For example, the tendency of steel to bend disappears after it is surrounded with concrete; concrete also increases steel’s resistance to fire and corrosion. Furthermore, with the steel’s presence inside it, the tensile strength of concrete is enhanced.

The first of the three characteristic features of reinforced concrete buildings is the compensation of all tensile forces via steel rods; the second one is the integration of concrete and steel into each other like the adherence of flesh and bone; and finally, concrete and steel have the same thermal expansion coefficients. The thermal expansion coefficient is the value that determines the amount a material will expand or retract when impacted by heat. The thermal expansion coefficients of substances on Earth vary greatly. For instance, aluminum has a coefficient of 2,2×10-5 L/0C, copper of 1,7×10-5 L/0C, gold of 1,4×10-5 L/0C and glass of 0,85×10-5 L/0C (L= Length). It is harder for materials of different thermal expansion coefficients to have conforming movements. The most important reason for the harmonious union of concrete and steel is that their thermal coefficient values are almost the same (1,2×10-5 L/0C). If this was not the case, because of the temperature differences of inside and outside environments, the concrete and steel that make up the reinforced concrete would expand at different speeds, resulting in cracks and fractures of the load bearing elements of the building (columns, beams, flooring).

Though concrete and steel have vastly different properties, their thermal expansion coefficient values are the same and this causes them to move together during temperature changes. A similar system is put to use during the creation of cartilage, bone, and connective tissues in our body. The fibers of the connective tissue resemble the iron and steel, the cells are similar to gravel, and the intercellular matrix resembles the cement. The difference is that this system is renewed dynamically, and is flexible and strong.

In the past, the area missing a tooth could be filled by bridge implants by eroding the enamel on neighboring teeth. In cases where there was a large gap or no teeth to use as connectors, removable implants were used. In other words, present healthy teeth would be treated to compensate for the missing teeth; if the number and health of the remaining teeth was not sufficient, removable implants would be produced that gave the “ready to fall out” feeling. The imperfections of this type of implant led scientists to pursue new ideas.

Scientists have tried to fill in missing teeth with artificial roots and with implants mounted over these by mimicking the existing tooth root. This way, there is no need to treat and erode the healthy enamel of neighboring teeth in the gap. These artificial roots, which are positioned into the jaw bone by a surgical operation, are called a “tooth implant.” Modern-day implants are generally composed of two main parts.

One of these is the fixture part which is secured into the jaw bone by screws; the other is the support part (abutment) which mimics the visible parts of the tooth in the mouth. Approximately 3-4 months of curing time is required for the fusion of bone and implant (osseointegration), which is screwed together by a surgical operation. Towards the end of this time, the implant is built over the abutment. The length of time necessary for the implant to integrate with the bone to replace a tooth which can be extracted so quickly is rather noteworthy despite ongoing studies to reduce the wait time and successful attempts to do so.

Employed materials

Even though the main logic for implants is the mimicry of the tooth and the root, the materials utilized are quite variable. The history of such implants goes back thousands of years. The employment of bamboo sticks in tooth restorations could be seen in some civilizations, such as ancient China. Mayans used sea shells, which were recently shown to be biologically suitable as implant material. Maggiolo produced a tooth root by using gold, in 1809. In the beginning of the 20th century, Lambotte prepared implants using materials such as aluminum, silver, brass, copper, and gold.

These newer implant methods have failed because of the insufficient strength of the majority of the materials and the failure to fit into biological tissues. The initial employment of titanium and its alloys in the 1950’s almost opened a new age in implantology and enabled the successful use of these materials up until today. However, these titanium implants, which are considered successful, have a very limited ability to mimic tooth roots:

• Once the implant is in place, for reasons such as aging and improper tooth brushing, tooth gum recession and resurfacing of the bright faces of the implants which mimic the root surface can take place. This leads to undesirable displays. Even though gum recession can also occur in natural teeth for similar reasons, this situation is not as disturbing as with implants. This is because the tooth root color is similar to that of the tooth surface.
• Under normal conditions, implants should be fused to integrate with the bone (osseointegration). Integrated implants are considered successful clinically. A similar case to this bondage, which is unwanted clinically, is the fusing of tooth and bone which can be seen generally in dead teeth and is called ankylosis. Many hardships can be encountered when the tooth that is fused with the jaw bone is required to be removed. The same thing also applies to the implant. If an implant is set to be extracted for a reason, even if just a small amount must be removed, the surrounding jaw bone must be removed as well. However, a natural tooth is not bonded so tightly to the jaw bone, as if the tooth is healthy, it is suspended over the jaw bone through small suspension-like structures. When a tooth is needed to be pulled as a result of trauma or tooth rotting, only these suspensions are detached; thus any damage to the jaw bone is averted. Present efforts to design similar mechanisms for implants have not been successful yet.
• When a disease develops in our natural teeth, we feel pain and take action before it is too late. However, diseases within implants are rarely encountered as pain; generally, when the pain is felt, the implant is already disconnected from the bone and it is lost. Toothache often felt as a strong pain is a blessing granted to us. If the implants were built with pain mechanisms, just like in our natural teeth, we could take action at the beginning of the disease and avoid the time and financial losses.
• Even a healthy tooth, which we think of as immobile, can move via microscopic ligaments for 0.1 mm around its root on a type of pad. The tooth root is created in a perfect fashion to resist the strong chewing power that can be generated from many directions in the mouth through these ligaments, which are wrapped around different sides and which come from different angles. However, these ligaments, which act as a suspension, do not exist in between the implant and jaw bone. Therefore, implants are almost immobile. Even though it may seem like a good thing for them to be immobile and tightly fixed, there may be intense power spots generated on the implant or jaw bone since these forces acting on the implants are transmitted to the jaw bone without being dispersed. Forces densely acting on small areas can lead to fractures of the material, including tiny screws or porcelain plating, and can damage the bone tissue. Investigators once understood that these tiny, suspension-like structures won’t form around the implant, so they engaged in mounting tiny Teflon or spring pieces inside the implant to generate suspension. However, these imitated suspensions failed to resist the chewing forces that can go up to 400 kg at times, and their use was aborted after a short time.
• Teeth can be examined by the method of tapping with small hand tools (percussion). These small impacts cause pain in case of an abscess at the tooth root. By taking necessary actions, the tooth can survive longer. It is impossible to do such determination and diagnosis with implants.

As it is seen, making less successful artificial implants as opposed to real teeth is quite a cumbersome, costly, painful, and time consuming job. Despite all of these imperfections, because of their numerous advantages over traditional implants, the popularity of dental implants continues to increase, and is preferred by dentists and patients. In addition, implants are seen as an inevitable treatment option when tooth loss occurs, and may ultimately provide patient relief in the long run.

Despite progress made in implants, it’s clear that our teeth were created in such a perfect way, down to the very smallest detail, that they cannot be replaced. Science is well aware of the fact that we will never fully be able to replicate tooth structure. Therefore, studies are shifting towards stem cell research. This way, instead of foreign substances, the missing tooth will be compensated as if by planting tooth seeds by using human’s own cells. Nonetheless, the opportunities that are discovered via all these efforts will never replace the natural teeth that were so perfectly created for us.

Organic substances in the soil go through oxidative decomposition depending on factors such as temperature, air, humidity, and pH balance. This is a slow burning (oxidation) event of organic substances. However, oxidative decay is hindered if one of the aforementioned factors is lacking. Then, a slow decay of organic materials in soil called humification takes place.

Humification occurs in an open system in contact with air. For example, early chemical processes start with leaves changing color in autumn. The break down and partial ingestion of leaves by soil organisms follows. During this time, water soluble carbohydrates and proteins leave the leaf tissue. What remains behind are plant structures like cellulose and lignin, which are not broken down yet. Since leaf shapes are not completely deformed, species identification can still be possible at this stage. In the decay step, however, the cellulose and lignin are decomposed by various fungi species and converted to humus.

Humic substances and their properties

Humic substances are intermediate products that occur as the result of organic materials going through a series of chemical reactions. These intermediate products are humic acid, fulvic acid, and humate. Their molecular weights are around 1.000-10.000 gr/mol, 10.000-100.000 gr/mol, and 100.000-10.000.000 gr/mol, respectively. Humic acids contain weak aliphatic (carbon chains) and aromatic (carbon rings) organic acids that are soluble in water when it has a base medium but insoluble under acidic conditions.

Fulvic acids with smaller size molecular structures can reach plant roots, branches, and leaves easily because they are soluble in water under all pH conditions (acidic, neutral, and basic). Thus, trace elements such as iron, zinc, copper, manganese, and boron can be easily transported to plant tissues via fulvic acid.

Humates, however, are insoluble in water. Only the portion of a humate called ulmic acid can dissolve in alcohol.

Major functions have been assigned to humic matter in the nutrient and carbon cycle, as they are inseparable members of the ecosystem. Plants capture significantly more nutrients from humic matter than from clay minerals. Even though they can be depleted from soil by certain agricultural practices in less than 50 years, they can still remain in natural soils, outside human activity, for hundreds or even thousands of years without being degraded. This very long presence in soil enables them to continue their functions longer. According to radiocarbon dating, humates can last approximately 1140 years; and humic acid and fulvic acid last for 1235 and 870 years, respectively, in natural soils.

Positively charged nutritious elements (cations) remain in the soil by binding to negatively charged (anions) in humic matter. Because this bond is weak, useful elements for the plant can easily be exchanged with another cation, becoming free and getting absorbed by the plant. On the other side, cations such as iron, copper, zinc, magnesium, manganese, and calcium, which are hazardous to plants when taken excessively, are held in the soil, bound to humic matter and thus not causing toxicity.

Another significant feature of humic and fulvic acid is their ability to form water bridges. Water bridges facilitate the movement of nutrient ions towards roots via soil solutions.

Aside from agriculture, humic matter, with its aforementioned properties, serve humankind in the industrial, environmental, and biomedical fields.

Industrial and environmental applications

Humic matter is utilized in the staining of leather works, as wood lining paint (natural blue color), as well as water based stripping material for furniture stains. Humic matter is also used in the production of durable, resistant papers in the paper industry, to provide mechanical strength to processed ceramics, and as an additive. It is also applied as a coloring, hardening, and plasticizing agent in plastic fabrication.

Humic and fulvic acids gain significance regarding their ability to form water soluble substances with many metal compounds containing radioactive elements in their structure.

In environmental chemistry, the main role of the humic matter is to remove toxic substances, human sourced organic chemical matter, and other pollutants from water. Calcium humate, obtained from humic matter, can bind and remove nickel, iron, cadmium, and copper in addition to radioactive elements produced at nuclear power plants from water.

Humus based filters are designed to treat sewage water and mud waste. Oils, stains, poisonous phenolic substances, and pesticides are removed from sewage via these materials. In poultry, humic substances are employed to absorb and eliminate the odor of waste gases.

Biomedical applications

Drugs for the treatment of human and animal diseases are developed from humic matter. These can be used for the treatment of viral and bacterial illnesses, in the prevention of blood clots, to cure infections, and to remedy estrogen deficiencies. Clinical studies have shown that common viral diseases of children’s respiratory tracks can be treated with fulvic acid supplements. A lot of medical research has shown that humic matter, especially fulvic acids, have the ability to provide protection against cancer causing viruses. In a study, laboratory mice were given ethanol to trigger gastritis and it was determined that humic acids supplied to mice led to a significant reduction in the harm gastritis caused. The fact that humic acids can form compounds with heavy metals, such as cadmium, enables the excretion of heavy metals from organisms.

In our universe there is no place for waste. Once every particle completes its task, it is returned in a different fashion to be assigned another job. Humification is a good example to this reassignment as a complex recycling event in the soil. It is amazing to observe everything being generated from one thing and everything converted into one thing so easily and in such a crafty, balanced, and organized fashion. In fact, the power and wisdom behind the conversion of the remains of millions of different organisms into a few similar substances to be employed in different tasks are no less amazing.

With all of its faculties, a human being can be thought of as an index of the whole universe. Therefore, we witness correlations between the processes taking place in the human body and in the universe. Accordingly, the world we live in has a correspondence to human biology. For example, the cyclical processes in the environment (water cycle, carbon cycle, etc.) ensure the continuous recycling of the same matter, hence the cleanliness of the habitat for all. Similarly, the human body includes mechanisms to cleanse itself from harmful and unnecessary materials.

Prior to the development of such an understanding, the prevailing attitude encouraged consuming natural resources and using the environment as a “trash can.” Even today, we live in a world that promotes excessive consumption of daily goods leading to accumulation of incredible amounts of trash. For example, in developed Western societies, an average family discards more than one ton of trash every year, which is mostly paper, packaging material, and kitchen waste.

Nevertheless, as we realize the importance of the recycling systems in nature and the multi-faceted harms of trash accumulation on the environment, recycling of conventional and technological waste is encouraged by collecting plastics, glass, paper, and tins. On a larger scale, recycling centers have been developed to minimize the damage to the environment and to meet the need for raw materials.

The recycling process consists of three main steps as depicted by the famous three-arrows symbol representing 1) the collection of materials, 2) the remanufacture of new materials from the collected ones, and 3) reselling or reusing as new products. Thus, recycling centers not only contribute to the economy, but also serve as clearance sites to maintain the harmony of the environment.

Cellular recycling through “fasting”

Similar to recycling centers at the macro level, there are recycling centers in the cellular level too. These centers have the duty to help with the digestion of cellular trash (i.e. damaged cellular organelles, misfolded proteins, toxic load) so that energy can be generated and raw material obtained for the construction of new cellular units. This recycling phenomenon was simply named as autophagy (i.e. self-eating) by cell biologists. What is interesting, though, is that autophagy is primarily activated or enhanced via fasting or food deprivation.

How autophagy works

Autophagy is a process that occurs when astarving cell starts to form double membrane containers through an orchestration of several proteins. These containers are called autophagic vesicles or autophagosomes ¹. Their main role is to target and collect cellular trash. Then, they start to fuse with lysosomes, the digestion centers of the cells, to degrade the trash into building blocks—amino acids. The amino acids can then be used both for the construction of new proteins needed by the cell and in the production of ATP, which is a source of energy for the cell.

The whole process corresponds to micro-scale representation of a real world recycling concept: collection, re-manufacture and resell/reuse. Through autophagy, a cell recycles its own material and obtains energy ².

Fasting: An emerging trend

With the discovery of mechanisms initiating autophagy and its involvement in various diseases such as cancer, neurodegenerative disorders, auto-immune diseases etc., autophagy has gained a unique significance that is progressively increasing ³. After the year 2000, the number of publications on autophagy-related research began to increase exponentially. Moreover, due to the increased conviction about the link between fasting and autophagy, fasting started to become a real trend in modern civilizations. Let’s examine a few of the important recent findings that reveal the relationship between autophagy and fasting.

In a study involving mice, the response to fasting was assessed in liver cells (hepatocytes) by tracking the presence of a protein (GFP-LC3) that indicates autophagy. It was seen that the lack of food, which is the source of energy, led to the disintegration of mitochondria, which are the power plants of the cells. Subsequently, the components that made up those mitochondria were re-utilized for the building of other necessary proteins⁴. These results indicate that unnecessary mitochondria were eliminated for the sake of recycling organic materials during fasting.

Neurodegenerative diseases, such as Alzheimer’s or Parkinson, etc, are linked to the accumulation of trash in the brain cells, which is indicative of a lack of autophagy. Drugs developed for these diseases do not possess effective treatments since they are unable to penetrate into the brain cells (a concept known as the blood-brain barrier). During another study involving mice, in one track, animals were exposed to fasting, and in the other, their brain cells, (more precisely cortical neurons and Purkinje cells) were isolated and exposed to food deprivation. In both tracks, researchers observed that fasting enhanced autophagy, suggesting that fasting could be a simple, cheap, and safe therapeutic cure for prevention of neurodegenerative diseases ⁵.

In another study, this time involving a subset of kidney cells (proximal tubule cells), a lack of autophagy resulted in the accumulation of dysfunctional mitochondria and other cellular debris. As a result, the cells grew in size abnormally (hypertrophy), decreasing the functionality of the kidney. This suggested that autophagy was part of the continuous maintenance of proximal tubule cells and that inducing autophagy in the kidney may provide a novel therapeutic approach to minimize acute kidney injury ⁶.

As a final example, one more study revealing the association between autophagy and the immune response should be mentioned. It was found that the number of autophagic vesicles (chambers) in the macrophages, a subset of immune cells that are the first to perceive threats to our body, increased as a response to invading bacteria. These vesicles wrapped, sequestered, and digested the bacteria eaten by macrophages ⁷. Thus, fasting has the potential to improve the fighting ability of macrophages against invading pathogens by enhancing autophagic machinery.

Taken together, the autophagy process seems to be a recycling mechanism with minor variations depending on the cell type and activation triggers. Once initiated, it leads to a) reduced accumulation of cellular trash (toxic protein aggregates); b) an improved immune response for removing bacteria (intracellular pathogens); and c) the protection of the interior of the cell (cytosol). As one of the main stimulators of autophagy, fasting or food deprivation seems to be a way for improving health.

Next time you fast, keep in mind that while you are starving, your cells are feasting for your health. Just as the natural world is structured to continually cleanse and renew the earth, fasting seems to trigger similar processes inside the human body. While individuals may choose to fast for spiritual cleansing, their physical bodies experience a cleansing as well.

Abdullah Acar is freelance writer in the US with a special interest in biology.

References

1. Mizushima, N., et al., Autophagy fights disease through cellular self-digestion. Nature, 2008. 451(7182): p. 1069-75.
2. Mizushima, N. and M. Komatsu, Autophagy: renovation of cells and tissues. Cell, 2011. 147(4): p. 728-41.
3. Yang, Z. and D.J. Klionsky, Eaten alive: a history of macroautophagy. Nat Cell Biol, 2010. 12(9): p. 814-22.
4. Kim, I. and J.J. Lemasters, Mitochondrial degradation by autophagy (mitophagy) in GFP-LC3 transgenic hepatocytes during nutrient deprivation. Am J Physiol Cell Physiol, 2011. 300(2): p. C308-17.
5. Alirezaei, M., et al., Short-term fasting induces profound neuronal autophagy. Autophagy, 2010. 6(6): p. 702-10.
6. Kimura, T., et al., Autophagy protects the proximal tubule from degeneration and acute ischemic injury. J Am Soc Nephrol, 2011. 22(5): p. 902-13.
7. Fujita, N. and T. Yoshimori, Ubiquitination-mediated autophagy against invading bacteria. Curr Opin Cell Biol, 2011. 23(4): p. 492-7.

Nanoscience and nanotechnology started off in the early 1980s when scientists were able to detect materials on the nano-level through microscopic systems. This development enabled the synthesis of nano-level materials such as carbon nanotubes, nano crystals, and metal oxide nanoparticles. Nanotechnology is a type of technology, resulting from the research conducted on the atomic, molecular and macromolecular levels. A nanometer is one-billionth of a meter. Nano-level studies are conducted with materials whose sizes range between one to a hundred nanometers. Studies on the nano-level are conducted in the contemporary science fields such as chemistry, materials science, physics, biology, etc. One of the most compelling reasons that renders the research with nano-level materials so significant is that nanoparticles reflect a lot more different characteristics than when they do at the macro-level. Due to their small sizes, nanoparticles, especially those under 20 nm, have magnificent optical, magnetic, and chemical properties.[1] Nanoparticles include much more energy than the macro-level materials; this is because the ratio of the surface area of nanoparticles to their volume is much more bigger than the ratio in macro-level materials. A significant amount of energy is stored in nanoparticles as free surface energy. This energy revealed on the nano-level not only increases the reactivity of iron nanoparticles (the propensity to chemical reactivity), but also renders the magnetic qualities of materials quite differently than they would be at the macro-level.

Many types of nanoparticles are widely used in our daily lives. Iron, gold, silver and cadmium sulphide nanoparticles are some of the most commonly investigated nanoparticles. Yet iron nanoparticles receive special attention from scientists essentially in the field of biotechnology. Iron nanoparticles demonstrating different magnetic features have a wide range of use in fields, including but not limited to health care and electric/electronic industry. Owing to its magnetic feature, iron is also used in magnetic recording. The production of needle-shaped iron nanoparticles with high magnetic features has facilitated the manufacturing of mobile electronic devices with a high recording capacity. In this paper, we will focus on the use of iron nanoparticles’ contribution to the advances in the field of biotechnology, among numerous other contributions of iron nanoparticles in other fields.

Nanobiotechnology

Nanobiotechnology, among other fields of nanotechnology, is the field that focuses on biological systems. Nano-level devices designed to work with biosystems, nano-level cell biology, cell and nanoparticle interactions are some of the applications used in nanobiotechnology. Through those applications, biochemical processes and reactions in living beings can be scrutinized in great detail, which, in turn, enables scholars to come up with innovations in both diagnosis and treatment of various illnesses.

The following are the primary application areas of magnetic nanoparticles in the field of bionanotechnology: development of magnetic resonance imaging systems, and cancer research. Especially, iron oxides (magnetite, Fe3O4, maghemite, Fe2O3), owing to their cohesion with the chemical structure of biological systems, are prevalently used in biotechnology.

Magnetic Resonance Imaging (MRI)

MRI, mostly used in the medical field, is the method to monitor the internal structure of living mechanisms. Through the magnetic area and radio frequency waves, the image of a living tissue is formed. MRI is a complex system that produces images based on the intensity and movements of hydrogen atoms in the tissue. The MRI technique is used to diagnose almost all sorts of illnesses today. Yet it is most frequently used with illnesses pertaining to the central nervous system, brain and spinal cord. It has also been used to diagnose muscle-related and skeleton-related medical conditions, such as meniscus and herniated disc symptoms, as well as all types of neurological illnesses. MRI has not been found detrimental to any living organism thus far.

It is the paramagnetic ions such as gadolinium that are most frequently used as contrast enhancement agents in MRI applications. Although gadolinium has a high moment, this moment is too low compared to superparamagnetic materials. For this reason, superparamagnetic iron oxide nanoparticles are known to be more efficient MRI contrast enhancement agents. Known as such, those iron oxide nanoparticles are quite advantageous over gadolinium. Those nanoparticles can easily be functionalized to interact with biological samples. For example, superparamagnetic nanoparticles, which are not normally taken up by cells efficiently, can do so after being covered with another material (e.g. Dextran) that can ordinarily go into a cell. Thus, MR images of particular tissues could be obtained clearly, which enables us to make more accurate diagnoses and treatments.

Iron oxide nanoparticles are also deemed to be an efficient potential future method in cancer treatment. The results of several studies conducted to fulfill this goal are encouraging.

Iron oxide superparamagnetic nanoparticles are being tested as a method in hyperthermia treatment. Hyperthermia is defined as an abnormally high body temperature, and its treatment is carried out through the removal of certain tissues by increasing its temperature up to (42–46) 0C for 30 minutes. For instance, cancer infected liver tissues are exterminated through the hyperthermia method, which sends biologically activated iron oxide nanoparticles to those infected tissues. Moreover, none of the healthy tissues are damaged during this process. You may find more detailed information in references [1, 2, 4, 6] on how nanoparticles are aptly sent to the cancer infected tissues only while the surrounding healthy tissues remain unaffected by them. Hundreds of researchers carry out experiments and publish their findings on this topic everyday. Yet, further research needs to be done in order to reach solid conclusions.

Iron, which seems to carry greater potential significance than we previously thought, should receive much attention from scholars due to the fact that a chapter (surah) in the Holy Qur’an is entitled “Iron” (Hadeed). The question is, why was a 29-line chapter in the Qur’an is called (Iron) when the word “iron” was only mentioned once throughout the entire chapter.

The chapter “Iron” first begins by drawing the reader’s attention to the attributes and praised names of God. It invites people to believe in God and his messenger Muhammad (peace be upon him) by exalting God as the Almighty, Sovereign, Ruler, One whose existence is without a beginning and an end, Manifest and Hidden. Then, the chapter goes on to encourage believers to donate their wealth for the sake of God, for those who follow the word of God are rewarded with a place in Heaven. It also advises believers never to lose their ardor, while reminding them that even the earth will be resurrected after all has perished. And the wisdom behind the creation of iron is explained as such:

Assuredly We have sent Our Messengers with manifest truths (and clear proofs of their being Messengers), and We have sent down with them the Book and the Balance so that (relations among) humankind may live by equity. And We have sent down iron in [the essence] which is stern might and benefits for humankind, so that God may mark out those who help (the cause of) God and His Messengers, though they do not see Him. Surely God is All-Strong, All-Glorious with irresistible might. (57:25)

This particular verse includes several remarkable points. First, the very use of the phrase “sending down” for iron is so striking that it was also mentioned in [3, 5]. Another perplexing statement is, We sent down iron in [the essence] which is stern might and benefits for humankind, which might pave the way for thought-provoking venues regarding nanotechnology. The verse also indicates that which makes iron so special, its indiscernible or hidden qualities, rather than the outer surface of it. The specific reference to the “essence” of iron hints at this point. If the message of the verse had been related to the external qualities of iron, then the choice of the words would differ accordingly. Since the Qur’an is the word of God, there is wisdom behind the selection and sequencing of each word and letter. From this point of view, we can interpret that this verse informs us about the significance of the essence of iron on the nano level.

The significance of iron as stated in a single verse of the Qur’an has been briefly discussed. Numerous studies on the use of iron in nanotechnology seem to be on the horizon, which will only contribute to our admiration for the miracle of the Qur’an.

Kamil Ezgin is pursuing a PhD degree in chemistry in USA. For correspondence with the author kamilezgin@gmail.com.

References

1. Dale L. Huber. Synthesis, Properties, and Applications of Iron Nanoparticles, small, 2005, 1, No. 5, 482-501.
2. An-Hui Lu, E.L. Salabas, and Ferdi Schuth, Magnetic Nanoparticles: Synthesis, Protection, Functionalization, and Application, Angew. Chem. Int. Ed. 2007, 46, 1222-1244.
3. Edib Masûkî. “Enteresan Bir Tespit: Demirin Sakladiði Sir,” Sizinti, 1985, No. 73.
4. Peter Majewski and Benjamin Thierry. “Functionalized Magnetic Nanoparticles- Synthesis, Properties, and Bio-Applications,” Critical Reviews in Solid State and Materials Sciences, 2007, 32, 203-215.
5. http://www.mergeous.com/bullet.asp?tag=72
6. Volker Mailander and Katharina Landfester, “Interaction of Nanoparticles with Cells,” Biomacromolecules 2009, 10, 2379–2400.

Scientists were working on ways of obtaining complex micro or nano (a billionth of a meter) structures by using simple inorganic substances like silicon. Producing a micro-scale device such as a transistor required difficult and expensive processes such as cutting a silicon layer neatly. A species of sponge (tethya aurantia) has proved to be a model for a possible solution.

Like every other creature, sea sponges are given the ability to use chemical substances in the exact proportions they need to carry out their vital functions like an expert chemist. A sea sponge obtains siliceous acid from the water around it a few hundred meters under the sea. By a mechanism where chemical energy is used at high efficiency and silicatein enzyme functions as a catalyzer, this acid is transformed into silicon dioxide or silica, and perfect three-dimensional structures are built from it.

The most noteworthy aspect of this process is that there is no need for the poisonous chemicals or high temperatures scientists use to obtain complex inorganic structures. Sea sponges are granted the ability to build these complex structures far more effectively than the engineers who try to produce semi-conductive materials. When the outer tissue of a sponge is removed, the 2mm-long skeletal structure, which is thinner than human hair and which takes the form of glass needles, becomes visible.

Sponges fall into three categories with respect to the abundance of their cavities and the intricacy of the channels between them. Those with the maximum proportion of cavities and channels are the most desired ones. We can better understand how wonderful are the nano-scale structures within sponges by observing the relation between a sponge and water. When we dip a hand-size sponge in water and take it out, we see that it holds water equivalent to thousands of times more than its own weight. This is caused by the countless nano-cavities invisible to the naked eye within the body of the sponge. In these minute capillary distances, the adhesion and surface tension forces are given a dominant role between water and the substance of the sponge by the divine will. Sponges, which are classified as simple structured animals by some biologists, are granted some specialties to inspire us in making high technology products such as computer microchips and solar cells.

Daniel Morse and two of his colleagues from the University of California are working on some semi-conductive materials with amazing electronic features like turning daylight into electricity. The most important application field of this new technique will be more efficient photovoltaic solar cells. Presently, solar cells are produced under high temperatures and low pressure, which requires too much energy. However, the method taught to sea sponges is highly efficient and does not require high energy. Scientists have managed to produce simpler and cheaper solar cells by imitating sea sponges and using zinc oxide instead of silicon. This way the billion-dollar facilities where the semi conductive materials are produced can possibly be replaced by smaller units of production. The world of living beings has always opened doors to new horizons. Things we take for granted and to which we do not give much thought are waiting to be reflected upon and seen through the eye of wisdom.

References

• Paul Marks, Sea sponge leads way to cheaper solar cells, New Scientist, 24 March 2007, p. 32.

In general, the most common approach in tissue engineering is to develop tools as needed. Physicians treat patients and define the requirements for a better cure. Then, biologists study the targeted problem and learn what the mechanism is that caused the failure. Later, chemists and materials scientists manufacture the tools needed to treat the problem. Finally, the tools are delivered to doctors to treat the patients. Thus, tissue engineering requires a good understanding of how body parts work and come into existence, and this involves precise and sensitive application. Precise, aware and regular study of the interactions involved in tissues and organs must be practiced by the researchers who are interested in developing techniques for the manufacture of potential body parts. One of the first scientific approaches used for tissue engineering is to simply inject the body with molecules, such as growth factors, which are known to promote organ formation.

The growth factors are naturally occurring proteins which are assigned for cell proliferation and differentiation. Different parts of the body require different types of growth factors to signal to the cells to multiply or to replace the cells which have died or have been damaged. For example, it has been discovered that bone morphogenic proteins are responsible for the beginning of bone cell reproduction. For someone with a fractured bone that can not heal on its own within a reasonable period of time, the injection of bone growth factors to the site can direct the body to where bone cells are needed to be produced to repair the fracture.

In more severe conditions, the body may not receive the signal only with a simple injection of the growth factors. In this case, there is a need for more intricate treatment. Another way to treat organ malfunction starts with the harvesting of cells from the patient. The harvested cells can be multiplied in an artificial scaffold to eventually be implanted into the wound site. Because cells inhabit a different world than we do, we need a way to speak their language. The artificial scaffold should provide everything a cell needs and be able to direct the targeted cells toward the desired purpose. Basic knowledge gained from biology can help us to design potential artificial environments for cells.

A critical challenge in tissue engineering is how to design and make the artificial scaffolds. The cells must be fed through the blood vessel and are grown in the scaffold by the body; the scaffold should be able to communicate with the cells and finally the scaffold should disappear when its mission has been completed. The best example of a perfect scaffold is the natural environment of the cells, the extracellular matrix (ECM). The ECM provides support and anchorage for the cells and regulates communication between cells. There are various biological signals found in the ECM that help cell survival. For example, proteins called collagens provide mechanical support for cells through adhesive proteins in the ECM and the handles on the cell surface, known as integrins. Cell adhesion is crucial for cell survival and proliferation. Growth factors are also found in the ECM for cell organization. Some growth factors promote blood vessel formation, which can provide nutrients for cells. Therefore, a simple artificial environment should include various biological signals found in the ECM.

Currently, there are natural and synthetic scaffolds that are being used to generate the optimal environment for cells. Natural polymers such as collagen, chitosan or glycosaminoglycans, and synthetic polymers, including polylactic acid, polyglycolic acid, polycaprolactone or self-assembled nanofibers, are some of the materials used or considered for scaffold production. Natural polymers can be obtained easily, however biological contamination is a concern since they are produced using components from animals or microorganisms. Synthetic polymers can usually avoid the problem of contamination. Sometimes the ability to process the polymers can be problematic. Researchers have developed self-assembled nanofibers to overcome the problems that arise with synthetic and natural polymers. These nanofibers are composed of small molecules which are programmed to come together under control and to form larger structures. The nanofibers in the solution can form a three-dimensional network and convert into a self-supporting gel which can encapsulate cells as an artificial scaffold. In general, small bioactive molecules can be conjugated to the self-assembled molecules or can be encapsulated in situ in the 3-D network of fibers.

One of the recent uses of tissue engineering is to replace tissue that has been damaged by cancer. Cancer surgery is one of the most challenging types of surgery in that the defective tissue must be reconstructed afterwards. Improvement in surgical technology gives the chance of transferring a tissue from different sites of the body but unfortunately most of the time it is not the same tissue, and does not have the same texture or function. Reconstructing a resected tongue or the feeding tube is possible with the use of skin from the leg or forearm. But this skin does not provide the normal mucosal function, so it does not enable taste or sense to be perceived in the same way nor does it produce mucus in the same way. Together with advances in tissue engineering surgeons have started using the tissue-engineered mucosa of patients to reconstruct the mouth and feeding passage defects, instead of using the skin from chest, leg or forearm skin. These clinical applications of tissue engineering are in their very early stages, but it would not be surprising if we were able to reconstruct a lost organ from a similar one in the future. It would be exciting to be able to replace the tongue of a tongue cancer patient with a brand new tongue grown from his/her own tissues produced in a laboratory. Tasting the same…sensing the same…moving and even articulating the same…instead of having a piece of meat from another part of the body…

Innovative and imaginative work which has been inspired by natural materials demonstrates how the treatment of organ malfunctions is feasible. Efforts in biotechnology to develop tissue-engineered products will benefit many people who are searching for a healthier life. Potentially, in the near future, tissue-engineered products will be more widely used to treat bone fractures, serious skin burns, spinal cord injuries, diabetes, and heart diseases. Before implanting the tissue-engineered products, it is vital that there be extensive testing of the materials to be used. Toxicology and efficacy studies should be performed on the materials to prevent damage to the original healthy cells, and the new cells and regenerated tissue must be compared to original healthy cells and tissue.

Mustafa Guler has a PhD in chemistry. He is currently a research associate at Northwestern University, Chicago, IL. Joseph Coreman is a medical doctor at the Ohio State University Medical College, Columbus, OH.

References

• Khariwala SS, Vivek PP, Lorenz RR, Esclamado RM, Wood B, Strome M, Alam DS. Swallowing outcomes after microvascular head and neck reconstruction: a prospective review of 191 cases. Laryngoscope. 2007 Aug; 117(8):1359-63.
• Sauerbier S, Gutwald R, Wiedmann-Al-Ahmad M, Lauer G, Schmelzeisen R. Clinical application of tissue-engineered transplants. Part I: mucosa. Clin Oral Implants Res. 2006 Dec; 17(6):625-32.
• Hotta T, Yokoo S, Terashi H, Komori T. Clinical and histopathological analysis of healing process of intraoral reconstruction with ex vivo produced oral mucosa equivalent. Kobe J Med Sci. 2007;53(1-2):1-14.
• Ratner, Buddy D. “Biomaterials Science – An Introduction to Materials in Medicine” Elsevier, 2004.
• Lanza, Robert P., Robert S. Langer, William L. Chick, “Principles of Tissue Engineering”, Academic Press, 1997.
• Alberts, Bruce, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, Peter Walter, “Molecular Biology of the Cell” Garland Science, 2002.