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Repairing Wounds without Needle and Stitch

Wednesday, December 12, 2007

Iranian Researchers Produce Strongest Smart Tissue Adhesive in the World

Long ago, ants were used to repair wounds. As time went by, the quality of surgical stitches constantly increased. Today, Iranian researchers have produced the world’s strongest smart tissue adhesive, which is considered a major breakthrough in medicine.

We have interviewed Dr. Jalal Rasti, a pathologist; Dr. Abdoljalil Kalantar Hormozi, professor of Shahid Beheshti University of Medical Sciences and subspecialist in plastic surgery; as well as Dr. Mehdi Rasti, faculty member of Isfahan University of Medical Sciences and a fellow of plastic surgery at Shahid Beheshti University of Medical Sciences about the details of the invention. Dr. Kalantar Hormozi has led the research team while Dr. Mehdi Rasti has implemented the research plan to produce tissue adhesive.

“Tissue adhesive is used to keep wounded body parts close together. For example, when gut is damaged, the damaged tissue should be juxtaposed to promote healing.”

Dr. Kalantar Hormozi added that since stitches were introduced to medicine, some researchers maintained that if damaged parts could be juxtaposed using an adhesive, healing would be facilitated because the adhesive would bear mechanical pressure at the site of healing.

“In this way, industrial adhesives were introduced to medicine. However, invention of tissue adhesive dates back to the World War II (1940s) when researchers noticed that the main coagulant factor (fibrinogen) in human blood can be used as tissue adhesive. In this way, Fibrin Glue was invented in 1970s as the sole tissue adhesive in the world,” he noted.

Dr. Mehdi Rasti also noted that application of tissue adhesives was not common at that time due to various reasons including risk of viral infections, high price, and unavailability.

“Allergic reactions were a common problem with old adhesives. Proteins used in glues are different from body proteins and this can lead to allergic reactions,” he added.

Domestic adhesive, domestic researchers

Dr. Jalal Rasti says that about 60 scientific and news websites have reported breakthrough of Iranian researchers in producing the strongest smart tissue adhesive in the world.

He added, “Since proteins used to produce old adhesives were different from proteins of human body, they gave rise to allergic and hypersensitivity reactions. Therefore, we thought that if we could use everybody’s own proteins to produce such adhesives, the problem would be solved.”

Dr. Kalantar Hormozi then said, “However, to produce such an autologous adhesive, we were facing a big problem: in old methods, 4,000 milliliters of human plasma was needed to produce little amounts of adhesive. We cannot take that much plasma from a single human. Therefore, we decided to analyze components of an ideal adhesive and it took 12 months before we came up with a desirable formula.”

“High adhesive power, the ability to tolerate a lot of pressure and elasticity are major features of the adhesive that has been produced by us. Its elasticity is like Fibrin Glue, but is 7-10 times more capable of withstanding pressure while its adhesive power is the same. At the same time, it does not incite hypersensitivity reactions,” Dr. Mehdi Rasti said.

He added that the adhesive should include 11 elements to enjoy all the above features and Iranian researchers have tried to realize that goal by using a small amount of human blood.

“In addition, reducing the risk of viral infections is one of the most important characteristics of the new adhesive. Producing 3-5 milliliters of old adhesives like Fibrin Glue needed 10 units of human blood. Since the blood was taken from various people, the product increased the risk of transmission of viral infections,” he said.

Dr. Rasti also noted that some viruses cannot be diagnosed through normal laboratory methods. “Although the risk of transmission of some viral infections like hepatitis and AIDS has been reduced, but other viruses can still be transferred through blood,” the pathologist added.

“In this method we use 150 cc of blood to produce 3 cc of adhesive. Since the blood quantity is small, even patients with anemia can provide that much blood for production of tissue adhesive,” he explained.

In this way, Iranian researchers have produced one of the less dangerous medical products. This is the most powerful tissue adhesive in the world, not the first example of it. Dr. Kalantar Hormozi explained that such adhesives have been produced before, but they were not strong and were used to past skin on burns or to prevent bleeding from injured body surfaces without being able to obviate the need for surgical suture in vascular grafts.

Professor of Shahid Beheshti University of Medical Sciences stated that many tests have proven that the Iranian product is still the most powerful tissue adhesive. For example, in 2007, scientists used the most powerful tissue glue that had been known up to that time (Fibrin Glue) to put together the cut artery of a laboratory mouse. Instead of using 12 sutures, they used six sutures in addition to the glue.

Dr. Kalantar Hormozi added, “When the number of sutures was reduced to five, the adhesive was not able to keep the artery together and bleeding ensued.”

The specialist added that Fibrin Glue failed to promote gut healing and has not been successful in bone transplants.
“However, the adhesive produced by the Iranian researchers can put up with pressures 16 times higher than pressures tolerated by Fibrin Glue. We closed the main artery of a dog, which is 8 times thicker than that of a mouse, using only three sutures. Therefore, our adhesive is 16 times more powerful than Fibrin Glue,” he said.

High concentration of fibrin in the Iranian adhesive is a reason for high adhesive power. The highest concentration of fibrinogen in other products stood at 15 milligrams while its concentration in the Iranian product is 30-70 milligrams. In addition, the main advantage of the adhesive is that it contains high concentrations of growth factors.

Dr. Rasti has noted that growth factors are found in small quantities in the blood and promote tissue repair. In an interview with Hamshahri daily he noted that fresh plasma is not used in commercial tissue adhesives and they are devoid of growth factors.

“On the other hand, they lack fibronectin or contain low concentrations of it. Fibronectin increases tolerance of adhesive against pressure,” he added.

The above factors have made the Iranian product, the world’s most powerful tissue adhesive which not only juxtaposes damaged body parts, but also promotes healing and tissue repair due to presence of growth factors in it.

Iranian adhesive, powerful and smart

Dr. Kalantar Hormozi explained about smart nature of the Iranian adhesive by saying, “The adhesive will behave differently according to the place where it is applied. It does not behave the same in all tissues…. When applied to an artery, the adhesive will offer special precursors which enhance arterial healing. When applied to a bone, it will behave in such way as to promote bone healing.”

Asked about applications of the adhesive, Dr. Rasti said, “The adhesive has been successfully used to heal many animal samples including small and large arteries, nerves, bones and gut.”

He added that tissue adhesive would only be applied to those bones which are not exposed to high pressure.

“The adhesive is not used for bones in hands or feet, which should bear a lot of pressure, and has been successfully used for facial and cranial bones as well as small bones of the hand. Adhesives used for the skin are quite different. Although the smart adhesive can also be applied to skin, it is better used for more important cases,” he said.

Dr. Rasti explained that coetaneous adhesives are of two types: some of them keep two edges of skin close together and others are liquid adhesives with industrial composition like Epiglue, which are only applied to skin and cannot be used for internal organs.

Dr. Kalantar Hormozi noted that establishment of a center for producing tissue adhesive would cost about 3000 million rials, adding, “Such a center can produce tissue adhesives for 50 patients per day.”

“If a surgery is going to be carried out, the patient should be hospitalized a day earlier and blood sample should be taken of them. The next day, adhesive would be given to surgeon and red blood cells can be returned to the patient’s body…. Various stages of adhesive production take 6-18 hours. According to the type of surgery, composition of the adhesive would vary. The simplest adhesive can be produced in six hours, while production of the most complicated one may take 18 hours,” he said.

Various surgeries, however, would need different amounts of adhesive according to situation of the damaged organ and extent of surgery. Based on an average estimate, every person would need 2-3 milliliters of adhesive.

Dr. Rasti maintains that 3 milliliters of the adhesive is worth 1,000,000-1,500,000 rials while 2 milliliters of its foreign counterpart would be worth 5,000,000 rials. By the way, the foreign adhesive lacks unique characteristics of the Iranian adhesive.

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