SCI trans Med: polymers and proteins help repair damaged neurons

January 24, 2020 / biourn / -- researchers at the University of Pittsburgh School of medicine have created a biodegradable neural conduit (a polymer tube) containing growth promoting proteins that allow damaged nerves to grow from scratch without the need to transplant stem cells or donor nerves So far, the technology has been tested in monkeys, and the results of these experiments are published in science translational medicine today (image source: UPMC) Dr Kacey Marra, Professor of plastic surgery and senior author of the study, said: "we are the first to develop a technology that can bridge the 2-inch gap between the nerve and the target muscle without any cell guidance Our technique is comparable to that of nerve transplantation, and is superior to that of nerve transplantation in some aspects When soldiers are shot in four limbs, if there is no timely treatment, it often leads to nerve damage and disability Among the common people, car accidents, mechanical accidents, cancer treatment, diabetes, and even birth trauma can cause serious nerve damage A third of an inch can grow on its own around the damaged nerve, but if the length of the damaged part is greater than this range, the nerve becomes disorganized because the target cannot be found Usually, the disoriented nerve knots into a pain ball called a neuroma For longer nerve injuries, the most common treatment is to remove the posterior part of the leg, cut it into three equal parts, sew them together and implant them into the end of the injured motor nerve But usually only about 40% to 60% of the motor function recovered In the latest study, the authors successfully restored about 80% of fine motor control in the thumbs of four monkeys, each with a 2-inch forearm gap The method is made of the same material as the soluble suture and contains proteins that promote growth Two controls were set up: an empty polymer tube and a polymer tube with a nerve graft Because the legs of monkeys are relatively short, the routine clinical operation of removing and cutting the leg nerves is ineffective for monkeys So scientists removed a 2-inch-long ganglion from the monkey's forearm, turned it over and sewed it into place The results showed that the recovery of neural function of monkey after transplantation was as good as that of conventional grafts, and the performance of monkey in restoring nerve conduction and supplementing myelin sheath cells (the insulating layer around the nerve can enhance the electrical signal and support) was better than that of the grafts Regeneration In both cases, nerve regeneration takes a year The performance of the polymer tube is obviously unsatisfactory With these results in monkeys, Marra hopes to bring its neural guidance technology to human patients She is working with the U.S Food and Drug Administration (FDA) to conduct a first human clinical trial and set up an emerging company, axomax Technologies Inc Sources of information: researchers regrow damaged nerves with polymer and protein Original sources: N.B Fadia El Al., "long gap peripheral nerve repair through sustained release of a neural factor in nonheiman prices," Science Translational Medicine (2020) STM Sciencemag.org/lookup/doi / scitranslmed.aav7753