Studies have shown that human hair keratin(HHK) has no antigenicity and excellent mechanical properties. Schwann cells, as unique glial cells in the peripheral nervous system, can be induced by interleukin-1β to secr...Studies have shown that human hair keratin(HHK) has no antigenicity and excellent mechanical properties. Schwann cells, as unique glial cells in the peripheral nervous system, can be induced by interleukin-1β to secrete nerve growth factor, which promotes neural regeneration. Therefore, HHK with Schwann cells may be a more effective approach to repair nerve defects than HHK without Schwann cells. In this study, we established an artificial nerve graft by loading an HHK skeleton with activated Schwann cells. We found that the longitudinal HHK microfilament structure provided adhesion medium, space and direction for Schwann cells, and promoted Schwann cell growth and nerve fiber regeneration. In addition, interleukin-1β not only activates Schwann cells, but also strengthens their activity and increases the expression of nerve growth factors. Activated Schwann cells activate macrophages, and activated macrophages secrete interleukin-1β, which maintains the activity of Schwann cells. Thus, a beneficial cycle forms and promotes nerve repair. Furthermore, our studies have found that the newly constructed artificial nerve graft promotes the improvements in nerve conduction function and motor function in rats with sciatic nerve injury, and increases the expression of nerve injury repair factors fibroblast growth factor 2 and human transforming growth factor B receptor 2. These findings suggest that this artificial nerve graft effectively repairs peripheral nerve injury.展开更多
Objective:To explore the mechanism of the degradation of human hair keratin (HHK) scaffold material implanted in damaged skeletal muscle tissues. Methods: Six New Zealand rabbits with HHK scaffold material implants (c...Objective:To explore the mechanism of the degradation of human hair keratin (HHK) scaffold material implanted in damaged skeletal muscle tissues. Methods: Six New Zealand rabbits with HHK scaffold material implants (composed of 3 different types of HHK material with varied degradation speed) after musclectomy were divided into 3 groups (2 in each group) to observe the degradation of the material at 1, 3, 6weeks after operation. Another rabbit without operation was used as the control group. The degradation of HHK was observed with light microscopy, histochemistry of ubiquitin and electron microscopy. Results:Light microscopy showed that human hair cuticles fell off from the HHK material and emerged, and the macrophagocytes and multinucleate giant cells were attached onto the surface of the material, which became homogeneous at the first postoperative week. The HHK scaffold material was degraded into particles that was phagocytosed by macrophagocytes and multinucleate giant cells at the third week. Ubiquitin enzymatic histochemistry showed that the macrophagocytes and the multinucleate giant cells were positive at the first week. Under electron microscope, HHK scaffold material was degraded into particles, and at the sixth week,part of HHK scaffold material was further degraded. Conclusion: Large mass of the HHK scaffold material is degraded via ubiquitin system, and the resultant particles are phagocytosed and degraded with the cooperation of lysosome and ubiquitin.展开更多
Objective: To explore the method to repair injured peripheral nerve using conduits made of human hair keratin (HHK). Methods: The tibial nerves of rabbits were transected leaving a gap 10 mm in length between the 2 se...Objective: To explore the method to repair injured peripheral nerve using conduits made of human hair keratin (HHK). Methods: The tibial nerves of rabbits were transected leaving a gap 10 mm in length between the 2 severed ends, which were either routinely sutured or bridged using HHK nerve conduits. Electro-physiological , anatomical and histological examinations were performed at different time postoperatively. Results: Electrophysiological study showed more obvious improvement in the neural function recovery in rabbits with HHK conduits bridging as compared with that in rabbits with routine suture. In the former group, HHK conduits were gradually degraded and absorbed with large amount of myelinated nerve fibers and Schwann cells regenerated around HHK conduits. In the latter group, however, the nerve tissues around the suture were degenerated and replaced by connective tissues. Conclusion: HHK may induce the regeneration of the nerve fibers and provides an ideal approach to repair nerve damages.展开更多
基金supported by Military Medical Science&Technology Youth Training Program,No. 19QNP005President Foundation of Nanfang Hospital,Southern Medical University,No. 2020B028 (both to JY)。
文摘Studies have shown that human hair keratin(HHK) has no antigenicity and excellent mechanical properties. Schwann cells, as unique glial cells in the peripheral nervous system, can be induced by interleukin-1β to secrete nerve growth factor, which promotes neural regeneration. Therefore, HHK with Schwann cells may be a more effective approach to repair nerve defects than HHK without Schwann cells. In this study, we established an artificial nerve graft by loading an HHK skeleton with activated Schwann cells. We found that the longitudinal HHK microfilament structure provided adhesion medium, space and direction for Schwann cells, and promoted Schwann cell growth and nerve fiber regeneration. In addition, interleukin-1β not only activates Schwann cells, but also strengthens their activity and increases the expression of nerve growth factors. Activated Schwann cells activate macrophages, and activated macrophages secrete interleukin-1β, which maintains the activity of Schwann cells. Thus, a beneficial cycle forms and promotes nerve repair. Furthermore, our studies have found that the newly constructed artificial nerve graft promotes the improvements in nerve conduction function and motor function in rats with sciatic nerve injury, and increases the expression of nerve injury repair factors fibroblast growth factor 2 and human transforming growth factor B receptor 2. These findings suggest that this artificial nerve graft effectively repairs peripheral nerve injury.
文摘Objective:To explore the mechanism of the degradation of human hair keratin (HHK) scaffold material implanted in damaged skeletal muscle tissues. Methods: Six New Zealand rabbits with HHK scaffold material implants (composed of 3 different types of HHK material with varied degradation speed) after musclectomy were divided into 3 groups (2 in each group) to observe the degradation of the material at 1, 3, 6weeks after operation. Another rabbit without operation was used as the control group. The degradation of HHK was observed with light microscopy, histochemistry of ubiquitin and electron microscopy. Results:Light microscopy showed that human hair cuticles fell off from the HHK material and emerged, and the macrophagocytes and multinucleate giant cells were attached onto the surface of the material, which became homogeneous at the first postoperative week. The HHK scaffold material was degraded into particles that was phagocytosed by macrophagocytes and multinucleate giant cells at the third week. Ubiquitin enzymatic histochemistry showed that the macrophagocytes and the multinucleate giant cells were positive at the first week. Under electron microscope, HHK scaffold material was degraded into particles, and at the sixth week,part of HHK scaffold material was further degraded. Conclusion: Large mass of the HHK scaffold material is degraded via ubiquitin system, and the resultant particles are phagocytosed and degraded with the cooperation of lysosome and ubiquitin.
基金Supported by National 863 Project of China (No. 102090503)
文摘Objective: To explore the method to repair injured peripheral nerve using conduits made of human hair keratin (HHK). Methods: The tibial nerves of rabbits were transected leaving a gap 10 mm in length between the 2 severed ends, which were either routinely sutured or bridged using HHK nerve conduits. Electro-physiological , anatomical and histological examinations were performed at different time postoperatively. Results: Electrophysiological study showed more obvious improvement in the neural function recovery in rabbits with HHK conduits bridging as compared with that in rabbits with routine suture. In the former group, HHK conduits were gradually degraded and absorbed with large amount of myelinated nerve fibers and Schwann cells regenerated around HHK conduits. In the latter group, however, the nerve tissues around the suture were degenerated and replaced by connective tissues. Conclusion: HHK may induce the regeneration of the nerve fibers and provides an ideal approach to repair nerve damages.
基金This study is supported by National Natural Science Foundation of China (NSFC) (39830390) National 863 High-Tech Research and Develop- ment Project (102090503)+1 种基金 National 973 Basic Research Program (G1999054308) Guangzhou Science and Technology Progr
基金Supported by National Natural Science Foundation of China (39830390)Guangdong Social Development Project (2002A30202020102)Natural Science Foundation of Guangdong Province (010599)
