Promoting regeneration of peripheral nerves in-vivo using new PCL-NGF/Tirofiban nerve conduits

Poly(ε-caprolactone) (PCL) scaffolds were modified by grafting nerve growth factor (NGF) and Tirofiban (TF), a clinical anti-thrombosis drug, as a new biomaterial for producing nerve conduits to promote the regeneration of sciatic nerves. The successful grafting of NGF and TF onto PCL scaffolds was confirmed by FTIR and ESCA spectra. In-vitro growths of the PC12 cells in PCL-NGF and PCL-NGF/TF scaffolds, determined by MTS, were significantly higher (P < 0.05, n = 4) than those in the PCL scaffolds following three days of cultivation. Interestingly, this study evaluation of the PCL, PCL-NGF, and PCL-NGF/TF nerve conduits in a 12 mm long gap of the rat sciatic nerve defect model that the gastrocnemius muscle mass of the tested rats in the PCL-NGF/TF groups significantly exceeded those in the PCL-NGF and PCL group. In the rats that had been implanted with PCL-NGF/TF conduits, the generated nerves passed through those conduits, expressing beta-III tubulin (TB), growth association protein-43 (GAP-43) and myelin basic protein (MBP) along their longitudinal axis, and the proximal and distal nerve ends of the rats were successfully connected. Those that had been implanted with PCL and PCL-NGF conduits did not exhibit these effects, as revealed by an immunochemical study of the expressions of the proteins in the conduits. Moreover, counting within the dorsal horn of the spinal cord (C₅) demonstrated that the numbers of CTB-HRP-labeled neurons in the rats that had been implanted with PCL-NGF/TF conduits were significantly higher than those in the other groups. In this study, in-vivo examinations of the use of newly designed PCL-NGF/TF conduits to promote the generation of nerves in a defective rat model significantly increased the gastrocnemius muscle mass, and led to the successful regeneration of nerves that bridged a 12 mm long defected gap of nerves in rats. However, more rats must be tested to confirm the efficacy the newly designed nerve conduits.