Poly (ε-caprolactone) scaffolds functionalized by grafting NGF and GRGD promote growth and differentiation of PC12 cells.

Poly(ε-caprolactone) (PCL) scaffolds functionalized by grafting nerve growth factor (NGF) and Asp-Arg-Gly-Asp (GRGD)(PCL-NGF/GRGD) for neural tissue engineering. The influences of PCL-NGF/GRGD scaffolds on the growth and differentiation of PC12 cells were investigated. The successfully grafting NGF and GRGD into PCL-CS scaffold were verified by FTIR spectra. The densities of GRGD and NGF in the scaffolds were about 2.10×10(-1) µmol/cm(2) and 1.51×10(-3) nmol/cm(2) . Growths of PC12 cells in PCL-GRGD and PCL/NGF-GRGD scaffolds via MTS measurements were significantly higher (p < 0.01, n = 4) than that in PCL-CS or PCL-NGF ones for three days of cultivation that was consistent with SEM observations. Moreover, the differentiation of PC12 cells, induced by NGF at 50 ng/mL for four days, in PCL-NGF/GRGD scaffolds were qualitatively more numbers and longer outgrowth of neurites than those in PCL-CS, PCL-GRGD, and PCL-NGF ones by SEM observations. The synergistic effects of grafting both NGF and GRGD ligands to PCL-CS scaffolds on the growth and differentiation of PC12 cells provide a new biomaterial for neural tissue engineering.

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 (C(5)) 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.