Tissue Regeneration through Self-Assembled PeptideAmphiphile Nanofibers

Tissue Regeneration through Self-Assembled Peptide Amphiphile Nanofibers

Introduction: In the present study, we hypothesized that a novelapproach to promote vascularization would be to create injectablethree dimensional (3-D) scaffolds within growth factor that enhancethe sustained release of growth factor and induce the angiogenesis.Material and Methods: We demonstrate that a 3-D scaffold can beformed by mixing of peptide-amphiphile (PA) aqueous solution withhepatocyte growth factor (HGF) solution. PA was synthesized bystandard solid phase chemistry that ends with the alkylation of theNH2 terminus of the peptide. The sequence of arginine-glycineasparticacid (RGD) was included in peptide design as well. A 3-Dnetwork of nanofibers was formed by mixing HGF suspensions withdilute aqueous solution of PA.Results: Scanning electron microscopy (SEM) examination revealedthe formation of fibrous assemblies with an extremely high aspectratio and high surface areas with mean diameter of less than 200 nm.In vitro HGF release profile of 3-D nanofibers was investigated whileangiogenesis induced by the released HGF was being assessed. Invivo potential ability of PA nanofibers to induce angiogenesis wasassessed through subcutaneous injection of PA solution, HGFsolution, and PA in combination with HGF solutions. Injection of PAwith HGF induced significant angiogenesis around the injected site,in marked contrast to HGF injection alone and PA injection alone.Conclusion: The combination of HGF-induced angiogenesis is apromising procedure to improve tissue regeneration.

Introduction: In the present study, we hypothesized that a novel approach to promote vascularization would be to create injectable three dimensional (3-D) scaffolds within growth factor that enhance the sustained release of growth factor and induce the angiogenesis. Material and Methods: We demonstrate that a 3-D scaffold can be formed by mixing of peptide-amphiphile (PA) aqueous solution with hepatocyte growth factor (HGF) solution. PA was synthesized by standard solid phase chemistry that ends with the alkylation of the NH2 terminus of the peptide. The sequence of arginine-glycine-aspartic acid (RGD) was included in peptide design as well. A 3-D network of nanofibers was formed by mixing HGF suspensions with dilute aqueous solution of PA. Results: Scanning electron microscopy (SEM) examination revealed the formation of fibrous assemblies with an extremely high aspect ratio and high surface areas with mean diameter of less than 200 nm. In vitro HGF release profile of 3-D nanofibers was investigated while angiogenesis induced by the released HGF was being assessed. In vivo potential ability of PA nanofibers to induce angiogenesis was assessed through subcutaneous injection of PA solution, HGF solution, and PA in combination with HGF solutions. Injection of PA with HGF induced significant angiogenesis around the injected site, in marked contrast to HGF injection alone and PA injection alone. Conclusion: The combination of HGF-induced angiogenesis is a promising procedure to improve tissue regeneration.