Modulation of angiogenic potential of tissue-engineered peripheral nerve by covalent incorporation of heparin and loading with vascular endothelial growth factor

One of prominent shortcomings of nerve tissue engineering for repairing large segmental peripheral nerve defects is the poor ability to support angiogenesis. We report here an experiment to enhance angiogenic properties of tissue-engineered peripheral nerves. Our aim is to achieve this goal by covalently incorporating heparin into acellular nerve scaffolds and by physically immobilizing VEGF to heparin. We evaluated the growth of prevascularized tissue-engineered peripheral nerve in vitro and in vivo in dorsal subcutaneous pockets of nude mice. On histology, the structure of prepared acellular nerve scaffold was maintained, and the scaffolds were void of cellular components. Cellular viability assay revealed no cytotoxic effects. There was no significant difference in mechanical properties between scaffolds and fresh nerves (P > 0.05). Based on these scaffolds, tissue-engineered peripheral nerve with angiogenic potential had been prepared. In conclusion, this vascularized tissue-engineered peripheral nerve can be used as a new kind of material for repairing large segmental nerve defects.