Multilayered peptide incorporated collagen tubules for peripheral nerve repair.

Successful nerve regeneration process was achieved with improved mechanical strength by crosslinking tubular nerve guides made up of collagen. The multilayered collagen sheets were prepared from laminar evaporation of collagen solution. Scanning electron micrograph of the collagen tubes crosslinked with glutaraldehyde (GTA), microwave irradiation showed porous, fibrillar structures of collagen filaments in these matrices. The mechanical property of the crosslinked collagen tubes was carried out by tensile strength measurements. Fourier transform infrared spectra of the collagen films show that the native triple helicity was unaltered during multilayered preparation. It was observed that the structural integrity is unaltered during the multilayer preparation. Microscopic analysis indicates that the tubule surface acts as a surface of adherence and proliferation for the sprouting axons from the cut proximal nerve stumps. Solute diffusion studies on these tubes indicate that they are highly porous to wide range of molecular sizes during regeneration. Among the two types of crosslinking, the microwave irradiated collagen conduits results in ample myelinated axons compared with GTA group, where we observed more unmyelinated axons.