Characterization And Properties Of Electrospun Rana Chensinensis Skin Collagen Scaffolds With Different Fiber Orientations

Collagen was extracted from Rana chensinensis skin supplied from byproducts via an acid enzymatic extraction method.The extraction was determined by polyacrylamide gelelectrophoresis(Page),Fourier transform infrared spectra(FTIR),ultraviolet spectrophotometer,CD spectra.The secondary structure of the RCSC nanofibers was investigated by circular dichroism to confirm that the extracted substance was collagen.The result showed that the extraction was ? type collagen.The Rana chensinensis skin collagen(RCSC)and poly(L-lactide)(PLLA)were blended at a 3:7 ratio in 1,1,1,3,3,3-hexafluoroisopropanol(HFIP)at a concentration of 10%(g/mL)and electrospun to produce nanofibers in an aligned and random orientation.For comparison,pure PLLA nanofibrous membranes with aligned and random nanofiber orientation were also produced.The surface property of the nanofiber menbranes was tested by SEM.The blended nanofibers showed uniform,smooth,and bead-free morphologies and presented a smaller fiber diameter(278 nm and 259 nm)than the pure the ones of PLLA(559 nm and 439 nm)nanofibers.The presence of collagen in the blend nanofiber was verified by LSCM.The result showed that the collagen was uniformly distributed in the nanofibers.Four groups of nanofiber membranes were also determined by porosity test,water contact angle test,water uptake capacity test,FITR,DSC and mechanical test.The aligned nanofiber membranes showed lower porosity than the random nanofiber membranes and the composite RCSC/PLLA nanofiber membranes showed lower porosity than the pure PLLA nanofiber membranes.Composite RCSC/PLLA showed better properties in both water contact angles and water uptake capacity.The aligned PLLA nanofiber membrane showed best mechanical properties including Young's modulus,tensile strength,yield strength and elongation at break.In the contrast,the random PLLA showed the least in these properties.The composite aligned and random RCSC/PLLA nanofiber membranes were in the middle.It was found that the addition of RCSC and the modification ofthe nanofiber's orientation affected the fiber's diameter and the crystallization of PLLA.SEM and LSCM were taken to study the human skin fibroblast cells adhesion.Cell Counting Kit-8(CCK-8)essay was taken to study the cell proliferation on the nanofiber membranes.The result showed that all the nanofiber membranes could support the cells culturing.The cell viability studies with human fibroblast cells demonstrated that the RCSC/PLLA nanofibrous membranes formed by electrospinning exhibited good biocompatibility and that the aligned scaffolds could regulate the cell morphology by inducing cell orientation.The empirical results in this study indicated that the aligned RCSC/PLLA nanofibrous membrane is a potential wound dressing candidate for skin regeneration.