Fabrication of Multi-layered Composite Scaffolds by Bi-directional Electrospinning Method

A multi-layered composite scaffolds consisting of poly （ L- ne） （ P （LLA-CL） ）, collagen （COL） and chitosan （CS） were fabricated by a bi-directional electrospinnlng method. Synthetic P （LLA-CL） was used as the middle layer to enhance the strength, while natural COL/CS blending （9： 1, v/v） was used as the bioactive surfaces （inner and outer layers ） to improve the biocompatibility. Each three transitional layers were set between inner/outer layer and middle layer for delamination resistance. Scanning electron microscopy （SEM） was used to observe the fiber morphology. The Fourier transform infrared attenuated total reflectance spectroscopy （FTIR-ATR） spectra, X- ray diffraction （XRD） and thermogravimetry （TG） tests were used to analyze the physical properties of the scaffolds. The results showed that the modified clectrospinning method bad no negative effect on the components, crystal structure and thermostability of the scaffolds, but could effectively combine the mechanical property of synthetic material and biocompatibility of natural materials. Such method could be applied to the fabrication of composite scaffolds for vascular, skin. and nerve tissue engineering.

Fabrication and Characterization of Dual-layer Multichannel Nerve Guidance Conduit

Nowadays, muifichannel nerve guidance conduit （NGC） was designed by mimicking the architecture of nerve fascicles, and it was used to reduce dispersion of regenerating axons within the NGC lumen. In this paper, gelatin was used to prepare multichannel inner layer of NGC by freeze-drying, and poly （ L-lactic add-co-ε- caprolactone） （P（LLA-CL）） was used to fabricate nanofiber outer layer of NGC by electrospinning. The morphology of dual-layer mtlltichannel NGC was observed by scanning electron microscopy （SEM）. In vitro degradation experiment of the NGC demonstrated that the inner layer of NGC had the faster degradation rate than the outer layer of NGC. tell viability assay indicated that Schwann cells （SCs） showed better proliferation on dual-layer multichannel NGC than hollow NGC, because the multichannel structure introduced contact guidance for direct cell migration. Therefore, it was suggested that the dual-layer multichannel NGC had the potential for nerve lissue regeneration.