Fabrication of nano-fibrous poly(L-lactic acid) scaffold reinforced by surface modified chitosan micro-fiber.

To mimic the fibrillar structure of natural extracellular matrix and optimize the chemical composition of the scaffold, a nano-fibrous poly(L-lactic acid) (PLLA) scaffold reinforced by surface modified chitosan micro-fiber (MCTSF) was fabricated using the thermally induced phase separation method. The composite scaffold has a novel structure comprised of a nano-matrix with reinforcing micro-fibers, in which the nano-fibrous PLLA matrix promotes cell adhesion and proliferation, while the MCTSF provides the mechanical support and adjusts the biocompatibility. The morphology of the composite scaffold showed a nano-fibrous PLLA matrix (100-500 nm fiber diameter), an interconnected microporous structure (1.0-8.0 μm pore size), and high porosity (>90%). MCTSF were homogeneously distributed in the composite scaffold and had intimate interactions with PLLA matrix. As a result, the compressive modulus of PLLA/MCTSF (100:40, w/w) increased 4.7-fold compared with that of a pristine PLLA scaffold. The prepared composite scaffold also showed good properties including buffering the acidic degradation of PLLA during in vitro degradation, enhanced protein adsorption capacity, and good cytocompatibility, suggesting that the PLLA/MCTSF composite scaffolds are potential candidate materials in tissue engineering.