Structure and Properties of Chitosan/Poly-Lactic Acid Blend Scaffold and Chitosan Powder/Poly-Lactic Acid Blend Scaffold

Abstract

The chitosan (CS) /poly-L-lactic (PLLA) acid blend scaffolds were prepared by two kinds of blend solutions through immersion precipitation phase inversion method. CS/PLLA blend scaffold was fabricated by mixing the CS-HAc solution and PLLA-DMF solution, CSP/PLLA blend scaffold was fabricated by mixing chitosan powder (CSP) and PLLA-DMF solution. The results revealed that CS content in CSP/PLLA scaffold was 126 times higher than that in CS/PLLA scaffold. The difference of CS content made the structures of CS/PLLA scaffold and CSP/PLLA scaffold exhibit an obvious discrepancy, which resulted from the different thermodynamics and phase separation behavior of two blend solutions. CS/PLLA scaffold with a higher porosity took on an unsymmetrical structure with a compact upper surface and a porous cross-section containing the fingerlike macrovoids, while CSP/PLLA scaffold displayed a symmetrical structure with a porous upper surface and the sponge-like cross-section. WVTR and equilibrium swelling of CSP/PLLA blend scaffold were higher than that of CS/PLLA blend scaffold. WAXD analysis revealed that PLLA and CS did not crystallize in the course of CS/PLLA scaffold formation, while there were the diffraction peaks of PLLA and CS in the CSP/PLLA scaffold.