Coaxially electrospun core/shell structured poly(L-lactide) acid/chitosan nanofibers for potential drug carrier in tissue engineering.

Biodegradable core/shell structured poly(L-lactide) acid (PLLA)/chitosan (CS) nanofibers were fabricated by coaxial electrospinning. PLLA and CS were dissolved in dichloromethane and aqueous acetic acid solvents for spinning into core and shell layers, respectively. CS of high molecular weight was difficult to spin into nanofibers by electrospinning due to its high viscosity, but it was easier to achieve by coaxial electrospinning with PLLA. The preparation conditions were optimized by changing the ratios of PLLA/CS under different jet voltages. After being investigated by scanning electron microscope (SEM), a smooth structure was prepared using 2% CS as the shell solution with applied voltage 15 kV. Transmission electron microscopy (TEM) study and infrared spectrometry (IR) characterization of PLLA/CS nanofibers indicated that the core/shell structure was successfully fabricated. Brunauer-Emmett-Teller (BET) surface area and pore size distribution exhibited higher capacity of PLLA/CS than PLLA used as drug carrier in tissue engineering. The cytocompatibility of nanofibers were evaluated by co-cultured with human bone marrow-derived UE7T-13 cells, the 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) test exhibited good proliferation of PLLA/CS for cells. Results of blood compatibility tests showed decreased hemolytic ratio and platelets adhesion of PLLA/CS compared with PLLA. The results indicated that PLLA/CS nanofibers could be potential drug carrier for tissue engineering.