Formation of nanostructured poly(lactic-co-glycolic acid)/chitin matrix and its cellular response to normal human keratinocytes and fibroblasts

Electrospinning of poly(lactic-co-glycolic acid) (PLGA) and chitin in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and formic acid, respectively, was investigated to fabricate a biodegradable nanostructured composite matrix for tissue engineering. The average fiber diameter (310 nm) of PLGA nanofibers, obtained by electrospinning a 15 wt% PLGA solution in polar HFIP, was much smaller than the diameter (760 nm) of nanofibers electrospun at the same concentration in nonpolar chloroform. On the contrary, chitin was electrospun into nanosized particles at a lower concentration with negligible chain entanglement, because it can not produce continuous fibers by the electrospinning process even at high concentrations. In order to fabricate the biomimetic scaffolds for human keratinocytes and fibroblasts, we prepared the composite matrix (PLGA/chitin = 80/20, w/w) of chitin nanoparticles embedded within a PLGA nanofiber matrix by a newly-designed simultaneous electrospinning process using two polymer solutions. Chitin nanoparticles were distributed uniformly in the PLGA fibrous structure, and appeared to adhere strongly to PLGA nanofibers by simultaneous electrospinning. To assay the cytocompatibility and cell behavior on the PLGA and PLGA/chitin matrices, cell attachment and spreading of both normal human keratinocytes and fibroblasts seeded on the matrices were studied. Our results indicate that the PLGA/chitin composite matrix may be a better candidate than the PLGA matrix in terms of cell adhesion and spreading for normal human keratinocytes, and that the PLGA and PLGA/chitin matrices are good matrices for normal human fibroblasts. (C) 2004 Elsevier Ltd. All rights reserved.