Degradation Behavior and Cellular Response of Electrospun Chitin Nanofibers

Objectives: Chitin nanofibers (Chi-N) were fabricated by electrospinning chitin in 1,1,1,3,3,3-hexafluoro-2-propanol, and their degradation behavior was investigated and compared with commercial chitin microfibers (Beschitin W®; Chi-M) in vitro and in vivo. We also compared the cellular response to Chi-N and Chi-M in normal human keratinocytes and fibroblasts and the interaction between cells and both types of chitin fibers. Methods: The morphology of as-spun Chi-N and Chi-M was investigated by scanning electron microscopy. To assay and compare the cytocompatibility and cell behavior with Chi-N and Chi-M, cell attachment and spreading of normal human keratinocytes and fibroblasts seeded on chitin matrices and the interaction between cells and chitin fibers were studied. Results: From the image analysis, the average diameters of Chi-N and Chi-M were 163 nm and 8.77 µm, respectively. During in vitro degradation for 15 days, the degradation rate of Chi-N was faster than that of Chi-M, likely due to higher surface area of Chi-N. Chi-N that was grafted into rat subcutaneous tissue had almost degraded within 28 days, and no inflammation could be seen on the nanofiber surfaces or in the surrounding tissues (except in the early-stage wound). Relatively high cell attachment and spreading of all the cells tested were observed on Chi-N in comparison to Chi-M, and Chi-N treated with type I collagen significantly promoted the cellular response. Conclusion: Our results indicate that the Chi-N, alone or with ECM proteins (particularly type I collagen), could be potential candidates for the cell attachment and spreading of normal human keratinocytes and fibroblasts. This property of Chi-N might be particularly useful for wound healing and regeneration of oral mucosa and skin. Supported by a grant from the KOSEF through the IBEC at the Seoul National University.