Development of Chitosan Dermal Scaffold and its Characterization

Abstract

We have developed tensile and porous neutralized chitosan scaffold (NCS) whose pore size was controlled by freezing temperatures. At -70 oC, mean pore size of 112 μm was obtained. At -196 oC, mean pore size was approximately 70 μm at surface. The scaffold processed at -196 oC showed homogeneous small pores with structural integrity, which may be more useful as a guidance dermal scaffold for inward cell migration. The scaffold processed at –70 oC may be more useful for cell loading scaffold requiring wider pore. Since biodegradability and biocompatibility are crucial parameters for the development of dermal scaffold, we evaluated the rate of NCS degradation in the culture medium containing lysozyme by measuring weight loss as well as mean molecular weight of the scaffold. Approximately 40% weight loss at one week and 70% weight loss at 30 days was observed, which means that 70% of the scaffold will be degraded and releasable if the wound microenvironment is similar to the test condition. Again, mean molecular weight of the scaffold based on gel permeation chromatography was less than 1x105 after 10 day incubation. This result suggests that degradation of the NCS begins earlier than the observation of gross weight loss. We also evaluated whether degradation product of NCS are toxic to the human dermal fibroblast or not. Chitosan oligomer up to 1.0 mg/ml, which corresponds to 10% of the total degradation derivatives of the NCS, did not affect the viability of the dermal fibroblast based on MTT assay. This result along with the biodegradation data suggests that the NCS can be developed as suitable dermal scaffold.