Preparation and characterization of cross-linked carboxymethyl chitin porous membrane scaffold for biomedical applications

• We proposed the model of PDSM prepared from cross-linked CMC as only component.
• The novel sol–gel freeze-drying method for preparing PDSM was established.
• Mechanical property and degradability of PDSM were improved by self-cross linking.
• PDSM had suitable structure and properties as tissue engineering dermal scaffold.

Porous dermal scaffold membrane (PDSM) was successfully prepared by using a so-called sol–gel freeze-drying method. In this method, the carboxymethyl chitin (CMC) hydrosol was first cross-linked by 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS), and then lyophilized to form the PDSM. For the first time, this research focused on the cross-linked CMC as the only component for three-dimensional PDSM. The effects of cross-linking conditions on the performance of the PDSM were investigated. And PDSM with optimal performance was obtained through 4-h cross-linking at 4 wt% of CMC concentration in the hydrosol, where the mass ratio of EDC to NHS to CMC was 5:3:10. The porosity of the optimized PDSM was more than 90% and the water swelling rate was above 4000%. The pore size was well distributed and was between 100 μm and 200 μm. And the tensile strength was above 0.09 MPa. The as-made PDSM could be degraded above 80% in 12 days in the presence of a 0.2 mg/mL lysozyme solution. Very importantly, the PDSM had no cytotoxicity and good biocompatibility from MTT assays. Our results showed the application possibility of the as-prepared PDSM as dermal scaffold for skin tissue engineering.