Porous chitosan tubular scaffolds with knitted outer wall and controllable inner structure for nerve tissue engineering

In this study, a novel method was developed to create porous tubular scaffolds with desirable mechanical properties and controllable inner structure from chitosan, for nerve tissue engineering. Chitosan fiber-based yarns were first used to create porous hollow tubes, which served as the outer wall of the scaffolds, through an industrial knitting process. Then, an innovative molding technique was developed and used to produce inner matrices with multiple axially oriented macrochannels and radially interconnected micropores. Acupuncture needles were used as mandrels during molding to improve the safety and controllability of the process. In vitro characterization demonstrated that the scaffolds possessed suitable mechanical strength, porosity, swelling, and biodegradability for applications in nerve tissue engineering. In vitro cell culture experiments showed that differentiated Neuro-2a cells grew along the oriented macrochannels and the interconnected micropores were beneficial for nutrient diffusion and cell ingrowth to the scaffold's interior. Collectively, the well-defined architectural features in addition to the desirable mechanical and biological properties of the scaffolds make them promising for nerve tissue engineering.