Nanofibrous bacterial cellulose/chitosan scaffolds: Preparation, structure and mechanical properties

Biocompatible and biodegradable chitosan scaffolds were found to exhibit substantially improved mechanical properties with additions of bacterial cellulose (BC) nanofibres. Chitosan/BC nanocomposite scaffolds containing 9-23 wt% BC were prepared by freeze drying, and characterized by interconnected, highly porous structures with a porosity of approximately 97% and an average pore size of over 100 μm. The presence of BC did not significantly modify the pore size of chitosan scaffolds at lower contents whereas it decreased the pore size at higher contents. Along with improvements in compressive properties, the tensile modulus and tensile strength of chitosan scaffolds were enhanced by 305% and 95% by the addition of 17 wt% BC. Such enhancements are attributable to the intrinsic properties of BC nanofibres including a high stiffness, high strength, high aspect ratio and large surface area, and to the good dispersion of BC in chitosan matrix. The structure-property relationships of the chitosan/BC scaffolds were also discussed in detail. This work demonstrates that BC is a promising candidate for reinforcement of biopolymer scaffolds and that the resultant nanocomposite scaffolds have potential to be further developed for uses in tissue engineering.