In Vitro Biodegradation and Biocompatibility of Bacterial Nanocellulose-Chitosan-Based Hydrogel Scaffolds for Bone Tissue Engineering.

Bacterial nanocellulose (BNC) has many advantageous physicochemical characteristics, including high mechanical strength, high porosity, excellent water adsorption, and biocompatibility, making it a promising option for a wide range of biomedical applications. However, the limited biodegradability of BNC within the human body could reduce its utility in this field. In the present study, we investigated the in vitro biodegradability of a BNC composite of bacterial nanocellulose-chitosan-alginate-gelatin (BNC-CS-AG-GT). This BNC-CS-AG-GT hydrogel scaffold was shown to be gradually degraded during immersion in simulated body fluid (SBF) with the addition of lysozyme. Furthermore, the compressive strength of the BNC-CS-AG-GT hydrogel slowly decreased in correlation with incubation time: by 8 weeks of incubation in SBF, the compressive strength was reduced from ∼68 to ∼25 MPa, coupled with a 54% weight reduction. In cell culture, the BNC-CS-AG-GT scaffold was noncytotoxic. Cultivation of osteogenic MC3T3-E1 cells in osteogenic medium within a BNC-CS-AG-GT hydrogel for 4 weeks showed that the BNC-CS-AG-GT hydrogel supports cell adhesion and cell proliferation and promotes alkaline phosphatase (ALP) activity and mineralization in vitro. Moreover, BNC-CS-AG-GT exhibited strong antibacterial properties. The favorable biodegradability, mechanical properties, biocompatibility, and antibacterial activity of the BNC-CS-AG-GT hydrogel scaffold indicate that it has potential as a promising candidate for applications in bone tissue engineering. However, although these findings suggest that BNC-CS-AG-GT hydrogels have osteogenic potential in vitro, future additional studies in vivo and extended osteogenic differentiation assays are required to confirm the efficacy of BNC-CS-AG-GT scaffolds under physiological load conditions.