Injectable carboxymethyl chitosan/nanosphere-based hydrogel with dynamic crosslinking network for efficient lubrication and sustained drug release

The typical symptoms of arthritis are inflammation and lubrication deficiency in joints, which increase wear of articular cartilage along with pain of patients. In the present study, one kind of novel macromolecular/ microsphere-based injectable hydrogels (CMC-ODex NPs) with dual functionalities of drug release and lubrica-tion, was fabricated via dynamic Schiff base crosslinking network between carboxymethyl chitosan (CMC) and oxidation dextran nanoparticles (ODex NPs). The CMC-ODex NPs hydrogels exhibited typical viscosity-thinning phenomenon at wide range of shear rates and obvious gel-sol transition feature at specific strain. As a result, CMC-ODex NPs hydrogels presented low friction coefficient at the sliding interface of bovine articular cartilages, resulting from the boundary lubrication of hydrogel and the rolling friction effect of ODex NPs. Furthermore, the anti-inflammatory drug (dexamethasone, DXM) encapsulated in ODex NPs exhibited sustainable drug release behavior during the dynamic shearing process, which making CMC-ODex NPs hydrogels possessed good and stable anti-inflammatory effect. CMC-ODex NPs hydrogels was prepared without utilizing any toxic agents, thus demonstrated excellent cytocompatibility. Our experimental results reveal the CMC-ODex NPs hydrogels is promising to be used as functional lubricant for inhibiting the development of arthritis.

Automated summary

In this study, a novel macromolecular/microsphere-based injectable hydrogel (CMC-ODex NPs) was developed for dual functionalities of drug release and lubrication. The hydrogel exhibited viscosity-thinning phenomenon and gel-sol transition feature, resulting in low friction coefficient at the sliding interface of articular cartilages. The encapsulated anti-inflammatory drug (dexamethasone, DXM) in the hydrogel showed sustainable drug release, leading to good and stable anti-inflammatory effect.