Osteoarthritis, a lubrication dysfunction related disorder in joint, is characterized by articular cartilage degradation and joint capsule
inflammation. Enhancing joint lubrication, combined with anti-inflammatory
therapy, is considered as an effective strategy for
osteoarthritis treatment. Herein, based on the ball-bearing-inspired superlubricity and the mussel-inspired adhesion, a superlubricated
microsphere, i.e.,
poly (dopamine methacrylamide-to-
sulfobetaine methacrylate)-grafted microfluidic
gelatin methacrylate sphere (MGS@DMA-SBMA), is developed by fabricating a monodisperse, size-uniform
microsphere using the microfluidic technology, and then a spontaneously modified
microsphere with DMA-SBMA copolymer by a one-step biomimetic grafting approach. The
microspheres are endowed with enhanced lubrication due to the tenacious hydration layer formed around the charged headgroups (-N+ (CH3 )2 - and -SO3- ) of the grafted
poly sulfobetaine methacrylate (pSBMA), and simultaneously are capable of efficient drug loading and release capability due to their porous structure. Importantly, the grafting of pSBMA enables the
microspheres with preferable properties (i.e., enhanced lubrication, reduced degradation, and sustained drug release) that are highly desirable for intraarticular treatment of
osteoarthritis. In addition, when loaded with
diclofenac sodium, the superlubricated
microspheres with excellent biocompatibility can inhibit the
tumor necrosis factor α (TNF-α)-induced chondrocyte degradation in vitro, and further exert a
therapeutic effect toward
osteoarthritis in vivo.