HA-PAs hydrogel for enhanced cartilage repair in early osteoarthritis: A novel minimally invasive treatment strategy

Osteoarthritis (OA) is a degenerative joint disease characterized by joint inflammation, progressive degeneration and destruction of articular cartilage, ultimately resulting in irreversible damage. The treatment of OA is costly, has significant side effects, and yields limited efficacy. To improve OA therapy, we used 3-aminobenzoboronic acid (PBA) as a binding site for proanthocyanidins (PAs), with hyaluronic acid (HA) serving as a drug carrier. A simple method was employed to develop an injectable, biocompatible hydrogel (HA-PAs hydrogel) with sustained-release functionality, aimed is to promote the in vivo repair of cartilage and ligaments by enhancing the expression of collagen and glycosaminoglycans. Characterization results confirmed that HA and PAs crosslinked to form hydrogels through amide and borate ester bonds in PBA. The controlled release function of PAs was further validated through in vitro drug release experiments. The good biocompatibility of HA-PAs hydrogel was further confirmed by CCK-8 assay and cellular live/dead staining. More importantly, compared with PAs alone, the HA-PAs hydrogel exhibited superior ability to promote the expression of collagen and glycosaminoglycans. In a rat enzymatic OA model, the HA-PAs hydrogel significantly reduced joint inflammation in the early stages of cartilage destruction and accelerated cartilage formation. This work provides an inexpensive and efficacious strategy for minimally invasive treatment of early osteoarthritis.