Chemically crosslinked hyaluronic acid-chitosan hydrogel for application on cartilage regeneration

Articular cartilage is an avascular tissue that lines the ends of bones in diarthrodial joints, serves as support, acts as a shock absorber, and facilitates joint's motion. It is formed by chondrocytes immersed in a dense extracellular matrix (principally composed of aggrecan linked to hyaluronic acid long chains). Damage to this tissue is usually associated with traumatic injuries or age-associated processes that often lead to discomfort, pain and disability in our aging society. Currently, there are few surgical alternatives to treat cartilage damage: the most commonly used is the microfracture procedure, but others include limited grafting or alternative chondrocyte implantation techniques, however, none of them completely restore a fully functional cartilage. Here we present the development of hydrogels based on hyaluronic acid and chitosan loaded with chondroitin sulfate by a new strategy of synthesis using biodegradable di-isocyanates to obtain an interpenetrated network of chitosan and hyaluronic acid for cartilage repair. These scaffolds act as delivery systems for the chondroitin sulfate and present mucoadhesive properties, which stabilizes the clot of microfracture procedures and promotes superficial chondrocyte differentiation favoring a true articular cellular colonization of the cartilage. This double feature potentially improves the microfracture technique and it will allow the development of next-generation therapies against articular cartilage damage.

Automated summary

Articular cartilage is an important avascular tissue that provides support, shock absorption, and facilitates joint motion. Current surgical treatments for cartilage damage have limitations in restoring fully functional cartilage. This study presents the development of hydrogels based on hyaluronic acid and chitosan loaded with chondroitin sulfate, which have the potential to improve the microfracture procedure and promote the colonization of articular cartilage by chondrocytes. These hydrogels act as delivery systems for chondroitin sulfate and have mucoadhesive properties, making them promising for next-generation therapies against articular cartilage damage.