Advances and challenges in biomaterials for tendon and enthesis repair

Tendon and enthesis injuries are a global health problem affecting millions of people, causing huge medical expenditure and labor loss every year. However, due to their intricate tissue architecture, unique mechanical properties, and especially their sluggish and limited innate regenerative capacity, repairing these injuries remains a formidable clinical challenge. Here, we present a comprehensive review of biomaterials advances in tendon and enthesis repair recently. These biomaterials are categorized into two primary groups based on their potential clinical application conditions: biomaterials for T/E repairing and biomaterials for T/E replacement. The T/E repairing biomaterials were further divided into two groups: mechanical-enhanced biomaterials and bioactive biomaterials, according to the approaches they used to improve sutured tendon healing. We delve into the characteristics and underlying mechanisms of these various biomaterials to gain a deeper understanding of the current landscape in tendon and enthesis repair biomaterials. This review aims to highlight the prominent advancements while identifying the remaining gaps, ultimately inspiring future biomaterial design strategies.