Multifunctional inverse opal scaffold loaded with FGF2 for tendon regeneration

Tendon defects have long been a challenge in clinical treatment due to their poor regenerative capacity, which is attributed to low cellularity and limitedmetabolic activity. Herein, a scaffold with an inverse opal structure was fabricated through straightforward negative replication of a photonic crystal template. This scaffold exhibited excellent biocompatibility and mechanical properties. Meanwhile, the isotropic nanoporous structure significantly suppressed the formation of mature focal adhesions and accelerated cellular migration. Furthermore, the three-dimensionally interconnected cavity structure within the scaffold enabled efficientloading and sustained release of fibroblast growth factor 2 (FGF2). Experimental results demonstrated that FGF2 can significantly promote cell proliferation, as well as the secretion of tendon-specific proteins and extracellular matrix (ECM) during tendon regeneration. In a tendon defect animal model, the multifunctional scaffold was confirmed to rapidly recruit endogenouscells, accelerate microvascular neogenesis, and promote the secretion of regenerative proteins. Ultimately, these effects collectively facilitated rapid and orderly tendon regeneration. Taken together, these findings highlight the considerable potential of this inverse opal scaffold for wide-ranging applications in clinical tendon repair.