ZIF-8 composite nanofibrous membranes loaded with bFGF: a new approach for tendon adhesion prevention and repair

During tendon injury repair, deficiency of basic fibroblast growth factor (bFGF) is a critical factor leading to unsatisfactory repair results. This study aims to prepare bFGF-loaded zeolite imidazole framework-8 (ZIF-8) nanocrystals using a one-pot synthesis method. Subsequently, a bilayer nanofibrous membrane incorporating these drug-loaded nanocrystals was fabricated through electrospinning technology. The potential of this composite nanofibrous membrane to facilitate the continuous release of bFGF at the site of tendon injury was evaluated, with the aim of enhancing the quality of tendon repair. The efficacy of the nanofibrous membrane in promoting tendon differentiation, preventing tendon adhesion, and facilitating tendon repair was assessed through both <i>in vitro</i> and <i>in vivo</i> experiments. At the site of tendon injury, the degradation of ZIF-8 in an acidic microenvironment resulted in the release of bFGF and Zn²⁺, which contributed to the enhancement of tendon repair. ZIF-8 nanocrystals achieved an encapsulation efficiency of 50.13% ± 1.42%. Following a continuous release period exceeding 40 days, the cumulative <i>in vitro</i> release rate was determined to be 35.02% ± 4.27%. The incorporation of ZIF-8 nanocrystals into a nanofibrous membrane demonstrated the ability to effectively preserve the bioactivity of bFGF while enabling sustained release at the site of tendon injury, thereby facilitating tendon repair. The findings offer novel insights into the treatment of tendon injuries and provide significant theoretical guidance for the tendon repair process.