Highly Aligned Electrospun Collagen/Polycaprolactone Surgical Sutures with Sustained Release of Growth Factors for Wound Regeneration

Development of biocompatible and bioactive drug-loaded sutures is considered as an effective but challenging strategy for the wound healing process by delivering biological drugs (e.g., antibiotics) or growth factors (e.g., bFGF) at the surgical wound sites. Conventional offline suture strategies often lead to fast and uncontrollable release of drugs at wound sites, rendering wound healing to become a longer and painful process for patients. Herein, we propose an online suture strategy to fabricate electrospun polycaprolactone (PCL) fibrous yarns, incorporated with both collagen (COL) and bFGF, to produce bFGF-COL@PCL sutures. Upon demonstrating the well-oriented and aligned fibrous microstructure, high mechanical properties, and controlled release of bFGF from bFGF-COL@PCL sutures in vitro, we then applied bFGF-COL@PCL sutures to an incision wound healing mouse model in vivo. Further in vivo study showed that as compared to the commercialized Vicryl suture, bFGF-COL@PCL sutures significantly promoted the wound healing at different stages by accelerating granulation tissue formation, collagen deposition, and re-epithelialization. The enhanced wound healing efficiency of bFGF-COL@PCL sutures is likely attributed to two synergistic factors: (i) the well-oriented nanofibrous structure reduces tissue drag to minimize their trauma and (ii) the presence of both collagen and bFGF enhances the basement membrane (BM) reconstruction, cell proliferation, and angiogenesis. This work demonstrates an effective suture strategy and system for surgical suture applications.