Stage-controlled antibacterial surgical sutures based on curcumin@ZIF-8 functional coating for improved wound healing

Antibacterial surgical sutures play a significant role in preventing incision infections and promoting wound healing. However, the existing antibacterial sutures failed to match well with staged antibacterial requirements during wound healing progress. Herein, to endow the sutures with stage-controlled antibacterial properties, a simple and feasible strategy of decorating the suture surface with curcumin@zeolitic imidazolate framework-8 (Cur@ZIF-8) was proposed. The pH of the microenvironment changes during the wound healing process, which declines to acidic in the early postoperative stage due to the aseptic/bacterial inflammatory infection and returns to normal with wound healing. Coincidentally, benefiting from the pH-responsive behavior of ZIF-8, Zn2+ and Cur could be quickly released under an acidic environment, facilitating bacteria-killing efficiency and preventing surgical site infections timely. The release amount of Zn2+ and Cur decreased under a normal pH environment, protecting the cells/tissues from damage caused by their excessive release. In addition, in vitro and in vivo studies revealed that the developed functional sutures could enhance wound healing, as evidenced by stage-controlled release behavior, good antibacterial activity, reduced inflammatory reaction, re-epithelization, and collagen regeneration. Furthermore, thanks to the gentle preparation process, the original mechanical property and handling performance of the sutures were preserved, guaranteeing their practical clinical availability.