From nanofiber biomimetics to multitarget bioactivities: Oligochitosan/polycaprolactone absorbable sutures via...

Surgical site infections (SSIs) pose a severe threat to clinical outcomes by elevating mortality rates, creating an urgent demand for absorbable sutures that integrate high antibacterial activity with enhanced wound-healing potential. Nanofiber-biomimetic sutures, which replicate the structural features of the native extracellular matrix (ECM), have emerged as a promising solution to modulate cellular interactions and facilitate tissue repair. Herein, we report the design and fabrication of an innovative thread-like suture based on biomimetic oligochitosan (OCS)/polycaprolactone (PCL) composite nanofibers, via a hybrid strategy combining modified electrospinning and textile twisting technology. Compared to pure PCL sutures, the OCS/PCL composite sutures exhibit significantly reduced internal nanofiber diameter, which present a morphological feature that closely mimics the native ECM to facilitate cellular interactions. Critically, the OCS/PCL sutures retain sufficient mechanical strength for surgical applications, with the PCL + 3%OCS formulation achieving a breaking load of ∼21.3 N and reliable knot security (∼14.7 N), outperforming previously reported PCL-based nanofibrous sutures that struggled to balance functionality and mechanical strength. Notably, OCS incorporation endows the sutures with multifunctional bioactivities, including potent antibacterial efficacy (>99% inhibition against Escherichia coli and Staphylococcus aureus), high antioxidant capacity (∼62% DPPH radical scavenging), and excellent hemocompatibility (∼1.2% hemolysis rate). Molecular docking simulations confirm that OCS binds to four key wound-healing regulators, including EGFR, PDGFRβ, Integrin α5β1, and Integrin αVβ3, through multi-target and multi-mode interactions, supporting its role in coordinating cellular signaling and matrix adhesion for tissue repair. Furthermore, in vitro cell assays demonstrate that OCS/PCL sutures significantly enhance the adhesion and proliferation of human dermal fibroblasts (HDFs). Collectively, these results highlight the OCS/PCL composite nanofibrous threads as a promising multifunctional suture for reducing SSIs and accelerating wound healing in clinical settings.