Stage-Adaptable Silk-Based Nanofiber Film for Postoperative Uterine In Situ Repair and Fertility Preservation.

Uterine dysfunction arising from surgical procedures such as curettage and caesarean section often leads to adhesions, hyperplasia and fibrosis, undermining women's fertility and quality of life. Conventional pharmacological and physical therapies cannot fully restore uterine function. To overcome these limitations, we designed a composite, polysaccharide-coated silk nanofiber film as a staged scaffold to meet evolving healing demands. The hydrophilic polysaccharide layer provides early postoperative wet strength, conformability and physical isolation, while the underlying nanofibrous silk network mimics the extracellular matrix to support cell adhesion, proliferation and regeneration in later stages. In a rat model of severe uterine injury, implantation of this biodegradable film prevented postoperative adhesions and preserved reproductive capacity, achieving a fertility rate exceeding 80%. Mechanistically, the scaffold modulates the immune microenvironment by promoting M2 macrophage polarization, attenuating inflammation and accelerating tissue repair. It also upregulates angiogenic factors (VEGF-A, PDGF-BB), enhances type III collagen deposition and minimizes foreign-body reaction, collectively driving effective in situ uterine regeneration. Fabricated via aqueous electrospinning and mild coating, the scaffold is cost-effective, ecofriendly and readily scalable. As a biodegradable, staged platform tailored to dynamic uterine healing, this material offers a novel, versatile solution for clinical translation in uterine repair and broader regenerative-medicine applications.