Biodegradable Multi-layered Silk Fibroin-PCL Stent for the Management of Cervical Atresia: In Vitro Cytocompatibility and Extracellular Matrix Remodeling In Vivo

Cervical atresia is a rare congenital Müllerian duct anomaly that manifests as the absence or deformed nonfunctional presence of the cervix. Herein, a multi-layered biodegradable stent is fabricated using a homogeneous blend of silk fibroin with polycaprolactone using hexafluoroisopropanol as a common solution. Briefly, a concentric cylinder of 3D honeycomb layer is sandwiched within electrospun sheets for fixing at the cervico-uterine junction to pave the way of cervical reconstruction. An average length of 40 mm with 3 mm diameter is fabricated for the hybrid stent design. SEM evidences an evenly distributed pore architecture of the electrospun layer, and mechanical characterization of stent reveals a tensile strength of 1.7 ± 0.2 MPa, with a Young's modulus of 5.9 ± 0.1 MPa. Physico-chemical characterization confirms the presence of silk fibroin and poly caprolactone within the engineered stent. Following 14 days of pepsin enzymatic degradation, 18% degradation and a contact angle measurement of 97° are observed. In vitro cytocompatibility studies are performed using site-specific primary human cervical squamous, columnar epithelial cells, and human endometrial stromal cells. The study demonstrates non-cytotoxic cells' viability (no significant toxicity), improved cell anchoring, adherence among the stent layers, and proliferation in the 3D microenvironment. Furthermore, in vivo subcutaneous studies in the rodent model indicate that the implanted stent undergoes constructive remodeling, neo-tissue creation, neo-vasculature formation, and re-epithelialization while maintaining patency for 2 months.