An Integrated Dual-layer Heterogeneous PCL Scaffold Promotes Oral Mucosal Wound Healing through Inhibiting Bacterial Adhesion and Mediating HGF-1 Behaviour

Recently, the high incidence of oral mucosal defects and the subsequent functional impairments have attracted widespread attention. Controlling scaffold geometry pattern has been proposed as a strategy to promote cell behavior and facilitate soft tissue repair. In this study, we innovatively construct an integrated dual-layer heterogeneous polycaprolactone (PCL) scaffold using melt electrowriting (MEW) technology. The outer layer was disordered, while the inner layer featured oriented fiber patterns: parallel (P-par), rhombic (P-rhomb), and square (P-sq). Our findings revealed that the P-rhomb and P-sq scaffolds exhibited superior surface wettability, roughness, and tensile strength compared to the pure disordered PCL scaffolds (P) and P-par. Compared to the commercial collagen membranes, the outer layer of PCL can effectively inhibit bacterial adhesion and biofilm formation. Furthermore, the P-rhomb and P-sq groups demonstrated higher gene and protein expression levels related to cell adhesion and cell migration rates than did the P and P-par groups. Among them, P-sq plays an important role in inducing the differentiation of gingival fibroblasts into myofibroblasts rich in α-smooth muscle actin (α-SMA). Additionally, P-sq could reduce inflammation, promote epithelial regeneration, and accelerate wound healing when used in full-thickness oral mucosal defects in rabbits. Overall, the integrated dual-layer heterogeneous PCL scaffold fabricated by MEW technology effectively inhibited bacterial adhesion and guided tissue regeneration, offering advantages for clinical translation and large-scale production. This promising material holds important potential for treating full-thickness mucosal defects in a bacteria-rich oral environments.