Ideal wound dressings provide optimal microenvironment for the reconstruction of damaged tissue. In this work, we fabricated a bilayer asymmetric dressing to mimic gradient structure of epidermis and dermis of skin by combining electrostatic spinning and 3D printing method with properties including surface hydrophilic and hydrophobic, porosity, mechanical as well as antibacterial properties. The outer layer was prepared by optimized PCL/PLA (PP) via electrostatic spinning to mimick epidermis with water repellency and against bacterial penetration, which has a tensile modulus of 19.69 ± 0.66 MPa. While, the inner layer was 3D printed by optimized sodium alginate/polyvinyl alcohol/chitosan quaternary ammonium salt (SPH). The tensile modulus of SPH with a porosity of 70–90% is 0.82 ± 0.01 MPa, and the water content can be achieved above 85%. The antibacterial efficacy of inner layer was tested against Staphylococcus aureus indicating forming inhibition zone with a diameter of 1.61 ± 0.35 cm. In addition, Cell Counting Kit-8 and Live/Dead assay was used to test the viability of human dermal fibroblasts (HFBS), which showed that PP/SPH with 6% PVA had not significant cytotoxic effects. The double-layer asymmetric dressing meets the requirements of skin mechanical properties and provides an effective repair strategy for clinical skin trauma.

理想的伤口敷料为受损组织的重建提供了最佳的微环境。在这项工作中，我们通过结合静电纺丝和 3D 打印方法，制造了一种双层不对称敷料来模拟皮肤表皮和真皮的梯度结构，该敷料具有表面亲水和疏水、孔隙率、机械和抗菌性能等特性。外层是通过优化的 PCL/PLA (PP) 通过静电纺丝制备的，以模拟具有防水和抗细菌渗透的表皮，其拉伸模量为 19.69 ± 0.66 MPa。同时，内层采用优化的海藻酸钠/聚乙烯醇/壳聚糖季铵盐（SPH）3D打印。孔隙率为70-90%的SPH拉伸模量为0.82±0.01 MPa，含水率可达到85%以上。金黄色葡萄球菌表明形成抑制区，直径为 1.61 ± 0.35 cm。此外，使用Cell Counting Kit-8和Live/Dead测定法检测人真皮成纤维细胞（HFBS）的活力，结果表明含有6% PVA的PP/SPH没有明显的细胞毒作用。双层不对称敷料满足皮肤力学性能要求，为临床皮肤外伤提供了有效的修复策略。