Biomimicry of oil infused layer on 3D printed poly(dimethylsiloxane): Non-fouling, antibacterial and promoting infected wound healing.

The nepenthes-inspired slippery liquid-infused surface has led to multiple potentials in biomedical devices' design. This study aims to develop a biomimetic, environmentally-friendly slippery layer of oil-infused 3D printed polydimethylsiloxane with anti-bacterial nanosilver (iPDMS/AgNPs) for wound dressing. The engineered 3D printed iPDMS can cater the different requirements of wounds with antifouling, anti-blood staining, and kill bacteria. iPDMS/AgNPs not only exhibits biocompatibility, against adherence and effective antibacterial activity but also effectively promotes neo-epithelial and granulation tissue formation to accelerate wound healing in vivo. Optimized rheologic parameters were obtained for the 3D printable iPDMS pre-polymerization condition. Scanning electronic micrograph (SEM) and Energy Dispersive Spectrometer (EDS) show a uniform mesh with AgNPs dotted on the printed dressing. No cytotoxicity of iPDMS/AgNPs has been found via cell Counting Kit-8(CCK-8) assay. Meanwhile, the membranes infused with silicon oil effectively prevented from the adherence of the two standard drug-resistant bacteria, Staphylococcus aureus and Escherichia coli (PDMS vs. PDMS+oil, p < 0.05; PDMS+0.5%AgNPs vs. iPDMS+0.5%AgNPs, p < 0.05; PDMS+2.5%AgNPs vs. iPDMS+2.5%AgNPs, p < 0.05). By bacteria co-culture model iPDMS/AgNPs can kill about 80% of Staphylococcus aureus and Escherichia coli. When applied to a full-thickness wound defect model of murine, iPDMS/AgNPs was effective in anti-infection. It also promotes the epithelialization, the granulation tissue formation, and wound healing. These findings demonstrate that iPDMS/AgNPs may have therapeutic promise as an ideal wound dressing shortly.