Construction and Evaluation of an Acid-Responsive Antibacterial Coating with Laser-Induced Micro/Nano-Structured Titanium Surface Loaded LAMA3 pDNA@ZIF-8 Nanoparticles for Enhanced Soft Tissue Integration

Unlike natural teeth, dental implants exhibit distinct peri-implant structures characterized by only about one-third of the hemidesmosomal attachments and the absence of periodontal ligament fiber insertion, which compromise their long-term success. Guided epithelial ingrowth via laser-induced microgrooves combined with enhanced hemidesmosome formation through LAMA3 gene transfection represents a promising strategy to improve soft tissue integration. In this study, a micro/nano-textured surface was fabricated on titanium implants by laser patterning followed by anodization to promote directional cell growth. A layer-by-layer self-assembled coating composed of ZIF-8-encapsulated LAMA3 plasmid was constructed on this micro/nano-surface. This coating exhibited acid-responsive release behavior and demonstrated antibacterial activity. More importantly, it effectively delivered the LAMA3 plasmid into cells and upregulated the expression of hemidesmosome-related proteins integrin α6 and integrin β4, both in vitro and in a rat implantation model. RNA sequencing revealed that the coating modulated global gene expression profiles and subsequently influenced cellular functions. In immortalized keratinocytes, differentially expressed genes were enriched in the MAPK signaling pathway, which was further validated by protein expression analysis after MAPK blockade. These findings indicate that our functional coating endows dental implants with favorable prospects for enhancing soft tissue sealing, offering a novel strategy to improve the long-term stability of oral implants.