Layer-by-layer assembly of bioactive nanofilms for in situ gene transfection of a LAMA3 mutant on hydrogenated TiO₂ nanotubes: in vitro evaluation of epithelial adhesion and hemidesmosome formation.

BACKGROUND: Reliable peri-implant epithelial sealing is paramount for the prevention of peri-implantitis. Remarkably, both hemidesmosomes (HDs) and the internal basal lamina, which notably includes laminin332-essential for transmucosal epithelial sealing-are significantly diminished compared to their natural tooth counterparts. In situ gene therapy has emerged as a promising approach for the spatial regulation of HD formation.

METHODS: In this study, we aim to develop a bioactive coating with an exceptional capacity for the in situ transfection of a recombinant adenovirus carrying a mutant of the laminin α3 chain gene (Ad-mLAMA3), thereby improving transmucosal epithelial sealing. Dopamine (DA), graphene oxide (GO), and type Ⅳ collagen (COL-Ⅳ) multilayers-(DA/GO/COL-Ⅳ)10, designated DGC-were assembled layer by layer on hydrogenated TiO2 nanotubes. The resulting construct was termed H‑DGC. We characterized H-DGC and evaluated its effect on HD formation in vitro following integration with Ad-mLAMA3.

RESULTS: The DGC nanofilms were successfully established on hydrogenated TiO2 nanotubes, enhancing in situ transfection efficiency. The integration of H-DGC with Ad-mLAMA3 promoted epithelial cell adhesion and mature HD formation by upregulating the expression of laminin α3 and integrin β4.

CONCLUSIONS: Our findings demonstrate that H-DGC can be engineered as a bio-instructive and in situ interface, significantly enhancing epithelial cell adhesion and mature HD formation, and offering a strategy to prevent peri-implantitis.