Multilayer modification on titanium surface for in situ delivery of MicroRNAs

Abstract Micro-RNA (miRNA) gene therapy is a viable approach for enhancing implant osseointegration for clinical applications. However, an efficient in situ delivery system for coating the implants is needed. The present study combined dopamine-modified alginate and miRNA to construct multiple layers on titanium surface using the layer-by-layer technique. Water contact angle tests and fluorescence microscopy results showed that miRNAs were successfully loaded onto the multilayer. The in situ release behavior of miRNA was monitored and their transfection was confirmed by the fluorescence microscopy. Results from osteoblast viability tests showed that the multilayer significantly enhanced cell proliferation. Alkaline phosphatase activity was enhanced by the multilayer as well. In conclusion, the multilayer coating can serve as an effective in situ delivery method for miRNAs and can significantly enhance osteoblast proliferation and early differentiation.