Lactoferrin-Sodium Alginate Encapsulated Tanshinone For Ph-Responsive Antibacterial Coating

Poor sealing at titanium abutment-transmucosal tissue interfaces enables pathogen infiltration, increasing peri-implantitis risks and implant failure. This study develops an antibacterial/anti-biofilm biomacromolecule coating for titanium abutments, evaluating its inhibitory effects on Streptococcus mutants biofilm formation while maintaining biocompatibility. Lactoferrin and sodium alginate encapsulated tanshinone IIA formed charge-reversal nanoparticles (TA@NPs). Polydopamine-coated titanium (TP) was prepared via dopamine polymerization, followed by TA@NPs conjugation through electrostatic and covalent interactions to create TP@NPs. The inhibitory effects of TA@NPs and TP@NPs on free Streptococcus mutants and associated biofilm were verified, as well as the effects of pH-responsive release properties and charge reversal properties of TA@NPs and TP@NPs on the inhibitory effects. In addition, the biocompatibility of this system was evaluated. Charge-reversal TA@NPs have the ability to continuously release antimicrobial components under neutral conditions and positively charge-targeted antibacterial activity under acidic conditions. TP@NPs provides a dual antimicrobial effect through TA release and surface inhibition of biofilm formation effects, effectively preventing the formation of biofilm. In addition, the antimicrobial coating constructed from biomacromolecule exhibits good biocompatibility. Charge-reversal TA@NPs synthesized via lactoferrin/sodium alginate encapsulation form pH-responsive coatings, enhancing the antibacterial efficacy and biocompatibility of natural macromolecular coatings on abutments. This study provides new options for modification strategies in the transmucosal region of an implant-abutment.