One-Step Fabrication of Water-Dispersible Calcium Phosphate Nanoparticles with Immobilized Lactoferrin for Intraoral Disinfection.

Lactoferrin is a highly safe antibacterial protein found in the human body and in foods. Calcium phosphate (CaP) nanoparticles with immobilized lactoferrin could therefore be useful as intraoral disinfectants for the prevention and treatment of dental infections because CaP is a mineral component of human teeth. In this study, we fabricated CaP nanoparticles with co-immobilized lactoferrin and heparin using a simple one-step coprecipitation process. Heparin, a negatively charged polysaccharide, was used as both an immobilizing agent for lactoferrin and a particle-dispersing agent. The immobilization efficiency for lactoferrin in the CaP nanoparticles depended on the concentrations of both the lactoferrin and heparin in the reaction solution and was over 90% under optimal conditions. The nanoparticles had a hydrodynamic diameter of about 150-200 nm and could be well dispersed in water, owing to their relatively large negative zeta potential derived from heparin. They were found to exhibit antibacterial activity against Actinomyces naeslundii, which is involved in the initial formation of dental plaque that consequently leads to dental caries and periodontal disease. These results indicate the potential of the proposed nanoparticles as intraoral disinfectants.