Long-term release of chlorhexidine from dental adhesive resin system using human serum albumin nanoparticles

A functional dental adhesive resin system with antimicrobial properties was developed using human serum albumin (HSA) nanoparticles as the drug delivery carrier. HSA nanoparticles loaded with chlorhexidine (CHX) diacetate, a model antimicrobial drug, were prepared using a desolvation technique. The resulting CHX-loaded HSA nanoparticles were incorporated into a commercial methyl methacrylate (MMA)-based resin. The size of the nanoparticles ranged 50–300 nm, and the nanoparticles were dispersed homogeneously in the resin matrix. The CHX-loaded HSA nanoparticles showed an early release burst of ~20 % of the total CHX by day 5, followed by the sustained release of the remaining CHX over the next 20 days. In contrast, the resin matrix containing the HSA nanoparticles showed a sustained release of CHX without an early release burst in a 4-week immersion study. In the agar diffusion test, the resin matrix incorporating the CHX-loaded HAS nanoparticles showed a larger growth inhibition zone against Streptococcus mutans than the resin matrix alone, indicating that this delivery platform potently imparts antibacterial activity to the resins. These results also suggest that CHX, which inhibits the growth of oral bacteria, can be incorporated efficiently into the MMA-based resin matrix using HSA nanoparticles.