Abstract

Background: The aim of this study was to design an antimicrobial release system for periodontal therapy based on chitosan and copper nanoparticles and assess its in vitro antibacterial activity against Aggregatibacter actinomycetemcomitans. Methods: Copper nanoparticles were synthesized into a chitosan, starch and ascorbic acid bio-friendly system. Copper nanoparticles/chitosan gel nanocomposites were used to produce solid sponges and gel spheres with 100 µg/mL copper content. The nanocomposite materials were characterized by scanning electron microscopy and attenuated total reflectance with Fourier transform infrared spectroscopy. The antimicrobial activity was tested against A. actinomycetemcomitans by halo inhibition assay on semisolid agar medium. Copper release from the nanocomposites was measured up to 10 days of incubation in artificial saliva at 37° C by analyzing the Cu concentration with a Copper Ion Selective Electrode. Results: The formation of sponges and gel spheres of chitosan loaded with nanometric copper particles was confirmed. These materials inhibited the growth of A. Actinomycetemcomitans. Sphere nanocomposites presented higher stability in saliva and exhibited a controlled and sustained release of bactericidal copper concentrations. Conclusions: Copper nanoparticles/chitosan nanocomposites effectively inhibit growth of A. Actinomycetemcomitans and appear as promissory systems for the development of localized periodontal therapies.