Effect of Zinc Oxide Nanoparticle Addition to Polycaprolactone Periodontal Membranes on Antibacterial Activity and Cell Viability

During the design of membranes for guided tissue regeneration (GTR) to treat periodontal diseases, infection of the exposed membranes and postoperative complications can be prevented by increasing bacterial resistance. This study evaluated the antibacterial activity of PCL/ZnO membranes and their effect on cell viability via addition of antibacterial zinc oxide (ZnO) nanoparticles to a biocompatible and biodegradable material such as polycaprolactone (PCL). Neat PCL membranes and PCL/ZnO membranes containing 0.5 wt.% and 5 wt.% ZnO were produced, and divided into PCL (0% ZnO), LZ (0.5 wt.% ZnO), and HZ (5 wt.% ZnO) groups, respectively. The surface characteristics of the membranes including morphological features and changes in composition were analyzed. Adhesion of bacteria, including Streptococcus mutans and Porphyromonas gingi-valis, was analyzed using a crystal violet assay. The proliferation of MC3T3-E1 osteoblasts was evaluated using a WST-8 assay. Significant differences were analyzed using the Kruskal-Wallis test (P < 0.05). The results of groups were compared using the Mann-Whitney test (P < 0.017). ZnO nanoparticles were dispersed in the PCL matrix of PCL/ZnO membranes. Compared with neat PCL membranes, their ability to form crystals decreased and their amorphous structure increased. The adhesion of S. mutans and P. gingivalis in the LZ and HZ groups containing ZnO was significantly decreased compared with that of the neat PCL membranes (P < 0.05). No significant differences were observed in the proliferation of MC3T3-E1 cells between the PCL/ZnO membranes and the neat PCL membranes both on days 2 and 5 of culture (P > 0.05). This study has demonstrated that the PCL membranes carrying the ZnO nanoparticles inhibited bacterial adhesion without affecting the viability of osteoblasts, suggesting the potential application of ZnO in GTR to increase antibacterial activity of membranes.