Comparative Evaluation of Mesoporous Calcium Silicate Nanoparticles Loaded with Gentamicin and Chlorhexidine for its Antibacterial Properties against Enterococcus Faecalis: An In Vitro study

AIM OF THE STUDY: To evaluate the antibacterial effectiveness of mesoporous calcium silicate nanoparticles loaded with gentamicin and chlorhexidine against Enterococcus faecalis. MATERIALS AND METHODS: Mesoporous calcium silicate nanoparticles were synthesized by template method. Synthesized nanoparticles were characterized by HR SEM and elemental composition was analyzed by EDAX. Nanoparticles were grouped as follows: Group I-10%DMSO (negative control), Group II-CaSi, Group III-CaSi-G, and Group IV-CaSi-CHX. The antimicrobial efficacy of nanoparticles was determined against ATCC 29212 and two ORAL ISOLATES of E.faecalis by Agar well diffusion assay (at three different volumes - 50, 100, 150μl). Broth microdilution method was chosen for determining MIC/ MBC and Time kill assay to evaluate the time needed for the nanoparticles to destroy the bacteria. The values were tabulated and subjected to statistical analysis. RESULT: Nanoparticles loaded with gentamicin and chlorhexidine both showed inhibition at 50μl, 100μl and 150μl with gentamicin group showing slightly more inhibition compared to chlorhexidine against all 3 strains. Only with clinical isolate 2 at 100 microliters, gentamicin group showed equal inhibition as chlorhexidine. Minimum inhibitory/ minimum bactericidal concentration of the nanoparticles showed Casi-CHX effectiveness at lesser concentration compared to CaSi-G against all 3 strains of E.faecalis. Time kill assay showed that both the nanoparticles were effective against all 3 strains within 15 mins wih CaSi-G at a concentration of 0.5% and CaSi-CHX at a concentration of 0.008%. CONCLUSION: Both CaSi-G AND CaSi-CHX nanoparticles were effective at different volumes and concentrations against E.faecalis. Though CaSi-G showed slightly higher values than CaSi-CHX at all titrations, CaSi-CHXwas effective even at lesser concentrations than CaSi-G