Nanochitosan antimicrobial activity against Streptococcus mutans and Candida albicans dual-species biofilms.

OBJECTIVE: Chitosan nanoparticle (nanochitosan) has a broad antimicrobial spectrum against diverse pathogenic microorganisms. However, its effect on dental caries-associated microorganisms, such as Streptococcus mutans and Candida albicans is yet to be explored. These microorganisms are known for causing early childhood caries. Therefore, this study was aimed at investigating nanochitosan inhibition capacity against dual-species biofilms of S. mutans and C. albicans. In this study, nanochitosan antimicrobial activity is reported against mono and dual biofilm species of S. mutans and/or C. albicans at 3 and 18 h incubation time. Nanochitosan inhibition capacity was observed through biofilm mass quantity and cell viability. RESULTS: The present study successfully synthesized nanochitosan with average diameter of approximately 20-30 nm, and also established dual-species biofilms of S. mutans and C. albicans in vitro. With nanochitosan treatment, the cell viability of both microorganisms significantly decreased with the increasing concentration of nanochitosan. There was no significant decrease in biofilm mass both in the dual and single-species biofilms after 3 h of incubation. However, greater inhibition of biofilm was observed at 18 h incubation.

Enhanced bone regeneration capability of chitosan sponge coated with TiO2 nanoparticles.

Chitosan has been a popular option for tissue engineering, however exhibits limited function for bone regeneration due to its low mechanical robustness and non-osteogenic inductivity. Here we hybridized chitosan with TiO2 nanoparticles to improve its bone regeneration capability. Morphology and crystallographic analysis showed that TiO2 nanoparticles in anatase-type were distributed evenly on the surface of the chitosan sponges. Degradation test showed a significant effect of TiO2 nanoparticles addition in retaining its integrity. Biomineralization assay using simulated body fluid showed apatite formation in sponges surface as denoted by PO4- band observed in FTIR results. qPCR analysis supported chitosan - TiO2 sponges in bone regeneration capability as indicated by DMP1 and OCN gene upregulation in TiO2 treated group. Finally, cytotoxicity analysis supported the fact that TiO2 nanoparticles added sponges were proved to be biocompatible. Results suggest that chitosan-50% TiO2 nanoparticles sponges could be a potential novel scaffold for bone tissue engineering.