Antimicrobial Activity and Biocompatibility of Antibiotic-loaded Chitosan Hydrogels as a Potential Scaffold in Regenerative Endodontic Treatment.

Abstract Objective To determine the effectiveness of several antibiotic-loaded hydrogel scaffolds against Enterococcus faecalis, as well as their ability to stimulate proliferation and mineralization of dental pulp stem cells (DPSCs). Methods Fibrin (Fg) or chitosan-fibrin hydrogels (Ch) were prepared using 12.5 mg/mL fibrinogen and 0.4% (w/v) chitosan. Triple antibiotics, clindamycin-modified triple antibiotic paste, or double antibiotics were loaded in gels (1mg/mL). Antibacterial effect against E. faecalis biofilm was determined using colony forming unit (CFU) and confocal laser scanning microscope (CLSM). Cell viability and morphology were determined by loading cells into different gels at 7- and 14-days using the water-soluble tetrazolium salt-1 cell viability assay, and Live & Dead cell analysis. Mineralization was detected using alkaline phosphatase and alizarin red staining activity. Results Antibiotic-loaded Fg gel and Ch gel alone without antibiotics resulted in a significant reduction in CFUs compared to the positive control (P 0.05). Conclusions Double antibiotic-loaded Ch gel appears to enhance the antibacterial properties while maintaining higher cell viability, cell spreading, and mineralization activity, compared to all the other scaffolds investigated.