Cell viability and apoptotic changes of dental pulp stem cells treated with propolis, chitosan, and their nano counterparts

Aim Biocompatibility of materials used in regenerative endodontics is of prime importance. Thus, this study was conducted to evaluate and compare cytotoxicity and apoptotic changes of propolis, chitosan, and their nano counterparts on dental pulp stem cells. Materials and methods Aqueous and ethanolic extract of propolis, chitosan, propolis nanoparticles, and chitosan nanoparticles were prepared. Dental pulp stem cells were isolated from human third molars and characterized. Cultured cells were incubated with each extract of each material used for 24 and 72 h. Thereafter, cellular viability was assessed using MTT assay and DNA fragmentation using DNA fragmentation laddering assay. Control samples containing only medium were treated similarly. Differences in mean values of cell viability and DNA fragmentation between materials were assessed by using the one‑way analysis of variance and Tukey’s test. Results Nanoparticles of both materials expressed higher cell viability and lower DNA fragmentation in comparison to their original particles counterpart. Chitosan nanoparticles recorded a lower cytotoxicity and DNA fragmentation after 24 h, which increased by time, meanwhile that of propolis nanoparticles were decreased by time. Type of vehicle was a factor affecting the results of chitosan nanoparticles, while time was the factor affecting propolis nanoparticles. Conclusion Both propolis and chitosan nanoparticles displayed an acceptable biocompatibility and can be used in endodontic regeneration purposes.