Chitosan modified poly(lactic-co-glycolic) acid nanoparticles interaction with normal, precancerous keratinocytes and dental pulp cells

Introduction: Nanoparticles (NPs) can carry molecules to different body tissues. Due to their controlled delivery properties, chitosan covered poly-lacto-co-glycolic NPs (PLGAChi NPs) could be used to deliver drugs to oral tissues for the treatment of dental diseases or in anticancer therapy. The aim of this study was to determine the uptake and cytotoxicity of PLGAChi NPs on different types of cells found in the oral cavity. Methodology: Normal oral keratinocytes (NOKs), precancerous keratinocytes (POE9i) and dental pulp cells (DPCs) were exposed for 12h and 24h to 20 g/mL and 200 g/mL PLGAChi NPs covalently tagged with fluorescein. 3D organotypic tissues of oral mucosa were grown in vitro and exposed to 200g/mL PLGAChi NPs for 24h. Results: Both normal and premalignant oral mucosa cells (NOK and POE9i) displayed uptake of PLGAChiNPs in a time and concentration-dependent manner, both in 2D and 3D models. A higher and more rapid uptake of PLGAChi NPs by precancerous cell line POE9i was observed when compared to NOKs.Interestingly, DPCs did not display internalized PLGAChi NPs, even at the highest concentration of 200 g/mL. Conclusion: Chitosan-coated PLGAChi NPs proved to be able to cross the cellular membrane of oral keratinocytes, in 2D as well as in 3D cultures. The polymeric NPs used in the present study seem not to be suitable for applications that require NPs uptake by DPCs, as no evidence of uptake in these cells was found in this study. The finding that PLGAChi NPs showed significant internalization by human keratinocytes indicate that they could be used for drug delivery purposes to oral mucosa