Sustained simvastatin delivery via poly(lactide) nanoparticles enhances early osteogenic-associated responses in human periodontal ligament stem cells

Abstract Simvastatin has recognized osteoinductive properties, but its application in regenerative strategies is limited by poor aqueous behavior and a narrow cytocompatible dosing window. Here, we developed simvastatin-loaded poly(lactide) nanoparticles and evaluated whether nanoparticle-mediated delivery improves cytocompatibility and early osteogenic-associated responses of human periodontal ligament stem cells (hPDLSCs) compared with free simvastatin. Nanoparticles were prepared by nanoprecipitation and characterized by dynamic light scattering, transmission electron microscopy, and nanoparticle tracking analysis, showing spherical morphology and a mean diameter of approximately 150 nm. Cellular internalization was confirmed using rhodamine-labeled nanoparticles and confocal microscopy, demonstrating efficient uptake with predominantly cytoplasmic localization. In hPDLSCs, nanoparticle-delivered simvastatin improved short-term cytocompatibility and enhanced mineralization together with increased periostin and osteocalcin secretion, with the most pronounced differences observed at day 14, whereas mineralization outcomes converged between delivery formats by day 21. Complementary clonogenic assays in osteoblasts demonstrated that nanoparticle-mediated delivery attenuated simvastatin-associated loss of long-term proliferative capacity relative to free simvastatin under the tested conditions. These findings indicate that poly(lactide) nanoparticles may improve the cytocompatible delivery profile of simvastatin and preferentially enhance early osteogenic-associated responses in vitro in hPDLSCs, supporting further investigation of controlled simvastatin delivery strategies for periodontal regenerative applications.