PLGA hybrid porous microspheres as human periodontal ligament stem cell delivery carriers for periodontal regeneration

Periodontitis, a widespread disease, is the main cause of tooth loss in adults, and there is no ideal clinical therapy for patients with severe alveolar bone defects. Research investigating the potential of polymer porous microspheres (PMs) as stem cells delivery carriers has been a hot-spot topic for tissue engineering in recent years. However, to date, it remains largely unknown regarding application of PMs in periodontal regeneration with satisfied cell seeding efficiency. In this study, PLGA PMs and corresponding silk fibroin (SF) or / and hydroxyapatite (HA) modified PLGA counterparts were synthesized by double emulsion-solvent evaporation, desolvation and biomineralization. Then, human periodontal ligament stem cells (hPDLSCs) were seeded into these carriers with a specific “cell perfusion” technique. Cell viability and migration, proliferation as well as osteogenic differentiation properties of the hPDLSCs were evaluated in vitro. In vivo experiment examining the impact of hPDLSCs suspension group and four cell delivery carriers groups on rat periodontal tissue regeneration further suggested that the HA-SF-PLGA group displayed superior tissue repairing efficacy due to SF-dependent high adhesion and HA-dependent osteogenesis induction. This novel tissue regeneration strategy based on PLGA hybrid PMs combined with a specific “cell perfusion” technique present promising potential of local stem cell delivery for effective clinical periodontitis therapy development, which is also applicable to tissue regeneration in other body parts.