Light enhanced bone regeneration in an athymic nude mouse implanted with mesenchymal stem cells embedded in PLGA microspheres

BACKGROUND Biodegradable microspheres fabricated from poly (Lactic-co-glycolic acid) (PLGA) have attracted considerable attention in the bone tissue regeneration field. In this study, rabbit mesenchymal stem cells (rMSCs) adherent to PLGA microspheres were implanted into athymic nude mice and irradiated with 647 nm red light to promote bone formation. It was found that irradiating rMSCs with high levels of red light (647 nm) from an LED (light-emitting diode) increased levels of bone specific markers in rMSCs embedded on PLGA microspheres. RESULT These increased expressions were observed by RT-PCR, real time-QPCR, immunohistochemistry (IHC), and von Kossa and Alizarin red S staining. Microsphere matrices coated with rMSCs were injected into athymic nude mice and irradiated with red light for 60 seconds showed significantly greater bone-specific phenotypes after 4 weeks in vivo. CONCLUSION The devised PLGA microsphere matrix containing rMSCs and irradiation with red light at 647 nm process shows promise as a means of coating implantable biomedical devices to improve their biocompatibilities and in vivo performances.