In Vivo Hard and Soft Tissue Response of Two-Dimensional Nanoparticle Incorporated Biodegradable Polymeric Scaffolds

Current efforts in the design of bone tissue engineering scaffolds have focused on harnessing the physiochemical properties of two-dimensional organic and inorganic nanoparticles to improve bulk and surface properties of biodegradable polymers. Herein, we investigate the hard and soft tissue in vivo biocompatibility of two such constructs: 90% porous poly(lactic-co-glycolic acid) (PLGA) nanocomposite scaffolds incorporated with 0.2 wt % graphene oxide nanoplatelets (GONPs) or molybdenum disulfide nanoplatelets (MSNPs). Scaffolds were implanted in a noncritical sized monocortical defect in the tibia or subcutaneously on the dorsum of a rat model for 2 or 6 weeks. Hard and soft tissue in vivo biocompatibility of the nanoparticle reinforced scaffolds was comparable to that of the PLGA control. In addition, 2 weeks after implantation, significantly less bone growth (∼35%) was observed for the PLGA group compared to that of the empty defect group; it was not observed for the experimental groups which showed 20% and 15% greater bone growth compared to that of the PLGA group. This may indicate that the nanoparticles do play a role in assisting bone regeneration. Taken together, the results suggest that scaffolds incorporated with GONPs or MSNPs show promise for bone tissue engineering applications.