3D‐printed MgO nanoparticle loaded polycaprolactone β‐tricalcium phosphate composite scaffold for bone tissue engineering applications: In‐vitro and in‐vivo evaluation

Abstract Magnesium (Mg) plays an important role in controlling bone apatite structure and density and is a potential bioactive material in repairing critical‐sized bone defects. In this study, we aimed to evaluate the effect of adding NanoMgO to polycaprolactone/beta‐tricalcium phosphate (PCL/β‐TCP) scaffolds on bone regeneration. Novel 3D‐printed porous PCL/β‐TCP composite scaffolds containing 10% nanoMgO were fabricated by fused deposition modeling (FDM) and compared with PCL/β‐TCP (1:1) scaffolds (control). The morphology and physicochemical properties of the scaffolds were characterized by ATR‐FTIR, XRD, scanning electron microscope‐energy dispersive X‐ray analysis (SEM–EDX), transmission‐electron‐microscopy (TEM), water contact angle, and compressive strength tests and correlated to its cytocompatibility and osteogenic capacity in‐vitro. To evaluate in‐vivo osteogenic capacity, bone‐marrow‐derived stem cell (BMSC)‐loaded scaffolds were implanted into 8 mm rat critical‐sized calvarial defects for 12 weeks. The hydrophilic scaffolds showed 50% porosity (pore size = 504 μm). MgO nanoparticles (91.5 ± 27.6 nm) were homogenously dispersed and did not adversely affect BMSCs' viability and differentiation. Magnesium significantly increased elastic modulus, pH, and degradation. New bone formation (NBF) in Micro‐CT was 30.16 ± 0.31% and 23.56 ± 1.76% in PCL/β‐TCP/nanoMgO scaffolds with and without BMSCs respectively, and 19.38 ± 2.15% and 15.75 ± 2.24% in PCL/β‐TCP scaffolds with and without BMSCs respectively. Angiogenesis was least remarkable in PCL/β‐TCP compared with other groups ( p < .05). Our results suggest that the PCL/β‐TCP/nanoMgO scaffold is a more suitable bone substitute compared to PCL/β‐TCP in critical‐sized calvarial defects.