Development of polycaprolactone-akermanite nanobiocomposite scaffolds via 3D printing: Structural, mechanical, and biological evaluation for bone tissue regeneration
Rahmatollah Emadi, Pegah Dehghanpour, Yeganeh Salehi, Sayed Reza Mortazavi
Abstract
Bone tissue engineering (BTE) focuses on restoring damaged bone by integrating biological and mechanical properties. Three-dimensional (3D) printing facilitates the fabrication of bioscaffolds, with intricate architectures, where polymers like polycaprolactone (PCL) are widely utilized due to their favorable biocompatibility and processability. Incorporating bio-ceramics like akermanite (Ca 2 MgSi 2 O 7 , AKR) into polymer matrices enhances scaffold properties, including cell viability, osteogenesis, angiogenesis, and antibacterial effects. In this study, akermanite nanoparticles were synthesized via the sol-gel method and incorporated into 3D-printed PCL scaffolds at varying concentrations (0, 15, 30, and 60 wt%) using robocasting. Structural characterizations (SEM, FTIR, and XRD) confirmed successful integration of akermanite. The synthesized nanoparticles had an average size of 113 ± 0.12 nm, promoting better dispersion and interfacial bonding. Increased akermanite content led to improved porosity (59.81 %–72.17 %) and hydrophilicity (contact angle reduced from 102.31° to 65.71°). Mechanical testing showed notable improvements in compressive strength, yield strength, and Young's modulus, reaching 28.24 ± 0.37 MPa, 5.27 ± 0.91 MPa, and 54.44 ± 6.34 MPa at PCL-60 %AKR. Degradation in phosphate-buffered saline (PBS) over 28 days showed a 7.5-fold increase in weight loss for PCL-60 %AKR compared to pure PCL. Bioactivity assessment confirmed apatite formation in simulated body fluid, increasing with akermanite content. MTT assay verified non-cytotoxicity, while MG-63 cell adhesion and proliferation improved on composite scaffolds. This cellular response was attributed to the release of bioactive ions. Overall, the 3D-printed PCL-60 %AKR scaffold demonstrates excellent structural, mechanical, and biological properties for bone regeneration.