3D-printing of alginate-based nanocomposite hydrogels incorporated with bioactive glass and calcium oxide nanoparticles for tissue engineering application

Abstract

The current study focuses on optimizing alginate-based hydrogel ink for 3D bioprinting applications. A range of additives was utilized to enhance the properties of the alginate matrix, including pre-crosslinking treatments, varying concentrations of gelatin, and the incorporation of bioactive glass (BG) and calcium oxide (CaO) nanoparticles. Following the optimization of printing parameters, the formulation containing 7 % alginate and 2 % gelatin was selected as the control sample. Bioactive glass and calcium oxide nanoparticles were incorporated individually and in combinations at ratios of 70:30 and 50:50. These nanoparticles significantly improved the mechanical properties of the scaffolds, particularly tensile strength and elongation. Notably, the inclusion of nanoparticles in a 50:50 ratio increased the tensile strength of the scaffold from 105 kPa (control) to 185 kPa. Furthermore, the addition of nanoparticles enhanced the hydrophilicity of the scaffolds, reducing the contact angle from 63° (control) to 37° (50:50 sample), and improved cellular adhesion. The evaluation of cellular viability demonstrated a survival rate of 90 % for scaffolds with incorporated nanoparticles. Antibacterial tests revealed substantial effectiveness against Escherichia coli, whereas Staphylococcus aureus showed higher resistance. Overall, the findings indicate that alginate-based scaffolds, particularly those incorporating a 50:50 blend of BG and CaO with gelatin, achieve a favorable balance of mechanical performance, biocompatibility, and antibacterial properties, making them promising candidates for tissue engineering applications.