Antibacterial Photopolymer Composites Based on Methacrylate Resin With Metal Oxide Nanoparticles for 3D Printing of Biomedical Products

Photopolymer materials based on methacrylic acid esters are extensively utilized in additive manufacturing; nevertheless, their application in medicine is constrained by the absence of antimicrobial activity, which elevates the risk of infectious complications. The present paper puts forth a methodology for producing composites for stereolithographic 3D printing by introducing metal oxide nanoparticles (TiO₂, CuO, ZnO, and Ag₂O) into a methacrylate resin. The synthesis of the nanoparticles was accomplished via a laser ablation process in water, followed by their transfer to acetone and subsequent dispersion in the resin at concentrations ranging from 0.001 to 0.1 vol%. The utilization of dynamic and electrophoretic light scattering methodologies has elucidated that the nature of particle agglomeration in acetone is contingent upon the nature of the oxide and exhibits a correlation with the surface charge density, otherwise known as the zeta potential. It has been demonstrated that all composites retain their photopolymerizability, thereby enabling the fabrication of three-dimensional objects (i.e., test models and an orthodontic mouthguard). The antibacterial activity of the modified materials was assessed by measuring the inhibition of Escherichia coli growth over a 24-hour period. The results demonstrated a pronounced bacteriostatic effect for all modified materials. The composite with 0.1% Ag₂O exhibited the strongest effect, with a maximum of 58% inhibition. ZnO and CuO, at the same concentration, showed similar results, with 48% and 45% inhibition, respectively. In contrast, TiO₂ demonstrated saturation of activity at a lower concentration, with 0.01% resulting in complete inhibition. The study of the cytotoxic effect on human fibroblasts (HSF line) was conducted using fluorescence microscopy. The results indicated that cell viability on all composites exceeded 95% relative to the unmodified polymer. Consequently, the developed composites exhibit a synergistic combination of high antibacterial efficacy and low toxicity, along with technological suitability for 3D printing. This technological aptitude renders the composites promising candidates for utilization in the fabrication of implants, surgical templates, and dental structures that possess enhanced antiseptic properties.