Otimização da Impressão 3D de Scaffolds de Biovidro 58S por Robocasting Empregando Hidrogéis de Alginato de Sódio Funcionalizados com Nanopartículas de Prata

Abstract

Otimização da Impressão 3D de Scaffolds de Biovidro 58S por Robocasting Empregando Hidrogéis de Alginato de Sódio Funcionalizados com Nanopartículas de Prata

The development of synthetic substitutes for bone grafts represents a significant challenge in tissue engineering, particularly due to the limitations associated with autologous and allogeneic grafts. In this context, this study aimed to develop and characterize ceramic scaffolds based on 58S bioglass, fabricated by three-dimensional printing via robocasting, using sodium alginate as a temporary polymeric matrix and silver nanoparticles as a functionalizing agent with potential antimicrobial activity. The 58S bioglass was synthesized through the sol–gel route and characterized by X-ray diffraction, X-ray fluorescence, pycnometry, and particle size analysis, confirming its predominantly amorphous structure and chemical composition consistent with the SiO₂–CaO–P₂O₅ system. Ceramic pastes containing 30 vol% solid loading were formulated with different alginate concentrations and evaluated regarding their rheological behavior, exhibiting pseudoplastic characteristics suitable for extrusion based processing. The scaffolds were fabricated layer by layer, presenting interconnected macroporous architecture and good geometric fidelity. After drying, organic binder removal, and sintering at 1250 °C, the structures maintained dimensional integrity, with total porosity ranging from approximately 58% to 61%. Uniaxial compression tests indicated an average strength of 22.28 MPa for non functionalized scaffolds and 18.63 MPa for silver-functionalized scaffolds, values compatible with the range reported for human trabecular bone. Surface incorporation of silver nanoparticles was confirmed by microstructural analysis, demonstrating the feasibility of functionalization without significant structural compromise. The results demonstrate the viability of integrating sol–gel synthesis, rheological control, and additive manufacturing for the development of bioactive scaffolds with controlled architecture, potential application in bone regeneration, and the possibility of geometric customization according to patient-specific needs.