Fabricação por manufatura aditiva de scaffolds cerâmicos porosos com infiltração de biovidro para uso biomédico

Abstract

Bone injuries and defects often require materials capable of promoting tissue repair, replacement, or regeneration. In this context, ceramic scaffolds have emerged as promising alternatives for mimicking and replacing damaged tissues due to their biocompatibility and structural versatility. To this end, this work presents the development of alumina-zirconia scaffolds produced by additive manufacturing by material extrusion (3D printing) and subsequently infiltrated with bioglass (45S5). The filaments for additive manufacturing by material extrusion were obtained in a twin-screw extruder by mixing ceramic powders (55% by mass) with low-density polyethylene polymer (45% by mass). To create a degradation curve for polymer removal after printing, a thermogravimetric analysis test was necessary. The produced and sintered scaffolds were subjected to bioglass infiltration and evaluated through morphological and biological analyses. The debinding (polymer removal) and sintering processes resulted in parts with internal pore sizes between 500 µm and 1 mm, with a dimensional reduction of approximately 30%, allowing bioglass infiltration. The presence of Si, Ca, and P was identified in all mixtures, elements responsible for contributing to the biological response. Biological tests demonstrated that the printed scaffolds, composed of alumina, zirconia, and a combination of both, with or without bioglass infiltration, did not present significant cytotoxicity in 3T3 or VERO renal epithelial fibroblasts after 72 h. Among these, the alumina-zirconia scaffold infiltrated with bioglass stood out for increasing cell viability and proliferation at 72 h (~150% increase). It also promoted strong cell adhesion and extracellular matrix release after 5 days, demonstrating superior biocompatibility and potential osteoinductive activity. It is worth noting that a combination of bioactive ceramic composites for the manufacture of scaffolds demonstrated strong potential in promoting tissue regeneration, preserving the integrity of the host tissue, an essential aspect for the prevention of clinical failures. [resumo fornecido pelo autor]