Enhanced mechanical strength and bioactivity of 3D-printed (3-TCP scaffolds coated with bioactive glasses

Author(s)

Melo, Marcia Cristina Bezerra ; Spirandeli, Bruno Roberto ; Barbosaa, Lucas ; dos Santos, Veronica Ribeiro ; de Campos, Tiago Moreira Bastos ; Thim, Gilmar Patrocinio ; Triches, Eliandra de Sousa

• Document type: Journal article
• Source: JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS; v. 163, p. 10-pg., 2024-12-06.

Abstract

3D printing in scaffold production offers a promising approach, enabling precise architectural design that closely mimics the porosity and interconnectivity of natural bone. (3-Tricalcium phosphate ((3-Ca3(PO4)2, (3-TCP), with a chemical composition similar to the inorganic component of bone, is a widely used material for scaffold fabrication. Recent advances have made it possible to functionalize ceramic scaffolds to improve bone regeneration and repair while enabling the in situ release of therapeutic agents to treat bone infections. In this study, 3Dprinted (3-TCP scaffolds were coated with bioactive glasses, 45S5 (45SiO2 - 24.5Na2O - 24.5CaO - 6P2O5, wt. %) and 58S (58SiO2 - 33CaO - 9P2O5, wt.%), using sol-gel solutions through a vacuum impregnation technique. The (3-TCP ink exhibited pseudoplastic behavior, which facilitated its 3D printing. The resulting scaffolds demonstrated high fidelity to the designed model, featuring well-aligned filaments and minimal collapse of the lower layers after sintering. Elemental mapping revealed that 45S5 glass formed a surface coating around the scaffold struts, whereas 58S glass penetrated the internal structure, this occurred due to their differing viscosities at high temperatures. Compared to uncoated (3-TCP scaffolds, the coatings significantly improved mechanical strength, with increases of 63% and 126% for scaffolds coated with 45S5 and 58S, respectively. Bioactivity was confirmed through an apatite mineralization assay in simulated body fluid, which demonstrated hydroxyapatite precipitation on both coated scaffolds, albeit with distinct morphologies. Since this study focused on acellular scaffolds, further research is necessary to fully explore the potential of these bioactive scaffolds with optimized mechanical properties in biological systems. (AU)

• FAPESP's process: 20/12874-9 - Infiltration graded by glass in an experimental composite based on whiskers of alumina and zircônia: development, microstructural characterization and optical and mechanical properties
• Grantee: Tiago Moreira Bastos Campos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 20/12507-6 - Development and characterization of wollastonite cement for bone tissue engineering
• Grantee: Gilmar Patrocínio Thim
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/19594-4 - 3D pritting of bioactive and resorbable scaffolds by robocasting: synthesis, processing and antibacterial activity
• Grantee: Eliandra de Sousa Trichês
• Support Opportunities: Regular Research Grants
• FAPESP's process: 23/16554-7 - Development of multilayer cellular scaffolds containing a bioactive glass with hierarchical pore structure by combining electrospinning and additive manufacturing techniques for applications in regenerative medicine
• Grantee: Verônica Ribeiro dos Santos
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors