Bezerra Melo Márcia Cristina, Spirandeli Bruno Roberto, Barbosa Lucas, Ribeiro Dos Santos Verônica, Bastos de Campos Tiago Moreira, Thim Gilmar Patrocínio, de Sousa Trichês Eliandra
Federal University of São Paulo, Institute of Science and Technology, Bioceramics Laboratory, 330 Talim St, 12231-280, São José dos Campos, SP, Brazil.
Federal University of São Paulo, Institute of Science and Technology, Bioceramics Laboratory, 330 Talim St, 12231-280, São José dos Campos, SP, Brazil; Federal Institute of São Paulo (IFSP), São José dos Campos, 12223-201, São Paulo, Brazil.
J Mech Behav Biomed Mater. 2025 Mar;163:106850. doi: 10.1016/j.jmbbm.2024.106850. Epub 2024 Dec 2.
3D printing in scaffold production offers a promising approach, enabling precise architectural design that closely mimics the porosity and interconnectivity of natural bone. β-Tricalcium phosphate (β-Ca₃(PO₄)₂, β-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, 3D-printed β-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 β-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 β-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.
3D打印技术在支架生产中提供了一种很有前景的方法，能够实现精确的结构设计，紧密模拟天然骨的孔隙率和连通性。β-磷酸三钙（β-Ca₃(PO₄)₂，β-TCP）的化学成分与骨的无机成分相似，是一种广泛用于支架制造的材料。最近的进展使得对陶瓷支架进行功能化成为可能，以改善骨再生和修复，同时能够原位释放治疗剂来治疗骨感染。在本研究中，通过真空浸渍技术，使用溶胶-凝胶溶液对3D打印的β-TCP支架进行了生物活性玻璃涂层处理，生物活性玻璃分别为45S5（45SiO₂ - 24.5Na₂O - 24.5CaO - 6P₂O₅，重量百分比）和58S（58SiO₂ - 33CaO - 9P₂O₅，重量百分比）。β-TCP油墨表现出假塑性行为，这有利于其3D打印。所得支架与设计模型高度吻合，具有排列良好的细丝，并且在烧结后下层的塌陷最小。元素映射显示，45S5玻璃在支架支柱周围形成了表面涂层，而58S玻璃则渗透到内部结构中，这是由于它们在高温下的粘度不同所致。与未涂层的β-TCP支架相比，涂层显著提高了机械强度，涂有45S5和58S的支架的机械强度分别提高了63%和126%。通过在模拟体液中的磷灰石矿化试验证实了生物活性，该试验表明在两种涂层支架上均有羟基磷灰石沉淀，尽管形态不同。由于本研究聚焦于无细胞支架，因此有必要进一步研究，以充分探索这些具有优化机械性能的生物活性支架在生物系统中的潜力。
