Departamento de Química en Ciencias Farmacéuticas, Facultad de Farmacia, Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Hospital 12 de Octubre i+12, Plaza Ramón y Cajal s/n, 28040 Madrid, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina, CIBER-BBN, Madrid, Spain; The University of Queensland, School of Dentistry, Herston, QLD, Australia.
Departamento de Química en Ciencias Farmacéuticas, Facultad de Farmacia, Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Hospital 12 de Octubre i+12, Plaza Ramón y Cajal s/n, 28040 Madrid, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina, CIBER-BBN, Madrid, Spain.
Mater Sci Eng C Mater Biol Appl. 2020 Apr;109:110572. doi: 10.1016/j.msec.2019.110572. Epub 2019 Dec 20.
Three-dimensional Mesoporous bioactive glasses (MBGs) scaffolds has been widely considered for bone regeneration purposes and additive manufacturing enables the fabrication of highly bioactive patient-specific constructs for bone defects. Commonly, this process is performed with the addition of polymeric binders that facilitate the printability of scaffolds. However, these additives cover the MBG particles resulting in the reduction of their osteogenic potential. The present work investigates a simple yet effective phosphate-buffered saline immersion method for achieving polyvinyl alcohol binder removal while enables the maintenance of the mesoporous structure of MBG 3D-printed scaffolds. This resulted in significantly modifying the surface of the scaffold via the spontaneous formation of a biomimetic mineralized layer which positively affected the physical and biological properties of the scaffold. The extensive surface remodeling induced by the deposition of the apatite-like layer lead to a 3-fold increase in surface area, a 5-fold increase in the roughness, and 4-fold increase in the hardness of the PBS-immersed scaffolds when compared to the as-printed counterpart. The biomimetic mineralization also occurred throughout the bulk of the scaffold connecting the MBGs particles and was responsible for the maintenance of structural integrity. In vitro assays using MC3T3-E1 pre-osteoblast like cells demonstrated a significant upregulation of osteogenic-related genes for the scaffolds previously immersed in PBS when compared to the as-printed PVA-containing scaffolds. Although the pre-immersion scaffolds performed equally towards osteogenic cell differentiation, our data suggest that a short immersion in PBS of MBG scaffolds is beneficial for the osteogenic properties and might accelerate bone formation after implantation.
三维介孔生物活性玻璃（MBG）支架已广泛用于骨再生目的，而添加剂制造能够制造出高度生物活性的、针对特定患者的骨缺损结构。通常，这个过程需要添加聚合物粘合剂来提高支架的可打印性。然而，这些添加剂会覆盖 MBG 颗粒，从而降低其成骨潜力。本研究提出了一种简单而有效的磷酸盐缓冲盐水浸泡方法，可去除聚乙烯醇粘合剂，同时保持 MBG 3D 打印支架的介孔结构。这导致支架表面发生显著变化，通过自发形成仿生矿化层来积极影响支架的物理和生物学性质。与原始打印支架相比，类磷灰石层的沉积引起了广泛的表面重塑，导致支架的比表面积增加了 3 倍，粗糙度增加了 5 倍，硬度增加了 4 倍。仿生矿化还贯穿整个支架，连接 MBG 颗粒，保持结构完整性。体外使用 MC3T3-E1 成骨样前体细胞进行的测试表明，与原始打印的含有 PVA 的支架相比，先前在 PBS 中浸泡过的支架的成骨相关基因表达显著上调。尽管预浸泡支架在成骨细胞分化方面表现相当，但我们的数据表明，MBG 支架在 PBS 中短时间浸泡对成骨特性有益，并可能加速植入后的骨形成。
