Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Universitat Politècnica de Catalunya (UPC), Av. Eduard Maristany 16, 08019, Barcelona, Spain; Barcelona Research Centre in Multiscale Science and Engineering, Universitat Politècnica de Catalunya (UPC), Av. Eduard Maristany 16, 08019, Barcelona, Spain.
Institute of Health and Biomedical Innovation and the Australia-China Centre for Tissue Engineering and Regenerative Medicine (ACCTERM), Queensland University of Technology, Brisbane, QLD 4059, Australia.
Biomaterials. 2018 Oct;181:318-332. doi: 10.1016/j.biomaterials.2018.07.058. Epub 2018 Jul 31.
Immune cells are sensitive to the microstructural and textural properties of materials. Tuning the structural features of synthetic bone grafts could be a valuable strategy to regulate the specific response of the immune system, which in turn modulates the activity of bone cells. The aim of this study was to analyse the effect of the structural characteristics of biomimetic calcium deficient hydroxyapatite (CDHA) on the innate immune response of macrophages and the subsequent impact on osteogenesis and osteoclastogenesis. Murine RAW 264.7 cells were cultured, under standard and inflammatory conditions, on chemically identical CDHA substrates that varied in microstructure and porosity. The impact on osteogenesis was evaluated by incubating osteoblastic cells (SaOS-2) with RAW-CDHA conditioned extracts. The results showed that macrophages were sensitive to different textural and structural properties of CDHA. Under standard conditions, the impact of inflammatory cytokine production by RAW cells cultured on CDHA played a significant role in the degradation of substrates, suggesting the impact of resorptive behaviour of RAW cells on biomimetic surfaces. Osteoblast differentiation was stimulated by the conditioned media collected from RAW cells cultured on needle-like nanostructured CDHA. The results demonstrated that needle-like nanostructured CDHA was able to generate a favourable osteoimmune environment to regulate osteoblast differentiation and osteogenesis. Under inflammatory conditions, the incubation of RAW cells with less porous CDHA resulted in a decreased gene expression and release of pro-inflammatory cytokines.
免疫细胞对材料的微观结构和质地特性敏感。调整合成骨移植物的结构特征可能是一种有价值的策略，可以调节免疫系统的特定反应，进而调节骨细胞的活性。本研究旨在分析仿生钙缺失羟基磷灰石（CDHA）的结构特征对巨噬细胞固有免疫反应的影响，以及随后对成骨和破骨的影响。在标准和炎症条件下，将鼠 RAW 264.7 细胞培养在化学性质相同但微观结构和孔隙率不同的 CDHA 基底上。通过将成骨细胞（SaOS-2）与 RAW-CDHA 条件培养基孵育来评估成骨的影响。结果表明，巨噬细胞对 CDHA 的不同质地和结构特性敏感。在标准条件下，在 CDHA 上培养的 RAW 细胞产生炎性细胞因子的影响在底物的降解中起着重要作用，这表明 RAW 细胞在仿生表面的吸收行为的影响。从在针状纳米结构 CDHA 上培养的 RAW 细胞收集的条件培养基刺激成骨细胞分化。结果表明，针状纳米结构 CDHA 能够产生有利的骨免疫环境，调节成骨细胞分化和成骨作用。在炎症条件下，用孔隙率较低的 CDHA 孵育 RAW 细胞会导致基因表达和促炎细胞因子的释放减少。
