In Situ Spectroscopic Screening of Osteosarcoma Living Cells on Stoichiometry-Modulated Silicon Nitride Bioceramic Surfaces
In Situ Spectroscopic Screening of Osteosarcoma Living Cells on Stoichiometry-Modulated Silicon Nitride Bioceramic Surfaces
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DOI：
10.1021/acsbiomaterials.6b00126
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发表时间：
2016-07-01
影响因子：
5.8
通讯作者：
Bal，B. Sonny
中科院分区：
文献类型：
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作者：
Pezzotti，Giuseppe;McEntire，Bryan J.;Bal，B. Sonny
骨肉瘤细胞的活力，增殖，并分化成骨细胞的氮化硅生物陶瓷进行了检查，作为其作为消防表面的化学修饰的功能。生物学和光谱分析表明：（i）烧结后在氮气中退火显著提高了人骨肉瘤（SaOS-2）细胞磷灰石的形成;（ii）原位拉曼光谱监测揭示了SaOS-2细胞新的代谢细节，包括细胞内RNA和膜磷脂的细微差异;和（iii）增强的磷灰石形成源自高密度的带正电荷的表面基团，包括在N2气体中退火期间形成的氮空位（VN 3+）和氮N-N键（N4+）。在稳态pH下，这些正表面电荷促进蛋白质结合到去质子化硅烷醇（SiO-）的带负电荷表面上。提出了一种偶极样电荷，它包括VN 3 +/N4+和SiO-缺陷位点，作为一种机制来解释跨膜蛋白与COO-和NH 2+末端之间的吸引力。这类似于矿物羟基磷灰石中发生的机制，其中蛋白质基团被带正电荷的钙位点（Ca+）和非化学计量的磷位点（PO 42-）的存在特异性地置换。
Osteosarcoma cell viability, proliferation, and differentiation into osteoblasts on a silicon nitride bioceramic were examined as a function of chemical modifications of its as-fired surface. Biological and spectroscopic analyses showed that (i) postsintering annealing in N2gas significantly improved apatite formation from human osteosarcoma (SaOS-2) cells; (ii) in situ Raman spectroscopic monitoring revealed new metabolic details of the SaOS-2 cells, including fine differences in intracellular RNA and membrane phospholipids; and (iii) the enhanced apatite formation originated from a high density of positively charged surface groups, including both nitrogen vacancies (VN3+) and nitrogen N–N bonds (N4+) formed during annealing in N2gas. At homeostatic pH, these positive surface charges promoted binding of proteins onto an otherwise negatively charged surface of deprotonated silanols (SiO–). A dipole-like electric-charge, which includes VN3+/N4+and SiO–defective sites, is proposed as a mechanism to explain the attractive forces between transmembrane proteins and the COO–and NH2+termini, respectively. This is analogous to the mechanism occurring in mineral hydroxyapatite where protein groups are specifically displaced by the presence of positively charged calcium loci (Ca+) and off-stoichiometry phosphorus sites (PO42–).