Petrakova Nataliya V, Teterina Anastasia Yu, Mikheeva Polina V, Akhmedova Suraya A, Kuvshinova Ekaterina A, Sviridova Irina K, Sergeeva Natalya S, Smirnov Igor V, Fedotov Alexander Yu, Kargin Yuriy F, Barinov Sergey M, Komlev Vladimir S
Ceramic Composite Materials, A.A. Baikov Institute of Metallurgy and Materials Science RAS, Leninskiy Prospect 49, Moscow 119334, Russia.
Forecast Lab, P.A. Herzen Moscow Research Oncology Institute-Branch of FSBI NMRRC of the Ministry of Health of Russia, The 2-nd Botkinskiy pr, 3, Moscow 125284, Russia.
ACS Omega. 2021 Mar 9;6(11):7487-7498. doi: 10.1021/acsomega.0c06016. eCollection 2021 Mar 23.
Octacalcium phosphate (OCP), a new-generation bone substitute material, is a considered precursor of the biological bone apatite. The two-layered structure of OCP contains the apatitic and hydrated layers and is intensively involved in ion-exchange surface reactions, which results in OCP hydrolysis to hydroxyapatite and adsorption of ions or molecular groups presented in the environment. During various procedures, such as biomaterial solubility, additive release studies, or the functionalization technique, several model solutions are applied. The composition of the environmental solution affects the degree and rate of OCP hydrolysis, its surface reactivity, and further and properties. The performed study was aimed to track the structural changes of OCP-based materials while treating in the most popular model solutions of pH values 7.2-7.4: simulated body fluid (SBF), Dulbecco's phosphate-buffered saline (DPBS), supersaturated calcification solution (SCS), normal saline (NS), and Dulbecco's modified Eagle's medium (DMEM). Various degrees of OCP hydrolysis and/or precipitate formation were achieved through soaking initial OCP granules in the model solutions. Detailed data of X-ray diffraction, Fourier-transform infrared spectroscopy, atomic emission spectrometry with inductively coupled plasma, and scanning electron microscopy are presented. Cultivation of osteosarcoma cells was implemented on OCP pre-treated in DMEM for 1-28 days. It was shown that NS mostly degraded the OCP structure. DPBS slightly changed the OCP structure during the first treatment term, and during further terms, the crystals got thinner and OCP hydrolysis took place. Treatment in SBF and SCS caused the precipitate formation along with OCP hydrolysis, with a larger contribution of SCS solution to precipitation. Pre-treating in DMEM enhanced the cytocompatibility of materials. As a result, on performing the procedures, careful selection of the contact solution should be made to avoid the changes in materials structure and properties and get adequate results.
八钙磷酸酯（OCP）是一种新一代骨替代材料，被认为是生物骨磷灰石的前体。OCP的双层结构包含磷灰石层和水合层，并大量参与离子交换表面反应，这导致OCP水解为羟基磷灰石，并吸附环境中存在的离子或分子基团。在各种过程中，如生物材料溶解性、添加剂释放研究或功能化技术，会应用几种模型溶液。环境溶液的组成会影响OCP水解的程度和速率、其表面反应性以及其他性能。所进行的研究旨在追踪基于OCP的材料在pH值为7.2 - 7.4的最常用模型溶液中处理时的结构变化：模拟体液（SBF）、杜尔贝科磷酸盐缓冲盐水（DPBS）、过饱和钙化溶液（SCS）、生理盐水（NS）和杜尔贝科改良伊格尔培养基（DMEM）。通过将初始OCP颗粒浸泡在模型溶液中实现了不同程度的OCP水解和/或沉淀形成。给出了X射线衍射、傅里叶变换红外光谱、电感耦合等离子体原子发射光谱和扫描电子显微镜的详细数据。在DMEM中预处理1 - 28天的OCP上进行骨肉瘤细胞培养。结果表明，NS对OCP结构的降解作用最大。DPBS在第一次处理期间对OCP结构有轻微改变，在后续处理期间，晶体变薄且发生OCP水解。在SBF和SCS中处理会导致沉淀形成以及OCP水解，SCS溶液对沉淀的贡献更大。在DMEM中预处理可增强材料的细胞相容性。因此，在进行这些过程时，应仔细选择接触溶液，以避免材料结构和性能发生变化并获得满意的结果。
