| Backgrounds: Mesoporous silica have been widely used in catalysis, separation and biomedical fields due to their unique physi-chemical properties such as stable mesoporous structure, large surface areas, tunable pore size and easily surface functionalities. Especially, Mesoporous silica being applied in drug and gene delivery systems have attracted more and more attention. It is likely researched that surface modification plays a significant role in the toxicity. Given the frequent contact with the HUVECs, the damage of cardiovascular system should net be ignored.Objective: This study choose SBA-15 type Mesoporous silica and human umbilical vein endothelial cell line as the research object, by grafting the organic groups onto the surface of the mesoporous silica, to study the cardiovascular toxicity effect of mesoporous materials, aims to offer safety guideline for the drug carriers of Mesoporous silica safety use.Methods: The surface of the SBA-15 are functionalized with amino and carboxyl groups by grafting the organic groups onto the surface of the mesoporous silica. The structure and physicochemical properties of the materials were characterized with transmission electron microscopy(TEM), N2 absorption-desorption, FT-IR spectroscopy, Zeta Potential, X-ray powder diffraction(XRD). CCK-8 and MTT assays were used to detect the cytotoxicity of SBA-15 and surface modified SBA-15( 0、12.5、25.0、50.0、100、200、400、800μg/m L)on HUVECs, at the same time, to indentify the exposure dose of the following assays. HUVECs were exposed to SBA-15 and surface modified SBA-15 with different concentrations(0、100、200μg/m L)for 24 hours. The expression levels of cell reactive oxygen species(ROS) and lactate dehydrogenate(LDH) activity in the medium supernatant were detected byDCFH-DA method and trace enzyme standard method respectively. Nitric oxide(NO) content in cell culture supernatant was determined using nitrate enzyme reduction method. The expression levels of ICAM-1、VCAM-1 protein were measured by Western-Blot. Results: 1. Characterization of surface modified SBA-15Amino- and Carboxyl- had been successfully grafted on the surface of SBA-15. It was shown that the NH2-SBA-15 and COOH-SBA-15 materials contain well ordered, one-dimensional pore structure, similar to that of the pure SBA-15.What’s more, all of the materials kept in a stable dispersion without aggregation. 2. Cytotoxicity of surface modified SBA-15Compared with the negative control group(0μg/m L), the cell inhibitory effect of different kinds of SBA-15 shows an increasing trend along with the rise of the exposure concentration(P<0.05).At the same dose, the inhibitory effect of unmodified SBA-15 was higher than the modified ones, and the amino modified groups is higher than carboxyl modified ones(P<0.05).Compared with the negative control group(0μg/m L), LDH activity in the medium supernatant of SBA-15、NH2-SBA-15、COOH-SBA-15 group were significantly increased(P<0.05), also have obvious dose-effect relationship along with the increased dose. The LDH activity in the medium supernatant of functionalization groups were lower than SBA-15 group at the same dose. 3. Oxidative stress caused by surface modified SBA-15Compared with the negative control group(0μg/m L), intracellular ROS levels of SBA-15、NH2-SBA-15、COOH-SBA-15 group were significantly increased(P<0.05), also have obvious dose-effect relationship along with the increased dose. The intracellular ROS levels of fictionalization groups were lower than SBA-15 group at the same dose. As was shown by Fluorescence Microscope, both SBA-15 group and modified ones showed green fluorescence in different degree. Compared with the SBA-15 group, the modified ones exhibited weaker fluorescence intensity; especially the COOH-SBA-15 group had the weakest fluorescence intensity. 4. Analysis of cell function affected by surface modified SBA-15Compared with the standard control group, there was a significant increase in the expression levels of NO, ICAM-1 and VCAM-1 in human umbilical vein endothelial cells along with the concentration of materials. The NO, ICAM-1 and VCAM-1 levels of functionalization groups were lower than SBA-15 group at the same dose(P<0.05), and COOH-SBA-15 group showed the least expression level. Conclusions: Both the SBA-15 and the surface modified SBA-15 groups damage the cytomembrane and exist the cytotoxicity to HUVECs, however, functionalized materials show lower toxicity, especially the COOH-SBA-15 group shows better biocompatible with the least toxicity. Oxidative and cytomembrane damage may be two kinds of mechanism of cytotoxicity induced by Silica materials. Mesoporous Si O2 materials exposure may lead to the toxicity of cardiovascular system by activating the expression levels of NO, ICAM-1 and VCAM-1 in human umbilical vein endothelial cells... |
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