Biocompatibility Evaluation Of (Y_0.95Eu_0.05)₂O₃ Rare-Earth Fluorescent Material

With the development of modern science and technologies such as nanomaterials and biomedical science, the designing, preparation and modification of fluorescent nanomaterials and its application in the field of biomedical research is becoming a hot spot. Compared with traditional fluorescent materials such as organic fluorescent dyes, fluorescent nanomaterials are more adjustable and diverse in terms of physical and chemical properties, such as more flexible size, morphology and surface structure. In addition, the fluorescence properties of nanomaterials are excellent and they are easier to be functionally modified. In this paper, the biocompatibility of(Y0.95Eu0.05)2O3 rare-earth fluorescent materials made by our research group was studied to explore its potential suitability as a fluorescent marker material.Firstly, the method for extracting and purifying of primary rat Vascular Smooth Muscle Cells(VSMCs) was discussed. Cells were extracted using a tissue adherent method and a large number of active cells were obtained, which suggests that tissue adherence method works well for extracting cells, and it can provide a reliable source of cells for the experiment. VSMCs were identified through specific ?-SM Actin by immunofluorescence, indicating that the isolated cells were vascular smooth muscle cells, and the purity was above 90%. MTT assay was performed to determine the cell proliferation rate, and the results showed that the highest proliferative activity was in 4 to 6 days, cells at this stage may be taken for the experiment.The third generation of VSMCs was cultured with different concentrations of both unmodified and amine-functionalized(Y0.95Eu0.05)2O3 rare-earth fluorescent material. Morphological changes of cells were observed, CCK-8 assay was performed to evaluate the cytotoxicity of materials, and the cells were observed under fluorescence microscope after treated with Hoechst33342 and PI staining. Materials and cells were co-cultured to evaluate cell apoptosis with flow cytometry, and cell imaging was conducted by fluorescence microscopy. The results indicated that the cell toxicity level of both materials were grade one, and that the amine-functionalized(Y0.95Eu0.05)2O3 material has a better biocompatibility. Cell imaging results showed high fluorescence intensity and stability, revealing that amine-functionalized(Y0.95Eu0.05)2O3 material as a fluorescent probe has great prospects of application in biological imaging.The material was in direct contact with blood, and its BCI, which is the hemoglobin absorbance value, was measured at different time periods, in order to compute the degree of activation of the coagulation factors. The results suggested that the material exhibits a certain anti-clotting properties, and that the unmodified material has a better anticoagulant capability than modified materials. The hemolysis rate of materials was evaluated after direct contact with blood, and the results showed that the hemolysis rate of both materials were relatively low, which were 0.18% and 0.72% respectively, in compliance with the national standards for biological materials.