Research And Application Of CaTiO₃/Al³⁺/Pr³⁺/Sm³⁺ Materials For The Separation Of Human Serum Exosomes

Exosomes,as nanoscale membrane vesicles,are widely present in human body fluids.Compared with traditional body fluid biopsy materials,such as circulating tumor cells and cell-free DNA,exosomes have many advantages and are ideal body fluid biopsy materials,which have great value in clinical diagnosis and postoperative monitoring.However,the existing exosome isolation and extraction technology limits its promotion and application in the field of diagnosis.In this study,Ca Ti O₃/Al³⁺/Pr³⁺/Sm³⁺materials were successfully synthesized by hydrothermal method and the related materials were characterized.In order to explore the feasibility of this material,this material was applied to the enrichment and separation of human serum exosomes and the enrichment conditions were further optimized.The results showed that compared with the exosomes obtained by ultracentrifugation,the yield of 5 mg exosomes was 94.7%after incubation with 100μL human serum for 10 min under the optimal enrichment conditions.In addition,analysis showed that Al³⁺plays an important role in exosome isolation among Al³⁺、Pr³⁺and Sm³⁺.Compared with the reported exosome enrichment material Ti O₂,Ca Ti O₃/Al³⁺/Pr³⁺/Sm³⁺material has stronger enrichment ability for human serum exosomes,and the enriched exosomes have higher purity.The stability evaluation experiment of enrichment ability showed that the material had no significant effect on enrichment efficiency and had good stability after repeated use for three times.The utility of the composite material was further tested in serum exosome enrichment in patients with Alzheimer’s disease（AD）.Exosomes enriched with this material were separated by 2-D electrophoresis and analyzed by mass spectrometry to try to screen potential serum exosome marker proteins for AD.The results showed that 17 proteins were identified in the healthy control group and 21 proteins were identified in the AD group,and the expression levels of 6 proteins were significantly different.Among the detected proteins,5 proteins were upregulated and 1 protein was downregulated.The upregulation of Serum amyloid P-component precursor may be related to the pathology of AD.In conclusion,the material is simple to prepare,simple and rapid to operate,and the exosomes enriched from human serum not only have high yield,but also good purity.It has great application potential in clinical disease diagnosis and postoperative monitoring.