Synthesis Of BSA-regulated Organic Coordination Polymerization Nanoparticles And Their Biological Applications

As a kind of nano-metal organic structure,coordination polymer nanoparticles could be served as a new theranostic nano-platform.It combines the advantages of nanomaterials and organic complexes,eg,biodegradability,compositional diversity,and ease of preparation,and has a broad prospect of medical applications.Therefore,in this paper,albumin?BSA?which has a high sequence homology with human serum albumin?HSA?was designed as a biological template to tune the synthesis of coordination polymeric nanoparticles,and we conducted a research of applications in tumor diagnosis and treatment.The content is as follows.Part one,the synthesis and biological application of BSA-assisted ultra-small gallic acid-iron coordination polymer nanoparticles?GA-Fe@BSA NPs?.In order to further improve biocompatibility,we use BSA to tune synthesis of GA-Fe@BSA NPs,a newly developed theranostic nano-platform.Firstly,based on the fact that BSA enriched in N-terminal amino and O-terminal amino acid residues,these sites can strongly coordinate with transition-metal ions.The BSA-Fe³⁺complex was formed by adding an aqueous solution of FeCl₃ to BSA solution.Secondly,by adding GA monomer to the BSA-Fe³⁺complex,the phenolic hydroxyl group and carboxyl group in the GA chelated with Fe³⁺to form GA-Fe@BSA NPs.Finally,GA-Fe@BSA NPs was purified by ultrafiltration.The obtained GA-Fe@BSA NPs exhibit ultra-small size?3.5 nm?,good biocompatibility,a lower r₂:r₁ratio?r₂/r₁=1.06?,and strong absorption in the vis-NIR region,which could achieve rapid kidney clearance,and be used for T₁-weighted MRI imaging and photo-thermotherapy of tumors.Part two,the synthesis and biological application of GA-Fe@BSA-PTX assembled nanoparticles.Although the ultrasmall GA-Fe@BSA NPs have many advantages,the ultra-small particle size leads to a short residence time and rapid metabolism in body.Thus,these NPs can not effectively enrich in the tumor.To solve the problem,we cleverly used paclitaxel?PTX?to assemble GA-Fe@BSA NPs and successfully assembled GA-Fe@BSA-PTX NPs?100 nm?.In vitro experiments showed that the obtained GA-Fe@BSA-PTX NPs not only have the original strongly absorption in vis-NIR region and good biocompatibility of GA-Fe@BSA NPs,but also exhibit better T₁-weighted MRI performance.In vivo MRI tests demonstrated that intravenous administration of GA-Fe@BSA-PTX NPs can effectively enrich in the tumor.In addition,it has the dual effect of photothermal therapy and chemotherapy which causes more effective treatment for tumors.