Biological Activity Study Of Metal Complexes And Their Composite Systems

Transition metal（Ru,Ir,and Os）complexes have many excellent properties such as optical properties,light stability,high phosphorescence quantum yield,long phosphorescence lifetime,and extraordinary biocompatibility,they have been widely used as anticancer drugs and bioluminescent probes.In this paper,five different Ru,Ir,and Os polypyridine complexes have been designed and synthesized,their recognition for thiol molecules,lysosomes,and human serum proteins have been studied.Furthermore,the Ru-taggeting-peptide compound was designed and its targeting antitumor activitity was studied.1.The ruthenium polypyridine complex（Ru 1）with two hydroxyl groups was designed and characterized by EA,¹H NMR,and ESI-MS.Ru 1 could selectively coordinate with Cu²⁺to form a stable Ru-Cu ensamble with no interference from other metal ions.Both absorption intensity and fluorescence intensity decreased upon the formation of Ru-Cu ensamble.Cu²⁺could distinctively bind with the oxygen and imidazole nitrogen,the stoichiometric ratio of Ru1 and Cu²⁺was 1:2.Based on its many advantages such as fast response,no interference from other amino acids protein,and pH value,Ru-Cu ensamble could be used as effective extracellular and intracellular fluorescent probe for GSH,Hcy,and Cys.The fluorescence of Ru complex experienced a“On-Off-On”conversion.Firstly,Ru 1 could emit strong fluorescence,after coordination with Cu²⁺to form Ru-Cu ensamble,the fluorescence disappeared.Finally,the fluorescence of Ru complex recovered upon addition of thiol molecules such as GSH,Cys or Hcy.This was due to the binding of-SH with the Cu²⁺of Ru-Cu ensamble,and the fluorescence of Ru complex recovered after losing Cu²⁺.2.The complexes of Ru 2 and Os 2 with similar structure were synthesized and characterized by EA,¹H NMR,and ESI-MS.The luminescence properties of Ru 2 and Os 2were studied by UV spectrua and fluorescence spectra.The results indicated that both Ru 2 and Os 2 had relatively strong fluorescence.In addition,both Ru 2 and Os 2 exhibited no obvious cytotoxicity under dark conditions.However,Ru 2 exhibited high cytotoxicity upon 465nm irradiation,while Os 2 exhibited high cytotoxicity upon 633nm irradiation.Furthermore,Ru 2could enter into the mitochondria and Os 2 could enter into the lysosome.Therefore,Os 2 could be served as lysosome probe and photodynamic therapy reagent,while Ru 2 could be served as mitochondria probe and photodynamic therapy reagent.3.The ruthenium complex（Ru 3）with carboxyl group was designed and synthesized.The two Ru-targetting-peptide ensambles were obtained by Ru 3 conjuncted to the normal sequence（FQHPSFI）or reverse sequence（IFSPHQF）.The Ru-targetting-peptide ensambles were characterized by HPLC and ESI-MS.UV absorption spectrua results indicated that Ru 3 and Ru-Ala-FQHPSFI were stable in PBS.The cytotoxicities of Ru 3,Ru-Ala-FQHPSFI,Ru-Ala-IFSPHQF,and cisplatin were studied.The results indicated that Ru-Ala-IFSPHQF showed superior target selectivity towarding liver cancer cells,while rather low toxicity for normal cells.Cell uptake research showed that the content of Ru in liver cancer cells which were incubated with Ru-Ala-FQHPSFI was much more than in those cells incubated with Ru 3 and Ru-Ala-IFSPHQF.AO/EB staining test results indicated that Ru-Ala-FQHPSFI could induce apoptosis and destruct cell membranes,while Ru 3 couldn’t.The apoptosis mechanism of Ru-Ala-FQHPSFI was studied and the results indicated that the activity of caspase 3 increased significantly in treated cells,which further proved that Ru-Ala-FQHPSFI could kill cancer cells by inducing apoptosis.The ability of Ru-Ala-FQHPSFI to induce Hep-G2 cells ball apoptosis was tested by Calcein-AM staining experiment,the results showed that Ru-Ala-FQHPSFI exhibited excellent anti-tumor activity on three-dimensional tumor cell model.Consequently,Ru-Ala-FQHPSFI ensamble exhibited outstanding target recognition for liver cancer,but relatively low toxicity for normal cells,which indicating that Ru-Ala-FQHPSFI may be a promised candidate for novel targeted therapeutics.4.Iridium complex（Ir 1）was synthesized and characterized by EA,¹H NMR,ESI-MS,and single crystal diffractometer.Ir 1 was stable and able to emit strong phosphorescence.The phosphorescence intensity increased with increasing the HSA concentration,which implied that Ir 1 could be acted as phosphorescence probe for HAS,and could response quickly to HSA with no disturb of pH value and other proteins in cells.Furthermore,as a novel fluorescent dye,Ir 1was more sensitive and convenien than the commercial fluorescent dye Coomassie Blue.