Investigation of Vipera Anatolica Venom Disintegrin via Intracellular Uptake with Radiolabeling Study and Cell-Based Electrochemical Biosensing Assay.

Snake venoms are a natural biological source that has potential therapeutic value with various protein compounds. Disintegrins originally were discovered as a family of proteins from snake venoms composed of cysteine rich low molecular weight polypeptides. Disintegrins exhibit specific binding and higher affinity toward integrin with potential inhibition of function. Trans-membrane receptors of the integrin family may involve in many pathological conditions such as inflammation and tumor progression with important processes related to invasion and migration. Since disintegrins have the ability to bind to integrins, they could be used for cancer detection and treatment, and in monitoring of therapy in select cancer types. The main purpose of the study is to investigate disintegrin containing Vipera anatolica (VAT) crude venom potential for radiolabeling and intracellular uptake as well as electrochemical biosensing assay against U87MG human brain glioblastoma cells. For this purpose, VAT crude venom containing U87MG cell-specific disintegrin was investigated in terms of radiolabeling and intracellular uptake as well as electrochemical biosensing assay in comparison with echistatin (ECT) disintegrin in cells. The interaction between VAT crude venom and ECT with HEK293 human non-tumorigenic embryonic kidney cells and glioblastoma U87MG cells was electrochemically investigated using pencil graphite electrodes (PGEs). The interaction of the VAT crude venom and ECT with HEK293 and U87MG cells was detected according to the changes in oxidation signals. Then, VAT crude venom and echistatin were labeled with 131I via iodogen method. Intracellular uptakes of radiolabeled molecules were investigated in U87MG cell line. 131I-VAT can be an agent for imaging of glioblastoma cancer. Further work will focus on the production of large quantities of pure VAT disintegrin with a biotechnological approach to improving imaging agent.

Photodynamic therapy and nuclear imaging activities of zinc phthalocyanine-integrated TiO2 nanoparticles in breast and cervical tumors.

In recent years, phthalocyanines (Pcs) have been widely used as photosensitizer in photodynamic therapy applications. Because of their strong absorptions in the near-infrared region (640-700 nm). The integration of phthalocyanine derivatives to a nanoparticle is expected to be efficient way to improve the activity of the photosensitizer on the targeted tissue. It is known that the integrated molecules not only show better accumulation on tumor tissue but also reduce toxicity in healthy tissues. In this study, the ZnPc molecule was synthesized and integrated to the TiO2 nanoparticle, to investigate the potential of PDT and its cytotoxicity. Additionally, ZnPc and ZnPc-TiO2 molecules were labeled with 131 I and it was aimed to put forth the nuclear imaging/therapy potentials of 131 I labeled ZnPc/ZnPc-TiO2 by determining in vitro uptakes in mouse mammary carcinoma (EMT6), human cervical adenocarcinoma (HeLa). In result of our study, it was observed that the radiolabeling yields of the synthesized ZnPc and ZnPc-TiO2 with 131 I were quite high. In vitro uptake studies shown that 131 I-ZnPc-TiO2 could be a potential agent for nuclear imaging/treatment of breast and cervical cancers. According to PDT results, ZnPc-TiO2 might have as to be a potential PDT agent in the treatment of cervical tumor. ZnPc and ZnPc-TiO2 might be used as theranostic agents.

Investigation of in vitro PDT activities of zinc phthalocyanine immobilised TiO2 nanoparticles.

Phthalocyanines (Pcs) are commonly used as Photosensors (PSs) in Photodynamic Therapy (PDT) applications due to their intense absorption in the far red-near IR spectral region with a high extinction coefficient and high ability for generating singlet oxygen. Pcs targetspecifically tumors, and do not show any considerable toxic effects under the absence of light. In particular, their chemical versatility has allowed the introducion a number of substituent at the periferal or axial positions which provide modulating photophysical properties, increases the solubility of these compounds in organic solvents. Nanoparticles increase the bioavailability, stability, and transport of PSs to target tissue. TiO2 nanoparticles are prefered in these applications because of their non toxic, low cost and high chemical stability properties. In our study, a Zinc Phthalocyanine (ZnPc) was used as a photosensor. The design of ZnPc integrated TiO2 nanoparticles is intended to make PSs a more effective PDT agent. With the aim to examine the nuclear imaging/treatment potentials of ZnPc and ZnPc-TiO2 in hepatocellular carcinoma (HepG2), colorectal adenocarcinoma (HT29) tumor and human healthy lung (WI38) cell lines in vitro study ZnPc and TiO2-ZnPc were also labeled with 131I. It is determined that 131I-ZnPc-TiO2 nanoparticle show a potential as an agent for the imaging/treatment of hepatocellular cancer by in vitro. The toxicity studies revealed that TiO2 nanoparticle decreases the toxicity of ZnPc. In vitro PDT results show that TiO2-ZnPc has a potential as a PDT agent in colon tumor treatment. Consequently, synthesized ZnPc and ZnPc-TiO2 could be promising candidates as theranostic agents.

Intracellular uptake and fluorescence imaging potential in tumor cell of zinc phthalocyanine.

A near IR absorbing phthalocyanine bearing four binaphtyl group has been synthesized in order to investigate its cytotoxicity and intracellular uptake of sensitizer on MCF-7 (human breast cancer), MDAH (ovarian cancer), HeLa (human epitheloid cervix carcinoma), EMT-6 (mouse breast cancer) and WI-38 (human fibroblast lung) cell lines. ZnPc showed four time higher intracellular uptake in carcinoma cells (MCF-7) than normal (WI-38) cell lines. With the aim of studying in detail the biodistribution feature and tumor nuclear imaging capacity, ZnPc was also labeled with I-131. The efficiency of radiolabeled compound was 95±4.6%. In addition, ZnPc reveals to be very efficient singlet oxygen generators (ΦΔ=0.612 in DMSO) and promising PS for PDT application. In vitro fluorescence imaging study with MCF-7 cells showed that ZnPc localized in cytoplasm of the cells. This results showed that synthesized ZnPc is promising candidate for dual fluorescence/nuclear imaging breast cancer and shows potential PS for PDT application.

Investigation of In vitro PDT Activities and In vivo Biopotential of Zinc Phthalocyanines Using (131)I Radioisotope.

Novel octylthio-containing asymmetrically substituted Zn(II) phthalocyanine (Zn(II)Pc1) and a symmetric derivative (Zn(II)Pc2) have been prepared to investigate the biological potential and ability to photosensitize singlet oxygen for photodynamic therapy applications. In this study, the singlet oxygen generation potential and in vitro photodynamic activities of these compounds have been tested. Both ZnPcs reveal to be very efficient singlet oxygen generators and promising PSs for PDT applications. In vitro PDT activities of the compounds were evaluated in EMT-6 murine mammary carcinoma and HeLa human cervix carcinoma cell lines. Moreover, Zn(II)Pc1 displayed the phototoxic effects in the mammary cancer cell line (6.25 µm concentration at 30 J/cm(2) light dose and 12.5 µm concentration at 20 J/cm(2) light dose), while Zn(II)Pc2 did not show any phototoxic effects both in two cell lines. Zn(II)Pcs were radiolabeled with (131) I in high yields. Biodistribution studies revealed that the radiolabeled Zn(II)Pc1 showed significant uptake in l. intestine, pancreas, brain, and ovary, while Zn(II)Pc2 has significant uptake in ovary and pancreas in normal rats. Hence, these Pcs derivatives could be promising candidate for tumor nuclear imaging.

Synthesis, Radiolabeling, and Bioevaluation of Bis(Trifluoromethanesulfonyl) Imide.

Imidazolium salts have antitumor potential and toxicological effects on various microorganisms. The authors' aim is to synthesize a new imidazolium salt and to assess its pharmacokinetic and antitumor potentials by in vitro and in vivo studies. In this study, bis(trifluoromethanesulfonyl) imide (ITFSI) was synthesized and labeled with (131)I using the iodogen method. The efficiency of radiolabeling was determined with high yield (95.5% ± 3.7%). Pharmacokinetic properties of the compound were investigated in albino Wistar rats using radiolabeled compound. The radiolabeled compound ((131)I-ITFSI) has been stable during a period of 3 hours in human serum. The uptake of (131)I-ITFSI reached maximum in the spleen, liver, and blood at 60 minutes, large intestine and heart at 30 minutes, and ovary at 120 minutes. It is observed that intracellular uptake of the radiolabeled compound is higher in the CaCo-2 (colon adenocarcinoma tumor) cell line than HEK-293 (human epithelial kidney) cell line. In further study, antitumor potential of ITFSI on a colon adenocarcinoma tumor-bearing animal model may be investigated.