Radiolabeling, In Vitro Cell Uptake, and In Vivo Photodynamic Therapy Potential of Targeted Mesoporous Silica Nanoparticles Containing Zinc Phthalocyanine.

Photodynamic therapy (PDT) is a noninvasive therapy based on the photodynamic effect. In this study, we sought to determine intracellular uptake and in vivo photodynamic therapy potential of Zn phthalocyanine-loaded mesoporous silica nanoparticles (MSNP5) against pancreatic cancer cells. MSNP5 were labeled with 131I; the radiolabeling efficiency was found to 95.5 ± 1.2% in pH 9 and 60 min reaction time. Besides, the highest intracellular uptake yields of 131I-MSNP5 nanoparticles in MIA PaCa-2, AsPC-1, and PANC-1 cells were determined as 43.9 ± 3.8%, 41.8 ± 0.2%, and 37.9 ± 1.3%, respectively, at 24 h incubation time. In vivo PDT studies were performed with subcutaneous xenograft cancer model nude mice with AsPC-1 pancreatic cancer cells. For photodynamic therapy, 685 nm red laser light 100 J/cm2 light dose using and 5-20 µM ZnPc containing MSNP5 concentrations were applied. Histopathological studies revealed that the ratio of necrosis in tumor tissue was higher in the treatment group than the control groups.

Subphthalocyanine as a fluorescence imaging agent for breast tumor.

Tri-tert-butyl-carboxyl subphthalocyanine (SubPc) was synthesized and evaluated as a fluorescence agent. Fluorescence imaging for breast tumor in vivo was performed using nude mice as models. Results indicate high uptake in tumor at 20 h. Tumor-non tumor ratio was determined as 2.25. The imaging results demonstrate the potential of this fluorescence-imaging agent in the diagnosis of breast tumor. In the future, subphthalocyanine is also developing as a dual functional, which is fluorescence imaging and as a photodynamic therapeutic agent for the treatment and diagnosis of cancer.

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.

Selective Photokilling of Human Pancreatic Cancer Cells Using Cetuximab-Targeted Mesoporous Silica Nanoparticles for Delivery of Zinc Phthalocyanine.

BACKGROUND: Photodynamic therapy (PDT) is a non-invasive and innovative cancer therapy based on the photodynamic effect. In this study, we sought to determine the singlet oxygen production, intracellular uptake, and in vitro photodynamic therapy potential of Cetixumab-targeted, zinc(II) 2,3,9,10,16,17,23,24-octa(tert-butylphenoxy))phthalocyaninato(2-)-N29,N30,N31,N32 (ZnPcOBP)-loaded mesoporous silica nanoparticles against pancreatic cancer cells. RESULTS: The quantum yield (ΦΔ) value of ZnPcOBP was found to be 0.60 in toluene. In vitro cellular studies were performed to determine the dark- and phototoxicity of samples with various concentrations of ZnPcOBP by using pancreatic cells (AsPC-1, PANC-1 and MIA PaCa-2) and 20, 30, and 40 J/cm² light fluences. No dark toxicity was observed for any sample in any cell line. ZnPcOBP alone showed a modest photodynamic activity. However, when incorporated in silica nanoparticles, it showed a relatively high phototoxic effect, which was further enhanced by Cetuximab, a monoclonal antibody that targets the Epidermal Growth Factor Receptor (EGFR). The cell-line dependent photokilling observed correlates well with EGFR expression levels in these cells. CONCLUSIONS: Imidazole-capped Cetuximab-targeted mesoporous silica nanoparticles are excellent vehicles for the selective delivery of ZnPcOBP to pancreatic cancer cells expressing the EGFR receptor. The novel nanosystem appears to be a suitable agent for photodynamic therapy of pancreatic tumors.

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.

Synthesis and investigation of anticancer potential of radiolabeled naphthalene monoimide bearing imidazolium salt.

Imidazolium salts and derivatives have antitumor efficacy and toxic effects in different micro-organisms. In this study, an imidazolium bromide salt (NMI) was synthesized, and its antitumor potential was investigated by in vitro studies. Radiolabeling of synthesized NMI was carried out by iodogen method using 131 I radionuclide. The yield of radiolabeling was determined as 98.5 ± 0.1%. After that, cytotoxicity and intracellular uptake studies were evaluated in various cell lines. The cytotoxicity of NMI was determined as 35, 20, 10, and 1 µm for HEK-293, PC-3, CaCo-2, and MCF-7 cells, respectively. In addition, the intracellular uptake of 131 I-NMI was investigated in the cell lines, and the uptake was significantly found as 4 hr for MCF-7 and 6 hr for PC-3. In future studies, antitumor efficacy of 131 I-NMI on tumor-bearing animal model might be studied in light of these results.

Intracellular uptake study of radiolabeled anticancer drug and impedimetric detection of its interaction with DNA.

Topoisomerase I inhibitor topotecan (TPT) is the only single-agent therapy certified for the remedy of repetitive small cell lung cancer (SCLC). In this study, TPT was labeled with (131)I via iodogen method and its quality control was determined using thin layer radiochromatography and paper electrophoresis methods. Intracellular uptake study was carried out with human lung adenocarcinoma cell line (A-549) and human lung fibroblast cell line (WI-38). The interaction of (131)I-TPT with healthy DNA and cancer DNA was also investigated using single-use sensor technology combined with electrochemical impedance spectroscopy (EIS). The change at the charge transfer resistance (Rct) obtained before/after interaction was evaluated. Similar to the results of intracellular uptake study, it was found that (131)I-TPT could more interact with the cancer DNA than healthy DNA according to the impedimetric results. (131)I-TPT is promising in terms of a new nuclear imaging agent for lung cancer.

Dual Nuclear/Fluorescence Imaging Potantial of Zinc(II) Phthalocyanine in MIA PaCa-2 Cell Line.

BACKGROUND AND OBJECTIVE: Pancreatic cancer is very common and difficult to diagnose in early stage. Imaging systems for diagnosing cancer have many disadvantages. However, combining different imaging modalities offers synergistic advantages. Optical imaging is the most multidirectional and widely used imaging modality in both clinical practice and research. METHODS: In present study, Zinc(II) phthalocyanine [Zn(II)Pc] was synthesized, labeled with iodine- 131 and in vitro study was carried out. The intracellular uptake studies of radiolabeled Zn(II)Pc were performed in WI-38 [ATCC CCL-75™, tissue: human fibroblast lung] and MIA PaCa-2 [ATCC CRL-1420™, tissue: human epithelial pancreas carcinoma] cell lines. RESULTS: The intracellular uptake efficiency of radiolabeled Zn(II)Pc in MIA PaCa-2 cells was determined two times higher than WI-38 cells. Also, fluorescence imaging (FI) efficiency of synthesized Zn(II)Pc was investigated in MIA PaCa-2 cells and significant uptake was observed. CONCLUSION: Zn(II)Pc might be used as a new agent for dual fluorescence/nuclear imaging for pancreatic cancer.

Nuclear imaging potential and in vitro photodynamic activity of symmetrical and asymmetrical zinc phthalocyanines.

Photodynamic therapy (PDT) is based on exposing a light-sensitive material that has been localized in target tissues with visible light. In the current study, symmetric Zn(II) octaoctadodecylphthalocyanine (1) and the asymmetrically substituted hydroxyhexyloxy derivative (2) were examined as a multifunctional agent for tumour nuclear imaging and for PDT potential. Zn(II)Pc 1 and Zn(II)Pc 2 were radiolabelled with (131) I using an iodogen method with high efficiency (93.5 ± 3.5% and 93.0 ± 2.8%, respectively) under the optimum conditions. Biodistribution study results showed that radiolabelled Zn(II)Pc 1 had a high uptake in the large intestine and unchanging uptake in the ovary. However, radiolabelled Zn(II)Pc 2 uptake was statically significant in the large intestine, pancreas, ovary and lung. For the PDT studies, EMT6/P (mouse mammary cell line) and HeLa (cervical adenocarcinoma cell line) with Zn(II)Pc 1 and Zn(II)Pc 2 were exposed to red light (650 nm) at 10-30 J/cm(2) . Zn(II)Pc 1 and Zn(II)Pc 2 had a good PDT efficacy in the EMT6/P cell line. In conclusion, radiolabelled Zn(II)Pc 1 might be a promising imaging agent for pancreas, ovary and colon tumours. However, the radiolabelled Zn(II)Pc 2 might be a promising nuclear imaging and PDT agent for colon, lung, pancreas and ovary tumours.

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.

131I-Zn-Chlorophyll derivative photosensitizer for tumor imaging and photodynamic therapy.

In recent years, the photodynamic therapy studies have gained considerable attention as an alternative method to surgery, chemotherapy and radiotherapy which is commonly used to fight cancer. In this study, biological potentials of a benzyloxy bearing zinc(II) pheophorbide-a (Zn-PH-A) were investigated via in vivo and in vitro experiments. Zn-PH-A was labeled with (131)I with high efficiency (95.3 ± 2.7%) and its biodistribution studies were investigated on female Albino Wistar rats. The radiolabeled photosensitizer had been intravenously injected into the tail vein, and then the animals were sacrificed at 30, 60 and 120 min post injection. The percent of radioactivity per gram of organs (%ID/g) was determined. The radiolabeled Zn-PH-A showed high uptake in ovary. In addition, photodynamic therapy studies of the photosensitizer were conducted in EMT6, murine mammary carcinoma and HeLa, human cervix carcinoma cell lines. For the photodynamic therapy studies, the cells with Zn-PH-A were exposed to red light (650 nm) at the doses of 10-30 J/cm(2). The results showed that Zn-PH-A has stronger PDT effect in EMT6 than HeLa cell. Our present work demonstrates (131)I-labeled photosensitizer as a bifunctional agent (PDT and nuclear imaging) which could be improved in future by using EMT6 growing tumor in nude mice.

Evaluation of cancer imaging potential and photodynamic therapy efficacy of copper (II) benzyloxypheophorbide-a.

The biological potential of a synthetic copper chlorophyll derivative was investigated via in vivo and in vitro experiments. The Cu-chlorophyll derivative photosensitizer (Cu-PH-A) was labeled with (131)I with high efficiency (92.9 ± 4.2%) using the iodogen method. Cell culture studies were performed with the MCF-7 and MDAH-2774 cell lines after radiolabeling. The photosensitizing activity of Cu-PH-A was more effective in MDAH-2774 cells than in MCF-7 cells at a concentration of 50 µM. When the biodistribution in female Albino Wistar rats was examined, uptake of the radiolabeled photosensitizer was maximal in the liver and ovaries after 60 min. It is concluded that radiolabeled Cu-chlorophyll derivative photosensitizer has high uptake in ovaries in normal rats. In addition, the intercellular uptake and PDT efficacy of the Cu-PH-A in MDAH-2774 were good compared with MCF-7 cells. This photosensitizer could be useful for both ovary tumour imaging and PDT.

Bacterial biofilm formation and treatment in soft tissue fillers.

Injection of soft tissue fillers plays an important role in facial reconstruction and esthetic treatments such as cosmetic surgery for lip augmentation and wrinkle smoothening. Adverse events are an increasing problem, and recently, it has been suggested that bacteria are the cause of a vast fraction these. We developed a novel mouse model and evaluated hyaluronic acid gel, calcium hydroxyl apatite microspheres, and polyacrylamide hydrogel for their potential for sustaining bacterial infections and their possible treatments. We were able to culture Pseudomonas aeruginosa, Staphylococcus epidermidis, and Probionibacterium acnes in all three gels. When contaminated gels were left for 7 days in a mouse model, we found sustainment of bacterial infection with the permanent gel, less with the semi-permanent gel, and no growth within the temporary gel. Evaluation of treatment strategies showed that once the bacteria had settled (into biofilms) within the gels, even successive treatments with high concentrations of relevant antibiotics were not effective. Our data substantiate bacteria as a cause of adverse reactions reported when using tissue fillers, and the sustainability of these infections appears to depend on longevity of the gel. Most importantly, the infections are resistant to antibiotics once established but can be prevented using prophylactic antibiotics.

Evaluation of (131)I-pentamidine for scintigraphy of experimentally Leishmania tropica-infected hamsters.

We aimed to assess the ability of (131)I-Pentamidine scintigraphy to detect the lesions of Leishmania tropica infection. An experimental model of cutaneous leishmaniasis was developed. The presence of cutaneous leishmaniasis was confirmed. Pentamidine was radioiodinated with (131)I. The radiolabeled pentamidine was validated by the requisite quality control tests to check its radiolabeling efficiency, in vitro stability. (131)I-Pentamidine (activity: 18.5 MBq/100 µl) was injected intracardiacally into infected hamsters. Static whole body images of the hamsters were acquired under the gamma camera at 5 and 30 min, 2, 6 and 24 h following the administration. On the scintigrams, anatomically adjusted regions of interest (ROIs) were drawn over the right feet (target) and left feet (not-target) and various organs. Accumulation of (131)I-Pentamidine at sites of infection is expressed as the target to non-target (T/NT) ratio. The results T/NT ratio decreased with time. In concluding the (131)I-Pentamidine has poor sensitivity in detection of L. tropica infection.

Design of (99m) Tc-DTPA-CLP and preliminary evaluation in rats.

Radiopharmaceuticals are localized in (malignant) tumor tissues by different mechanisms. One of these mechanisms, gelatinase enzyme activity, is associated with poor prognosis in cancer patients and potential targets for tumor imaging. There are some gelatinases to be associated with metastatic potential for tumor imaging to possibly predict metastases. In this study, a cyclic decapeptide conjugate, DTPA-CLP (DTPA-Cys-Leu-Pro-Gly-His-Trp-Gly-Phe-Pro-Ser-Cys), was selected as a peptide conjugate because of its selective inhibitory activity toward gelatinases. Peptide-conjugated DTPA-CLP was labeled with (99m) Tc with a radiolabeling efficiency of 97.0 ± 2.8%. After determining optimization conditions for radiolabeling, a biodistribution study of radiolabeled peptide in albino Wistar rats was performed. According to biodistribution data, (99m) Tc-DTPA-CLP showed high uptake in the lung, liver, uterus, and spleen. These results show that (99m) Tc-DTPA-CLP may be used for the imaging of gelatinase activity in metastatic tumors.