Nucleation of the electroactive γ phase and enhancement of the optical transparency in low filler content poly(vinylidene)/clay nanocomposites

Poly(vinylidene fluoride), PVDF, based nanocomposites with different clays structures have been processed by solvent casting and melt crystallisation. Depending on the melting temperature of the polymer, the nanocomposite recrystalises in the electroactive or non electroactive β-phase of the polymer. This fact is related to the thermal behaviour of the clay. For montmorillonite clay, the full crystallisation of the electroactiveγ-phase occurs for clay contents lower than 0.5 wt%, allowing the nanocomposites to maintain the mechanical properties of the polymer matrix. The electroactivity of the material has been proven by measuring the piezoelectric d33 response of the material. The obtained value of d33 is -7 pC/N, lower than in β-PVDF obtained by mechanical stretching, but still among the largest coefficients obtained for polymers. Further, the optical transmittance in the visible range is strongly enhanced with respect to the transmittance of the pure polymer. Finally, it is demonstrated that the nucleation of the β-phase can be also obtained in other clays, such as in kaolinite and laponite.Fundação para a Ciência e a Tecnologia (FCT) - NANO/NMed-SD/0156/2007, PTDC/CTM/69316/2006, PTDC/CTM-NAN/112574/2009, SFRH/BD/62507/2009.FEDER funds through the "Programa Operacional Factores de Competitividade – COMPETECOST Action MP1003, the ‘European Scientific Network for Artificial Muscles’ (ESNAM)

Human malarial disease: a consequence of inflammatory cytokine release

Malaria causes an acute systemic human disease that bears many similarities, both clinically and mechanistically, to those caused by bacteria, rickettsia, and viruses. Over the past few decades, a literature has emerged that argues for most of the pathology seen in all of these infectious diseases being explained by activation of the inflammatory system, with the balance between the pro and anti-inflammatory cytokines being tipped towards the onset of systemic inflammation. Although not often expressed in energy terms, there is, when reduced to biochemical essentials, wide agreement that infection with falciparum malaria is often fatal because mitochondria are unable to generate enough ATP to maintain normal cellular function. Most, however, would contend that this largely occurs because sequestered parasitized red cells prevent sufficient oxygen getting to where it is needed. This review considers the evidence that an equally or more important way ATP deficency arises in malaria, as well as these other infectious diseases, is an inability of mitochondria, through the effects of inflammatory cytokines on their function, to utilise available oxygen. This activity of these cytokines, plus their capacity to control the pathways through which oxygen supply to mitochondria are restricted (particularly through directing sequestration and driving anaemia), combine to make falciparum malaria primarily an inflammatory cytokine-driven disease

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

WOS: 000374698900005PubMed ID: 27059543Photodynamic 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 I-131 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 (650nm) at 10-30J/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

Evaluation of nuclear imaging potential and photodynamic therapy efficacy of symmetrical and asymmetrical zinc phthalocyanines

WOS: 000378453600018Photodynamic therapy (PDT) is a medical treatment for the removal of target tissues involving the delivery of a photosensitizer agent followed by irradiation with visible light. In the present study, symmetric Zn(II)Pc 1 and asymmetrically substituted Zn(II)Pc 2 were synthesized and examined multifunctional agents for tumor nuclear imaging, and PDT potential. The Zn(II)Pc 1 and Zn(II)Pc 2 were radiolabeled with I-131 with high efficiency (93.4 +/- 1.6% and 91.4 +/- 1.6%, respectively). The results of the biodistribution study showed that radiolabeled Zn(II)Pc 1 had high uptake on lung, large intestine, ovary and pancreas. However, the uptake of radiolabeled Zn(II)Pc 2 was statically significant in pancreas and intestine. In PDT studies, EMT6/P (mouse mammary cell) and HeLa (cervical adenocarcinoma cell) with Zn(II)Pc 1 and Zn(II)Pc 2 were exposed to red light at the doses of 10-30 J/cm(2). Although PDT activity of Zn(II)Pc 2 in HeLa cell line was determined, Zn(II)Pc 1 showed no phototoxic effect in both cell lines. In conclusion, radiolabeled Zn(II)Pc 1 might be a promising imaging agent for the lung, the ovary pancreas, and the colon tumors. However, radiolabeled Zn(II)Pc 2 might be a promising nuclear imaging agent for the colon and the pancreas tumors and promising PDT agent for cervical tumors. (C) 2016 Elsevier B.V. All rights reserved.Scientific and Technological Research Council of Turkey, TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [112T565]The authors gratefully acknowledge the financial support by the Scientific and Technological Research Council of Turkey, TUBITAK (Grant no: 112T565)

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

WOS: 000390228800005PubMed ID: 27363481Background 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 (TM), tissue: human fibroblast lung] and MIA PaCa-2 [ATCC CRL-1420 (TM), 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.Scientific and Technological Research Council of Turkey, TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [112T565]The authors gratefully acknowledge financial support by The Scientific and Technological Research Council of Turkey, TUBITAK (Grant no: 112T565)

Investigation of In vitro PDT Activities and In vivo Biopotential of Zinc Phthalocyanines Using I-131 Radioisotope

WOS: 000370485300007PubMed ID: 26348246Novel 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 mu M concentration at 30 J/cm(2) light dose and 12.5 mu M 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 I-131 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.Scientific and Technological Research Council of Turkey, TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [112T565]The authors gratefully acknowledge financial support by The Scientific and Technological Research Council of Turkey, TUBITAK (Grant no: 112T565)

Photodynamic therapy and nuclear imaging activities of zinc phthalocyanine-integrated TiO 2 nanoparticles in breast and cervical tumors

PubMed ID: 29136341In 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 TiO 2 nanoparticle, to investigate the potential of PDT and its cytotoxicity. Additionally, ZnPc and ZnPc-TiO 2 molecules were labeled with 131 I and it was aimed to put forth the nuclear imaging/therapy potentials of 131 I labeled ZnPc/ZnPc-TiO 2 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-TiO 2 with 131 I were quite high. In vitro uptake studies shown that 131 I-ZnPc-TiO 2 could be a potential agent for nuclear imaging/treatment of breast and cervical cancers. According to PDT results, ZnPc-TiO 2 might have as to be a potential PDT agent in the treatment of cervical tumor. ZnPc and ZnPc-TiO 2 might be used as theranostic agents. © 2017 John Wiley & Sons A/S114Z430The authors gratefully acknowledge financial support by The Scientific and Technological Research Council of Turkey, TUBITAK (Grant no: 114Z430). -