| Photodynamic therapy (photodynamic therapy, PDT) means tumor tissue under the effect of photosensitizer, oxygen and light together, the organism cells or biological molecules change their morphological or functional form to lead to cell damage and necrosis. This is a new therapy of being studied and rapid developing,which has become one of the most active research areas in the World Cancer Prevention science. Phthalocyanine with high efficiency and low toxicity has become the focus of anticancer drug. In this paper, we mainly studied the anticancer activity of ten kinds of zinc phthalocyanine compounds containing different side chains,according its localization in cells to explore the mechanisms of action of the lead photosensitizer, and to explore the molecular mechanism of anti-cancer effect to guide our future development of metal phthalocyanines.This article selects three series of phthalocyanines and its derivatives as research subjects. According to the structural characteristics of phthalocyanine, the series one is zinc phthalocyanine with different substituents on the side chain: benzyl alcohol phthalocyanine (ZnPcl), benzylamine phthalocyanine (ZnPc2) and carboxyethyl phthalocyanine (ZnPc3). The series two is zinc phthalocyanines with different numbers of carboxyl groups on the side chain: tetranethylcarboxyl phthalocyanine(ZnPc4), octamethylene carboxyphenyl phthalocyanine (ZnPc5) and hexadecyl carboxophthalocyanine (ZnPc6). The series three is sodium carboxyl ate phthalocyanines: carboxyethyl sodium salt phthalocyanine (ZnPc7),tetracarboxymethyl sodium salt phthalocyanine (ZnPc8), octacarboxyl sodium salt phthalocyanine (ZnPc9), cetylmethyl sodium salt phthalocyanine (ZnPc10).First, compare the photophysical and photochemical properties of those three zinc phthalocyanine. Second, compare the cell uptake of the phthalocyanine and its water-soluble derivatives. And explore the subcellular localization of the photosensitizer by laser confocal, because of the subcellular localization of the photosensitizer technique directly affects the effect of the photosensitizer. Third, in order to study the mechanism of phthalocyanine in cells, test the production of reactive oxygen in cells by using different detection probes. Finally, compare the photosensitivity and antitumor activity of three series of phthalocyanines. Those researchment provides a research basis to further explore the phthalocyanine in the application of PDT. The main findings are as follows:(1) security. The effect of phthalocyanine on the proliferation of tumor cells was detected by MTT (3-(4,5-dimethylthiazol-2)-2,5-diphenyltetrazolium bromide). Its confirmed that three series of phthalocyanine had low toxicity to cervical cancer cells Hela and lung cancer cell A549, and carboxyl group phthalocyanine had good safety.(2) Cell uptake rate. The results showed that the uptake rate of benzylamine phthalocyanine was the best, and the carboxyl phthalocyanine followed. With the increase of the number of carboxyl groups, the uptake capacity of tumor cells was decreased gradually. Carboxyl phthalocyanine in the preparation of sodium salt, the tumor cells on its uptake rate was significantly increased.(3) Subcellular localization. The subcellular localization of the drug was observed by laser confocal microscopy after staining with mitochondria, lysosomes and cell membrane fluorescent dyes. The results show that benzyl alcohol phthalocyanine, benzylamine phthalocyanine are located in the lysosome,carboxyethyl, carboxymethyl phthalocyanine are located in the lysosome and mitochondria, octacarboxyl phthalocyanine is located in the lysosome,Hexachlorocarboxylate phthalocyanine is located in the lysosome and cell membrane.(4) Intracellular reactive oxygen species. The active oxygen production capacity of benzyl phthalocyanine was poor, benzylamine phthalocyanine mainly produced singlet oxygen. While the carboxy-type phthalocyanine in the production of singlet oxygen, and also produced a strong superoxide and hydrogen peroxide at the same time. And with the number of carboxyl groups increasing, the production capacity of singlet oxygen increased. Therefore, carboxyl-type phthalocyanine is mainly based on type I, type II dual photodynamic mechanism.(5) Cell apoptosis. ZnPc5 was located in the lysosome, resulting in necrosis of the most cells. Drugs are located in the lysosome, which cause local damage of lysosomes with light stimulation and deliver to mitochondria in different ways to cause cells apoptosis followed by mitochondria-induced apoptosis. ZnPc6 was located in the cell membrane to cause cells apoptosis by the extracellular signal activation of intracellular apoptosis of the enzyme.(6) Photosensitive antitumor activity. The results of MTT showed that the three series of zinc phthalocyanines had good photosensitivity and antitumor activity.Mainly in:①resulting change in tumor cell morphology and nuclear chromatin damage;② Compared with benzyl alcohol phthalocyanine and benzylamine phthalocyanine, carboxy phthalocyanine showed a strong inhibition rate of tumor cells. With the increasing of the number of carboxyl groups, the photosensitivity and anti-tumor activity were decreased. After the sodium salt of carboxyl phthalocyanine was made, the photosensitivity and antitumor activity were weakenedThe experimental results show that the carboxy-type phthalocyanines and their water-soluble derivatives have good safety, photosensitivity and antitumor activity. Its photosensitivity and antitumor activity are positively correlated with intracellular reactive oxygen species, and carboxyl-type phthalocyanine is mainly based on type Ⅰ,type Ⅱ dual photodynamic mechanism. This provide a reference for designing and synthesizing new phthalocyanine with good photosensitivity, and further promote the clinical application of metallophthalocyanine photosensitizer in PDT field. |
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