Inhibition of Laser-Induced Choroidal Neovascularization by Hematoporphyrin Dimethylether-Mediated Photodynamic Therapy in Rats.

This study aimed to investigate the effect of hematoporphyrin dimethylether (HDME)-mediated photodynamic therapy for laser-induced choroidal neovascularization (CNV) in adult Brown Norway rats. HDME was administered via tail vein at 14 d after the laser photocoagulation, and the rats received irradiance with a laser light at 570 nm at 15 min after injection. CNV was evaluated by fundus photography, fundus fluorescein angiography, optical coherence tomography, and hematoxylin and eosin staining. We found that CNV was occurred at 7 d after photocoagulation and reaching peak activity at 14 d after photocoagulation. There is a significant reduction in the total area of the fluorescein leakage and the number of strong fluorescein leakage spots on 7 d after HDME-mediated photodynamic therapy (PDT). The results suggest that HDME-mediated PDT inhibits laser-induced CNV in rats, representing a promising therapy for wet age-related macular degeneration.

Antibacterial and anticancer activities of green-synthesized silver nanoparticles using Photinia glabra fruit extract.

Aims: We prepared Photinia glabra (PG) aqueous fruit extract, utilized it to synthesize silver nanoparticles (PG-Ag NPs) and evaluated the antibacterial and anticancer activities of the nanoparticles (NPs). Materials & methods: Silver nitrate aqueous solution was reduced to PG-Ag NPs using aqueous PG fruit extract. NP shape, size, composition and functionalization were determined using transmission electron microscopy, x-ray photoelectron spectroscopy, Fourier transform infrared and x-ray diffraction. Results & conclusions: PG-Ag NPs were spherical, approximately 39-77 nm-sized, functionalized surfaces with notable antibacterial activity against both Escherichia coli and Staphylococcus aureus, with an MIC <30 ug/ml and cytotoxicity toward esophageal cancer cells, with IC50 values less than 20 ug/ml. PG-Ag@rt NPs have been shown to be a potent antibacterial and anticancer agent, and their enriched particle surfaces can be conjugated with other compounds for multibiomedical applications.

The present study reports for the first time the preparation of Photinia glabra (PG) aqueous fruit extract and its use for the synthesis of smaller silver particles (PG-Ag NPs) from bulk aqueous silver nitrate solution (AgNO₃). The preparation followed the reduction ability of PG fruit extract phytochemical under different preparation conditions: at room temperature (PG-Ag@rt), at 70°C (PG-Ag@70) and in the presence of cerium oxide at 70°C (PG-Ag+CeO₂@70). The prepared smaller particles were found using transmission electron microscopy to be spherical in shape with sizes 39, 77 and 44 nm for PG-Ag@rt, PG-Ag@70 and PG-Ag+CeO₂@70, respectively. The NPs contained different functional groups on their surfaces due to the capping ability of PG fruit extract components. Among all, PG-Ag@rt NPs showed strongest antibacterial activity against Escherichia coli and Staphylococcus aureus with MIC 7.0 µg/ml and 28.0 µg/ml, respectively, and commendable anticancer activity toward Eca-109 cancer cells with IC₅₀ less than 20 ug/ml.

Tetraphenylporphyrin derivatives possessing piperidine group as potential agents for photodynamic therapy.

Photodynamic therapy (PDT) is a noninvasive therapeutic and promising procedure in cancer treatment and has attracted considerable attention in recent years. In the present paper, 2-piperidinetetraphenylporphyrin derivatives (P1-P3) conjugated with different substituents (Cl, Me, MeO group) at phenyl position were synthesized via nucleophilic substitution of 2-nitroporphyrin copper derivatives with piperidine by refluxing under a nitrogen atmosphere and then demetalization. The combination of 1H NMR, 13C NMR and HR-MS was used to elucidate the identities of them. Their photophysical and photochemical properties, intracellular localization, cytotoxicity in vitro and in vivo against QBC-939 cells were investigated. They have absorption at wavelength about 650nm. All synthesized photosensitizers showed low dark cytotoxicity and comparable with that of hematoporphyrin monomethyl ether (HMME). And they were more phototoxic than HMME to QBC-939 cells in vitro. In bearing QBC-939 tumor BALB/c nude mice, when it treated with 5mg/kg dose of PS and laser light (650nm, 100J/cm2, 180mW/cm2), the growth of tumor was inhibited compared to the control group. Among them, P3 exhibited better photodynamic antitumor efficacy on BALB/c nude mice at lower concentration. These results indicate that P3 is a new potential antitumor photosensitizer in photodynamic therapy and deserves further investigation.

Photosensitizing effectiveness of a novel chlorin-based photosensitizer for photodynamic therapy in vitro and in vivo.

PURPOSE: Photodynamic therapy (PDT) is a promising noninvasive treatment, which has been approved by the US Food and Drug Administration for the treatment of localized tumors. With the aim to select an appropriate photosensitizer for tumor treatment in PDT, the antitumor effect of a novel chlorin-based photosensitizer, meso-tetra (3-morphlinomethyl-4-methoxyphenyl) chlorin (TMMC) (Fig. 1a) on two types of human malignant tumor cells in vitro and a esophageal cancer model in nude mice, was evaluated in the present paper. Fig. 1 Chemical structure and spectrum properties of TMMC in DMF. a Chemical structure of TMMC in DMF. b UV-Vis absorption spectrum of TMMC in DMF. Its maximum absorbance is at 423 nm, and at 527, 555, 600, 655 nm and 712 nm, also it has absorption. c Emission spectrum of TMMC, which was excited at 514 nm, and its peaks were at 656 and 720 nm. d The matrix of excitation and emission spectra (Ex: 300-550 nm, Em: 600-780 nm) METHODS: The efficiency of TMMC-PDT in vitro was analyzed by MTT assay and clonogenic assay. The intracellular distribution of photosensitizers was detected with laser scanning confocal microscopy. The accumulation of TMMC in human malignant tumor cells was measured by Fluorescence Spectrometer, and the pathway of cell death was analyzed by flow cytometry. Eca-109 tumor model was used to evaluate the antitumor effects of TMMC-mediated PDT. And the singlet oxygen quantum yield of TMMC was also measured using DPBF as substrate. RESULTS: TMMC shows a singlet oxygen quantum yield of 0.59 and displays a characteristic long wavelength absorption peak at 655 nm. The accumulation of TMMC increased in time-dependent manner, and it was found in cytoplasm and nuclear membranes. TMMC-PDT induced cell death by the major death pathway of necrosis and significantly reduced the growth of Eca-109 tumors in nude mice (180 mW/cm(2), 120 J/cm(2)). CONCLUSION: The studies suggest that TMMC is an effective photosensitizer for PDT to tumors. Therefore, TMMC has great potentials for tumor treatment in PDT and deserves further investigation.