Changing Models for Commercialization and Implementation of Biocontrol in the Developing and the Developed World

Photodynamic therapy (PDT) is a non-invasive, selective, and cost-effective cancer therapy. The development of readily accessible templates that allow rapid structural modification for further improvement of PDT remains important. We previously reported thiophene-based organic D-π-A sensitizers consisted of an electron-donating (D) moiety, a π-conjugated bridge (π) moiety, and an electron-accepting (A) moiety as valuable templates for a photosensitizer that can be used in PDT. Our preliminary structure-activity relationship study revealed that the structure of the A moiety significantly influences its phototoxicity. In this study, we evaluated the photoabsorptive, cellular uptake, and photo-oxidizing abilities of D-π-A sensitizers that contained different A moieties. The level of phototoxicity of the D-π-A sensitizers was rationalized by considering those three abilities. In addition, we observed the ability of amphiphilic sensitizers containing either a carboxylic acid or an amide in an A moiety to form aggregates that penetrate cells mainly via endocytosis

Aqueous-based tissue clearing in crustaceans

Abstract Background Investigation of the internal tissues and organs of a macroscopic organism usually requires destructive processes, such as dissection or sectioning. These processes are inevitably associated with the loss of some spatial information. Recently, aqueous-based tissue clearing techniques, which allow whole-organ or even whole-body clearing of small rodents, have been developed and opened a new method of three-dimensional histology. It is expected that these techniques will be useful tools in the field of zoology, in which organisms with highly diverse morphology are investigated and compared. However, most of these new methods are optimized for soft, non-pigmented organs in small rodents, especially the brain, and their applicability to non-model organisms with hard exoskeletons and stronger pigmentation has not been tested. Results We explored the possible application of an aqueous-based tissue clearing technique, advanced CUBIC, on small crustaceans. The original CUBIC procedure did not clear the terrestrial isopod, Armadillidium vulgare. Therefore, to apply the whole-mount clearing method to isopods with strong pigmentation and calcified exoskeletons, we introduced several pretreatment steps, including decalcification and bleaching. Thereafter, the clearing capacity of the procedure was dramatically improved, and A. vulgare became transparent. The internal organs, such as the digestive tract and male reproductive organs, were visible through sclerites using an ordinary stereomicroscope. We also found that fluorescent nuclear staining using propidium iodide (PI) helped to visualize the internal organs of cleared specimens. Our procedure was also effective on the marine crab, Philyra sp. Conclusions In this study, we developed a method to clear whole tissues of crustaceans. To the best of our knowledge, this is the first report of whole-mount clearing applied to crustaceans using an aqueous-based technique. This technique could facilitate morphological studies of crustaceans and other organisms with calcified exoskeletons and pigmentation

Activity control of pH-responsive photosensitizer bis(6-quinolinoxy)P(V)tetrakis(4-chlorophenyl)porphyrin through intramolecular electron transfer

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Dependence of neutral red negative area on laser power

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A screenshot of thermography of a sample dish after 30 sec. irradiation at average power of 200 mW

Relaxation Process of Photoexcited <i>meso</i>-Naphthylporphyrins while Interacting with DNA and Singlet Oxygen Generation

Electron donor-connecting cationic porphyrins <i>meso</i>-(1-naphthyl)-tris­(<i>N</i>-methyl-<i>p</i>-pyridinio)­porphyrin (1-NapTMPyP) and <i>meso</i>-(2-naphthyl)-tris­(<i>N</i>-methyl-<i>p</i>-pyridinio)­porphyrin (2-NapTMPyP) were designed and synthesized. DFT calculations speculate that the photoexcited states of 1- and 2-NapTMPyPs can be deactivated via intramolecular electron transfer from the naphthyl moiety to the porphyrin moiety. However, the quenching effect through the intramolecular electron transfer is insufficient, possibly due to the orthogonal position of the electron donor and the porphyrin ring and the relatively small driving force: Gibbs energies are 0.11 and 0.07 eV for 1- and 2-NapTMPyPs, respectively. It was speculated that more than 0.3 eV of the driving force is required to realize effective electron transfer in similar electron-donor connecting porphyrin systems. These porphyrins aggregated around the DNA strand, accelerating the deactivation of their excited singlet state and decreasing their photosensitized singlet oxygen-generating activities. In the presence of a sufficiently large concentration of DNA, these porphyrins can bind to a DNA strand stably, leading to an increased fluorescence quantum yield and lifetime. Singlet oxygen generation was also suppressed by the aggregation of porphyrins around DNA. Although the quantum yield of singlet oxygen generation was recovered in the presence of sufficient DNA, the singlet oxygen generated by DNA-binding porphyrins was significantly smaller than that without DNA. These results suggest that DNA-binding drugs limit the generation of photosensitized singlet oxygen by quenching the DNA strand

Photosensitized protein damage by water-soluble phthalocyanine zinc(II) and gallium(III) complexes through electron transfer and singlet oxygen production

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