scholarly journals Development of Polymeric Cargo for Delivery of Photosensitizer in Photodynamic Therapy

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Byoung-chan Bae ◽  
Kun Na

Photodynamic therapy (PDT), which employs photosensitizers (PSs), a light source with appropriate wavelength, and oxygen molecules, has potential for the treatment of various tumors and nononcological diseases due to its high efficiency in directly producing cellular death, vascular shutdown, and immune activation. After the clinical success of Photofrin (porphyrin derivative), many PSs were developed with improved optical and chemical properties. However, some weak points such as low solubility and nonspecific phototoxicity induced by hydrophobic PSs still remain. In order to overcome these problems, various polymeric carriers for PS delivery have been intensively developed. Here, we report recent approaches to the development of polymeric carriers for PS delivery and discuss the physiological advantages of using polymeric carriers in PDT. Therefore, this paper provides helpful information for the design of new PSs without the weaknesses of conventional ones.

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5666
Author(s):  
Valéria Verebová ◽  
Jiří Beneš ◽  
Jana Staničová

Photosensitive compounds found in herbs have been reported in recent years as having a variety of interesting medicinal and biological activities. In this review, we focus on photosensitizers such as hypericin and its model compounds emodin, quinizarin, and danthron, which have antiviral, antifungal, antineoplastic, and antitumor effects. They can be utilized as potential agents in photodynamic therapy, especially in photodynamic therapy (PDT) for cancer. We aimed to give a comprehensive summary of the physical and chemical properties of these interesting molecules, emphasizing their mechanism of action in relation to their different interactions with biomacromolecules, specifically with DNA.


The possibility of creating polymers with fluorescence, derivatives of poly (3-aminopropene) (PAP) by alkylation of amino groups with aromatic or heterocyclic aldehydes by Leykart-Wallach reaction with own fluorescence was investigated. Synthesis of N-alkylated PAP derivatives was performed by sequential conversion: acrylamide → PAA (Mν = 100 kDa) → PAP → alkylated PAP. Due to the impossibility of using LiAlH4 to reduce the amide groups of polyacrylamide to amine due to the low solubility of PAA in the non-aqueous (diethyl ether, tetrahydrofuran, etc.) solvents, the reduction of PAA by other reducing agents was optimized. It was found that the best conditions for the reduction of amide groups of PAA to amine - acetic acid - dioxane as a solvent and NaBH4 (suspended in anhydrous 1,4-dioxane) as a reducing agent. According to IR spectroscopy, the products obtained are copolymers of 3-aminopropene (the main amount of elementary units), acrylamide and acrylic acid. To modify the structure of the obtained polymer, the Leuckart-Wallach reaction was used, where the following aldehydes having luminescence were selected: pyrene-3-aldehyde, 2-hydroxy-1-naphthaldehyde, anthracene-9-carbaldehyde, and 3.5 phenyl-1-(4-formylphenyl)-2-pyrazoline. To obtain N-Ar/Het-methylene derivatives, a mixture of PAP, aldehyde and 98% formic acid was heated under harsh conditions (6 hours, glycerol bath), isolated and purified. The obtained modified samples of polymers are intensely fluorescent both in the solid state and in the form of solutions, which indicates the successful passage of the Leykart-Wallach reaction. Spectral characteristics were obtained for solutions in a mixed solvent – ethyl acetate – formic acid (9 : 1). For both the original aldehydes and the copolymers in the mixed solvent used, the spectral fluorescence curves lose their oscillatory structure, probably due to the specific effect of the mixed solvent on the phosphor molecules (for the original aldehydes) and the side methylamino-N-arylmethylene - […СН2-СН(СН2-NH-CH2-Ar)- …] and methylamino-N-getarylmethylene […-СН2-СН(СН2-NH-CH2-Het)-…] groups both in the ground and in the excited state, and for polymers of inhomogeneity of the medium with local polarity zones.


RSC Advances ◽  
2017 ◽  
Vol 7 (84) ◽  
pp. 53362-53372 ◽  
Author(s):  
Yani Gong ◽  
Chengbing Qin ◽  
Wenjun He ◽  
Zhixing Qiao ◽  
Guofeng Zhang ◽  
...  

Graphene oxide (GO) with unique physical and chemical properties, such as high specific surface area, chemical stability and environmental friendliness, has been considered as an excellent adsorbent to remove organic dyes from polluted water.


2013 ◽  
Vol 864-867 ◽  
pp. 1319-1322
Author(s):  
Shan Hong Lan ◽  
Rui Chen ◽  
Ping Ma ◽  
Cong Cong Li ◽  
Hui Xia Lan

The method of activated sludge has been widely used in the process of sewage treatment for its high-efficiency and low-consumption. The effect of Fe3+ on microbial growth and physical and chemical properties of activated sludge were studied to obtain relevant parameters for the running of activated sludge system in this paper. Firstly, study on the effect of Fe3+ on microbial growth was carried out. The experiment results showed that the lag phase of microbial growth was obviously reduced with the presence of Fe3+, obtaining advancing into the logarithmic phase. Whats more, the value of OD600 reached to the maximum of 0.615 at 12h when the concentration of Fe3+ was 30mg/L. Secondly, the effects of Fe3+ on the wastewater treatment and that of the performance index include SVI and MLSS were studied. The results indicated that SVI decreased with increasing the dosages of Fe3+,while MLSS and removal rate of COD obviously increased which reach to the maximum of 88.21% when the concentration of Fe3+ was 30mg/L.


Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 57
Author(s):  
Huan Liu ◽  
Quan Li ◽  
Benqiao He ◽  
Zhengguang Sun ◽  
Feng Yan ◽  
...  

The efficient separation of Sr2+/Mg2+ through nanofiltration (NF) technology is a great challenge because Sr2+ and Mg2+ ions are congeners with the same valence and chemical properties. In this work, an NF membrane under an electric field (EF) was successfully employed to separate Mg2+ and Sr2+ ions for the first time. The effects of current densities, Mg2+/Sr2+ mass ratios, pH of the feed, and coexisting cations on separation performance were investigated. Dehydration of Sr2+ or Mg2+ ions under EF was proved by molecular dynamics simulation. The results showed that a high-efficient separation of Mg2+/Sr2+ was achieved: Mg2+ removal of above 99% and increase in Sr2+ permeation with increasing EF. A separation factor reached 928 under optimal conditions, far higher than that without EF. The efficient separation of Mg2+/Sr2+ ions was mainly due to rejection of most Mg2+ ions by NF membrane and in situ precipitation of partly permeated Mg2+ ions by OH− generated on the cathode under EF. Meanwhile, preferential dehydration of Sr2+ ions under EF due to lower hydration energy of Sr2+ compared with Mg2+ resulted in an increase of permeation of Sr2+ ions. This work provided a new idea for separation of congener ions with similar valence and chemical properties.


2021 ◽  
Vol 36 (1) ◽  
pp. 315-322
Author(s):  
Amir Soltanbeigi ◽  
Mustafa Yildiz ◽  
Erhan Sakartepe

The agronomic and chemical characteristics of aromatic plants are affected by nutritional sources. Salvia officinalis (common sage) is an aromatic plant extensively used in food, popular medicine, and many pharmacological research studies. In this study, the effects of NPK, vermicompost and two types of microbiological fertilizer were investigated on the agronomic parameters and volatile oil characteristics of S. officinalis grown in the greenhouse. The plants were harvested two times (1st and 2nd cuttings) during the growing season. The consumption of NPK has the highest effect on stem number (54 no plant-1), fresh and dry herb weight (96.8 and 27.2 g p-1), fresh and dry leaf weight (74.6 and 19.6 g p-1), and volatile oil percentage (1.64%). While the herb weight at the 1st cutting (74.3 g p-1) was higher than the 2nd cutting (70.2 g p-1), the fresh (58.2 g p-1) and dry (16.6 g p-1) leaf weights and the leaf ratio (80.5 %) at the 2nd cutting were higher than the 1st cutting. Moreover, the volatile oil contents at the 1st cutting (1.44%) were higher than the 2nd cutting (1.18%). In total, 31 compounds were identified in the volatile oils by using GC/FID-MS. The percentages of α-Thujone (22.4-31.4%) and Camphor (21.0-25.4%) were found higher than other compounds. The content of α-Thujone was higher in NPK and vermicompost treatments. Based on the results, the application of different nutritional sources improved the yield and chemical properties of S. officinalis. Among the non-chemical nutrient sources, vermicompost had high efficiency.


2013 ◽  
Vol 9 ◽  
pp. 2793-2802 ◽  
Author(s):  
Hideki Amii ◽  
Aiichiro Nagaki ◽  
Jun-ichi Yoshida

Organo-fluorine compounds are the substances of considerable interest in various industrial fields due to their unique physical and chemical properties. Despite increased demand in wide fields of science, synthesis of fluoro-organic compounds is still often faced with problems such as the difficulties in handling of fluorinating reagents and in controlling of chemical reactions. Recently, flow microreactor synthesis has emerged as a new methodology for producing chemical substances with high efficiency. This review outlines the successful examples of synthesis and reactions of fluorine-containing molecules by the use of flow microreactor systems to overcome long-standing problems in fluorine chemistry.


1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.


Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.


Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.


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