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101.
Dr. Ying‐Ying Huang Dr. Thiagarajan Balasubramanian Dr. Eunkyung Yang Dr. Dianzhong Luo Dr. James R. Diers Prof. David F. Bocian Prof. Jonathan S. Lindsey Prof. Dewey Holten Dr. Michael R. Hamblin 《ChemMedChem》2012,7(12):2155-2167
A series of four stable synthetic bacteriochlorins was tested in vitro in HeLa cells for their potential in photodynamic therapy (PDT). The parent bacteriochlorin (BC), dicyano derivative (NC)2BC and corresponding zinc chelate (NC)2BC–Zn and palladium chelate (NC)2BC–Pd were studied. Direct dilution of a solution of bacteriochlorin in an organic solvent (N,N‐dimethylacetamide) into serum‐containing medium was compared with the dilution of bacteriochlorin in Cremophor EL (CrEL; polyoxyethylene glycerol triricinoleate) micelles into the same medium. CrEL generally reduced aggregation (as indicated by absorption and fluorescence) and increased activity up to tenfold (depending on bacteriochlorin), although it decreased cellular uptake. The order of PDT activity against HeLa human cancer cells after 24 h incubation and illumination with 10 J cm?2 of near‐infrared (NIR) light is (NC)2BC–Pd (LD50=25 nM ) > (NC)2BC > (NC)2BC–Zn ≈ BC. Subcellular localization was determined to be in the endoplasmic reticulum, mitochondria and lysosomes, depending on the bacteriochlorin. (NC)2BC–Pd showed PDT‐mediated damage to mitochondria and lysosomes, and the greatest production of hydroxyl radicals as determined using a hydroxyphenylfluorescein probe. The incorporation of cyano substituents provides an excellent motif for the enhancement of the photoactivity and photostability of bacteriochlorins as PDT photosensitizers. 相似文献
102.
Characterization of micellar systems produced by new amphiphilic conjugates of poly(ethylene glycol)
R. Pignatello V. Pantò L. Basile A. Leonardi C. Guarino C. La Rosa 《Drug development and industrial pharmacy》2014,40(11):1463-1467
This study proposes polymeric micelles produced using new amphiphilic conjugates between amino- or carboxy-mPEG2000 and three different α-lipoamino acids (PEG-LAA). The characterization of these colloidal systems showed CMC values, in the order of 10?5?M, that are interesting in the view of an in vivo administration. The PEG-LAA micelles also showed a good stability at 37?°C and upon dilution in aqueous media. Using a colored probe as a model lipophilic compound, the loading efficiency and in vitro release profile were also outlined. 相似文献
103.
S. Sajjadi 《应用聚合物科学杂志》2001,82(10):2472-2477
Semibatch emulsion polymerization processes with a monomer emulsion feed are of great importance in both academia and industry. Monomer emulsion feeds can be applied to semibatch reactors using either a stream of an emulsified monomer or two streams of a neat monomer feed and an aqueous solution of an emulsifier. The effect of the feeding policy on the rate of polymerization and on the secondary particle formation was studied for a seeded semibatch emulsion polymerization of styrene. When a single-stream monomer emulsion feed is applied to a semibatch process, the monomer-swollen micelles formed in the feed might become the locus of initiation upon entering the reaction vessel. Under the conditions of this study, the application of monomer emulsion feed in either one stream or two streams did not result in secondary particle formation. The incoming monomer-swollen micelles were disintegrated to supply emulsifier molecules for the stability of growing particles, before they can capture radicals and become polymer particles. The rate of polymerization was found to be independent of the way that the monomer emulsion feed is added. In the absence of nitrogen, the rate of polymerization decreased more appreciably for the monomer emulsion feed, due to the oxygen dissolved in the emulsified monomer. The number of particles, however, was not affected by the purging policy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2472–2477, 2001 相似文献
104.
Spaghetti were produced in a pilot plant from semolina and semolina blended with increasing amounts of barley flour. According to size exclusion high-performance liquid chromatography (SE-HPLC), barley proteins interact with semolina proteins during pasta making, forming polymers of high molecular weight. Of these, the unextractable polymeric proteins (UPP) were at significantly higher concentrations than in spaghetti made from semolina. The decrease of both S–S bonds and –SH free groups in barley semolina spaghetti, with respect to that made of semolina, suggested that polymerisation among the different classes of proteins involves a new bonding arrangement. Due to β-glucan hydrophilicity and competition with starch for water, the replacement of increasing amounts of semolina with barley flour was able to increase the optimal cooking time. The sensory properties of composite spaghetti were judged as better than the control because of the higher firmness and the lower bulkiness and stickiness of the former. 相似文献
105.
A facile synthesis of a novel three‐phase nanocomposite: Single‐wall carbon nanotube/silver nanohybrid fibers embedded in sulfonated polyaniline
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Rajesh K. Agrawalla Subhasish Paul Pratap K. Sahoo Amit K. Chakraborty Apurba K. Mitra 《应用聚合物科学杂志》2015,132(12)
A three‐phase water‐soluble nanocomposite of single wall carbon nanotube/silver nanoparticle hybrid fibers embedded in sulfonated polyaniline has been synthesized by a simple chemical solution mixing process. The nanocomposite has been characterized by high resolution electron microscopy, X‐ray diffractometry, FTIR spectroscopy, Raman spectroscopy, and thermogravimetric analysis. Optical and electrical characteristics of the nanocomposite have been determined by UV–vis absorption spectroscopy, photoluminescence spectroscopy, and four‐probe electrical conductivity measurement. A surface plasmon absorption band obtained around 460 nm indicates the presence of silver nanoparticles in the composite. The optical band gap calculation for sulfonated polyaniline vis‐a‐vis the nanocomposite supported the conductivity measurement. Over 1300 times increase in DC electrical conductivity has been observed for the three‐phase nanocomposite, with a filler loading of 20 wt %, at 306 K. This observation could be explained by Mott's variable range hopping model considering a three‐dimensional conduction. Such a nanocomposite has immense potential for use as a cathode material in lithium‐ion batteries and supercapacitors. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41692. 相似文献
106.
ε‐Branched Flexible Side Chain Substituted Diketopyrrolopyrrole‐Containing Polymers Designed for High Hole and Electron Mobilities
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A‐Reum Han Gitish K. Dutta Junghoon Lee Hae Rang Lee Sang Myeon Lee Hyungju Ahn Tae Joo Shin Joon Hak Oh Changduk Yang 《Advanced functional materials》2015,25(2):247-254
Based on the integrated consideration and engineering of both conjugated backbones and flexible side chains, solution‐processable polymeric semiconductors consisting of a diketopyrrolopyrrole (DPP) backbone and a finely modulated branching side chain (ε‐branched chain) are reported. The subtle change in the branching point from the backbone alters the π?π stacking and the lamellar distances between polymer backbones, which has a significant influence on the charge‐transport properties and in turn the performances of field‐effect transistors (FETs). In addition to their excellent electron mobilities (up to 2.25 cm2 V?1 s?1), ultra‐high hole mobilities (up to 12.25 cm2 V?1 s?1) with an on/off ratio (Ion/Ioff) of at least 106 are achieved in the FETs fabricated using the polymers. The developed polymers exhibit extraordinarily high electrical performance with both hole and electron mobilities superior to that of unipolar amorphous silicon. 相似文献
107.
pH‐ and NIR Light‐Responsive Micelles with Hyperthermia‐Triggered Tumor Penetration and Cytoplasm Drug Release to Reverse Doxorubicin Resistance in Breast Cancer
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Haijun Yu Zhirui Cui Pengcheng Yu Chengyue Guo Bing Feng Tongying Jiang Siling Wang Qi Yin Dafang Zhong Xiangliang Yang Zhiwen Zhang Yaping Li 《Advanced functional materials》2015,25(17):2489-2500
The acquisition of multidrug resistance (MDR) is a major hurdle for the successful chemotherapy of tumors. Herein, a novel hybrid micelle with pH and near‐infrared (NIR) light dual‐responsive property is reported for reversing doxorubicin (DOX) resistance in breast cancer. The hybrid micelles are designed to integrate the pH‐ and NIR light‐responsive property of an amphiphilic diblock polymer and the high DOX loading capacity of a polymeric prodrug into one single nanocomposite. At physiological condition (i.e., pH 7.4), the micelles form compact nanostructure with particle size around 30 nm to facilitate blood circulation and passive tumor targeting. Meanwhile, the micelles are quickly dissociated in weakly acidic environment (i.e., pH ≤ 6.2) to release DOX prodrug. When exposed to NIR laser irradiation, the hybrid micelles can trigger notable tumor penetration and cytosol release of DOX payload by inducing tunable hyperthermia effect. In combination with localized NIR laser irradiation, the hybrid micelles significantly inhibit the growth of DOX‐resistant MCF‐7/ADR breast cancer in an orthotopic tumor bearing mouse model. Taken together, this pH and NIR light‐responsive micelles with hyperthermia‐triggered tumor penetration and cytoplasm drug release can be an effective nanoplatform to combat cancer MDR. 相似文献
108.
109.
Removal of nitrogen and phosphorus (P) from wastewater is successfully and widely practiced in systems employing both granular sludge technology and enhanced biological P removal (EBPR) processes; however, the key parameter, anaerobic reaction time (AnRT), has not been thoroughly investigated. Successful EBPR is highly dependent on an appropriate AnRT, which induces carbon and polyphosphate metabolism by phosphorus accumulating organisms (PAOs). Therefore, the long-term impact of AnRT on denitrifying P removal performance and granular characteristics was investigated in three identical granular sludge sequencing batch reactors with AnRTs of 90 (R1), 120 (R2) and 150 min (R3). The microbial community structures and anaerobic stoichiometric parameters related to various AnRTs were monitored over time. Free nitrite acid (FNA) accumulation (e.g., 0.0008–0.0016 mg HNO2–N/L) occurred frequently owing to incomplete denitrification in the adaptation period, especially in R3, which influenced the anaerobic/anoxic intracellular intermediate metabolites and activities of intracellular enzymes negatively, resulting in lower levels of poly-P and reduced activity of polyphosphate kinase. As a result, the Accumulibacter-PAOs population decreased from 51 ± 2.5% to 43 ± 2.1% when AnRT was extended from 90 to 150 min, leading to decreased denitrifying P removal performance. Additionally, frequent exposure of microorganisms to the FNA accumulation and anaerobic endogenous conditions in excess AnRT cases (e.g., 150 min) stimulated increased extracellular polymeric substances (EPS) production by microorganisms, resulting in enhanced granular formation and larger granules (size of 0.6–1.2 mm), but decreasing anaerobic PHA synthesis and glycogen hydrolysis. Phosphorus removal capacity was mediated to some extent by EPS adsorption in granular sludge systems that possessed more EPS, longer AnRT and relatively higher GAOs. 相似文献
110.
Various types of synthetic polymeric membranes have been fabricated for separation purposes in industry/laboratory. Zeolite is ceramic-based material and well known for its antiwear resistance and high mechanical strength. Mixed matrix membranes are the latest membrane technology constituting inorganic nanoparticle phase and organic polymer phase. The review represents various types and applications of zeolite-reinforced polymeric membranes. Consequently, fabrication procedure and working principle of zeolite-reinforced mixed matrix (polyimide, polysulfone, polycarbonate) membranes have been discussed. The significant relevance of polymer/zeolite membranes is in water purification, medical, catalytic, and gas separation industries. Improvement in polymeric membrane properties has been observed through incorporation of zeolite filler. 相似文献