Photocatalytic hydrogen (H₂ ) production is significant to overcome challenges like fossil fuel depletion and carbon dioxide emission, but its efficiency is still far below that which is needed for commercialization. Herein, we achieve long-term stable H₂ bubbling production from water (H₂ O) and lactic acid via visible-light-driven photocatalysis in a porous microreactor (PP12); the catalytic system benefits from photocatalyst dispersion, charge separation, mass transfer, and dissociation of O-H bonds associated with H₂ O. With the widely used platinum/cadmium-sulfide (Pt/CdS) photocatalyst, PP12 leads to a H₂ bubbling production rate of 602.5 mmol h^-1 m^-2 , which is 1000 times higher than that in a traditional reactor. Even when amplifying PP12 into a flat-plate reactor with an area as large as 1 m² and extending the reaction time to 100 h, the H₂ bubbling production rate still remains at around 600.0 mmol h^-1 m^-2 , offering great potential for commercialization.

2017-05-01·European Journal of Pharmaceutics and Biopharmaceutics2区 · 医学

Poloxamer-based thermoresponsive ketorolac tromethamine in situ gel preparations: Design, characterisation, toxicity and transcorneal permeation studies

2区 · 医学

Article

作者: Alany, Raid G ; El-Garhy, Omar H ; M A Fathalla, Zeinab ; Vangala, Anil ; Hussein, Amal K ; Longman, Michael ; Khaled, Khaled A

This study was aimed at preparing, characterising and evaluating in situ gel formulations based on a blend of two hydrophilic polymers i.e. poloxamer 407 (P407) and poloxamer 188 (P188) for a sustained ocular delivery of ketorolac tromethamine (KT). Drug-polymer interaction studies were performed using DSC and FT-IR. The gelation temperature (T_sol-gel), gelation time, rheological behaviour, mucoadhesive characteristics of these gels, transcorneal permeation and ocular irritation as well as toxicity was investigated. DSC and FT-IR studies revealed that there may be electrostatic interactions between the drug and the polymers used. P188 modified the T_sol/gel of P407 bringing it close to eye temperature (35°C) compared with the formulation containing P407 alone. Moreover, gels that comprised P407 and P188 exhibited a pseudoplastic behaviour at different concentrations. Furthermore, mucoadhesion study using mucin discs showed that in situ gel formulations have good mucoadhesive characteristics upon increasing the concentration of P407. When comparing formulations PP11 and PP12, the work of adhesion decreased significantly (P<0.001) from 377.9±7.79mNmm to 272.3±6.11mNmm. In vitro release and ex vivo permeation experiments indicated that the in situ gels were able to prolong and control KT release as only 48% of the KT released within 12h. In addition, the HET-CAM and BCOP tests confirmed the non-irritancy of KT loaded in situ gels, and HET-CAM test demonstrated the ability of ocular protection against strongly irritant substances. MTT assay on primary corneal epithelial cells revealed that in situ gel formulations loaded with KT showed reasonable and acceptable percent cell viability compared with control samples.

2009-10-12·Biomacromolecules2区 · 化学

Engineering Surfaces for Substrate-Mediated Gene Delivery Using Recombinant Proteins

2区 · 化学

Article

作者: Shea, Lonnie D. ; Gibly, Romie F. ; Barron, Annelise E. ; Rea, Jennifer C. ; Davis, Nicolynn E.

Immobilized fibronectin and other natural proteins have been utilized to enhance substrate-mediated gene delivery, with apparent contributions from the intrinsic bioactivity and also physical properties of the immobilized proteins. In this report, we investigated the use of recombinant proteins, compared to the full-length fibronectin protein, as surface coatings for gene delivery to investigate the mechanisms by which fibronectin enhances gene transfer. The recombinant fibronectin fragment FNIII(7-10) (FNIII) contains the alpha(5)beta(1) binding domain of fibronectin and supports cell adhesion, whereas the recombinant protein polymer PP-12 is also negatively charged and has a molecular weight similar to FNIII, but lacks cell binding domains. Transfection was compared on surfaces modified with FNIII, full-length fibronectin, or PP-12. The full-length fibronectin provided the greatest extent of transgene expression relative to FNIII or PP-12, which was consistent with the amount of DNA that associated with cells. FNIII had 4.2-fold or 4.7-fold lower expression levels relative to fibronectin for polyplexes and lipoplexes, respectively. PP-12 produced expression levels that were 317-fold and 12.0-fold less than fibronectin for polyplexes and lipoplexes, respectively. Although expression was greater on FNIII relative to PP-12, the levels of DNA associated per cell with FNIII were similar to or less than those with PP-12, suggesting that the bioactive sequences may contribute to an enhanced intracellular trafficking. For lipoplexes delivered on FNIII, the efficiency of intracellular trafficking and levels of caveolar DNA were greater than that observed with either the full-length fibronectin or PP-12. For polyplexes, fibronectin fragment resulted in greater intracellular trafficking efficiency compared to PP-12 protein polymer. Recombinant proteins can be employed in place of full-length extracellular matrix proteins for substrate-mediated gene delivery, and bioactive sequences can influence one or more steps in the gene delivery process to maximize transfection.

100 项与 PP-012 相关的药物交易

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