Poly-(L-Lactic Acid) and Citric Acid-Crosslinked Gelatin Composite Matrices as a Drug-Eluting Stent Coating Material With Endothelialization, Antithrombogenic, and Drug Release Properties.

Poly-(L-lactic acid) and citric acid-crosslinked gelatin composite matrices as a drug-eluting stent coating material with endothelialization, antithrombogenic, and drug release properties.

Filed under: Drug and Alcohol Rehabilitation

J Biomed Mater Res A. 2012 Dec 22;
Inoue M, Sasaki M, Katada Y, Fujiu K, Manabe I, Nagai R, Taguchi T

Biodegradable composite matrices comprising poly-(L-lactic acid) (PLLA) and citric acid-crosslinked alkali-treated gelatin (AlGelatin) with endothelialization, antithrombogenic, and drug release properties were prepared. The characterization of composite matrices with various mixing ratios was performed by evaluating their swelling ratio, endothelial cell culture, antithrombogenic tests, and drug release behavior. Tamibarotene (Am80), which specifically inhibits smooth muscle cell proliferation, was employed as the drug. The swelling ratio of composite matrices decreased as the PLLA content decreased. The number of endothelial cells cultured on the surfaces of composite matrices was maximal at the PLLA/AlGelatin-TSC ratio of 80/20. Antithrombogenic tests revealed that the levels of platelets and fibrin network formation decreased as the AlGelatin-TSC content increased. The Am80 release test indicated that the release rate decreased as PLLA content increased. Using the resulting composite matrix, Am80-eluting stents possessing a smooth surface and a coating thickness of ?15 ?m were successfully obtained. Am80 was continuously released from the resulting stent at ?40%, up to 28 days without burst release. Therefore, Am80-eluting stent with its antithrombogenic and endothelialization properties has great potential for clinical use. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
HubMed – drug

 

Cluster-based molecular docking study for in silico identification of novel 6-fluoroquinolones as potential inhibitors against mycobacterium tuberculosis.

Filed under: Drug and Alcohol Rehabilitation

J Comput Chem. 2012 Dec 19;
Minovski N, Perdih A, Novic M, Solmajer T

A classical protein sequence alignment and homology modeling strategy were used for building three Mycobacterium tuberculosis-DNA gyrase protein models using the available topoII-DNA-6FQ crystal structure complexes originating from different organisms. The recently determined M. tuberculosis-DNA gyrase apoprotein structures and topoII-DNA-6FQ complexes were used for defining the 6-fluoroquinolones (6-FQs) binding pockets. The quality of the generated models was initially validated by docking of the cocrystallized ligands into their binding site, and subsequently by quantitative evaluation of their discriminatory performances (identification of active/inactive 6-FQs) for a set of 145 6-FQs with known biological activity values. The M. tuberculosis-DNA gyrase model with the highest estimated discriminatory power was selected and used afterwards in an additional molecular docking experiment on a mixed combinatorial set of 427 drug-like 6-FQ analogs for which the biological activity values were predicted using a prebuilt counter-propagation artificial neural network model. A novel three-level Boolean-based [T/F (true/false)] clustering algorithm was used to assess the generated binding poses: Level 1 (geometry properties assessment), Level 2 (score-based clustering and selection of the (T)-signed highly scored Level 1 poses), and Level 3 (activity-based clustering and selection of the most “active” (T)-signed Level 2 hits). The frequency analysis of occurrence of the fragments attached at R(1) and R(7) position of the (T)-signed 6-FQs selected in Level 3 revealed several novel attractive fragments and confirmed some previous findings. We believe that this methodology could be successfully used in establishing novel possible structure-activity relationship recommendations in the 6-FQs optimization, which could be of great importance in the current antimycobacterial hit-to-lead processes. © 2012 Wiley Periodicals, Inc.
HubMed – drug

 

Renal uptake of substrates for organic anion transporters Oat1 and Oat3 and organic cation transporters Oct1 and Oct2 is altered in rats with adenine-induced chronic renal failure.

Filed under: Drug and Alcohol Rehabilitation

J Pharm Sci. 2012 Dec 29;
Komazawa H, Yamaguchi H, Hidaka K, Ogura J, Kobayashi M, Iseki K

Chronic renal failure (CRF) leads to decreased drug renal clearance and glomerular filtration rate. However, little is known about renal tubular excretion and reabsorption in CRF. We examined transport activity of renal transporters using rats with adenine-induced CRF. We examined the effect of adenine-induced CRF on mRNA level, protein expression of transporters expressed in kidney by real-time polymerase chain reaction, and western blotting. In vivo kidney uptake clearances of benzylpenicillin and metformin, which are typical substrates for renal organic anion transporters Oat1 and Oat3 and organic cation transporters Oct1 and Oct2, respectively, were evaluated. Protein and mRNA expression levels of Oat1, Oat 3, Oct1, and Oct2 were significantly decreased in adenine-induced CRF rats. On the contrary, levels of P-glycoprotein and Mdr1b mRNA were significantly increased in adenine-induced CRF rats. The mRNA expression levels of Oatp4c1, Mate1, Urat1, Octn2, and Pept1 were significantly decreased. Kidney uptake clearance of benzylpenicillin and that of metformin were significantly decreased in adenine-induced CRF rats. Also, serum from CRF rats did not affect Oat1, Oat3, Oct1, and Oct2 function. In conclusion, our results indicate that adenine-induced CRF affects renal tubular handling of drugs, especially substrates of Oat1, Oat3, Oct1, and Oct2. © 2012 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci.
HubMed – drug

 

Chronic methamphetamine exposure produces a delayed, long-lasting memory deficit.

Filed under: Drug and Alcohol Rehabilitation

Synapse. 2012 Dec 27;
North A, Swant J, Salvatore MF, Gamble-George J, Prins P, Butler B, Mittal MK, Hasting R, Clark JT, Khoshbouei H

Methamphetamine (METH) is a highly addictive and neurotoxic psychostimulant. Its use in humans is often associated with neurocognitive impairment. Whether this is due to long-term deficits in short-term memory and/or hippocampal plasticity remains unclear. Recently, we reported that METH increases baseline synaptic transmission and reduces LTP in an ex-vivo preparation of the hippocampal CA1 region from young mice. In the current study, we tested the hypothesis that a repeated neurotoxic regimen of METH exposure in adolescent mice decreases hippocampal synaptic plasticity and produces a deficit in short-term memory. Contrary to our prediction, there was no change in the hippocampal plasticity or short-term memory when measured after 14 days ofMETH exposure. However, we found that at 7, 14, and 21 days of drug abstinence, METH-exposed mice exhibited a deficit in spatial memory, which was accompanied by a decrease in hippocampal plasticity. Our results support the interpretation that the deleterious cognitive consequences of neurotoxic levels of METH exposure may manifest and persist after drug abstinence. Therefore, therapeutic strategies should consider short-term as well as long-term consequences of methamphetamine exposure. Synapse, 2012. © 2012 Wiley Periodicals, Inc.
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