Modification of Polysulfones by Click Chemistry: Amphiphilic Graft Copolymers and Their Protein Adsorption and Cell Adhesion Properties

WOS: 000286344300012Well-defined amphiphilic graft copolymer with hydrophobic polysulfone (PSU) backbone and hydrophilic poly(acrylic acid) (PAA) side chains were synthesized and characterized. For this purpose, commercially available PSU was converted to azido-functionalized polymer (PSU-N-3) by successive chloromethylation and azidation processes. Independently, poly(tert-butyl acrylate) (PtBA) with an alkyne-end-group is obtained by using suitable initiator in atom transfer radical polymerization (ATRP). Then, this polymer was successfully grafted onto PSU-N3 by click chemistry to yield polysulfone-graft-poly(tert-butyl acrylate), (PSU-g-PtBA). Finally, amphiphilic polysulfone-graft-poly(acrylic acid), (PSU-g-PAA), membranes were obtained by hydrolyzing precursor the PSU-g-PtBA membranes in trifluoroacetic acid. The final polymer and intermediates at various stages were characterized by H-1 NMR, FTIR, GPC, and SEM analyses. Protein adsorption and eukaryotic and prokaryotic cell adhesion on PSU-g-PAA were studied and compared to those of PSU-g-PtBA and unmodified PSU. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 110 117, 2011Istanbul Technical UniversityIstanbul Technical University; State Planning Organization of Turkey (DPT) [2005K120920]; Hormozgan University, IranThis work was supported by Istanbul Technical University and the State Planning Organization of Turkey (DPT, project no 2005K120920) One of the authors (H. T.) wants to thank to Hormozgan University, Iran for financial support by means of visiting scholarship

Polysulfone based amphiphilic graft copolymers by click chemistry as bioinert membranes

WOS: 000291778800039A series of well-defined amphiphilic graft copolymers with hydrophobic polysulfone (PSU) as backbones and hydrophilic poly( ethylene glycol) (PEG) as side chains were synthesized and characterized. For this purpose, PSUs were converted to azido-functionalized polymers by successive chloromethylation and azidation processes to give clickable PSUs. Then, the (omega-hydroxyl function of the commercially available PEG-OH was converted into propargyl functionality by simple esterification process. Ultimately, the alkyne functionalized PEO was successfully grafted onto the PSUs by click chemistry. The final polymers and intermediates at various stages were characterized by H-1 NMR, FT-IR, and GPC techniques. The bioinert character of PEG grafted PSU was confirmed by static protein adsorption and prokaryotic and eukaryotic cell adhesion studies, and compared to that of unmodified PSU. (C) 2011 Elsevier By. All rights reserved.Istanbul Technical UniversityIstanbul Technical University; State Planning Organization of Turkey (DPT); Turkish Academy of SciencesTurkish Academy of Sciences; Research FundThe authors thank Istanbul Technical University, Research Fund and the State Planning Organization of Turkey (DPT) for financial support. One of the authors (Y.Y.) thanks the Turkish Academy of Sciences for partial financial support

Modification of Polydivinylbenzene Microspheres by a Hydrobromination/Click-Chemistry Protocol and their Protein-Adsorption Properties

WOS: 000285932600016PubMed ID: 20945305Hydrophobic-and/or hydrophilic-polymer-grafted PDVB microspheres are synthesized by the combination of hydrobromination and click-chemistry processes. The modified-PDVB microspheres and the intermediates at various stages of synthesis are characterized using GPC, H-1 NMR and FTIR spectroscopy and TGA analysis. Use of the microspheres as a support matrix for reversible protein immobilization via adsorption is investigated. The system parameters such as the adsorption conditions (i.e., enzyme concentration, medium pH) and desorption are studied and evaluated with regards to the biocatalytic activity and adsorption capacity.Istanbul Technical University (ITU)Istanbul Technical University; Ege UniversityEge UniversityThis work was supported by Istanbul Technical University (ITU) and Ege University research funds

Polysulfone/Pyrene Membranes: A New Microwell Assay Platform for Bioapplications

WOS: 000294985200011PubMed ID: 21728233The use of PSU-Py prepared by click chemistry as a platform in membrane-bottom microwell plates for oxidase and hydrolase/oxidase-based enzyme assays is studied. For the GOx assay, the postulated fluorescence mechanism is based on the consumption of glucose by dissolved oxygen and GOx in the microwell plates covered with the PSU-Py membrane. For the AG-GOx assay, maltose is used as AG substrate and hydrolyzed to glucose which is then oxidized by the GOx activity. It is shown that the PSU-Py membrane acts as a fluorescence indicator of the enzymatic reactions, and both GOx and AG/GOx enzyme assays are successfully applied for glucose, maltose and acorbose analysis in the range 0.125-2.0 x 10(-3) M glucose, 0.05-0.5 x 10(-3) M maltose, and 0.0125-0.1 mg . mL(-1) acorbose, respectively.State Planning Organization of Turkey (DPT) [2005K120920]; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [109T573]; EBILTEM (Ege University, Research and Application Center of Science and Technology)Ege University [2010BIL004]; Ege UniversityEge University [11 FEN 039]; Istanbul Technical UniversityIstanbul Technical University; Hormozgan University, IranThis project was supported by The State Planning Organization of Turkey (DPT, Project no 2005K120920), TUBITAK (Project no 109T573), EBILTEM (Ege University, Research and Application Center of Science and Technology, Project no: 2010BIL004), Ege University (Project no; 11 FEN 039) and Istanbul Technical University Research Funds. One of the authors (H. T.) is grateful to Hormozgan University, Iran, for financial support by means of a visiting scholarship. K. Dornbusch is acknowledged for DICM images

Electrochemical deposition of polypeptides: bio-based covering materials for surface design

WOS: 000336804800024A simple and efficient approach for the electrochemical deposition of polypeptides as bio-based covering materials for surface design is described. The method involves N-carboxyanhydride (NCA) ring-opening polymerization from its precursor to form a thiophene-functionalized polypeptide macromonomer (T-Pala), followed by electropolymerization. The obtained conducting polymer, namely polythiophene-g- polyalanine (PT-Pala), was characterized and utilized as a matrix for biomolecule attachment. The biosensing applicability of PT-Pala was also investigated by using glucose oxidase (GOx) as a model enzyme to detect glucose. The designed biosensor showed a very good linearity for 0.01-1.0 mM glucose. Finally, the antimicrobial activities of newly synthesized T-Pala and PT-Pala were also evaluated by using the disc diffusion method

Functional poly(p-phenylene)s as targeting and drug carrier materials

WOS: 000375958100002Polymers have a substantial attention in drug delivery systems owing to the diverse intrinsic advantages. It is important to carry the drug to the target site and release to exert its effects. Herein, poly(p-phenylene)s with amino and poly(ethylene glycol) substituents (PPP-NH2-g-PEG) were used as a carrier for doxorubicin (DOX), an anticancer drug, and haloperidol, a sigma receptor targeting ligand. Both human cervix adenocarcinoma cell line (HeLa) and human keratinocyte cell line (HaCaT) having different Sigma receptor 1 (SigmaR1) expression levels were compared. HeLa was found to express twofold SigmaR1 compared to HaCaT cells. Cell imaging studies showed that, DOX cell uptake was higher in HeLa cells when targeted with haloperidol. [GRAPHICS] .Ege UniversityEge University; Aliye USTER Foundation; Istanbul Technical University, Research FundEge University, Aliye USTER Foundation, and Istanbul Technical University, Research Fund, are acknowledged for financial support

Comparison Of The Effects Of Dexmedetomidine Vs. Ketamine In Cardiac Ischemia/Reperfusion Injury In Rats - Preliminary Study

Objectives. Following ischemia/reperfusion injury, antioxidant defense mechanisms may remain insufficient depending on the duration of ischemia which is caused by any reason (MI, after percutaneous coronary intervention, during cardiac surgery). After that, free oxygen radicals increasing within the cell cause structural deterioration. Cytokines which activate a series of reactions that cause tissue damage and inflammatory response are released during reperfusion of ischemic tissues. In this study, we aimed to compare the effects of dexmedetomidine and ketamine in cardiac ischemia/reperfusion injury. Material and Methods. The study included 18 rats randomly divided into three groups. Group I/R (n = 6): control, Group I/R-K (n = 6): ketamine, and Group I/R-D (n = 6): dexmedetomidine. Before the 10 min surgery, after the 20 min ischemia and 20 min reperfusion period, hemodynamic parameters were compared among the three groups. After the 45 min ischemia and 120 min reperfusion period, tissue samples were obtained from the rat hearts, and MDA, SOD, GSH-Px, IL-1 beta and TNF-alpha levels were compared. Results. MDA and GSH-Px levels were significantly higher in the control group compared to the ketamine and dexmedetomidine groups. However, both levels were similar in the ketamine and dexmedetomidine groups. SOD levels were significantly lower in the ketamine and dexmedetomidine groups compared to the control group, but they were similar in the ketamine and dexmedetomidine groups. IL-1 beta levels were similar in all groups. TNF-alpha levels were significantly lower in the ketamine and dexmedetomidine groups compared to the control group. They were similar in the ketamine and dexmedetomidine groups. Conclusions. According to our study, it can be concluded that dexmedetomidine and ketamine have similar effects on reducing myocardial ischemia reperfusion injury. Dexmedetomidine provides better heart rate control but causes hypotension, so, because of cardiac depression, we think that its clinical use may necessitate further investigationWoSScopu