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Averick S.,Allegheny Health Network Research Institute | Mehl R.A.,Oregon State University | Das S.R.,Carnegie Mellon University | Matyjaszewski K.,Carnegie Mellon University
Journal of Controlled Release | Year: 2015

The use of reversible deactivation radical polymerization (RDRP) methods has significantly expanded the field of bioconjugate synthesis. RDRP procedures have allowed the preparation of a broad range of functional materials that could not be realized using prior art poly(ethylene glycol) functionalization. The review of procedures for synthesis of biomaterials is presented with a special focus on the use of RDRP to prepare biohybrids with proteins, DNA and RNA. © 2014 Elsevier B.V. All rights reserved.

Falatach R.,Miami University Ohio | McGlone C.,Miami University Ohio | Al-Abdul-Wahid M.S.,Miami University Ohio | Averick S.,Allegheny Health Network Research Institute | And 3 more authors.
Chemical Communications | Year: 2015

Hydrophilic polymers were attached to lysozyme by a combination of grafting-to and grafting-from approaches using RAFT polymerization. A hydrophilic oligomer was synthesized, and attached to the protein. The protein-oligomer hybrid contained the RAFT end group, enabling chain extension in solution. Lysozyme maintained activity throughout this process. This journal is © The Royal Society of Chemistry 2015.

Kelly K.M.,Allegheny Health Network Research Institute | Kelly K.M.,Allegheny General Hospital | Kelly K.M.,Drexel University | Miller E.R.,Allegheny Health Network Research Institute | And 5 more authors.
Epilepsy Research | Year: 2015

Posttraumatic epilepsy (PTE) has been modeled with different techniques of experimental traumatic brain injury (TBI) using mice and rats at various ages. We hypothesized that the technique of controlled cortical impact (CCI) could be used to establish a model of PTE in young adult rats. A total of 156 male Sprague-Dawley rats of 2-3 months of age (128 CCI-injured and 28 controls) was used for monitoring and/or anatomical studies. Provoked class 3-5 seizures were recorded by video monitoring in 7/57 (12.3%) animals in the week immediately following CCI of the right parietal cortex; none of the 7 animals demonstrated subsequent spontaneous convulsive seizures. Monitoring with video and/or video-EEG was performed on 128 animals at various time points 8-619 days beyond one week following CCI during which 26 (20.3%) demonstrated nonconvulsive or convulsive epileptic seizures. Nonconvulsive epileptic seizures of >10. s were demonstrated in 7/40 (17.5%) animals implanted with 2 or 3 depth electrodes and usually characterized by an initial change in behavior (head raising or animal alerting) followed by motor arrest during an ictal discharge that consisted of high-amplitude spikes or spike-waves with frequencies ranging between 1 and 2. Hz class 3-5 epileptic seizures were recorded by video monitoring in 17/88 (19%) and by video-EEG in 2/40 (5%) CCI-injured animals. Ninety of 156 (58%) animals (79 CCI-injured, 13 controls) underwent transcardial perfusion for gross and microscopic studies. CCI caused severe brain tissue loss and cavitation of the ipsilateral cerebral hemisphere associated with cell loss in the hippocampal CA1 and CA3 regions, hilus, and dentate granule cells, and thalamus. All Timm-stained CCI-injured brains demonstrated ipsilateral hippocampal mossy fiber sprouting in the inner molecular layer. These results indicate that the CCI model of TBI in adult rats can be used to study the structure-function relationships that underlie epileptogenesis and PTE. © 2015 Elsevier B.V.

Li S.,Allegheny General Hospital | Cohen-Karni D.,Allegheny General Hospital | Beringer L.T.,Allegheny General Hospital | Wu C.,Allegheny Health Network Research Institute | And 4 more authors.
Polymer (United Kingdom) | Year: 2016

The modification of proteins with reactive handles has facilitated the use of these biomolecules in diverse fields including drug delivery, diagnostics, environmental remediation, and cell culture matrices. Recently, a new “click” type reaction, sulfur(VI) fluoride exchange (SuFEx), was reported between sulfuryl fluoride and various organic moieties (e.g. hydroxyl, amine) to yield a sulfamoyl fluoride ([Formula presented]2F) or fluorosulfate ([Formula presented]2F) moiety under biphasic conditions. The model protein bovine serum albumin (BSA) was reacted with SO2F2 gas under biphasic conditions to yield [Formula presented]2F functionalized protein. The resultant BSA-SO2F was characterized using gel electrophoresis, mass spectroscopy and Fourier transmission infrared spectroscopy to confirm the addition of [Formula presented]2F functional group. SuFEx modification of BSA caused a marked change in the pH dependent size and zeta potential of the protein as well as increased the protein's denaturation temperature. Crucially, BSA-SO2F was demonstrated to be biocompatible after 72 h incubation with A549 lung endothelial cells. Due to the unique and elective reactivity of the [Formula presented]2F group with amines, BSA-SO2F could be self-condensed to form a biocompatible hydrogel that was used in co-culture with HEK 293 cells. In addition, polyethylene glycol (PEG) with reactive [Formula presented]2F groups at chain end was conjugated with BSA under various pH conditions through SuFEx chemistry. This communication, to our knowledge, is the first report of the application of the SuFEx in the field of bioconjugates. © 2016 Elsevier Ltd

Falatach R.,Miami University Ohio | Li S.,Allegheny Health Network Research Institute | Sloane S.,Miami University Ohio | Mcglone C.,Miami University Ohio | And 4 more authors.
Polymer (United Kingdom) | Year: 2015

α-Chymotrypsin, a commonly used protease, was modified with well-defined oligomers synthesized by RAFT. The well defined polymers were synthesized based on the monomers N,N-dimethylacrylamide (DMAm) or oligo(ethylene oxide) methyl ether acrylate (OEOA). The polymers were conjugated to free amine groups on chymotrypsin through an in-situ 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling approach. The protein-polymer conjugates retained enzymatic activity, and the higher molecular weight DMAm and OEOA polymer, created protein-polymer conjugates with significantly enhanced stability, presumably due to the high molecular weight polymer preventing autolysis of the α-chymotrypsin. © 2015 Elsevier Ltd.

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