Synthesis, Characterization, and Cyclopolymerization of a Functional Non-Symmetric Divinyl Monomer

A non-symmetric divinyl monomer with terminal carboxylic acid functionality was readily synthesized from the reaction of ethyl α-hydroxymethylacrylate (EHMA) with maleic anhydride. The new monomer (EHMA–MA) was homopolymerized in both bulk and ethyl acetate using AIBN as an initiator to give cyclopolymers. The synthesis of the monomer and cyclopolymers were followed by 13C NMR, 1H NMR, and FTIR. 1H NMR was also utilized to obtain the degree of cyclization of the polymers, which were found to be 95% or higher in all cases. The molecular weights of the cyclopolymers were around 40–60,000 g/mol as estimated by SEC. The cyclopolymers were thermally stable up to 150 °C. Although the cyclopolymers obtained were not water-soluble; they were soluble in aqueous 1 M NaOH solution. In addition to the carboxylic acid functionality present, the cyclopolymers also had an ethyl ester and a lactone moiety. These functional groups were reacted with hexylamine to obtain a polymer with imide and amide moieties

Antibacterial Fluoromicas: A Novel Delivery Medium

Antibacterial fluoromicas were prepared by ion-exchanging fluoromicas with different antibacterial agents including various quaternary ammonium compounds, AgNO3, and norfloxacin. Antibacterial activities of the ion-exchanged fluoromicas were determined against Staphylococcus aureus and Escherichia coli. Minimum inhibitory concentration (MIC) and zone of inhibition (ZOI) tests were performed to determine both antibacterial effectiveness and mode of action associated with the fluoromicas. All treated fluoromicas showed excellent antibacterial activities against both types of bacteria. The antibacterial activities of treated fluoromicas were found to be either better than or the same as those of neat antibacterial agents. The repeated antibacterial activity tests demonstrated the extended activity of these systems. © 2007 Elsevier B.V. All rights reserved

Synthesis, Characterization, and Antibacterial Activities of Novel Methacrylate Polymers Containing Norfloxacin

A novel methacrylate monomer containing a quinolone moiety was synthesized and homopolymerized in N,N-dimethylformamide (DMF) by using azobisisobutyronitrile (AIBN) as an initiator. The new monomer was copolymerized with poly(ethylene glycol) methyl ether methacrylate (MPEGMA) in DMF using the same initiator. The monomer, homopolymer, and copolymer were characterized by elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), size exclusion chromatography (SEC), FTIR, 13C NMR, and 1H NMR. The antibacterial activities of the monomer as well as polymers were investigated against Staphylococcus aureus and Escherichia coli, which are representative of Gram-positive and Gram-negative bacteria, respectively. All compounds showed excellent antibacterial activities against these two types of bacteria. The antibacterial activities were determined using the shaking flask method, where 25 mg/mL concentrations of each compound were tested against 105 CFU/mL bacteria solutions. The number of viable bacteria was calculated by using the spread plate method, where 100 μL of the incubated antibacterial agent in bacteria solutions were spread on agar plates and the number of viable bacteria was counted after 24 h of incubation period at 37 °C

Synthesis and Characterization of Antibacterial and Temperature Responsive Methacrylamide Polymers

A new methacrylamide monomer ( MAMP) containing a pyridine moiety was synthesized by reacting methacrylic anhydride and 3-( aminomethyl) pyridine. The monomer was homopolymerized in 1,4-dioxane and copolymerized with N-isopropyl acrylamide in DMF at two different compositions using AIBN as an initiator. The pyridine groups of the homopolymer and copolymers were reacted with various bromoalkanes containing 12, 14, and 16 carbon alkyl chains to obtain the polymers with pendant pyridinium groups. The monomer and polymers were characterized by elemental analysis, NMR, FTIR, SEC, TGA, and DSC. The neutral and quaternized copolymers with low MAMP content were water-soluble and showed temperature-responsive behavior in aqueous solutions. The lower critical solution temperatures (LCSTs) of these polymers varied between the temperatures of 25 and 42 C. The LCST of quaternized copolymers were higher than that of the neutral copolymer because they were more hydrophilic. The LCST of the quaternized copolymers decreased with an increase in the alkyl chain length on the pyridinium group because the copolymers became more hydrophobic this way. The antibacterial activities of water-soluble copolymers were investigated against Staphylococcus aureus and Escherichia coli using the broth dilution and spread plate methods, whereas the water-insoluble polymers were tested for the antibacterial activity against the same types of bacteria using the shaking flask method. The quaternized water-soluble copolymers showed excellent antibacterial activities against both types of bacteria, whereas the neutral polymers and quaternized water-insoluble homopolymers and copolymers were not active

Novel Antibacterial Polymers

The research presented in this review covers the areas of low molecular weight antibacterial agents and antibacterial polymers. The review is divided into two main sections. In the first section, a detailed background information is provided about low molecular weight antibacterial agents (quaternary ammonium compounds and norfloxacin), antibacterial polymers with quaternary ammonium compounds and norfloxacin, and antibacterial activity tests pertinent to the research. In the second section, the syntheses and antibacterial activities of several new antibacterial polymers are discussed. These polymers are either acrylate/methacrylate or acrylamide/methacrylamide-type polymers with pendant biocidal groups, i.e. mono- and bis-quaternary ammonium compounds or norfloxacin. In general, two approaches were utilized to obtain the antibacterial polymers. The first approach involved the incorporation of the antibacterial agents to monomers, followed by their polymerization. The second approach, on the other hand, involved the linking of the antibacterial agents directly onto preformed functional polymers. The water-soluble and water-insoluble polymers were synthesized according to the pendant groups and comonomers present. All polymers were tested for antibacterial activity against Staphylococcus aureus and Escherichia coli, representatives of Gram-positive and Gram-negative bacteria, by using broth dilution and shaking flask methods

Synthesis and Antibacterial Activities of Water-Soluble Methacrylate Polymers Containing Quaternary Ammonium Compounds

New water-soluble methacrylate polymers with pendant quaternary ammonium (QA) groups were synthesized and used as antibacterial materials. The polymers with pendant QA groups were obtained by the reaction of the alkyl halide groups of a previously synthesized functional methacrylate homopolymer with various tertiary alkyl amines containing 12-, 14-, or 16-carbon alkyl chains. The structures of the functional polymer and the polymers with QA groups were confirmed with Fourier transform infrared and H-1 and C-13 NMR. The degree of conversion of alkyl halides to QA sites in each polymer was determined by H-1 NMR to be over 90% in all cases. The number-average molecular weight and polydispersity of the functional polymer were determined by size exclusion chromatography to be 32,500 g/mol and 2.25, respectively. All polymers were thermally stable up to 180 degrees C according to thermogravimetric analysis. The antibacterial activities of the polymers with pendant QA groups against Staphylococcus aureus and Escherichia coli were determined with broth-dilution and spread-plate methods. All the polymers showed excellent antibacterial activities in the range of 32-256 mu g/mL. The antibacterial activity against S. aureus increased with an increase in the alkyl chain length for the ammonium groups, whereas the antibacterial activity against E. coli decreased with increasing alkyl chain length. (c) 2006 Wiley Periodicals, Inc

Synthesis and Antibacterial Activities of New Quaternary Ammonium Monomers

New monomers and polymers with amine and quaternary ammonium groups on the side chain were synthesized. The first series of monomers were the derivatives of 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM). Hydroxylated secondary and tertiary amine derivatives were prepared by reaction of AHM with various amines. One of the amine monomers was quaternized with bromohexane to give a quaternary ammonium monomer. A second series of amine and quaternary ammonium monomers were based on acrylamide and methacrylamide derivatives. New acrylamide/methacrylamide monomers with tertiary amine groups were synthesized and quaternized with various alkyl halides. All monomers were homo-polymerized and co-polymerized with 2-hydroxyethylmethacrylate (HEMA). The synthesized monomers and polymers were tested for antibacterial activities against Staphylococcus aureus and Escherichia coli bacteria. Amine monomers, their homo-polymers and co-polymers did not show any antibacterial activities. It was also found that the antibacterial activity of the quaternized methacrylamide-3-(aminomethyl) pyridine (METH-PYR) monomers increased as the alkyl chain length on nitrogen increased

Tuning drug release from polyoxazoline-drug conjugates

Poly(2-oxazoline)-drug conjugates with drugs attached via releasable linkages are being developed for drug delivery. Such conjugates with pendent ester linkages that covalently bind drugs to the polymer backbone exhibit significantly slower hydrolytic release rates in plasma than the corresponding PEG- and dextran-drug conjugates. The slow drug release rates in-vitro of these POZ-drug conjugates contribute to extended in-vivo pharmacokinetic profiles. In some instances, the release kinetics may be relatively sustained and ideal for once-a-week subcutaneous injection, whereas the native drug by itself may only have an in-vivo half-life of a few hours. The origin of this unusual kinetic and pharmacokinetic behavior is proposed here to involve folding of the POZ conjugate such that the relatively hydrophobic drug forms a central core, and the relatively hydrophilic polymer wraps around the core and slows enzymatic attack on the drug-polymer chemical linkage. Here we present evidence supporting this hypothesis and demonstrate how the hypothesis can be used to tune hydrolytic release rates and pharmacokinetics. Evidence for the folding hypothesis is taken from hydrolysis kinetics of a range of drugs in plasma, pharmacokinetics of a range of drugs following subcutaneous injection in laboratory animals, and nuclear magnetic resonance (NMR) studies showing folding of the POZ-rotigotine molecule. The drugs included in this study to test the hypothesis are: rotigotine, buprenorphine, dexanabinol, cannabidiol (CBD), Delta(9)-tetrahydrocannabinol (THC) and cannabigerol (CBG)