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A straightforward strategy is proposed to impart antimicrobial properties to biodegradable poly(oxepan-2-one) (poly(ɛ-caprolactone) or PCL), which is based on the grafting of pendant ammonium salts by “click” chemistry. First, statistical copolymerization of 3-chlorooxepan-2-one (α-chloro-ɛ-caprolactone or αClɛCL) with oxepan-2-one (ɛ-caprolactone or ɛCL) was initiated by 2,2-dibutyl-2-stanna-1,3-dioxepane (DSDOP). In a second step, pendant chlorides were converted into azides by reaction with sodium azide (NaN3). Finally, quaternary ammonium containing alkynes were quantitatively added to the pendant azide groups of PCL by the copper-catalyzed Huisgen's 1,3-dipolar cycloaddition, which is a typical “click” reaction. An alternative two-step strategy based on the cycloaddition of the amine containing alkyne onto the pendant azides, followed by quaternization turned out to be less efficient. The antimicrobial activity was analyzed by the “shaking flask method” in the presence of Escherichia coli (E. coli).

To combine low cost, good mechanical properties, and antibacterial activity in one material, a nonquaternized polymeric biocide, i.e., poly[2-(tert-butylamino)ethyl methacrylate] (PTBAEMA), was dispersed within a commodity plastic, i.e., polypropylene (PP). The high immiscibility of the two polymers was tackled by reactive compatibilization and thus by reaction of commercially available maleic anhydride grafted polypropylene with primary amine-end-capped PTBAEMA. This reactive polymethacrylate was synthesized by atom-transfer radical polymerization with an azide-containing initiator. The azide end group was converted into a primary amine by the Huisgen [3 + 2] cycloaddition of propargylamine. The accordingly formed PP-g-PTBAEMA copolymer was melt dispersed within neat PP and processed as fibers, whose antimicrobial properties were assessed by the viable cell counting method against Escherichia coli. The antibacterial activity was long-lasting as a result of the anchoring of the PTBAEMA chains onto PP, which prevented them from being released from the surface of the fibers.

Poly[2-(tert-butylamino)ethyl methacrylate] (PTBAEMA) belongs to a novel class of water-insoluble biocides. Dispersion of a poly(ethylene-co-butylene)-b-poly[2-(tert-butylamino)ethyl methacrylate] diblock copolymer (PEB-b-PTBAEMA) within low-density polyethylene (LDPE) imparts antimicrobial properties to the polyolefin as assessed by the viable cell counting method against Escherichia coli (E. coli). This diblock copolymer has been synthesized by atom transfer radical polymerization (ATRP) with a poly(ethylene-co-butylene) (PEB) oligomer end-capped by an activated bromide as a macroinitiator for the polymerization of 2-(tert-butylamino)ethyl methacrylate (TBAEMA). Morphological changes of E. coli bacteria in contact with modified LDPE have been observed by transmission and scanning electron microscopy and indicate that the diblock copolymer is bactericide rather than bacteriostatic. Finally, the action mode of the PEB-b-PTBAEMA copolymer more likely relies on the displacement of the Ca(2+) and/or Mg(2+) ions of the outer membrane of the bacteria, which is disorganized and finally disrupted.

A straightforward strategy is proposed for grafting hydroxyl, carboxylic acid and epoxide groups along poly(e-caprolactone) chains. Statistical copolymerization of e-caprolactone (eCL) with α-chloro-e-caprolactone (αCleCL) has been initiated by 2,2-dibutyl-2-stanna-1,3-dioxepane (DSDOP), followed by the atom transfer radical addition (ATRA) of but-3-en-1-ol, vinylacetic acid and 1,2-epoxyhex-5-ene, respectively, onto the α-chloro units of a poly(αCleCL-co-eCL) copolymer. αCleCL is easily prepared by the Baeyer–Villiger oxidation of 2-chlorocyclohexanone. The influence of the experimental conditions, i.e. temperature, solvent, catalyst, on the grafting yield has been discussed. Because ATRA is tolerant of the investigated functional groups, no protection/deprotection reaction is required, which is a major advantage of the method.

Efficient antibacterial surfactants have been prepared by the quaternization of the amino groups of poly(ethylene-co-butylene)-b-poly[2-(dimethylamino)ethylmethacrylate] (PEB-b-PDMAEMA) diblock copolymers by octyl bromide. The diblock copolymers have been synthesized by ATRP of 2-(dimethylamino)ethylmethacrylate (DMAEMA) initiated by an activated bromide-end-capped poly(ethylene-co-butylene). In the presence of CuBr, 1,4,7,10,10-hexamethyl-triethylenetetramine (HMTETA), and toluene at 50 °C, the initiation is slow in comparison with propagation. This situation has been improved by the substitution of CuCl for CuBr, all the other conditions being the same. Finally, the addition of an excess of CuCl2 (deactivator) to the CuCl/HMTETA catalyst is very beneficial in making the agreement between the theoretical and experimental number-average molecular weights excellent. The antibacterial activity of PEB-b-PDMAEMA quaternized by octyl bromide has been assessed against bacteria and is comparable to the activity of a commonly used disinfectant, that is, benzalkonium chloride. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1214-1224, 2006

Novel copolymer brushes have been synthesized by a two-step "grafting from" method that consists of the electrografting of poly(2-phenyl-2-(2,2,6,6-tetramethyl-piperidin-1-yloxy)-ethylacrylate) onto stainless steel, followed by the nitroxide-mediated radical polymerization of 2-(dimethylamino ethyl)acrylate and styrene or n-butyl acrylate, initiated from the electrografted polyacrylate chains. The grafted copolymers were quaternized in order to endow them with antibacterial properties. Peeling tests have confirmed the strong adhesion of the grafted copolymer onto the stainless steel substrate. Quartz crystal microbalance experiments have proven that fibrinogen adhesion is lower on the hydrophilic quaternized films compared to the nonionic counterpart. Such quaternized copolymers exhibit significant antibacterial activity against the Gram-positive bacteria S. aureus and the Gram-negative bacteria E. coli.

A highly versatile strategy was implemented in order to attach a range of polymer grafts and functional groups along the backbone of poly(e-caprolactone). α-Chloro-e-caprolactone (αCleCL) was first prepared by the Baeyer−Villiger oxidation of α-chlorocyclohexanone. This monomer (αCleCL) was then copolymerized with e-caprolactone in the presence of 2,2-dibutyl-2-stanna-1,3-dioxepane. Finally, the pendant activated chlorides of the copolymer were used to initiate (i) the “grafting from” of poly(methyl methacrylate) by atom transfer radical polymerization and (ii) the grafting of benzoate groups by atom transfer radical addition of 3-butenyl benzoate.

Thin films of polypyrrole doped by polyanions have been deposited onto stainless steel and carbon fibers by anodic electropolymerization of pyrrole in the presence of an anionic polyelectrolyte in water. Films with a thickness smaller than 600 nm have been formed, which strongly adhere to the solid supports. The polymeric dopant has been selected for its ability to complex silver ions. Scanning electron microscopy, Rutherford backscattering analyses, and IR spectroscopy have confirmed that silver is actually immobilized in the films and provides them with an antibacterial activity against the Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus.

A commercially available poly(ethylene-co-butylene) copolymer, endcapped by a short polyisoprene block and a hydroxyl group (PI-b-PEB-OH), has been derivatized into a macroinitiator for atom transfer radical polymerization (ATRP) by esterification of the hydroxyl end-group by an activated bromidecontaining acyl bromide. Two types of triblock copolymers, PI-b-PEB-b-poly- (dimethylaminoethyl methacrylate) (PDMAEMA) and PI-b-PEB-b-poly[2-(tert-butylamino) ethyl methacrylate] (PTBAEMA), have been synthesized and used to coat polystyrene particles. These coatings have been permanently immobilized by UV cross-linking of the isoprene units. They exhibit a biocidal activity against Gramnegative bacteria either intrinsically in case of the PTBAEMA block or upon quaternization of the PDMAEMA block by octyl bromide. The antimicrobial activity is directly related to the concentration of coated PS particles in the medium.

We report on the original synthesis of a poly(methacrylamide) bearing (oxidized) 3,4-dihydroxyphenylalanine specially designed to (i) insure film growth by covalent coupling, (ii) covalently bind an antibacterial peptide and (iii) contribute to the film cross-linking that is essential for the durability of the properties.

International audience; Here we report on an all-in-one approach to prepare robust antimicrobial films on stainless steel. The strategy is based on the layer-by-layer deposition of polyelectrolytes. A polycationic copolymer bearing 3,4-dihydroxyphenylalanine units (DOPA, a major component of natural adhesives) was synthesized and co-deposited with precursors of silver nanoparticles as the first layer. The presence of DOPA units ensures a strong anchoring on the stainless steel substrate, and the silver nanoparticles are sources of biocidal Ag+, providing stainless steel with antimicrobial activity. We show that multilayered films, obtained by alternating this nanoparticle-loaded polycationic copolymer with polystyrene sulfonate, a commercial polyanion, results in stainless steel with high antibacterial activity against Gram-negative E. coli bacteria. The polycationic layers are a reservoir of Ag+ that can be reactivated after depletion. The whole process of film formation, including the synthesis of the copolymer, is conducted in aqueous media under very mild conditions, which makes it very attractive for industrial scale-up and sustainable applications.

Background: In recent years, oncogenic understanding of T-ALL has led to the identification of multiple molecular markers. However, each molecular abnormality accounts for a small proportion of cases and risk stratification at diagnosis still relies on age, clinical presentation, and early response to therapy. NOTCH1 and/or FBXW7 mutations have been recently reported to be a recurrent abnormality in T-ALL, both leading to activation of the NOTCH pathway. Studies in pediatric series have suggested a favorable outcome for NOTCH1 mutated T-ALL, but this has not been evaluated in large series of adult cases. Furthermore, FBXW7 prognostic impact remains unknown in both populations. Methods: In order to evaluate the incidence of these mutations and their prognostic impact in adults, we performed a retrospective analysis of 141 patients (median age, 28 years) with T-ALL treated within the LALA-94 (N=87) or the more recent GRAALL-2003 (N=54) French trials. These patients were representative of the overall population since their outcome did not differ from the overall T-ALL cases treated in either LALA-94 (estimated 3-year OS, 41%) or GRAALL-2003 (estimated 3-year OS, 66%) trial. Furthermore, the patients from the LALA-94 and the GRAALL-2003 trials did not differ with respect to sex ratio, age, WBC, and initial complete remission rate (92% and 98%, respectively). Exons 26 (HD N-terminal), 27 (HD C-terminal), 28 (juxtamembrane domain) and 34 (transactivation domain TAD and the PEST domain) of NOTCH1 and exons 9, 10 and 12 of WD40 domain of FBXW7 were sequenced. Results: We identified 101 cases with NOTCH1 and/or FBXW7 mutations (72%) and 40 wild type (WT) samples (28%). NOTCH1 was mutated in 88 patients (59 HD only, 15 HD+PEST, 9 PEST only, 5 other). FBXW7 was mutated in 34 patients, alone in 13 cases or in association with NOTCH1 mutations in 21 cases. There was no significant correlation between NOTCH1 and/or FBXW7 mutations and immunophenotypic or oncogenetic features. There was a trend for a higher WBC and more frequent CNS involvement in patients demonstrating WT NOTCH1 and FBXW7. Similarly, high-risk MRC/ECOG criteria (age>35y and/or WBC>100G/L) were found in 56% of patients from the mutated subgroup versus 73% in the WT subgroup (P=0.06). The prognostic impact of NOTCH1 mutations alone did not reach statistical significance on multivariate analysis (P=0.09). On the other hand, multivariate analysis showed that the GRAALL-2003 trial and the presence of NOTCH1 and/or FBXW7 mutations were the only factors associated with a longer EFS (P=0.001 and 0.035, respectively). Median EFS was 36 months for patients with NOTCH1 and/or FBXW7 mutations versus 17 months for WT patients. Conclusions: These data demonstrate that NOTCH pathway activation by either NOTCH1 or FBXW7 mutation identifies a large group of T-ALL adult patients (72%) with a favorable outcome that could be used for treatment stratification.