@article{BapolisiKielbBekiretal.2022, author = {Bapolisi, Alain Murhimalika and Kielb, Patrycja and Bekir, Marek and Lehnen, Anne-Catherine and Radon, Christin and Laroque, Sophie and Wendler, Petra and M{\"u}ller-Werkmeister, Henrike and Hartlieb, Matthias}, title = {Antimicrobial polymers of linear and bottlebrush architecture}, series = {Macromolecular rapid communications : publishing the newsletters of the European Polymer Federation}, volume = {43}, journal = {Macromolecular rapid communications : publishing the newsletters of the European Polymer Federation}, number = {19}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-3927}, doi = {10.1002/marc.202200288}, pages = {14}, year = {2022}, abstract = {Polymeric antimicrobial peptide mimics are a promising alternative for the future management of the daunting problems associated with antimicrobial resistance. However, the development of successful antimicrobial polymers (APs) requires careful control of factors such as amphiphilic balance, molecular weight, dispersity, sequence, and architecture. While most of the earlier developed APs focus on random linear copolymers, the development of APs with advanced architectures proves to be more potent. It is recently developed multivalent bottlebrush APs with improved antibacterial and hemocompatibility profiles, outperforming their linear counterparts. Understanding the rationale behind the outstanding biological activity of these newly developed antimicrobials is vital to further improving their performance. This work investigates the physicochemical properties governing the differences in activity between linear and bottlebrush architectures using various spectroscopic and microscopic techniques. Linear copolymers are more solvated, thermo-responsive, and possess facial amphiphilicity resulting in random aggregations when interacting with liposomes mimicking Escheria coli membranes. The bottlebrush copolymers adopt a more stable secondary conformation in aqueous solution in comparison to linear copolymers, conferring rapid and more specific binding mechanism to membranes. The advantageous physicochemical properties of the bottlebrush topology seem to be a determinant factor in the activity of these promising APs.}, language = {en} } @article{FloydSongHapeshietal.2022, author = {Floyd, Thomas G. and Song, Ji-Inn and Hapeshi, Alexia and Laroque, Sophie and Hartlieb, Matthias and Perrier, Sebastien}, title = {Bottlebrush copolymers for gene delivery: influence of architecture, charge density, and backbone length on transfection efficiency}, series = {Journal of materials chemistry : B, materials for biology and medicine}, volume = {10}, journal = {Journal of materials chemistry : B, materials for biology and medicine}, number = {19}, publisher = {Royal Society of Chemistry}, address = {London [u.a.]}, issn = {2050-750X}, doi = {10.1039/d2tb00490a}, pages = {3696 -- 3704}, year = {2022}, abstract = {The influence of polymer architecture of polycations on their ability to transfect mammalian cells is probed. Polymer bottle brushes with grafts made from partially hydrolysed poly(2-ethyl-2-oxazoline) are used while varying the length of the polymer backbone as well as the degree of hydrolysis (cationic charge content). Polyplex formation is investigated via gel electrophoresis, dye-displacement and dynamic light scattering. Bottle brushes show a superior ability to complex pDNA when compared to linear copolymers. Also, nucleic acid release was found to be improved by a graft architecture. Polyplexes based on bottle brush copolymers showed an elongated shape in transmission electron microscopy images. The cytotoxicity against mammalian cells is drastically reduced when a graft architecture is used instead of linear copolymers. Moreover, the best-performing bottle brush copolymer showed a transfection ability comparable with that of linear poly(ethylenimine), the gold standard of polymeric transfection agents, which is used as positive control. In combination with their markedly lowered cytotoxicity, cationic bottle brush copolymers are therefore shown to be a highly promising class of gene delivery vectors.}, language = {en} } @article{Hartlieb2022, author = {Hartlieb, Matthias}, title = {Photo-iniferter RAFT polymerization}, series = {Macromolecular rapid communications : publishing the newsletters of the European Polymer Federation}, volume = {43}, journal = {Macromolecular rapid communications : publishing the newsletters of the European Polymer Federation}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-3927}, doi = {10.1002/marc.202100514}, pages = {25}, year = {2022}, abstract = {Light-mediated polymerization techniques offer distinct advantages over polymerization reactions fueled by thermal energy, such as high spatial and temporal control as well as the possibility to work under mild reaction conditions. Reversible addition-fragmentation chain-transfer (RAFT) polymerization is a highly versatile radical polymerization method that can be utilized to control a variety of monomers and produce a vast number of complex macromolecular structures. The use of light to drive a RAFT-polymerization is possible via multiple routes. Besides the use of photo-initiators, or photo-catalysts, the direct activation of the chain transfer agent controlling the RAFT process in a photo-iniferter (PI) process is an elegant way to initiate and control polymerization reactions. Within this review, PI-RAFT polymerization and its advantages over the conventional RAFT process are discussed in detail.}, language = {en} } @article{ReifarthBekirBapolisietal.2022, author = {Reifarth, Martin and Bekir, Marek and Bapolisi, Alain M. and Titov, Evgenii and Nusshardt, Fabian and Nowaczyk, Julius and Grigoriev, Dmitry and Sharma, Anjali and Saalfrank, Peter and Santer, Svetlana and Hartlieb, Matthias and B{\"o}ker, Alexander}, title = {A dual pH- and light-responsive spiropyrane-based surfactant}, series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, volume = {61}, journal = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, number = {21}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1433-7851}, doi = {10.1002/anie.202114687}, pages = {10}, year = {2022}, abstract = {A cationic surfactant containing a spiropyrane unit is prepared exhibiting a dual-responsive adjustability of its surface-active characteristics. The switching mechanism of the system relies on the reversible conversion of the non-ionic spiropyrane (SP) to a zwitterionic merocyanine (MC) and can be controlled by adjusting the pH value and via light, resulting in a pH-dependent photoactivity: While the compound possesses a pronounced difference in surface activity between both forms under acidic conditions, this behavior is suppressed at a neutral pH level. The underlying switching processes are investigated in detail, and a thermodynamic explanation based on a combination of theoretical and experimental results is provided. This complex stimuli-responsive behavior enables remote-control of colloidal systems. To demonstrate its applicability, the surfactant is utilized for the pH-dependent manipulation of oil-in-water emulsions.}, language = {en} }