Core‐crosslinking as a pathway to develop inherently antibacterial polymeric micelles

Abstract

Positively charged polymeric materials have been an alternative to combat bacteria as they exhibit inherently antibacterial potency via bacteria membrane disruption. In this study, we report facile preparation of positively charged core‐crosslinked polymeric micelles with inherent antibacterial properties. Spherical micelles were prepared by self‐assembling of poly(4‐vinylpyridine)‐b‐(oligoethylene glycol methyl ether methacrylate) copolymer in aqueous solution. Herein, quaternization reaction was utilized for the first time to core crosslink the micelles through the pyridine rings utilizing their hydrophobic core and thus resulting positively charged nanostructures. Dynamic light scattering (DLS) results identified that the micelles have an average hydrodynamic diameter of 114 nm with a polydispersity index ranging between 0.105 and 0.114. The electrophoretic light scattering (ELS) measurements demonstrated that the micelles have zeta potential values ranging from +38 to +63 mV. It was evident from both ELS and DLS results that the micelles in solution exhibit long‐term stability as the samples were able to maintain their size and charge even after a year of storage. Further, the micelles exhibited inherently antibacterial activity against Escherichia coli and furthermore, this antibacterial efficacy was sustained over a period of 1 year. These stable core‐crosslinked micelles are proposed to have great potential as antibacterial materials for long‐term applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48393.

Antibacterial properties of cationic copolymers as a function of pendant alkyl chain length and degree of quaternization

“…These bands enable the interpretation of the number of quaternized groups on the polymer chains. 19 As seen in the FTIR spectra of the resulting quaternized copolymers (Fig. 1), the bands at 1600 and ca 1660 cm −1 assigned to the pyridine of 4VP and the carbonyl group of pyrrolidone were observed in the spectra of all samples.…”

“…This was attributed to the lack of diffusion ability of the non-quaternized and quaternized polymers into the MHA due to their size and charge. 19 Second, the broth microdilution method was used as a quantitative method to determine the antibacterial activity of the quaternized copolymers and the bare non-quaternized copolymer by means of MIC values. The bare non-quaternized copolymer did not show any antibacterial activity within the range of examined concentrations of the copolymer.…”

“…16 Its application in biological areas, however, is limited because of its toxicity and hydrophobicity. 17 Therefore, various monomers such as oligoethyleneglycol methacrylate, 18,19 Nvinylpyrrolidone (NVP) 20 and hydroxyethyl methacrylate 18,21 are included in the structure of the antibacterial quaternary ammonium polymers to obtain non-toxic and biocompatible watersoluble antibacterial polymers. For instance, 4-vinylpyridine (4VP) and NVP monomers were polymerized and then quaternized with benzyl halide to achieve antibacterial polymers.…”

The evaluation of biotechnological potential of Gp144, the key molecule of natural predator bacteriophage K in Staphylococcus aureus hunting mechanism

“…After incubation for 16–18 h at 37°C, MIC values were determined by both spectrophotometric measurements (OD 600 nm) and standard plate counting methods. [ 64 ] Also, the disc diffusion method was carried out as described previously [ 65 ] and the results were evaluated by measuring the diameter of the inhibition zone around the agar wells. Briefly, the sterile filter disc (diameter 6 mm) containing 10 μL of test sample was placed onto the bacteria‐spreaded MHA plates and then the plates were aerobically incubated at 37°C for 24 h. After that, antimicrobial activity was evaluated by measuring the zone (mm) of inhibition against the test organisms.…”

Effect of polyelectrolyte complex formation on the antibacterial activity of copolymer of alkylated 4-vinylpyridine

“…Cationic polymers attract considerable interest in the field of biomedical applications as antibacterial agents due to their inherent bacteria-killing activity and easy synthesis and modification [1,2]. Polymers bearing quaternary ammonium groups are the most prominent polycations used for antibacterial purposes [3].…”