The rise of antibiotic-resistant microorganisms has become a critical issue in recent years and has promoted substantial research efforts directed to the development of more effective antimicrobial therapies utilizing different bactericidal mechanisms to neutralize infectious diseases. Modern approaches employ at least two mixed bioactive agents to enhance bactericidal effects. However, the combinations of drugs may not always show a synergistic effect, and further, could also produce adverse effects or stimulate negative outcomes. Therefore, investigations providing insights into the effective utilization of combinations of biocidal agents are of great interest. Sometimes, combination therapy is needed to avoid resistance development in difficult-to-treat infections or biofilm-associated infections treated with common biocides. Thus, this contribution reviews the literature reports discussing the usage of antimicrobial polymers along with nanomaterials or other inhibitors for the development of more potent biocidal therapies.

Kinetic investigations of the quaternization reactions of poly[2‐(dimethylamino)ethyl methacrylate] (PDMAEMA) with alkyl halides (1‐iodobutane, 1‐iodoheptane, and 1‐iododecane) are carried out at different temperatures. For this purpose, a PDMAEMA (M_n = 17.8 kDa, Ð = 1.35) synthesized via reversible addition fragmentation chain transfer polymerization is utilized. The progress of the quaternization reactions is followed by proton nuclear magnetic resonance. As expected, the rate of quaternization is higher with increasing temperature. The experimental data are used to determine the following kinetic parameters: order of the reaction, Arrhenius' pre‐exponential factor, and activation energy. To the best of knowledge, this is the first contribution that provides detailed kinetic data of the quaternization reactions on PDMAEMA.

We describe an efficient strategy for the preparation of hydrophobically associating multiblock copolymers using the RAFT technique. Polymerization reactions were carried out by a one-pot aqueous RAFT polymerization at 70 °C using a symmetrical trithiocarbonate as a chain transfer agent (CTA) in aqueous media. The macroRAFT polyacrylamide (PAM) was synthetized and chain extended by polymerization of N,N′-dihexylacrylamide (DHAM) and acrylamide (AM), respectively. The resultant polymers were intensely characterized by size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) spectroscopy, diffusion-ordered spectroscopy (DOSY), Fourier transform-infrared (FT-IR) spectroscopy and rheology. The structure and insertion of a hydrophobic block (PDHAM) into the backbone were carefully demonstrated. The rheological measurements confirmed the effect of the hydrophobic block number on the viscosity of polymers at different concentrations and the formation of a reversible physical network of entangled polymers in aqueous media. Moreover, the incorporation of the hydrophobic block (PDHAM) was established by the oscillatory measurement.

Liposome-based technologies derived from lipids and polymers (e.g., PEGylated liposomes) have been recognized because of their applications in nanomedicine. However, since such systems represent myriad challenges and may promote immune responses, investigation of new biomaterials is mandatory. Here, we report on a biophysical investigation of liposomes decorated with bioconjugated copolymers in the presence (or absence) of amantadine (an antiviral medication). First, copolymers of poly(N,N-dimethylacrylamide-co-fluoresceinacrylate-co-acrylic acid-N-succinimide ester)-block-poly(N-isopropylacrylamide) (PDMA-b-PNIPAM) containing a fluorescence label were biofunctionalized with short peptides that resemble the sequence of the loops 220 and 130 of the binding receptor of the hemagglutinin (HA) protein of the influenza A virus. Then, the bioconjugated copolymers were self-assembled along with liposomes composed of 1,2 dimyristoyl-sn-glycero-3-phosphocholine, sphingomyelin, and cholesterol (MSC). These biohybrid systems, with and without amantadine, were systematically characterized using differential scanning calorimetry (DSC), dynamic light scattering (DLS), and cryogenic transmission electron microscopy (cryoTEM). Finally, the systems were tested in an in vitro study to evaluate cytotoxicity and direct immunofluorescence in Madin Darbin Canine Kidney (MDCK) cells. The biohybrid systems displayed long-term stability, thermo-responsiveness, hydrophilic–hydrophobic features, and fluorescence properties and were presumable endowed with cell targeting properties intrinsically integrated into the amino acid sequences of the utilized peptides, which indeed turn them into promising nanodevices for biomedical applications.

Much of the research on biodegradable polymers is currently aimed at developing alternative materials to fossil fuel plastics.