A Perspective Looking Backward and Forward on the 25th Anniversary of Conjugated Polyelectrolytes

Conjugated polyelectrolytes are π-conjugated polymers that contain ionic charged groups such as sulfonate (R-SO3-), carboxylate (R-COO-), or ammonium (R-NR3+) combined with a π-conjugated backbone. This perspective provides a summary review of the key developments in the field, starting from the first reports of their synthesis and properties to application-focused developments. The applications include optical sensors for molecular and biomolecular targets, organic electronic applications, and specific biological applications including cellular imaging and photodynamic therapy. This perspective concludes with a discussion of where the field of conjugated polyelectrolytes is expected to lead in the coming years.

A Novel Cationic Polymer Surfactant for Regulation of the Rheological and Biocidal Properties of the Water-Based Drilling Muds

The copolymer of N,N-diallyl-N,N-dimethylammonium chloride and N-[3-(Dimethylamino)propyl]methacrylamide (DADMAC-DMAPMA) was synthesized by radical polymerization reaction in an aqueous solution in the presence of the initiator ammonium persulfate (NH₄)₂S₂O₈. The molar compositions of the synthesized copolymers were determined using FTIR and ¹H NMR-spectroscopy, elemental analysis, and conductometric titration. It was found that in the radical copolymerization reaction, the DMAPMA monomer was more active than the DADMAC monomer; for this reason, the resulting copolymers were always enriched in the DMAPMA monomers. The study of the influence of the DADMAC-DMAPMA copolymer on structure-formation in the bentonite suspension showed that this copolymer significantly increased the static shear stress (SSS) of the system. In this case, the structure-forming properties of the copolymer depended on the pH of the medium. The lower the pH level, the better the structure-formation was in the suspension in the presence of the copolymer. The study of antibacterial activity showed that the DADMAC-DMAPMA copolymer had a biocidal effect against sulfate-reducing bacteria (CRB) at a concentration of not less than 0.05 wt.% and can be used to inhibit the growth of this bacteria.

The prospects of antimicrobial coated medical implants

The implants are increasingly being a part of modern medicine in various surgical procedures for functional or cosmetic purposes. The progressive use of implants is associated with increased infectious complications and prevention of such infections always remains precedence in the clinical settings. The preventive approaches include the systemic administration of antimicrobial agents before and after the surgical procedures as well as the local application of antibiotics. The relevant literature and existing clinical practices have highlighted the role of antimicrobial coating approaches in the prevention of implants associated infections, although the applications of these strategies are not yet standardized, and the clinical efficacy is not much clear. The adequate data from the randomized control trials is challenging because of the unavailability of a large sample size although it is compulsory in this context to assess the clinical efficacy of preemptive practices. This review compares the efficacy of preventive approaches and the prospects of antimicrobial-coated implants in preventing implant-related infections.