Quaternary ammonium-based biomedical materials: State-of-the-art, toxicological aspects and antimicrobial resistance

Abstract

a b s t r a c tMicrobial infections affect humans worldwide. Many quaternary ammonium compounds have been synthesized that are not only antibacterial, but also possess antifungal, antiviral and anti-matrix metalloproteinase capabilities. Incorporation of quaternary ammonium moieties into polymers represents one of the most promising strategies for preparation of antimicrobial biomaterials. Various polymerization techniques have been employed to prepare antimicrobial surfaces with quaternary ammonium functionalities; in particular, syntheses involving controlled radical polymerization techniques enable precise control over macromolecular structure, order and functionality. Although recent publications report exciting advances in the biomedical field, some of these technological developments have also been accompanied by potential toxicological and antimicrobial resistance challenges. Recent evidenced-based data on the biomedical applications of antimicrobial quaternary ammonium-containing biomaterials that are based on randomized human clinical trials, the golden standard in contemporary medicinal science, are included in the present review. This should help increase visibility, stimulate debates and spur conversations within a wider scientific community on the implications and plausibility for future developments of quaternary ammonium-based antimicrobial biomaterials.Published by Elsevier B.V.

Advanced Materials by Atom Transfer Radical Polymerization

“…Environmentally benign zwitterionic polymers and coatings are resistant to marine fouling . Indeed many surface responsive polymer layers have been tethered to a solid surface including block brush copolymers, mikto‐brush copolymers, and ionic and zwitterionic brushes that respond to various stimuli, such as temperature, pH, light, and properties of contacting solutions . Bioresponsive surfaces provide improved biocompatibility and lubrication for artificial joints, important for several applications …”

Tailoring Macromolecular Structure of Cationic Polymers towards Efficient Contact Active Antimicrobial Surfaces

“…[11][12] Most of the studied systems are polycations, in particular those with quaternary nitrogen atoms. [13][14] Although their mechanism of action is not fully understood, these polycationic structures interact electrostatically with the negative charged bacterial membrane, causing disruption of the wall and the posterior death of the microorganism. Many investigations have been focused on discussing the optimal chemical structure and the factors affecting the antimicrobial activity of these cationic polymers such as the hydrophobic/hydrophilic balance, the charge density, the length of the alkyl chain as well as molecular weight of the polymers.…”

Ammonium‐Charged Sterically Hindered Phenols with Antioxidant and Selective Anti‐Gram‐Positive Bacterial Activity

“…The presence of a phenolic hydroxy and a hydrazone moiety in the structure of these compounds may also cause them to exhibit antioxidant properties . On the other hand, it is known that quaternary ammonium salts have pronounced antimicrobial properties due to the ability to bind to the negatively charged surface of the bacterial cell membrane . In our opinion, the combination of a phenolic substituent, a hydrazone moiety and an ammonium center in one molecule will solve the problem of the solubility of the target compounds in water along with high antioxidant and antimicrobial activities.…”