Phosphonate/quaternary ammonium copolymers as high-efficiency antibacterial coating for metallic substrates

High Hydrophilic and Antibacterial Efficient UV-Curable Silicone-Containing Choline Chloride Quaternary Ammonium Salts Functionalized Materials

Antibacterial materials with high hydrophobicity have drawbacks such as protein adsorption, bacterial contamination, and biofilm formation, which are responsible for some serious adverse health events. Therefore, antibacterial materials with high hydrophilicity are highly desired. In this paper, UV-curable antibacterial materials are prepared from silicone-containing Choline chloride (ChCl) functionalized hyperbranched quaternary ammonium salts (QAS) and tri-hydroxylethyl acrylate phosphate (TAEP). The materials show high hydrophilic performance because their water contact angle is as low as 19.3°. The materials also exhibit quite high antibacterial efficiency against S. aureus over 95.6%, fairly high transmittance over 90%, and good mechanical performance with tensile strength as high as 6.5 MPa. It reveals that it is a feasible strategy to develop antibacterial materials with low hydrophobicity from silicone-modified ChCl-functionalized hyperbranched QAS.

Light-degradable nanocomposite hydrogels for antibacterial wound dressing applications

Skin injuries infected by bacteria can cause life-threatening human diseases if not treated properly. In this work, we developed a light-degradable nanocomposite hydrogel to achieve both controlled antibiotic delivery and hydrogel degradation using light as the sole stimulus. Specifically, we incorporated triclosan-loaded, poly(N-isopropylacrylamide)-based nanogels (TCS-NGs) that exhibited potent antibacterial efficacy, into a light-degradable poly (ethylene glycol) (PEG)-based hydrogel matrix via simple physical entrapment method. Upon exposure to 365 nm light, the hydrogel matrix could rapidly degrade, which subsequently released the entrapped TCS-NGs into the surrounding environment. Our results demonstrated that TCS-NGs released from light-degradable nanocomposite hydrogels still possessed remarkable antibacterial efficacy by inhibiting the growth of Staphylococcus aureus both in solution (a fivefold reduction in optical density compared to the blank control) and on bacteria-infected porcine skins (a fivefold reduction in colony-forming units compared to the blank control). Finally, using an alamarBlue assay on human dermal fibroblasts, we determined that each component of the nanocomposite hydrogel exhibited excellent biocompatibility (>90% cell viability) and would not cause significant cytotoxicity. Overall, the fabricated light-degradable nanocomposite hydrogels could serve as novel material for antibacterial wound dressing applications.

Leveraging the Dielectric Barrier Discharge Plasma Process to Create Regenerative Biocidal ePTFE Membranes

The utilization of dielectric barrier discharge (DBD) plasma treatment for modifying substrate surfaces constitutes an easy and simple approach with a potential for diverse applications. This technique was used to modify the surface of a commercial porous expanded poly(tetrafluoroethylene) (ePTFE) film with either dimethylaminoethyl methacrylate (DMAEMA) or (trimethylamino)ethyl methacrylate chloride (TMAEMA) monomers, aiming to obtain antibacterial ePTFE. Physicochemical analyses of the membranes revealed that DBD successfully enhanced the surface energy and surface charge of the membranes while maintaining high porosity (>75%) and large pore size (>1.0 μm). Evaluation of the bacteria killing-releasing (K-R) function revealed that both DMAEMA and TMAEMA endowed ePTFE with the ability to kill Escherichia coli bacteria. However, only TMAEMA-grafted ePTFE allowed for the release of dead bacteria from the surface upon washing with sodium hexametaphosphate (SHMP) saline solution, owing to its cationic charge derived from the quaternary amine. Washing with SHMP disturbed the electrostatic force between the polymer brushes and dead bacteria, which caused the release of the dead bacteria. Lastly, dead-end bacteria filtration showed that the TMAEMA-grafted ePTFE was able to kill 99.78% of the bacteria, while approximately 61.55% of bacteria were killed upon contact. The present findings support the feasibility of using DBD plasma treatment for designing surfaces that target bacteria and aid in the containment of disease-causing pathogens.

Mussel-Inspired Multicomponent Codeposition Strategy toward Antibacterial and Lubricating Multifunctional Coatings on Bioimplants

Bacterial infections and limited surface lubrication are the two key challenges for bioimplants in dynamic contact with tissues. However, the simultaneous lubricating and antibacterial properties of the bioimplants have rarely been investigated. In this work, we successfully developed a multifunctional coating with simultaneous antibacterial and lubricating properties for surface functionalization of bioimplant materials. The multifunctional coating was fabricated on a polyurethane (PU) substrate via polydopamine (PDA)-assisted multicomponent codeposition, containing polyethyleneimine (PEI) and trace amounts of copper (Cu) as synergistic antibacterial components and zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) as the lubricating component. The obtained PDA(Cu)/PEI/PMPC coating showed excellent antibacterial activity (antibacterial efficiency: ∼99%) to both Escherichia coli and Staphylococcus aureus compared with bare PU. The excellent antibacterial properties were attributed to the combined effect of anti-adhesion capability of hydrophilic PMPC and PEI and bactericidal activity of Cu in the coating. Meanwhile, the coefficient of friction of the coating was significantly decreased by ∼52% compared with bare PU owing to the high hydration feature of PMPC, suggesting the superior lubricating property. Furthermore, the PDA(Cu)/PEI/PMPC coating was highly biocompatible toward human umbilical vein endothelial cells demonstrated by in vitro cytotoxicity tests. This study not only contributes to the chemistry of PDA-assisted multicomponent codeposition but also provides a facile and practical way for rational design of multifunctional coatings for medical devices.

Polyisocyanide Quaternary Ammonium Salts with Exceptionally Star-Shaped Structure for Enhanced Antibacterial Properties

The development of non-polluting and non-hazardous polymeric antimicrobial agents has become a hot issue in current research and development. Among them, polymer quaternary ammonium salts are thought to be one of the most promising materials for antibacterial efficacy. Here, we present an efficient strategy for synthesizing polyisocyanide quaternary ammonium salts (PQASs) with a novel star-shaped structure. Benefitting from the novel structure, increased cation density and enhanced water solubility, the prepared star polyisocyanide quaternary ammonium salts (S-PQASs) exhibit excellent antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In particular, S-POcQAS-M₅₀ (where M stands for isonitrile monomer and 50 stands for the initial feeding ratio) showed the best antimicrobial activity with minimum inhibitory concentration (MIC) of 17 and 20 µg/mL against E. coli and S. aureus, respectively. It was also found that the unique star-shaped structure can give QASs with improved antimicrobial performance compared with our previously prepared linear quaternary ammonium salts (L-PQASs). These results demonstrated that the antibacterial activity of QASs is closely related to its structure. This work provides an idea for the design of efficient polymeric antimicrobial agents.

Functionalized aliphatic polyketones with germicide activity

Surfaces coated by polyketones bearing quaternary ammonium compounds showed excellent bactericidal properties with antibacterial rate of 99%.

Multifunctional Carbon Dots-Based Nanoplatform for Bioimaging and Quaternary Ammonium Salt/Photothermal Synergistic Antibacterial

The emergence of drug resistance and superbugs poses a devastating threat to public health, even lead to death. Thus, it is significant to develop a novel antibacterial agent to combat...