There is currently an urgent need for the development of new antibacterial agents to combat the spread of antibiotic-resistant bacteria. We explored the synthesis and antibacterial activities of novel, sugar-functionalized phosphonium polymers. While these compounds exhibited antibacterial activity, we unexpectedly found that the control polymer poly(tris(hydroxypropyl)vinylbenzylphosphonium chloride) showed very high activity against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus and very low haemolytic activity against red blood cells. These results challenge the conventional wisdom in the field that lipophilic alkyl substituents are required for high antibacterial activity and opens prospects for new classes of antibacterial polymers.

Polyphosphonium semi-interpenetrating networks were prepared and studied as antibacterial surfaces to elucidate the structural aspects leading to bacterial killing.

Polyelectrolyte complexation, the combination of anionically and cationically charged polymers through ionic interactions, can be used to form hydrogel networks. These networks can be used to encapsulate and release cargo, but the release of cargo is typically rapid, occurring over a period of hours to a few days and they often exhibit weak, fluid-like mechanical properties. Here we report the preparation and study of polyelectrolyte complexes (PECs) from sodium hyaluronate (HA) and poly­[tris­(hydroxypropyl)­(4-vinylbenzyl)­phosphonium chloride], poly­[triphenyl­(4-vinylbenzyl)­phosphonium chloride], poly­[tri­(n-butyl)­(4-vinylbenzyl)­phosphonium chloride], or poly­[triethyl­(4-vinylbenzyl)­phosphonium chloride]. The networks were compacted by ultracentrifugation, then their composition, swelling, rheological, and self-healing properties were studied. Their properties depended on the structure of the phosphonium polymer and the salt concentration, but in general, they exhibited predominantly gel-like behavior with relaxation times greater than 40 s and self-healing over 2–18 h. Anionic molecules, including fluorescein, diclofenac, and adenosine-5′-triphosphate, were encapsulated into the PECs with high loading capacities of up to 16 wt %. Fluorescein and diclofenac were slowly released over 60 days, which was attributed to a combination of hydrophobic and ionic interactions with the dense PEC network. The cytotoxicities of the polymers and their corresponding networks with HA to C2C12 mouse myoblast cells was investigated and found to depend on the structure of the polymer and the properties of the network. Overall, this work demonstrates the utility of polyphosphonium-HA networks for the loading and slow release of ionic drugs and that their physical and biological properties can be readily tuned according to the structure of the phosphonium polymer.

There is currently an urgent need for the development of new antibacterial agents to combat the spread of antibiotic-resistant bacteria. We explored the synthesis and antibacterial activities of novel, sugar-functionalized phosphonium polymers.While these compounds exhibited antibacterial activity,w eu nexpectedly found that the control polymer poly(tris(hydroxypropyl)vinylbenzylphosphonium chloride) showed very high activity against both Gram-negative Escherichiac oli and Gram-positive Staphylococcus aureus and very low haemolytic activity against red blood cells.T hese results challenge the conventional wisdom in the field that lipophilic alkyls ubstituents are required for high antibacterial activity and opens prospects for new classes of antibacterial polymers.

We describe the synthesis of three different phosphonium salts and their reaction with poly(ethylene glycol) dimethacrylate to create cationic hydrogels. The hydrogels were loaded with an anionic dye and an anionic anti-inflammatory drug through ionic interactions and compared with an analogous ammonium gel. The release rates of these anions depended on their structure and pKa values, as well as the pH and ionic strength of the release medium.