Hydrophobic PEGylation of Chitosan: A Graft Copolymer Approach toward Developing Nontoxic Antimicrobial Chitosan

Abstract

Though chitosan-based antimicrobial polymers have been well-known for a long time, selectivity of such derivatives remains always an issue, especially selective bacteria killing using chitosan-derived antimicrobials are far less addressed to the best of our knowledge. In this context, a series of graft copolymers were prepared via chemoselective grafting of acrylate telechelic hydrophobic PEGs onto a chitosan backbone at the C2–NH2 position. The graft copolymers show superior and selective antimicrobial efficacy (with respect to both types of bacteria and RBC) with low toxicity. Based on grafting density, selective bacteria killing was noted between Escherichia coli and Staphylococcus aureus. In the current study, MIC (S. aureus)/ MIC (E. coli) for graft copolymers with a lesser grafting density (CHT-g-OPEG10) is calculated as 1.68, and for graft copolymers with a higher grafting density (CHT-g-OPEG30) MIC (E. coli)/MIC (S. aureus) is reported as 2.14, indicating that CHT-g-OPEG10 may be used preferentially for killing E. coli (with a much lesser effect for S. aureus); whereas CHT-g-OPEG30 may be utilized for the preferential killing of S. aureus (with a much lesser effect on E. coli).

Mesoporous degradable chitosan-based monoliths: synthesis and applications toward water purification

“…It is important to note that the thermal stability of the monolith is slightly lower than the original chitosan polymer, which can be ascribed to the thermal degradation of the PEG macro-crosslinker at ∼200 °C. 56,57 Additionally, the chemical stability of the monolith in various solvents was determined via gravimetric analysis (Fig. S7b†).…”

Preparation of Antibacterial and UV-Protective Cotton through Coating with TiO2-Modified Chitosan-Based Schiff Bases

“…In recent years, various antibacterial agents have been used to develop cotton fabrics with multifunctional antibacterial properties. These include antibacterial agents such as chitosan, metal oxides, and metal ions, quaternary ammonium salts, polyguanidine, and N -haloamine compounds . As a natural antibacterial agent, chitosan is a deacetylated form of natural polysaccharide chitin and is the most abundant biopolymer after cellulose .…”