N-Trimethylation of nanochitin for high dispersibility and pH-independent antibacterial activity
Partially deacetylated nanochitins (NH2NCs) possess cationic properties that allow their stable dispersion in acidic water. Their surface charge plays a crucial role in their antibacterial functions, which occur through electrostatic interactions. However, NH2NCs lose their positive charge upon depr...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-03-01
|
| Series: | Carbohydrate Polymer Technologies and Applications |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666893925000271 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Partially deacetylated nanochitins (NH2NCs) possess cationic properties that allow their stable dispersion in acidic water. Their surface charge plays a crucial role in their antibacterial functions, which occur through electrostatic interactions. However, NH2NCs lose their positive charge upon deprotonation under basic conditions, leading to aggregation and significant reductions in their effectiveness. Thus, a strategy to maintain the positive charge of the material regardless of the pH must be developed. In this study, NH2NCs were modified by N-trimethylation to prevent the loss of their positive charge. The total degree of substitution for methyl groups was 0.96, while that for N-trimethylamino groups was 0.15, as determined by 13C NMR spectroscopy, FT-IR spectroscopy, elemental analysis, and conductivity titration. The structure of the modified NH2NCs contained N-methyl, N-dimethyl, and O-methyl groups. Methylated nanochitins (MeNCs) maintained a positive zeta potential regardless of the pH owing to the presence of quaternary ammonium salts. Thus, they remained stably dispersed, even under basic conditions. Furthermore, their high surface charge improved their grinding efficiency and reduced their proportion of large agglomerated particles. Whereas the NH2NCs lost their antibacterial properties against Staphylococcus aureus at neutral to basic pH levels, the MeNCs retained their high antibacterial effectiveness. The improvement of dispersibility and antibacterial properties through chemical modification will promote the use of nanochitin, derived from waste crab shells, in cosmetics and health foods. |
|---|---|
| ISSN: | 2666-8939 |