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N-Reacetylated Oligochitosan: pH Dependence of Self-Assembly Properties and Antibacterial Activity.

N-Reacetylated Oligochitosan: pH Dependence of Self-Assembly Properties and Antibacterial Activity.

Authors :
Blagodatskikh IV
Kulikov SN
Vyshivannaya OV
Bezrodnykh EA
Tikhonov VE
Source :
Biomacromolecules [Biomacromolecules] 2017 May 08; Vol. 18 (5), pp. 1491-1498. Date of Electronic Publication: 2017 Apr 12.
Publication Year :
2017

Abstract

Oligochitosan (short chain chitosan) is more soluble in acidic aqueous media than a high molecular weight (MW) chitosan, but its antimicrobial activity decreases with increase in degree of acetylation (DA) and increase in pH above a critical pH threshold point. In the present study, oligochitosans varying in MW were additionally N-acetylated and their self-assembly properties and antibacterial activity toward Staphylococcus aureus and Escherichia coli were investigated in a wide pH range as a function of MW and DA. Light scattering studies reveals that reacetyleted oligochitosan with M <subscript>w</subscript> ≤ 11 kDa is completely soluble in alkaline media (up to pH 12.5), if its DA is not less than 16%. Reacetylated chitosans with DA ∼ 30% are solubile in the entire pH range up to 12.5, if their M <subscript>w</subscript> is not higher than 25 kDa, but they aggregate and precipitate from the solution at pH ≥ 8 when their M <subscript>w</subscript> is above 25 kDa. Considering the influence of DA and MW, the antibacterial activity of reacetylated oligochitosans is maximal in the short interval of DA 16-28% at pH 7.4. These results are promising for expanding practical application of oligochitosan in pharmaceutical, cosmetic, and food compositions.

Details

Language :
English
ISSN :
1526-4602
Volume :
18
Issue :
5
Database :
MEDLINE
Journal :
Biomacromolecules
Publication Type :
Academic Journal
Accession number :
28375595
Full Text :
https://doi.org/10.1021/acs.biomac.7b00039