The complex world of polysaccharides edited by Desiree Nedra Karunaratne
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- Bu səhifədəki naviqasiya:
- Chitosan details (DD, MW) Modification Assessment IC50
- Table 1.
- 17. Antimicrobial activity
The Complex World of Polysaccharides
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Chitosan details (DD, MW) Modification Assessment IC50 95% DD, 18.7 kDa Steric acid conjugation micelle In vitro ,A549 cells 369±27 μg/ml 95% DD, 18.7 kDa teric acid conjugation and entrapment in micelle In vitro ,A549 cells 234±9 μg/ml 97% DD, 65 kDa N-octyl-O-sulphate Invitro, primary rat hepatocytes >200 mg/ml 87% DD, 20, 45, 200, 460 kDa None, aspartic acid salt In vitro, Caco-2 cells, pH 6.2 0.67±0.24, 0.61±0.10, 0.65±0.20, 0.72±0.16 mg/ml
87% DD, 20, 45, 200, 460 kDa None, glutamic acid salt 0.56±0.10, 0.48±0.07, 0.35±0.06, 0.46±0.06 mg/ml
87% DD, 20, 45, 200, 460 kDa None, Lactic acid salt
0.38±0.13, 0.31±0.06, 0.34±0.04, 0.37±0.08 mg/ml
87% DD, 20, 45, 200, 460 kDa None, hydrochloride salt 0.23±0.13, 0.22±0.06, 0.27±0.08, 0.23±0.08 mg/ml
78% DD, <50 kDa None, lactic acid salt In vitro B16F10 cells 2.50 mg/ml 82% DD, 150–170 kDa
None, lactic acid salt In vitro B16F10 cells 2.00±0.18 mg/ml >80% DD, 60–90 kDa
None, glutamic acid salt In vitro B16F10 cells 2.47±0.14 mg/ml 77% DD, 180–230 kDa None, lactic acid salt In vitro B16F10 cells 1.73±1.39 mg/ml 85% DD, 60–90 kDa None, hydrochloric acid salt In vitro B16F10 cells 2.24±0.16 mg/ml 81% DD, 100–130 kDa
None, hydrochloric acid salt
In vitro B16F10 cells 0.21±0.04 mg/ml 100% DD, 152 kDa Glycol chitosan In vitro B16F10 cells 2.47±0.15 mg/ml 100% DD, 3–6 kDa 20, 44, 55% Trimethyl chitosan, chloride salt In vitro, MCF7 and COS7 cells, 6 h & 24 h >10 mg/ml 100% DD, 3–6 kDa 94% Trimethyl chitosan, chloride salt In vitro, MCF7, 6 h 1.402±0.210 mg/ml 100% DD, 3–6 kDa 94% Trimethyl chitosan, chloride salt In vitro, COS7, 6 h 2.207±0.381 mg/ml 100% DD, 100 kDa 36% Trimethyl chitosan, chloride sal In vitro, MCF7, 6 h 0.823±0.324 mg/ml 100% DD, 100 kDa 36% Trimethyl chitosan, chloride sal In vitro, COS7, 6 h >10 mg/ml Is Chitosan a New Panacea? Areas of Application
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Chitosan details (DD, MW) Modification Assessment IC50 84.7% DD, 400, 100, 50, 25, 5 kDa 40% Trimethyl chitosan In vitro, L929 cells, 3 h 30, 70, 90, 270, >1000 μg/ml 84.7% DD, 1.89 MDa 12% PEG modified 40% trimethyl chitosan In vitro, L929 cells, 3 h 220 μg/ml 84.7% DD, 3.6 MDa
25.7% PEG modified 40% trimethyl chitosan In vitro, L929 cells, 3 h 370 μg/ml 84.7% DD, 300 kDa 6.44% PEG modified 40% trimethyl chitosan (and all PEG modified TMC with lower Mw) In vitro, L929 cells, 3 h >500 μg/ml 97% DD, 65 kDa N-octyl-O-sulphate In vivo, IV, mice 102.59 mg/kg 97% DD, 65 kDa N-octyl-O-sulphate n vivo, IP, mice 130.53 mg/kg Table 1. Toxicity of chitosan and chitosan derivatives Table taken from [94] In a series of articles are described the effects of chitosans with differing molecular weights and degree of deacetylation in vitro and in vivo. Toxicity was found to be degree of deacetylation and molecular weight dependent. At high DD the toxicity is related to the molecular weight and the concentration, at lower DD toxicity is less pronounced and less related to the molecular weight [93]. A summary of toxicities of chitosan and derivatives assessed through IC 50 values is presented in the next table [94]. From this table it can be gathered that most chitosans (and derivatives) are not significantly toxic compared to a toxic polymer such as polyethylenimine [94]. It appears that the toxicity of chitosan is related to the charge density of the molecule, toxicity increases with increasing density. It appears that there is a threshold level below which there are too few contact points between a molecule and the cell components to produce a significantly toxic effect. This balance is between 40 and 60% DD, or degree of trimethylation, although any sufficiently small chitosan (<10 kDa) is not appreciably toxic. Modifications that do not increase the charge on the molecule seem to have little effect on the toxicity beyond that of the native molecule [94]. 17. Antimicrobial activity The exact mechanism by which chitosan exerts its antimicrobial activity is currently unknown, it has been suggested that the polycationic nature of this biopolymer that forms from acidic solutions below pH 6.5 is a crucial factor. Thus, it has been proposed that the positively charged amino groups of the glucosamine units interact with negatively charged components in microbial cell membranes, altering their barrier properties, and thereby Yüklə 27,58 Mb. Dostları ilə paylaş:
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