Characteristics of Cholesterol-Grafted Gelatin Micelles
Gelatin, a hydrophilic protein derived from collagen, has been widely used in drug delivery system because of its biocompatibility and biodegradability. However, its high water solubility limited its interaction with hydrophilic drugs. The current works propose a method to improve surface activity of gelatin by modifying it into an amphiphilic molecule via conjugating with cholesterol. High contents of cholesterol were conjugated to amino groups (-NH2) of gelatin using N,N’-Disuccinimidyl carbonate. Cholesterol contents were varied from 100% by mole of free -NH2 group in gelatin. The reduction of free -NH2 groups on gelatin determined by 2,4,6-trinitrobenzenesulfonic acid (TNBS) decreased with the increases of cholesterol used in the conjugation. The percentage of reduction of -NH2 content was 74.63 by mole respectively. Hydrophilicity/hydrophobicity changes were evaluated from water and ethylene glycol contact angles. The conjugated-gelatin were aggregated to form micelles at a critical micelle concentration (CMC) of 8 mg/ml in DI water (pH 5), determined by surface tension testing. Average size of the micelles were in range of 459.05±54.59 nm. The micelles were tested for curcumin entrapment for a cancer research.
S. Suttiruengwong and W. Sricharussin
M. Wareechuensook et al., "Characteristics of Cholesterol-Grafted Gelatin Micelles", Advanced Materials Research, Vols. 93-94, pp. 595-598, 2010