Insights into chitosan multiple functional properties: the role of chitosan conformation in the behavior of liposomal membrane.
Interactions between chitosan and the liposomal membrane are relevant to the physiological functionality of chitosan, including dietary fiber, antimicrobial action, and fabrication of a delivery system for bioactives. To elucidate the multiple functions of chitosan, the dependence of liposomal membrane properties on the biopolymer conformation was investigated. The concentration dependence of chitosan conformation in aqueous solution was quantified by fluorescence and viscosity measurements. As the concentration increased, the extended chains of chitosan (0-1.0 mg mL(-1)) partially crimped (1.0-1.5 mg mL(-1)), and then self-aggregated forming irregular coils (>1.5 mg mL(-1)). Adsorption of chitosan linear chains on the liposomal membrane surface tended to maintain the morphology of liposomes, decrease the membrane interior micropolarity and rigidify the liposomal membrane. However, these effects were negligible or even opposite in the case of chitosan coils. Analysis on the membrane fluidity revealed that the microviscosity of liposomes decorated by 1.5 mg mL(-1) concentration of chitosan decreased by 17% after being heated at 80 °C for 10 min, in contrast to the decreased percentage of 55 at 4 mg mL(-1). Additionally, compared with the poor oxidative stability of liposomes decorated by chitosan coils, those decorated by chitosan linear chains exhibited slight lipid peroxidation with the TBARS inhibition of around 10% and 6% against oxygen and ferric ions, respectively. These findings suggest that the conformational effects of chitosan on the liposomal membrane are responsible for its multiple functional properties.
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Lihu Road 1800, Wuxi, Jiangsu 214122, China. sqxia2006@hotmail.com and Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA.
Chen
C
Tan
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Lihu Road 1800, Wuxi, Jiangsu 214122, China. sqxia2006@hotmail.com.
Yating
Y
Zhang
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Lihu Road 1800, Wuxi, Jiangsu 214122, China. sqxia2006@hotmail.com.
Shabbar
S
Abbas
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Lihu Road 1800, Wuxi, Jiangsu 214122, China. sqxia2006@hotmail.com.
Biao
B
Feng
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Lihu Road 1800, Wuxi, Jiangsu 214122, China. sqxia2006@hotmail.com.
Xiaoming
X
Zhang
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Lihu Road 1800, Wuxi, Jiangsu 214122, China. sqxia2006@hotmail.com.
Shuqin
S
Xia
School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, China.
Dawei
D
Chang
D000327:Adsorption; D001704:Biopolymers / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry*; D015227:Lipid Peroxidation; D008081:Liposomes / Q000737:chemistry*; D017392:Thiobarbituric Acid Reactive Substances / Q000737:chemistry
D001704:Biopolymers; D008081:Liposomes; D017392:Thiobarbituric Acid Reactive Substances; D048271:Chitosan