title: Preventing the thermal degradation of astaxanthin through nanoencapsulation.
abstract: The encapsulation of astaxanthin into polymeric nanospheres by solvent displacement was compared for three chemically diverse polymers, namely; poly(ethylene oxide)-4-methoxycinnamoylphthaloylchitosan (PCPLC), poly(vinylalcohol-co-vinyl-4-methoxycinnamate) (PB4) and ethylcellulose (EC). Although capable of forming nanospheres themselves, EC could not encapsulate astaxanthin at all, whilst PB4 yielded a poor encapsulation efficiency. In contrast, PCPLC yielded reasonably good encapsulation efficiency (98%) at a loading of 40% (w/w). Moreover, the freeze-dried astaxanthin-encapsulated PCPLC nanospheres showed good dispersibility in water yielding stable aqueous suspensions of 300-320 nm nanoparticles. A steady release of astaxanthin from the nanospheres up to a maximum of approximately 85% payload over 60 min was also demonstrated, at least in acetone. NMR analysis indicated that after a two-hour-heating at 70 degrees C in an aqueous environment, PCPLC nanoencapsulated astaxanthin showed minimal heat degradation of olefinic functionality in contrast to that of the unencapsulated pigment molecules which were almost completely destroyed.
authors.affiliation: Sensor Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Amornset
authors.initials: A
authors.lastname: Tachaprutinun
authors.forename: Thanchanok
authors.initials: T
authors.lastname: Udomsup
authors.forename: Chuleeporn
authors.initials: C
authors.lastname: Luadthong
authors.forename: Supason
authors.initials: S
authors.lastname: Wanichwecharungruang
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D048271:Chitosan / Q000031:analogs & derivatives / Q000737:chemistry; D002934:Cinnamates / Q000737:chemistry; D003692:Delayed-Action Preparations; D004355:Drug Stability; D005612:Freeze Drying; D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy; D054118:Nanospheres; D010860:Pigments, Biological / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013997:Time Factors; D024341:Xanthophylls / Q000737:chemistry
chemical_list: D002934:Cinnamates; D003692:Delayed-Action Preparations; D010860:Pigments, Biological; D011108:Polymers; D011145:Polyvinyls; D012997:Solvents; D024341:Xanthophylls; C542476:poly(ethylene oxide)-4-methoxycinnamoylphthaloylchitosan; C542477:poly(vinylalcohol-co-vinyl-4-methoxycinnamate); D011092:Polyethylene Glycols; C013517:ethyl cellulose; C005948:astaxanthine; D002482:Cellulose; D048271:Chitosan