Biodegradable chitosan-glycolipid hybrid nanogels: A novel approach to encapsulate fucoxanthin for improved stability and bioavailability

This study aimed to improve the stability and biological availability of carotenoid fucoxanthin (FUCO) encapsulated in chitosan (CS) - sodium tripolyphosphate (TPP) - glycolipid (GL) nanogels, prepared by ionic gelation method. Scanning Electron Microscopic analysis and Dynamic Light Scattering examination revealed smooth and spherical nanogels with size range of 200-550 nm in weight ratios of CS: TPP (2.5:1), CS: GL (1:0.5). The zeta potential values (+30 to +50 mV) indicate that CS-NGs with FUCO + GL were more stable than that of CS-NGs + FUCO with no GL (+15 mV). The Fourier Transform Infrared Spectroscopy (FTIR) showed an extensive hydrogen bonding interaction between the FUCO and CS. X-ray Diffraction revealed FUCO is distributed in a disordered (amorphous) state in CS-NGs. Encapsulation efficiency, loading capacity and the yield of CS-NGs with FUCO + GL were 90%, 47% and 70%, respectively which is, significantly higher, than that of CS-NGs + FUCO without GL. Stability studies illustrated that glycolipid offers enhanced FUCO stability (t(1/2,) 45 h) with CS-NGs compared to that of with no GL (t(1/2,) 15 h) and standard FUCO (t(1/2,) <5 h). The bioavailability of FUCO in vitro from CS-NGs with GL was higher (68%) compared to that of CS-NGs + FUCO without GL (51%), FUCO with GL (35.5%) and control (21.5%). In conclusion, the stability and bioavailability of FUCO was improved by nanoencapsulation of FUCO with CS + GL. (C) 2014 Elsevier Ltd. All rights reserved.