Carboxymethyl chitosan-decorated proliposomes as carriers for improved stability and sustained release of flaxseed oil

Carboxymethyl chitosan coated alpha-linolenic acid nanoliposomes: Preparation, stability and release in vitro and in vivo

Nanoliposome encapsulation combined with carboxymethyl chitosan (CMCS) surface decoration was employed to improve physicochemical stability and oral bioavailability of alpha-linolenic acid (ALA). Different nanoliposome systems including ALA-loaded nanoliposomes (ALA-NLs) and CMCS-coated ALA-NLs (CMCS-ALA-NLs) were characterized through dynamic light scattering, transmission electron microscope, Fourier transform infrared spectroscopy and differential scanning calorimetry. The results showed that CMCS-ALA-NLs had good encapsulation efficiency of 79% and layer formation with nanosized spherical carrier. The physicochemical stability of CMCS-ALA-NLs was better than that of ALA-NLs. CMCS-ALA-NLs were able to regulate the release of ALA in a simulated gastrointestinal environment. In vivo testing found that ALA concentration of CMCS-ALA-NLs had an area under the curve of 1.32, which was 1.28 times higher than that of ALA-NLs and 2 times higher than that of ALA-emulsion. The absorption of ALA was improved by CMCS-ALA-NLs. It suggested that CMCS-coated nanoliposomes should be an available delivery strategy for transporting ALA.

Carboxymethyl chitosan coated medium-chain fatty acid nanoliposomes: structure, composition, stability and in vitro release investigation

Medium-chain fatty acids (MCFAs) have been proven as an easy energy source and active ingredient to prevent obesity and other metabolic disorders. However, the inherent hydrophobic nature of MCFAs causes poor aqueous solubility and dissolution in the gastrointestinal (GI) tract, thus limiting their applications in aqueous foods. To address these issues, a nutraceutical carrier system was developed by coating nanoliposomes with carboxymethyl chitosan (CMCS) through a series of well-designed processes, including thin-film hydration, dynamic high pressure microfluidization (DHPM) and surface modification. Electron microscopy investigation reveals an obvious morphology evolution from the uncoated nanoliposomes (UC-LPs) to the final CMCS coated nanoliposomes (CMCS-LPs). Together with the FTIR results, it confirms the successful coating of CMCS. More importantly, the resultant CMCS-LPs have a more negatively charged surface with a ζ-potential value of around -18.5 mV, which helps to increase the stability by avoiding severe particle aggregation. Owing to the above benefits, the encapsulated MCFAs can be safely retained in a long storage period of 90 days at 4 °C and the new carrier system also exhibits a more sustained release of MCFAs in the GI fluid.

Improved stabilization of coix seed oil in a nanocage-coating framework based on gliadin-carboxymethyl chitosan-Ca2

Coix seed oil (CSO) is easily suffered functional-loss by oxidation and hydrothermal-treatment. The environmental stable nanocage-coating-CSO particles (OGC-Ca) by the frameworks consist of gliadins, carboxymethyl chitosan (CMCS) and Ca²⁺ were investigated. Results showed Ca²⁺ was the key controller for fabricating this nanocage-coating-frameworks, bridging macromolecule-chains with electrostatic interaction and hydrogen bonds, detected by FTIR, CD, DSC and XRD. SEM displayed new-formed velvet-like twigs after cross-linking CMCS to gliadins. Ca²⁺ assisted the nanocage-coating by significant down-sizing conversion OGC to OGC-Ca with consumption of twigs. OGC-Ca displayed a good stability towards heat (60-80 °C, 0-80 min), pH (3-8), NaCl (0-0.5 mM), storage (4/25 °C, 12 days), and a reduce of the pre-oxidation value of CSO in water and the improved controlled release of CSO in simulated GI tract. It illustrated GC-Ca frameworks would be a suitable delivery carrier for the CSO like pharmaceuticals and nutraceuticals for the food or medical use.