Amphiphilic chitosan derivative-based core–shell micelles: Synthesis, characterisation and properties for sustained release of Vitamin D3

Novel amphiphilic chitosan derivative of N,N-dimethylhexadecyl carboxymethyl chitosan (DCMCs) was synthesised. The physical properties of DCMCs were characterised by Fourier transform-infrared spectroscopy, nuclear magnetic resonance spectroscopy, X-ray diffraction and differential scanning calorimetry. DCMCs can form core–shell micelles with low critical micelle concentration (31 mg L−1). The core–shell micelles exhibited spherical shape with positive charge (+50.7 mV) and narrow size distribution (polydispersity index <0.5). Vitamin D3 (VD3) was initially used to load into the core–shell micelles, and the solubility of VD3 was improved with higher encapsulation efficiency (53.2%). The in vitro release processes of VD3 from the core–shell micelles were initially rapid and then followed by a sustained release. The Higuchi model was the most suitable for describing the entire release procedure. DCMCs core–shell micelles are promising carriers for VD3 and other hydrophobic bioactive food factors.