Retinol-encapsulated water-soluble succinated chitosan nanoparticles for antioxidant applications.

The aim of this study was to stabilize all-trans-retinol (RE) by complexification with chitosan derivatives through H-bonding. Succinated chitosan (CHI-succ) with three different degrees (5, 10, 20 mol%) of succinylation were synthesized to form complexes with RE. Various weight ratios (w/w) of CHI-succ/RE complexes were prepared and characterized to produce stable complexes in nanometer size. The CHI-succ(0.20)/RE complex with approximate 250 nm in diameter was obtained using a CHI-succ(0.20) concentration of 0.005% (w/v) in double deionized water with various contents of RE. From fine-tuning the degree of succinylation and the weight ratio of the CHI-succ and RE, the formation of supramolecular complexes simultaneously improved water solubility and stability of RE. The cell viability of CHI-succ polymers and their RE complexes in 3T3 cells were all>85% relative to the control. The antioxidant ability of the CHI-succ(0.20)/RE complexes was significantly greater than that of pure RE using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay (p<0.01).