Micellar structure of decenyl succinic anhydride modified pullulan with degree of substitution dependence in aqueous solution

A broad distribution pullulan (PUL) sample was hydrophobically modified by a relative longer decenyl succinic anhydride (DCSA) side chains with seven different degree of substitution (DS) to obtain the PUL-DCSA. The micellar structure of PUL-DCSA with DS dependence was investigated by pyrene-probe fluorescence and small-angle X-ray scattering (SAXS) in 0.05 M aqueous NaCl. While PUL-DCSA with DS > 0.26, both the SAXS and fluorescence results can be explained by the flower necklace model, when DS FN and larger number of monomer (glucose residues) per unit flower micelle N0u of PUL-DCSA, mainly due to the difference in the different hydrophobic alkyl side chains. This research will provide a theoretical guidance for designing biomedical materials with appropriate scale and characteristic functions in drug delivery system. © 2024 Elsevier Ltd