Amphiphilic inulin-D-α-tocopherol succinate (INVITE) bioconjugates for biomedical applications

Herein is reported the synthesis and characterization of innovative inulin (INU)-vitamin E succinate (VITE) bioconjugates (INVITE). The obtained amphiphilic INU-based polymers, self-assembling in nanostructures, have been thought as new drug delivery systems (DDS) for the therapy of urinary tract infections (UTI). The synthesis of INVITE bioconjugates was carried out in bulk, without isolation of intermediate products, to reduce the amount of solvents used in the purification steps and to prevent possible VITE oxidation during work up. Six different INVITE conjugates (INVITE 1-6) have been synthesized by varying both the relative amount of VITE with respect to INU repetitive units and the reaction temperature. Afterwards, the ability of the new conjugates to form micelle systems, by applying two different established methods for critical aggregation concentration (CAC) evaluation, has been verified. Both methods produced similar CAC values ranging from 2.5 × 10(-3)mM to 2.4 × 10(-2)mM in agreement with the different degrees of derivatization shown by the INVITE 1-6 conjugates. The mean diameter of prepared INVITE micelles, resulted in the range 24-60 nm. The size of the obtained INVITE micelles did not change as measured at different time points up to 12 days, so confirming their stability upon storage.