Hydrogels generated by low-molecular-weight PEGylated luteolin and α-cyclodextrin through self-assembly for 5-fluorouracil delivery

Hydrophobic luteolin (LUT) was conjugated to the oligomeric chain of methoxypoly(ethylene glycol) (mPEG) to form novel amphiphilic mPEG(1900)-LUT conjugates. Then mPEG(1900)-LUT, by using its adjacent 3' and 4' hydroxyl groups, were assembled with magnetic Fe3O4 particles in an aqueous solution to form mPEG(1900)-LUT-Fe3O4 conjugates, which formed hybrid Fe3O4 particles. The spectral properties and micellization of the conjugates were studied. Both mPEG(1900)-LUT and mPEG(1900)-LUT-Fe3O4 conjugates were able to self-assemble into stable supramolecular hydrogels through alpha-cyclodextrin (alpha-CD) in water, and their gelation times and temperatures were determined. The hydrogels displayed typical porous structures, which are suitable for drug delivery. Therefore, 5-fluorouracil (5-FU) was loaded into the formed hydrogels to control its release in vitro. The drug release observations showed that introducing Fe3O4 particles into the hydrogel improved the sustained release effect.