Chitosan-PEG-folate-Fe(III) complexes as nanocarriers of epigallocatechin-3-gallate

Controlled release nanocarriers systems are promising for the administration of epigallocatechin-3-gallate (EGCG) in the treatment and prevention of several diseases. Therefore, the stability and therapeutic effects of EGCG must be enhanced from an encapsulation strategy. Thus, this research aims to explore a method to prepare EGCG nanocarriers based on coordination complexes from Fe (III) ions and blends of modified chitosan (Ch) with polyethylene glycol (PEG) and folic acid (F). Different degrees of deacetylated Ch and conjugated with F were evaluated, whose values determined the final amount of Fe (III) in the complexes. All these complexes were amorphous with a polydispersity index (PDI) higher than 0.3. The assembling and homogeneity were improved adding tripolyphosphate (TPP), yielding particle sizes near 200 nm, and PDI values of 0.2, measured by DLS and TEM. The EGCG encapsulation efficiency was about 60%, and the loading capacity was in the range of 26% to 50%. The EGCG release profile displayed a controlled release without a burst effect, providing the best fit with the Korsmeyer-Peppas model, indicating interactions among EGCG and the polymer matrix. The above results reveal the potential of these nanocarriers as suitable systems for controlled release and have not yet been reported.