Macroporous chitosan hydrogels: Effects of @entity599 on the loading and release behaviour of XXXX -based compounds.

@entity1522 @entity8959 @entity462 @entity5731 @entity3884 @entity5634 @entity2041 @entity1434 @entity4857 @entity599 @entity3689 @entity12274
Chitosan is a biodegradable, biocompatible polymer of natural origin widely applied to the preparation of functional hydrogels suitable for controlled release of drugs, peptides and proteins. Non-covalent interactions, expecially ionic interactions, are the main driver of the loading and release behaviour of @entity1522 or peptides from chitosan hydrogels. With the aim to improve the understanding of the mechanisms governing the behaviour of chitosan hydrogels on peptide uptake and delivery, in this paper the attention was focused on the role played by @entity599 on the interactions of chitosan hydrogels with @entity599 -containing @entity1522 (AA) and peptides. Hence, loading and release experiments on @entity462 , @entity1434 and @entity2041 (SH containing @entity3689 , @entity5634 and @entity12274 , respectively) as well as on @entity8959 and @entity4857 as apolar @entity1522 were carried out. For these puroses, chitosan hydrogels were prepared in an easy and reproducible manner by a freeze-gelation process on a @entity5731 coated support. The hydrogel surface pore size, uniformity and distribution were tested. Optimal results (D50=26  4 m) were obtained by using the @entity5731 positively-charged surface. The loading results gathered evidenced that the @entity599 -containing molecules presented an increased absorption both in terms of rate and extent by chitosan hydrogels with respect to nonpolar @entity1522 , mainly due to ionic and @entity3884 bond interactions. ATR-FTIR analysis carried out on chitosan hydrogels, with and without the AA related compounds to study putative interactions, supported these apparent @entity599 -dependent results. Finally, chitosan hydrogels displayed excellent retention capabilities (AA release <5%) for all AA, strongly supporting the use of chitosan hydrogels as matrix for controlled drug release.
