PVA-CO-AAM and peg-co-aam hydrogels as bromelain carriers

In this paper, hydrogels were prepared by copolymerization of acrylamide (AAm) with PVA and PEG to study the incorporation and release of bromelain. The association of bromelain with polyvinyl alcohol (PVA) or polyethylene glycol (PEG) in a hydrogel for controlled release has potential for burns noninvasive treatment and topical inflammatory occurrences. Total protein concentration and bromelain enzymatic activity was determined by Bradford and azocasein assay methods, respectively. Bro-PVA-co-AAm (bromelain loaded PVA hydrogels) incorporated 42.5 mg and 23.1 U, corresponding to 91.3% and 88.9%, respectively of protein content and enzymatic activity; while PEG hydrogels incorporated 41.4 mg and 16.0 U, corresponding to 88.9% and 53.8%, respectively. PVA and PEG hydrogels released less than 5% of the incorporated protein content after 24 h of study. However, release in terms of enzymatic activity reached 60% (Bro-PVA-co-AAm hydrogel) and 100% (BroPEG-co-AAm hydrogel). The joint analysis of hydrogels mechanical properties indicated that bromelain-loaded PVA hydrogels have more structural compatibility to biological conditions, due to a complex molecular architecture, with a lightweight, mucoadhesive, strong and soft constitution. Also, PVA-co-AAm synthesized hydrogels are able to absorb and release bromelain, indicating their potential use in a modified protein release system.

Automated summary

In this study, hydrogels were prepared by copolymerization to incorporate and release bromelain. The results showed that PVA hydrogels and PEG hydrogels had high efficiency in the incorporation and release of bromelain, with the ability to release controlled enzymatic activity within a certain time frame.