Dispersion of halloysite nanotube/lipase nanohybrids as nanofillers into polyvinyl alcohol-sodium alginate cryogel: Characterization and bio-catalytic activity analysis.

The purpose of this study is to formulate and characterize the cryogels containing halloysite nanotube (HNT)/lipase nanohybrid (NH-cryogel) in comparison to pure cryogels as well as cryogels containing lipase (lipase-cryogel). The cryogels were synthesized using polyvinyl alcohol (PVA) and sodium alginate (SA). The products are tested to explore the influence of the HNT/lipase nanohybride (NH) as nanofillers on the cryogel properties using methods such as swelling degree, water uptake measurement, TGA, XRD, FESEM and FTIR. Additionally, the effects of cryogels on the stability and biocatalytic activities of lipase and NH, were studied and compared to the free lipase to evaluate their potential applications as enzyme carriers. The addition of nanofillers into the cryogel improved is thermal stability. The results implied that NH-cryogel had better enzyme activity than lipase-cryogel and free lipase at different temperatures and pH values. The NH-cryogel residual activity was 85.5 % after ten cycles of reuse while lipase-cryogel showed lower residual activity (60.3 %). Furthermore, the NH-cryogel retained 81.1 % of its residual activity while this was 51.0 % for lipase-cryogel after thirty days of storage. Therefore, the presented results in this study provide a pathway to show that produced nano-composite cryogels could be useful substances for food and pharmaceutical industries applications.