Structure/function relationship of several biopolymers as related to invertase stability in dehydrated systems

SANTAGAPITA, PATRICIO R.; GÓMEZ BRIZUELA, LEISSY; MAZZOBRE, M. FLORENCIA; RAMIREZ, HÉCTOR L.; CORTI, HORACIO R.; VILLALONGA SANTANA, REYNALDO; BUERA, M. PILAR

BIOMACROMOLECULES

ACS Publications

Lugar: Washington, DC; Año: 2008 vol. 9 p. 741 - 747

1525-7797

Structure/function relationships of different biopolymers (alginate, dextran or B-cyclodextrin) were analyzed as single excipients or combined with trehalose in relation to their efficiency as enzyme stabilizers in freeze-dried formulations, and compared to trehalose. Particularly, a novel synthesized polymer beta-cyclodextrin-branched alginate (B-CD-A) was employed as excipient. During freeze-drying, the polymers or their mixtures did not confer better protection to invertase compared to trehalose. B-CD-A (with or without trehalose), B-cyclodextrin (B-CD) or dextran with trehalose were the best protective agents during thermal treatment, while B-CD and alginate showed a negative effect on invertase activity preservation. The B-CD linked alginate combined the physical stability provided by alginate with the stabilization of hydrophobic regions of the enzyme provided by cyclodextrin. B-CD-A was effective even at conditions at which trehalose lost its protective effect. A relatively simple covalent combination of two biopolymers significantly affected their functionalities and, consequently, their interactions with proteins, modifying enzyme stability patterns.