Emulsan-Alginate Beads for Protein Adsorption

CASTRO, GUILLERMO R; CHEN JINGSONG,; PANILAITIS BRUCE,; KAPLAN DAVID L.

JOURNAL OF BIOMATERIALS SCIENCE - POLYMER EDITION

Brill (Ingenta)

Año: 2009 vol. 20 p. 411 - 426

0920-5063

Emulsans are amphiphilic biopolymers that have native high protein adsorption capacity as well as biological activation properties. In the present study, emulsan-alginate gel microspheres were prepared and challenged for protein adsorption. Bovine Serum Albumin (BSA) binding to the emulsan-alginate microspheres improved two-fold over alginate bead controls. Increased temperature, from 24 to 37ºC, resulted in an increase of ~40% in BSA adsorption for both emulsan-alginate and alginate beads, while protein adsorption by the emulsan-alginate system was less sensitive to changes in ionic strength. BSA adsorption by the microspheres was a pH-dependent process. The BSA adsorption between pH 8.5 to 5.3 in alginate microspheres is ranging from 25.36% to 37.8%, meanwhile the presence of emulsan increased BSA adsorption from 62.5% to 100% in the same pH interval. Monolayer adsorption with kinetic constants at least 2 times higher for emulsan-alginate beads compared to alginate controls were found when the Langmuir adsorption model was applied to analyze the BSA-microsphere interactions. To further explore the utility of these novel emulsan-alginate bead systems, complex cell-free supernatants from some typical pathogenic microorganisms were exposed to the emulsan-alginate beads and increased protein adsorption was found when compared to the controls. These trends were also confirmed with α-hemolysin toxicity studies. The data suggest that the protein-binding capacity of emulsan-alginate beads exceeds alginate controls, attributable to the unique binding features of the emulsan. This feature enhances the potential utility of bead and gel systems in which this amphiphilic polymer is included and suggests new opportunities to bind proteins using these types of systems