title: Biocompatible micro-gel particles from cross-linked casein micelles.
abstract: The stability of internally cross-linked casein micelles against disruption by urea (which disrupts hydrogen bonds and hydrophobic interactions) and trisodium citrate (which sequesters micellar calcium phosphate) was investigated. Addition of urea (0-6 mol L-1) and/or citrate (0-50 mmol L-1) progressively reduced the turbidity of a suspension of casein micelles cross-linked by transglutaminase and increased particle size (determined by dynamic and static light scattering and small-angle neutron scattering), which was attributed to swelling of the micelles. Furthermore, model calculations, assuming a completely stable casein network, were performed to describe the decreases in turbidity on addition of urea and citrate. Measured and described turbidity values are in agreement, indicating that cross-linking of casein micelles with transglutaminase results in a covalently bound protein network, which is entirely stable to disruption by urea and/or citrate. This may offer potential applications for the use of cross-linked casein micelles as biocompatible protein micro-gel particles.
authors.affiliation: Department of Food and Nutritional Sciences, University College Cork, Cork, Ireland. t.huppertz@uq.edu.au
authors.forename: Thom
authors.initials: T
authors.lastname: Huppertz
authors.forename: Mary A
authors.initials: MA
authors.lastname: Smiddy
authors.forename: Cornelis G
authors.initials: CG
authors.lastname: de Kruif
mesh_terms: D002364:Caseins / Q000737:chemistry*; D008823:Micelles; D033363:Neutron Diffraction; D010316:Particle Size; D053838:Scattering, Small Angle; D011503:Transglutaminases / Q000737:chemistry
chemical_list: D002364:Caseins; D008823:Micelles; D011503:Transglutaminases