title: Production of monodisperse silica gel microspheres for bioencapsulation by extrusion into an oil cross-flow.
abstract: Silica gel microspheres are ideal materials for bioencapsulation due to their mechanical properties, biocompatibility, and stability. Encapsulated cells are isolated from the environment and protected from predators, changes in pH, and osmotic stress. However methods for the production of silica gel microspheres suitable for bioencapsulation are not well established. This paper describes a method for the production of monodisperse silicon alkoxide cross-linked silica nanoparticle (SNP) gel microspheres for bioencapsulation in which silica gel precursor is extruded from a needle into a cross-flowing stream of mineral oil. Microspheres produced ranged from 1.3 to 2.9 mm in diameter with coefficients of variation ranging from 2 to 6%. Microsphere size was mainly controlled by the flowrate of the cross-flowing oil and smaller microspheres generally had larger coefficients of variation. The method described in this paper can be optimised to produce silica gel microspheres with a diverse range of compositions and properties.
authors.affiliation: a Department of Mechanical Engineering , University of Minnesota , Minneapolis , MN , USA.
authors.forename: Joey J
authors.initials: JJ
authors.lastname: Benson
authors.affiliation: b Department of Biochemistry, Molecular Biology and Biophysics , University of Minnesota , Minneapolis , MN , USA.|c BioTechnology Institute, University of Minnesota , St. Paul , MN , USA.
authors.forename: Lawrence P
authors.initials: LP
authors.lastname: Wackett
authors.affiliation: a Department of Mechanical Engineering , University of Minnesota , Minneapolis , MN , USA.|c BioTechnology Institute, University of Minnesota , St. Paul , MN , USA.
authors.forename: Alptekin
authors.initials: A
authors.lastname: Aksan
keywords: Silica gel; bioencapsulation; emulsion; microsphere; sol-gel