Synthesis and transport characterization of alginate/aminopropyl-silicate/alginate microcapsule: application to bioartificial pancreas.
To develop a novel type of immunoisolation membrane for a microcapsule-shaped bioartificial pancreas, we attempted to use a sol-gel synthesized silicate. An aminopropyl-silicate membrane derived from 3-aminopropyltrimethoxysilane and tetramethoxysilane was formed on Ca-alginate gel beads via electrostatic interaction. The positively charged amino groups remaining on the surface of the resultant gel beads were neutralized by immersion in an aqueous Na-alginate solution. From measurements of the partition coefficients and effective diffusivities of different substances to the gel beads, it was found that the aminopropyl-silicate membrane prepared under optimized composition of silicon alkoxide precursors successfully rejected gamma-globulin, giving good permeability to substances having a low molecular weight. Islets could be encapsulated within the newly developed microcapsules while retaining their ability to secrete insulin.
Sakai
S
S
Department of Materials Process Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan. sakai@chem-eng.kyushu-u.ac.jp
Ono
T
T
Ijima
H
H
Kawakami
K
K
D000464:Alginates; D000818:Animals; D001672:Biocompatible Materials; D002214:Capsules; D005782:Gels; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism; D007332:Insulin Infusion Systems; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology / Q000378:metabolism; D008297:Male; D008422:Materials Testing; D008567:Membranes, Artificial; D051379:Mice; D010539:Permeability; D051381:Rats; D017208:Rats, Wistar; D017640:Silicates
D000464:Alginates; D001672:Biocompatible Materials; D002214:Capsules; D005782:Gels; D006603:Hexuronic Acids; D007328:Insulin; D008567:Membranes, Artificial; D017640:Silicates; D020723:Glucuronic Acid