title: Mouse and human islets survive and function after coating by biosilicification.
abstract: Inorganic materials have properties that can be advantageous in bioencapsulation for cell transplantation. Our aim was to engineer a hybrid inorganic/soft tissue construct by inducing pancreatic islets to grow an inorganic shell. We created pancreatic islets surrounded by porous silica, which has potential application in the immunoprotection of islets in transplantation therapies for type 1 diabetes. The new method takes advantage of the islet capsule surface as a template for silica formation. Mouse and human islets were exposed to medium containing saturating silicic acid levels for 9-15 min. The resulting tissue constructs were then cultured for up to 4 wk under normal conditions. Scanning electron microscopy and energy dispersive X-ray spectroscopy was used to monitor the morphology and elemental composition of the material at the islet surface. A cytokine assay was used to assess biocompatibility with macrophages. Islet survival and function were assessed by confocal microscopy, glucose-stimulated insulin release assays, oxygen flux at the islet surface, expression of key genes by RT-PCR, and syngeneic transplant into diabetic mice.
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana;
authors.forename: David B
authors.initials: DB
authors.lastname: Jaroch
authors.forename: Jing
authors.initials: J
authors.lastname: Lu
authors.forename: Rajtarun
authors.initials: R
authors.lastname: Madangopal
authors.forename: Natalie D
authors.initials: ND
authors.lastname: Stull
authors.forename: Matthew
authors.initials: M
authors.lastname: Stensberg
authors.forename: Jin
authors.initials: J
authors.lastname: Shi
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Kahn
authors.forename: Ruth
authors.initials: R
authors.lastname: Herrera-Perez
authors.forename: Michael
authors.initials: M
authors.lastname: Zeitchek
authors.forename: Jennifer
authors.initials: J
authors.lastname: Sturgis
authors.forename: J Paul
authors.initials: JP
authors.lastname: Robinson
authors.forename: Mervin C
authors.initials: MC
authors.lastname: Yoder
authors.forename: D Marshall
authors.initials: DM
authors.lastname: Porterfield
authors.forename: Raghavendra G
authors.initials: RG
authors.lastname: Mirmira
authors.forename: Jenna L
authors.initials: JL
authors.lastname: Rickus
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003922:Diabetes Mellitus, Type 1 / Q000628:therapy; D004339:Drug Compounding / Q000379:methods*; D006801:Humans; D007515:Islets of Langerhans / Q000166:cytology* / Q000502:physiology*; D016381:Islets of Langerhans Transplantation / Q000379:methods; D051379:Mice; D010100:Oxygen / Q000378:metabolism; D044367:Phase Transition; D012822:Silicon Dioxide / Q000737:chemistry*; D023822:Tissue Engineering / Q000379:methods
chemical_list: D020099:Coated Materials, Biocompatible; D012822:Silicon Dioxide; D010100:Oxygen
keywords: coating; encapsulation; islet; silica; tissue engineering