title: Silk matrices promote formation of insulin-secreting islet-like clusters.
abstract: Ex vivo expansion of endocrine cells constitutes an interesting alternative to be able to match the unmet need of transplantable pancreatic islets. However, endocrine cells become fragile once removed from their extracellular matrix (ECM) and typically become senescent and loose insulin expression during conventional 2D culture. Herein we develop a protocol where 3D silk matrices functionalized with ECM-derived motifs are used for generation of insulin-secreting islet-like clusters from mouse and human primary cells. The obtained clusters were shown to attain an islet-like spheroid shape and to maintain functional insulin release upon glucose stimulation in vitro. Furthermore, in vivo imaging of transplanted murine clusters showed engraftment with increasing vessel formation during time. There was no sign of cell death and the clusters maintained or increased in size throughout the period, thus suggesting a suitable cluster size for transplantation.
authors.affiliation: Division of Protein Technology, School of Biotechnology, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden.
authors.forename: Nancy Dekki
authors.initials: ND
authors.lastname: Shalaly
authors.affiliation: The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital, S-17176 Stockholm, Sweden.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Ria
authors.affiliation: Division of Protein Technology, School of Biotechnology, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden.
authors.forename: Ulrika
authors.initials: U
authors.lastname: Johansson
authors.affiliation: The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital, S-17176 Stockholm, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Åvall
authors.affiliation: The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital, S-17176 Stockholm, Sweden.
authors.forename: Per-Olof
authors.initials: PO
authors.lastname: Berggren
authors.affiliation: Division of Protein Technology, School of Biotechnology, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden; Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden. Electronic address: myh@kth.se.
authors.forename: My
authors.initials: M
authors.lastname: Hedhammar
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000737:chemistry*; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism; D016381:Islets of Langerhans Transplantation; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009842:Oligopeptides / Q000737:chemistry; D013508:Ophthalmologic Surgical Procedures; D047011:Silk / Q000737:chemistry*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D007328:Insulin; D009842:Oligopeptides; D047011:Silk; C047981:arginyl-glycyl-aspartic acid; D005947:Glucose
keywords: Insulin release; In vivo imaging; Islet-like clusters; Pancreatic islets; Recombinant spider silk; Vascularization