OBJECTIVE: Our study aim was to determine encapsulated islet graft viability in an omentum pouch and the effect of fibroblast growth factor 1 (FGF-1) released from our redesigned alginate microcapsules on the function of the graft. METHODS: Isolated rat islets were encapsulated in an inner core made with 1.5% low-viscosity-high-mannuronic-acid alginate followed by an external layer made with 1.25% low-viscosity high-guluronic acid alginate with or without FGF-1, in microcapsules measuring 300 to 400 µm in diameter. The 2 alginate layers were separated by a perm-selective membrane made with 0.1% poly-L-ornithine, and the inner low-viscosity-high-mannuronic-acid core was partially chelated using 55 mM sodium citrate for 2 minutes. RESULTS: A marginal mass of encapsulated islet allografts (∼2000 islets/kg) in streptozotocin-diabetic Lewis rats caused significant reduction in blood glucose levels similar to the effect observed with encapsulated islet isografts. Transplantation of alloislets coencapsulated with FGF-1 did not result in better glycemic control, but induced greater body weight maintenance in transplant recipients compared with those that received only alloislets. Histological examination of the retrieved tissue demonstrated morphologically and functionally intact islets in the microcapsules, with no signs of fibrosis. CONCLUSIONS: We conclude that the omentum is a viable site for encapsulated islet transplantation.
OBJECTIVE: Our study aim was to determine encapsulated islet graft viability in an omentum pouch and the effect of fibroblast growth factor 1 (FGF-1) released from our redesigned alginate microcapsules on the function of the graft. METHODS: Isolated rat islets were encapsulated in an inner core made with 1.5% low-viscosity-high-mannuronic-acid alginate followed by an external layer made with 1.25% low-viscosity high-guluronic acid alginate with or without FGF-1, in microcapsules measuring 300 to 400 µm in diameter. The 2 alginate layers were separated by a perm-selective membrane made with 0.1% poly-L-ornithine, and the inner low-viscosity-high-mannuronic-acid core was partially chelated using 55 mM sodium citrate for 2 minutes. RESULTS: A marginal mass of encapsulated islet allografts (∼2000 islets/kg) in streptozotocin-diabetic Lewis rats caused significant reduction in blood glucose levels similar to the effect observed with encapsulated islet isografts. Transplantation of alloislets coencapsulated with FGF-1 did not result in better glycemic control, but induced greater body weight maintenance in transplant recipients compared with those that received only alloislets. Histological examination of the retrieved tissue demonstrated morphologically and functionally intact islets in the microcapsules, with no signs of fibrosis. CONCLUSIONS: We conclude that the omentum is a viable site for encapsulated islet transplantation.
Authors: Alyssa A Appel; Veronica Ibarra; Sami I Somo; Jeffery C Larson; Alfred B Garson; Huifeng Guan; John Patrick McQuilling; Zhong Zhong; Mark A Anastasio; Emmanuel C Opara; Eric M Brey Journal: Tissue Eng Part C Methods Date: 2016-11 Impact factor: 3.056
Authors: John Patrick McQuilling; Sivanandane Sittadjody; Rajesh Pareta; Samuel Pendergraft; Clancy J Clark; Alan C Farney; Emmanuel C Opara Journal: Methods Mol Biol Date: 2017
Authors: Veronica Ibarra; Alyssa A Appel; Mark A Anastasio; Emmanuel C Opara; Eric M Brey Journal: J Biomed Mater Res A Date: 2016-05-18 Impact factor: 4.396
Authors: John P McQuilling; Sivanandane Sittadjody; Samuel Pendergraft; Alan C Farney; Emmanuel C Opara Journal: Biomater Sci Date: 2017-11-21 Impact factor: 6.843
Authors: Edward X Han; Juan Wang; Mehmet Kural; Bo Jiang; Katherine L Leiby; Nazar Chowdhury; George Tellides; Richard G Kibbey; Jeffrey H Lawson; Laura E Niklason Journal: J Tissue Eng Date: 2021-06-28 Impact factor: 7.813