P-260

Functional islet tissue engineering in subcutaneous site using fabricated islet cell sheets

H. Shimizu¹
Fukushima Medical University, Fukushima, Japan

Background: Cell-based therapy using pancreatic islets has been established as a promising new approach for treating insulin-dependent diabetes mellitus (DM). For advancing islet-based therapies for DM, further improvements are important in optimizing the conditions to maximize the longevity of the transplanted islets. The present study discusses our novel and scaffold-free based tissue engineering approach by fabricating a monolayered tissue sheet composed of dissociated pancreatic islet cells for creating functional and neo-islet tissues in the subcutaneous site.

Methods and Results: The temperature-responsive culture dish was prepared by covalently grafting the temperature-responsive polymer, poly(N-isopropylacrylamide) (PIPAAm) on the culture dish. Islet cell suspensions were obtained from Lewis rats, and were plated onto the PIPAAm dishes coated with rat laminin-5. After the cells reached confluency, islet cells were successfully harvested as a uniformly spread tissue sheet by lowering the culture temperature to 20°C for 20 min. The functional activity of the islet cell sheets was confirmed by histological examination and insulin secretion assay prior to in vivo transplantation. Histological examination and transmission electron microscopy showed that harvested cell sheet had a monolayered 2-D structure, which established and retained its structural cell-to-cell connections. Being covalently bounded on the culture dish, PIPAAm never be transferred to islet cell layer. The fabricated islet cell sheets were transplanted into the subcutaneous space of SCID mice. Histological assessments of the subcutaneous site revealed that thin layered neo-islet tissues formed in all the recipient mice. Recipient blood glucose levels revered to normal levels, confirming that therapeutic values could be provided by this islet bioengineering procedure.

Conclusions: The present study describes an approach to generate a functional sheet of islet cells, which can be subsequently transplanted in vivo. Furthermore, the DM therapeutic value of this cell sheet-based islet tissue engineering approach was experimentally confirmed in the present study.

P-260

Functional islet tissue engineering in subcutaneous site using fabricated islet cell sheets

H. Shimizu¹
Fukushima Medical University, Fukushima, Japan

Background: Cell-based therapy using pancreatic islets has been established as a promising new approach for treating insulin-dependent diabetes mellitus (DM). For advancing islet-based therapies for DM, further improvements are important in optimizing the conditions to maximize the longevity of the transplanted islets. The present study discusses our novel and scaffold-free based tissue engineering approach by fabricating a monolayered tissue sheet composed of dissociated pancreatic islet cells for creating functional and neo-islet tissues in the subcutaneous site.

Methods and Results: The temperature-responsive culture dish was prepared by covalently grafting the temperature-responsive polymer, poly(N-isopropylacrylamide) (PIPAAm) on the culture dish. Islet cell suspensions were obtained from Lewis rats, and were plated onto the PIPAAm dishes coated with rat laminin-5. After the cells reached confluency, islet cells were successfully harvested as a uniformly spread tissue sheet by lowering the culture temperature to 20°C for 20 min. The functional activity of the islet cell sheets was confirmed by histological examination and insulin secretion assay prior to in vivo transplantation. Histological examination and transmission electron microscopy showed that harvested cell sheet had a monolayered 2-D structure, which established and retained its structural cell-to-cell connections. Being covalently bounded on the culture dish, PIPAAm never be transferred to islet cell layer. The fabricated islet cell sheets were transplanted into the subcutaneous space of SCID mice. Histological assessments of the subcutaneous site revealed that thin layered neo-islet tissues formed in all the recipient mice. Recipient blood glucose levels revered to normal levels, confirming that therapeutic values could be provided by this islet bioengineering procedure.

Conclusions: The present study describes an approach to generate a functional sheet of islet cells, which can be subsequently transplanted in vivo. Furthermore, the DM therapeutic value of this cell sheet-based islet tissue engineering approach was experimentally confirmed in the present study.