P-258

A prevascularized implantable device for islet transplantation

S. Williams, L. Krishnan, R. Reed, L. Kleinert, L. Clayton, E. Boland, J. Hoying
Cardiovascular Innovation Institute, Louisville, USA

Objectives: The goal of our laboratory is to develop a dual-function islet delivery device that provides both immunoisolation and supports rapid neovascularization. The functional aspect of the device consists of an electrospun dual layer such that the inner layer restricts cellular infiltration, and the outer layer is designed to create an environment promoting the formation of blood vessels. Additional extracellular matrix-based, biocompatible surface coatings can be applied to the outer side in order to modulate the neovascularization response. Islet survival and function will be assessed after delayed implantation into such devices.

Methods: A novel electrospinning approach was used to create a dual porosity nylon matte formed into either a pouch or a tube over perforated implantable silicone tubing. Optimized conditions for electrospinning in a tubular design were used to create test device configurations. In parallel, we developed techniques for pro-vascularizing surface modifications of implantable polymers based on the adsorption of the extracellular matrix proteins laminin 332 and collagen type I. Further, we are evaluating the deposition of similar matrix molecules on the electrospun devices by cultured cells, which are lysed away with a detergent, to expose the underlying extracellular matrix, prior to implantation. Various functional aspects of the device are being evaluated in a mouse model of implantation.

Results: Electrospinning technology was used to achieve a dual porosity device with an inner layer providing cellular immunoisolation while maintaining solute flux and an outer layer supporting neovascularization.

Conclusions: Electrospinning and surface modification has been used to construct a dual porosity tubular device for islet transplantation. The device withstands manipulation and maintains structural integrity. External surface modification of polymers using matrix molecules supports accelerated neovascularization. The data suggest that this dual porosity electrospun device is an ideal islet transplantation vehicle.

P-258

A prevascularized implantable device for islet transplantation

S. Williams, L. Krishnan, R. Reed, L. Kleinert, L. Clayton, E. Boland, J. Hoying
Cardiovascular Innovation Institute, Louisville, USA

Objectives: The goal of our laboratory is to develop a dual-function islet delivery device that provides both immunoisolation and supports rapid neovascularization. The functional aspect of the device consists of an electrospun dual layer such that the inner layer restricts cellular infiltration, and the outer layer is designed to create an environment promoting the formation of blood vessels. Additional extracellular matrix-based, biocompatible surface coatings can be applied to the outer side in order to modulate the neovascularization response. Islet survival and function will be assessed after delayed implantation into such devices.

Methods: A novel electrospinning approach was used to create a dual porosity nylon matte formed into either a pouch or a tube over perforated implantable silicone tubing. Optimized conditions for electrospinning in a tubular design were used to create test device configurations. In parallel, we developed techniques for pro-vascularizing surface modifications of implantable polymers based on the adsorption of the extracellular matrix proteins laminin 332 and collagen type I. Further, we are evaluating the deposition of similar matrix molecules on the electrospun devices by cultured cells, which are lysed away with a detergent, to expose the underlying extracellular matrix, prior to implantation. Various functional aspects of the device are being evaluated in a mouse model of implantation.

Results: Electrospinning technology was used to achieve a dual porosity device with an inner layer providing cellular immunoisolation while maintaining solute flux and an outer layer supporting neovascularization.

Conclusions: Electrospinning and surface modification has been used to construct a dual porosity tubular device for islet transplantation. The device withstands manipulation and maintains structural integrity. External surface modification of polymers using matrix molecules supports accelerated neovascularization. The data suggest that this dual porosity electrospun device is an ideal islet transplantation vehicle.