Abstract: A biocompatible membrane composite including a cell impermeable layer and a mitigation layer is provided. The cell impermeable layer is impervious to vascular ingrowth and prevents cellular contact from the host. Additionally, the mitigation layer includes solid features. In at least one embodiment, mitigation layer has therein bonded solid features. In some embodiments, the cell impermeable layer and the mitigation layer are intimately bonded or otherwise connected to each other to form a composite layer having a tight/open structure. A reinforcing component may optionally be positioned external to or within the biocompatible membrane composite to provide support to and prevent distortion. The biocompatible membrane composite may be used in or to form a device for encapsulating biological entities, including, but not limited to, pancreatic lineage type cells such as pancreatic progenitors.

Abstract: A biocompatible membrane composite including a first layer (cell impermeable layer), a second layer (a mitigation layer), and a third layer (a vascularization layer) is provided. The mitigation layer may be positioned between the cell impermeable layer and the vascularization layer In some embodiments, the cell impermeable layer and the mitigation layer are intimately bonded to form a composite layer having a tight/open structure. A reinforcing component may optionally be positioned on either side of the biocompatible membrane composite or within the biocompatible membrane composite to provide support to and prevent distortion of the membrane composite. The biocompatible membrane composite may be used in or to form a device for encapsulating biological entities, including, but not limited to, pancreatic lineage type cells such as pancreatic progenitors.

Abstract: Cell encapsulation devices for biological entities and/or cell populations that contain at least one biocompatible membrane composite are provided. The cell encapsulation devices mitigate or tailor the foreign body response from a host such that sufficient blood vessels are able to form at a cell impermeable surface. Additionally, the encapsulation devices have an oxygen diffusion distance that is sufficient for the survival of the encapsulated cells so that the cells are able to secrete a therapeutically useful substance. The biocompatible membrane composite is formed of a cell impermeable layer and a mitigation layer. The cell encapsulation device maintains an optimal oxygen diffusion distance through the design of the cell encapsulation device or through the use of lumen control mechanisms. Lumen control mechanisms include a reinforcing component that is also a nutrient impermeable layer, internal structural pillars, internal tensioning member(s), and/or an internal cell displacing core.

Abstract: A biocompatible membrane composite that can provide an environment that is able to mitigate or tailor the foreign body response is provided. The membrane composite contains a mitigation layer and a vascularization layer. A reinforcing component may optionally be included to provide support to and prevent distortion of the biocompatible membrane composite in vivo. The mitigation layer may be bonded (e.g., point bonded or welded) or adhered (intimately or discretely) to an implantable device and/or cell system. The biocompatible membrane composite may be used as a surface layer for implantable devices or cell systems that require vascularization for function but need protection from the host's immune response, such as the formation of foreign body giant cells. The biocompatible membrane composite may partially or fully cover the exterior of an implantable device or cell system. The mitigation layer is positioned between the implantable device or bioactive scaffold and the vascularization layer.