Abstract: A branch prosthesis configured for placement in a branch vessel includes an expandable tubular body portion, an expandable annular flange attached to a proximal end of the body portion, and a sealing sleeve proximally extending from the annular flange. The sealing sleeve is adapted to deform to a generally straight cylindrical hollow shape during implantation. When deployed, the sealing sleeve rolls up to a tightly-wound coil that bears against the annular flange. When used in conjunction with a main prosthesis having a side opening and deployed within in a main vessel, the annular flange of the branch prosthesis engages an outer surface of the main prosthesis around a perimeter of the side opening and the sealing sleeve engages an inner surface of the main prosthesis around the perimeter of the side opening to form a fluid-tight seal between the main prosthesis and the branch prosthesis.

Abstract: A branch prosthesis configured for placement in a branch vessel includes an expandable tubular body portion, an expandable annular flange attached to a proximal end of the body portion, and a sealing sleeve proximally extending from the annular flange. The sealing sleeve is adapted to deform to a generally straight cylindrical hollow shape during implantation. When deployed, the sealing sleeve rolls up to a tightly-wound coil that bears against the annular flange. When used in conjunction with a main prosthesis having a side opening and deployed within in a main vessel, the annular flange of the branch prosthesis engages an outer surface of the main prosthesis around a perimeter of the side opening and the sealing sleeve engages an inner surface of the main prosthesis around the perimeter of the side opening to form a fluid-tight seal between the main prosthesis and the branch prosthesis.

Abstract: An implantable biological device including a semipermeable membrane formed into a geometric shape capable of encapsulating biological cells and capable of immunoisolating the biological cells upon introduction into the body, the semipermeable membrane including an amphiphilic copolymer network having hydrophobic segments and hydrophilic segments, wherein the hydrophobic segments include polyolefins terminated with radicals selected from the group consisting of acryloyl groups, methacryloyl groups and mixtures thereof and wherein the hydrophilic segments include polyacrylates. Also provided is a method of encapsulating and immunoisolating cells using the semipermeable membrane and method of treating ailments using the implantable biological device.