Abstract: Microencapsulation of pancreatic islets within a thin poly(ethylene glycol) (PEG) coat is provided. The PEG coat is functionalized with an insulinotropic agent, glucagon-like peptide 1 (GLP-1). The encapsulated pancreatic islets may be used for the treatment of type I diabetes.

Abstract: The invention provides methods and apparatus for encapsulating particles. An inverted selective withdrawal technique is employed. Two immiscible fluids are added to a container, a first fluid is an aqueous pre-polymer solution with a crosslinking reagent and a second fluid is denser highly viscous fluid. A selective withdrawal tube pulls particles suspended in the first fluid through the second fluid. The particles retain a thin coating of the first fluid. The coated particles are then subjected to a crosslinking process where the pre-polymer solution of the first fluid surrounding the particles is converted into a hydrogel capsule.

Abstract: Particles such as islet cells are encapsulated by a method that forms a coating of uniform thickness that conforms to the size and shape of the particles. Two substantially immiscible liquids of different densities are provided in a container as upper and lower liquids such that an interface exists between the liquids. The upper liquid is less dense and has a greater viscosity than the lower liquid which is a coating liquid containing particles to be encapsulated. A tube is positioned in the upper liquid such that an orifice of the tube is above the interface. A pump connected to the tube sucks liquid through the tube at a rate sufficient to form a spout containing substantially the lower liquid extending between the interface and the tube orifice. The spout has maximum diameter at the interface and decreases in diameter as the spout approaches the tube orifice.