Large Hydrogel Capsules (>1mm) for Encapsulation of Therapeutic Cells and Cell Aggregates

Biomedical devices for implantation with decreased pericapsular fibrotic overgrowth are disclosed. The device includes biocompatible materials and has specific characteristics that allow the device to elicit less of a fibrotic reaction after implantation than the same device lacking one or more of these characteristic that are present on the device. Biocompatible hydrogel capsules encapsulating mammalian cells having a diameter of greater than 1 mm, and optionally a cell free core, are disclosed which have reduced fibrotic overgrowth after implantation in a subject. Methods of treating a disease in a subject are also disclosed that involve administering a therapeutically effective amount of the disclosed encapsulated cells to the subject.