Figure 1: The Mouse Corneal Micropocket Assay: First, a small implant is formed out of a liquid scaffold, which can be cross linked into a solid tissue construct using gentle conditions, and thus is amenable to encapsulation of growth factors (as well as cells). The scaffold can be designed to contain degradable cross linkers which are collagenase or matrix metalloproteinase sensitive, and can be functionalized with covalently bound growth factors. Then the cross linked hydrogel is implanted into a small pocket made between the endothelial layer of the cornea and the epithelial layer, by slowly interrogating the corneal stromal layer with a von graefe knife. The resultant pocket is long enough and deep enough for implantation of a small (200 micron diameter, 80 micron thick) implant. The implant contains diffusible growth factors which slowly diffuse and attract vessel invasion from the perilimbic vasculature. Over time these vessels may secrete collagenases to degrade the degradable hydrogels. After microvascularization, the resultant constructs can be removed or imaged live. Three dimensional pictures from confocal microscopy can allow for detailed rendering and morphological analysis.