Abstract: Devices and methods are provided that allow for the casting of flat, controlled thickness layers of gel or polymer on a test surface, such as within the wells of a microplate. A spacer device is interposed between the test surface and the planar lower face of a movable pillar, defining a highly uniform volume. Addition of a gel or polymer precursor in solution followed by curing generates a highly uniform gel or polymer layer with a planar upper surface within this volume, which is exposed on removal of the pillar. In some embodiments a group of pillars is provided in a manifold that provides spacing and arrangement corresponding to a group of test wells. The pillars are mounted in the manifold so as to provide translation movement normal to the test surface, allowing them to rest against the spacer device and facilitating gentle removal from the wells. A variety of spacer devices are considered, including beads, flattened rings, and toroidal spacers.

Abstract: Devices and methods for the manipulation and handling of light blocking masks suitable for controlled illumination of the wells of multi-well test plates are described. Such controlled illumination can be used to generate simple or complex three dimensional forms within the wells when used in combination with suitable photoactivatable polymer or gel precursors. Light blocking masks of the inventive concept can include features that stabilize or grip a multiwell plate when in use. Such masks can have apertures having a fixed configuration, or can have apertures with transient or changeable configurations.

Abstract: The inventive subject matter provides methods for reproducibly fabricating hydrogel-based organ and tumor models inside multi-well plates. A hydrogel precursor, which can include cells, is instilled into a well. A pillar is inserted into the well to contact the hydrogel precursor with a surface that can be shaped or textured to provide a desired surface configuration or contour, for example that of a desired organoid or tumor feature. The hydrogel precursor is polymerized and the pillar removed. A second hydrogel precursor, which can contain a different cell type, is then instilled into the well and a second pillar, which can have a different configuration or texture, inserted. Subsequent polymerization generates a second hydrogel portion within the well. Polymerization can be carried out by photopolymerization. Different wells can be aligned with different, individually controlled light sources or a single, collimated light source.

Abstract: The inventive subject matter provides an apparatus for reproducibly fabricating hydrogel-based organ and tumor models inside multi-well plates. For example, tumor models made using the inventive apparatus can be used for studying the progression of cancer, cancer diagnostics, and therapeutic screening. A mold controls the thickness of each hydrogel layer. A photomask controls the size and shape of each hydrogel layer, allowing the hydrogel diameter to be smaller than the diameter of each well so that liquid media can be exchanged around both the sides and top of the hydrogels. A holder aligns the photomask with the multi-well plate, and polymerization is initiated by a light source.