Patent ID: 8877489

Claim:
A synthetic semipermeable membrane apparatus, comprising: a membrane having: a smooth front side, a back side, spatially interspersed thin and thick regions between the smooth front side and the back side, and a frame substantially surrounding a perimeter of the smooth front side of the membrane, the smooth front side facilitating the growth of a monolayer of cells, the thicker regions on the back side of the membrane being configured to prevent unwanted cell growth from cells growing on the smooth front side, the thin regions being a predetermined thickness of parylene-c, the predetermined thickness selected from a thickness between 0.01 μm to 5 μm, the thin regions configured to be permeable to protein-sized molecules and impermeable to cells, the thick regions comprising parylene-c and being at least 2 times thicker than the predetermined thickness of the thin regions, the interspersion of the thin and thick regions occurring in a patterned array with an average feature size of about 1 μm to 30 μm, and the frame configured to reduce unwanted migration of cells growing on the smooth front side of the membrane to the back side of the membrane.