Ultrathin parylene-c semipermeable membranes for biomedical applications

Abstract

Thin parylene C membranes having smooth front sides and ultrathin regions (e.g., 0.01 μm to 5 μm thick) interspersed with thicker regions are disclosed. The back sides of the membranes can be rough compared with the smooth front sides. The membranes can be used in vitro to grow monolayers of cells in a laboratory or in vivo as surgically implantable growth layers, such as to replace the Bruch's membrane in the eye. The thin regions of parylene are semipermeable to allow for proteins in serum to pass through, and the thick regions give mechanical support for handling by a surgeon. The smooth front side allows for monolayer cell growth, and the rough back side helps prevents cells from attaching there.

What is claimed is: 
     
         1 . A synthetic semipermeable membrane apparatus, comprising: a membrane having a smooth front side, a back side, and spatially interspersed thin and thick regions between the smooth front side and the back side, the thin regions being a predetermined thickness of parylene, the predetermined thickness selected from a thickness between 0.01 μm to 5 μm, the thick regions comprising parylene or another material 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 random or patterned array with an average feature size of about 1 μm to 30 μm.