Meltelectrowriting of Polycaprolactone Thin Membranes with High Porosity

Abstract

An emerging polymer fiber-forming, additive manufacturing (AM) technique, “Melt Electrowriting” (MEW), has been used to build polymer scaffolds for tissue engineering applications (TE). Compared to other polymer forming AM technologies, MEW is a solvent-free process that we are using to produce extremely fine fibers with accurate positioning. This is suitable for the production of biologically relevant pore geometries that may encourage cell attachment, production of extracellular matrix, vascularization, and tissue-specific physiology. In regards to restoring or creating tissue-specific physiological function, MEW is also one of the few biofabrication modalities capable of forming thin sheets (i.e., thin membranes) with controlled seeding densities (e.g., as thin as a single cell thick) that can be positioned contiguously. The interaction of adjacent layers of different cell types is a functional requirement of many organs. In order to expand the variety of geometries that can be manufactured, our device separately controls nozzle position and the collector platform, such as a flat surface or a spinning mandrel. With our MEW device we can modulate parameters involved in the process such as voltage, pressure, and collector translation/rotation speed, to obtain thin membranes of stacked micro-fibers that produce pore sizes of approximately 1000-, 500-, and 250 μm Achieving that level of accuracy of fiber deposition requires the programming of kinematics (i.e, simultaneous movement) that is implied by these and other MEW parameters.