The invention is directed to methods for fabricating devices from polymer precursors, along with devices so fabricated. The methods of the invention include the steps of plasma treating a polymer based resin, paste, preform billet, or extrudate, and employing the treated polymer in the fabricated device. According to one embodiment, the fabricated device can include implantable prosthetics such as heart valves, sutures, vascular access devices, vascular grafts, shunts, catheters, single layered membranes, double layered membranes, and the like. Devices fabricated according to one embodiment of the invention include regions having selected porosity, permeability and/or chemistry characteristics.