A method of making a medical implant is provided by electrospinning a polymer solution to form a preform around a mandrel. The formed preform distinguishes an inner surface and an outer surface. The formed preform is removed from the mandrel and flipped inside-out resulting in the inner surface of the formed preform becoming the outer surface of the inside-out flipped preform, and the outer surface of the formed preform becoming the inner surface of the inside-out flipped preform. At least part of the inside-out flipped preform forms the medical implant such as e.g. an artificial heart valve, an artificial leaflet, an artificial graft, or an artificial vessel. The products made according to the method of this invention greatly improve the performance and durability of the medical implant.