A stent scaffold combined with amniotic tissue provides for a biocompatible stent that has improved biocompatibility and hemocompatibility. The amnion tissue can be variously modified or unmodified form of amnion tissue such as non-cryo amnion tissue, solubilized amnion tissue, amnion tissue fabric, chemically modified amnion tissue, amnion tissue treated with radiation, amnion tissue treated with heat, or a combination thereof. Materials such as polymer, placental tissue, pericardium tissue, small intestine submucosa can be used in combination with the amnion tissue. The amnion tissue can be attached to the inside, the outside, both inside and outside, or complete encapsulation of the stent scaffold. In some embodiments, at least part of the covering or lining comprises a plurality of layers of amnion tissue. The method of making the biocompatible stent and its delivery and deployment are also discussed.

Medical devices in accordance with various embodiments of the present invention employ one or more coaxial screw gear sleeve mechanisms. In various embodiments, coaxial screw gear sleeve mechanisms include a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing the device to expand.