A wound closure device comprises a first frame and a flexible tubular section connected to the first frame, the first frame implantable through a wound in a patient's skin into a lumen of a blood vessel with a portion of the tubular section extending out through the skin. The tubular section has a first portion and a second portion, a wall of the tubular section defining a coaxial inner bore. Twisting the first portion relative to the second portion of the tubular section closes the bore is closed in an area of the tubular section between the first and second portions, thereby closing the wound. Also disclosed is an embodiment for closing an opening in a heart, as well as a delivery device, systems, and methods.