Methods and apparatus for a free-standing biodegradable patch suitable for medical applications, especially intravascular, minimally-invasive and intraoperative surgical applications are provided, wherein the patch comprises a free-standing film or device having a mixture of a solid fibrinogen component and a solid thrombin component that, when exposed to an aqueous environment, undergoes polymerization to form fibrin. In alternative embodiments the patch may comprise a solid fibrinogen component, with or without an inorganic calcium salt component. The patch may take a non-adherent form during delivery to a target location within a vessel or tissue, and thereafter may be activated to adhere to vessel wall or tissue, and may include a number of additives, including materials to improve the mechanical properties of the patch, or one or more therapeutic or contrast agents.