A self-healing, scratch resistant slippery surface that is manufactured by wicking a chemically-inert, high-density liquid coating over a roughened solid surface featuring micro and nanoscale topographies is described. Such a slippery surface shows anti-wetting properties, as well as exhibits significant reduction of adhesion of a broad range of biological materials, including particles in suspension or solution. Specifically, the slippery surfaces can be applied to medical devices and equipment to effectively repel biological materials such as blood, and prevent, reduce, or delay coagulation and surface-mediated clot formation. Moreover, the slippery surfaces can be used to prevent fouling by microorganisms such as bacteria.