A biodegradable device includes a substrate and a nano-ceramic/polymer composite coating thereon. The substrate may include MgY, AZ alloys, MgCa, MgZn, MgZnCa, MgZnCaZr, MgZnSr, MgLi, Ti, Ti-6Al-4V, CoCr, and CoCrMo. The composite coating may include a nano-ceramic and a polymer.