Drug-device systems based on biodegradable metals for bone applications: Potential, development and challenges

Drug-device systems based on biodegradable metals have been of great interest in the last decade due to their local-release regime and the ability of the biodegradable metals to degrade in the physiological environment facilitating tissue growth and gradual load transfer. The biodegradability of the biodegradable metals provides a promising medium that might enable other materials – such as drugs, bioactive materials and therapeutic agents - to be incorporated into the degradable metals to act as a drug-device system that would locally release the drugs or therapeutic agents onto the healing tissue. In comparison to systemic drug delivery, the locally released drug-device system makes the dose control over a specific targeted tissue more efficient and reduces the side effects on non-targeted tissues. This review outlines the current state of development of the biodegradable metals-based drug-device system and focuses in-depth on the potential interactions between the drugs, degradable metallic surfaces, drug carriers, ions and proteins inside the body fluids, which can be a challenge to producing a highly efficient drug-device system.