Biodegradable Inorganic Nanostructured Biomaterials for Drug Delivery

Biodegradable inorganic drug nanocarriers are widely investigated for efficient drug delivery with enhanced bioavailability and reduced side effects. An ideal drug nanocarrier should have high biocompatibility and good biodegradability to ensure high biosafety for applications in vivo. Many inorganic drug carriers including silica, metals, metal oxides, carbon-based materials are difficult to degrade, which may cause toxicity and restrict their clinical applications. Fortunately, biomineral-based drug nanocarriers including calcium phosphate, calcium carbonate, calcium silicate, etc. exhibit high biocompatibility and good biodegradability because they are the main inorganic constituents of biological hard tissues, and they can participate in the normal metabolism of the living body by dissolving into nontoxic ions. Thus, biomineral-based nanostructured materials are ideal biodegradable nanocarriers with high biocompatibility for drug delivery, and they are promising for clinical applications. In this review article, the recent advances of synthetic biomineral-based drug nanocarriers are discussed, and their characteristics, preparation, drug loading, and drug release, as well as their drug-delivery applications are highlighted. Finally, an outlook for the main future research directions and potential clinical applications of the synthetic biomineral-based drug nanocarriers is given.