Nanoporous Anodic Alumina (NAA) for Drug Delivery Applications

Abstract

To address limitations of conventional drug delivery associated with poor drug solubility, stability, unfavorable pharmacokinetics in biological environment, lack of selectivity and severe toxicity, development of nanotechnology approaches based on nanoporous nanomaterials as new drug carriers and devices is recognized as a promising strategy. Among them, nanoporous anodic alumina (NAA) fabricated by electrochemical methods, possessing desirable biocompatibility and physical and chemical properties with unique arrays of ordered nanostructures, is offering many advantages together with the ability to be used as an admirable drug carrier for designing new and advanced drug delivery systems. Recent studies clearly show the potential of NAA materials as localized drug delivery devices in orthopedics/dental implants, vascular stents, and immunoisolation where not only the controlled release of drugs, such as antibiotics or growth factors, is desired, but also appropriate bio-integration is needed. In this chapter, we collect and present some of the most relevant aspects of the recent research and development of NAA materials for drug delivery applications. To provide a comprehensive overview to the reader, this review firstly discusses biocompatibility aspects, which are the major prerequisite for the application of materials that come into contact with biological systems. Secondly, the basic aspects of the NAA materials including structure, fabrication, and properties are presented to better understand their potential and current development to demonstrate their applications for designing advanced and smart drug delivery systems. Most important examples of these demonstrated concepts are to improve NAA performances, their sustainable drug release, targeting, and triggered drug delivery systems. Other applications such as biocapsules and coronary stents have also been presented, including examples of in vitro and in vivo studies. Finally, a general overview and concluding remarks on recent trends, key challenges, and perspectives in the field of applications of NAA for drug delivery and their translation are presented.