Sustained Drug Release from Non-eroding Nanoporous Templates
Evin Gultepe, Dattatri Nagesha, Bernard D. F. Casse, Ravinder Banyal, Trifon Fitchorov, Alain Karma, Mansoor Amiji, and Srinivas Sridhar
Mechanically robust implants are being used in many different parts of the body for various applications in orthopedics, cardiovascular stents and defibrillators. However there are numerous problems to overcome: reducing infections, enhancing implant bonding, preventing restenosis in cardiovascular stents, among others. we present results of the release of a model drug, doxorubicin (Dox), from different non-eroding nanoporous coatings. Detailed studies of drug release from these platforms in forms of anodic aluminum oxides (AAO) and anodic titanium oxides (ATO) were carried out. We show that nanoporous surfaces can achieve the sustained release rate over periods of several weeks similar to the polymeric platforms without the risks of delamination or leaching since they are not degradable. We show that the kinetics of the sustained release from these nanoporous platforms is well described by an activated surface density dependent desorption model which appears to be universal for non-eroding platforms. The results prove that the nanoporous platforms can be used as non-eroding sustained release systems which can be utilized as coatings on currently available implants such as cardio-vascular stents, orthopedic/dental implants, fiducials or spacers.