Maria Porta-i-Batalla, Chris Eckstein, Elisabet Xifré-Pérez, Pilar Formentín, J. Ferré-Borrull and Lluis F. Marsal, at Department of Electronic, Electric and Automatics Engineering, Universitat Rovira i Virgili, have developed a way of using nanoporous anodic alumni (NAA), combined with layers of polyelectrolytes, to control drug release. How this works is that the drug is contained within a capsule with an anodized alumina layer, where the researchers could precisely control the size, distribution, and shape of the nanopores, and also layers of polyectrolytes, which would dissolve in response to and at rates controlled by the surrounding pH. They published their results in an article titled, “Sustained, Controlled and Stimuli-Responsive Drug Release Systems Based on Nanoporous Anodic Alumina with Layer-by-Layer Polyelectrolyte” published recently in Nanoscale Research Letters.

Porta-i-Batalla et al. first created the alumina portion of the system using a two-step anodization process, and then they assembled the polyelectrolyte layers (using two, five, and eight bilayers). They then tested this system with DOX hydrocholoride, and tested this system in phosphate buffered saline with pHs of 7.4 and 5.2. They then measured the release rates, and analyzed the delivery structure using scanning electron microscopy.

They concluded that this construction is highly effective at sustained, controlled, and stimuli-responsive drug release.