Permeability Variation Study in Collagen-Based Polymeric Capsules

Nanomedicine, the application of nanotechnologies to healthcare, is an area of nanotechnology which is promising and has extraordinary and far-reaching implications on human health both from the points of view of disease diagnosis and treatment. With regard to disease treatment, the possibility of developing new nanosystems for efficient drug delivery has attracted great attention. A prerequisite for nanotechnology-based delivery systems, in order to be effective, is that the encapsulated drug molecules have to be released at the site of interest. One method to obtain specific release is based on the development of systems sensitive to disease-associated overexpressed enzymes. In this study, we report on the fabrication of collagen-based containers for drug encapsulation and release by cellular demand by the action of the collagenolytic enzymes matrix metalloproteinases (MMPs). Collagen is the major component of the connective tissue and is involved in many biological functions. Its degradation is at the basis of different pathological processes. The up-regulated expression of MMPs is the cause of such degradation. Collagen-based capsules were fabricated by the layer-by-layer technique and characterized by scanning electron microscopy and confocal microscopy. Real-time monitoring of the release kinetics of loaded gold nanoparticles, having different diameters, was done by total reflection X-ray fluorescence. Excitation of the fluorescence was performed by grazing incidence X-ray beam of synchrotron radiation. This study represents the first attempt in estimating the distribution and dimension of pore size in polyelectrolyte nanoshells. © 2011 Springer Science+Business Media, LLC.