Functionalized biocompatible polyelectrolyte multilayers for drug delivery: In situ investigation of mechanical properties by dissipative quartz crystal microbalance

Nanostructured polymeric capsules have been applied in different fields, and specifically are regarded as promising for smart drug delivery applications. The physical-chemical and mechanical properties, and thus the permeability of the polyelectrolyte multilayer shell, play an important role in efficient delivery. Quartz crystal microbalance working in liquid has been used for the characterization of the buildup process and of the viscoelastic properties of biocompatible multilayers and of their functionalization by S-layer proteins. Optical and scanning electron microscopy have been used for the morphological characterization of nanostructured capsules obtained at physiological conditions by the assembly of the characterized multilayers onto spherical cores and by their subsequent removal. The proposed functionalized biocompatible capsules can be regarded as promising candidates for smart drug delivery applications. (C) 2013 Elsevier B.V. All rights reserved.