Self-assembling microparticles with controllable disruption properties based on cyclodextrin interactions

In this paper, we present the formation of particles by self-assembly of cyclodextrin polymers and hydrophobically modified dextran followed by a controlled disruption of the particles by addition of a trigger molecule competing for the cyclodextrin cavities. The produced particles are formed from poly(vinylpyrrolidone)-co-beta-cyclodextrin and dextran-benzoate, both biocompatible polymers, and are all in the nano-/micrometer range and hence suitable for drug delivery purposes. The particle formation was studied in different ratios of poly(vinylpyrrolidone)-co-beta-cyclodextrin and dextran-benzoate by visual inspections, dynamic light scattering, isothermal titration calorimetry and SEM. The triggering of particle disruption was achieved by addition of hydroxyadamantane which has a very strong affinity towards the beta-cyclodextrin cavities. The stepwise addition of hydroxyadamantane was followed by dynamic light scattering and SEM measurements, revealing a disruption of the particles due to the addition of this competitor. These particles are believed to be promising candidates for controlled drug delivery systems, due to their unique ability to disrupt in a controlled manner. (C) 2009 Elsevier B.V. All rights reserved.