Dresden 2006 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 12: POSTER Colloids, Nanoparticles and Self-Organizing Systems

CPP 12.6: Poster

Tuesday, March 28, 2006, 17:00–19:00, P3

Monitoring enzymatic degradation of polymeric nanoparticles with scattering methods — •Thomas Siegemund^1,2, Bernd-Reiner Paulke³, Herbert Schmiedel¹, Natalie Bordag², Steffen Lindert¹, and Wolfgang Härtig² — ¹Universität Leipzig, Institut für Experimentalphysik I, Physik der weichen Materie, Linnéstraße 5, 04103 Leipzig — ²Universität Leipzig, Paul-Flechsig-Institut für Hirnforschung, Jahnallee 59, 04109 Leipzig — ³Fraunhofer Institut für angewandte Polymerforschung, Geiselbergstraße 69, 14476 Potsdam

Nanoparticles can be used as carriers for the delivery of drugs. We prepared nanoparticles as carriers for the model drug thioflavin T that binds Alzheimer’s disease related fibrillar amyloid β-peptides in the brain. These polymer colloids are composed of a polystyrene core and a degradable poly(butyl-2-cyanoacrylate) shell with diameters from 60 to 170 nm. The enzymatic degradation of core-shell nanoparticles, as required in vivo, was observed after their treatment with porcine liver esterase, a non-specific esterase, and basic/acidic hydrolysis in vitro. Shells of nanoparticles were dose-dependently degraded while their polystyrene cores remained intact. We applied light scattering and neutron scattering as useful tools to monitor the particle diameters and to evaluate details of the degradation process, especially the degradation-dependent changes in the neutron scattering-length density profile. The degradation speed was studied at different temperatures as function of nanoparticle, enzyme and salt concentration at fixed pH. Deviations from Michaelis-Menten behavior are discussed within a simple model.