Regensburg 2013 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 13: Biomaterials and Biopolymers I (joint session CPP/BP)
CPP 13.10: Vortrag
Dienstag, 12. März 2013, 12:15–12:30, H34
Structure and disintegration of nanoparticles from clinically relevant polymers — •Margarita Dyakonova1, Anna Bogomolova2, Sergey Filippov2, Aurel Radulescu3, and Christine M. Papadakis1 — 1TU München, Physik-Department, Physik weicher Materie, Garching — 2Institute of Macromolecular Chemistry, Prague, Czech Republic — 3JCNS at FRM II, Garching
We investigate clinically relevant polymers based on N-(2-hydroxypropyl methacrylamide) (HPMA) which carry both a cancer drug, namely doxorubicin, and a hydrophobic targeting group, namely cholesterol derivatives. We focus on the dependence of the structure of the nanoparticles formed by these conjugates on the polymer architecture, the cholesterol content of cholesterol and the pH value [1]. Fluorescence correlation spectroscopy showed that the onset of nanoparticle formation depends on the cholesterol content. A step-like increase of the hydrodynamic radius with conjugate concentration indicates that the existing nanoparticles associate rather than to grow continuously. SANS revealed that even small amounts of cholesterol derivatives results in the formation of nanoparticles. At neutral pH values, these are ellipsoids, whereas under acidic conditions, cholesterol is released and forms large crystals. Time-resolved SANS during a stopped-flow experiment showed that, in dependence of the hydrophobicity of the cholesterol derivatives, a change in pH leads to changes of the conformation of the HPMA chains.
[1] S. Filippov, M. Dyakonova, C.M. Papadakis et al., Biomacromolecules 13, 2594 (2012)