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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 68: Hydrogels and Microgels II
CPP 68.10: Talk
Friday, March 24, 2017, 12:45–13:00, ZEU 260
Drug delivery by thermoresponsive polyelectrolyte complex coatings for bone healing — •Martin Müller1,2, David Vehlow1,2, and Birgit Urban1 — 1Leibniz-Institut für Polymerforschung Dresden e.V., Abteilung Polyelektrolyte und Dispersionen, 01069 Dresden, Germany — 2Technische Universität Dresden, Fachrichtung Chemie und Lebensmittelchemie, 01062 Dresden, Germany
Recently, polyelectrolyte complex (PEC) particle coatings were shown to release ionic bone therapeutic drugs in sustained manner immediately after contact to buffer solutions. To trigger thermally on demand the drug release thermoresponsive PEC particle coatings based on poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAM-AA) and cationic cellulose (EDAC) were fabricated. EDAC/PNIPAM-AA dispersions featured hydrodynamic radii RH=260-860 nm for T=25°C and RH=60-140 nm for T=50°C due to coil/globule transition (CGT) of PNIPAM moieties above lower critical solution temperature (LCST). Coatings of EDAC/PNIPAM-AA particles at germanium model substrates kept adhesive after buffer rinsing. FTIR spectroscopy at EDAC/PNIPAM-AA revealed significant hydrogen bonding state changes and broad phase transitions as a function of temperature as well as higher LCST values for dispersions (45°C) and coatings (50°C) compared to PNIPAM solutions (33°C). EDAC/PNIPAM-AA coatings were loaded with zoledronate (ZOL) and at T>LCST ZOL was released faster compared to T<LCST. Presumably, CGT partly compacts and defects the PEC phase enabling faster ZOL elution.