Title Adjusting and switching the elution of bone therapeutics from thermoaddressable coatings of poly(N-isopropylacrylamide-co-acrylic acid)/ethylenediaminocellulose complex particles
Date 01.07.2017
Number 50706
Abstract Thermoaddressable coatings based on poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAM-AA) complexed with ethylenediamine-modified cellulose (EDAC) are reported eluting bone therapeutic zoledronate (ZOL) in defined amounts. At T = 25 °C, phase-separated dispersions of EDAC/PNIPAM-AA contained particles sizing between DH = 0.52–1.72 µm, while at T = 50 °C, particles shrank to DH = 0.13–0.29 µm due to volume phase transition known for pure PNIPAM, when lower critical solution temperature (LCST) is exceeded. Temperature-sensitive EDAC/PNIPAM-AA particles were deposited onto germanium model substrates keeping adhesive after rinsing with HEPES buffer. ATR-FTIR spectroscopy in both dispersion and coating EDAC/PNIPAM-AA complexes revealed broad volume phase transitions as a function of temperature associated with changes of hydration and hydrogen bonding state. Transition temperature values for EDAC/PNIPAM-AA dispersions (41–48 °C) and coatings (45–54 °C) were significantly higher compared to that for pure PNIPAM solutions (33 °C). ZOL release from EDAC/PNIPAM-AA coatings was temperature dependent due to microstructural changes, so that at physiological T = 37 °C, ZOL was released far slower compared to that at T = 42–60 °C.
Publisher Colloid and Polymer Science
Identifier 0
Citation Colloid and Polymer Science 295 (2017) 1187-1199
Authors Müller, M. ; Urban, B. ; Vehlow, D. ; Möller, M.
Tags thermoresponsive coatings pnipam polyelectrolyte complex biomedical applications drug delivery ftir spectroscopy

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