posted on 2024-01-03, 16:33authored byIsabel
K. Sommerfeld, Hanna Malyaran, Sabine Neuss, Dan E. Demco, Andrij Pich
Stimuli-responsive microgels with ionizable functional
groups offer
versatile applications, e.g., by the uptake of oppositely charged
metal ions or guest molecules such as drugs, dyes, or proteins. Furthermore,
the incorporation of carboxylic groups enhances mucoadhesive properties,
crucial for various drug delivery applications. In this work, we successfully
synthesized poly{N-vinylcaprolactam-2,2′-[(5-acrylamido-1-carboxypentyl)azanediyl]diacetic
acid} [p(VCL/NTAaa)] microgels containing varying amounts of nitrilotriacetic
acid (NTA) using precipitation polymerization. We performed fundamental
characterization by infrared (IR) spectroscopy and dynamic and electrophoretic
light scattering. Despite their potential multiresponsiveness, prior
studies on NTA-functionalized microgels lack in-depth analysis of
their stimuli-responsive behavior. This work addresses this gap by
assessing the microgel responsiveness to temperature, ionic strength,
and pH. Morphological investigations were performed via NMR relaxometry,
nanoscale imaging (AFM and SEM), and reaction calorimetry. Finally,
we explored the potential application of the microgels by conducting
cytocompatibility experiments and demonstrating the immobilization
of the model protein cytochrome c in the microgels.