Cargo shuttling by electrochemical switching of core–shell microgels obtained by a facile one-shot polymerization† †Electronic supplementary information (ESI) available: Experimental details, elemental analysis, NMR data, detailed CV data and interpretation, chronoamperometry data, additional dynamic light scattering, uptake experiments, scanning transmission electron microscopy and cytotoxicity data. Experimental data for this article are available under request at https://hdl.handle.net/21.11102/b794f67f-caf8-11e8-a934-e41f1366df48. See DOI: 10.1039/c8sc04369h

Autor: Mergel, Olga, Schneider, Sabine, Tiwari, Rahul, Kühn, Philipp T., Keskin, Damla, Stuart, Marc C. A., Schöttner, Sebastian, de Kanter, Martinus, Noyong, Michael, Caumanns, Tobias, Mayer, Joachim, Janzen, Christoph, Simon, Ulrich, Gallei, Markus, Wöll, Dominik, van Rijn, Patrick, Plamper, Felix A.
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Chemical Science
ISSN: 2041-6539
2041-6520
Popis: Advancing biomedicine by tunable e-transfer into/from microgels.
Controlling and understanding the electrochemical properties of electroactive polymeric colloids is a highly topical but still a rather unexplored field of research. This is especially true when considering more complex particle architectures like stimuli-responsive microgels, which would entail different kinetic constraints for charge transport within one particle. We synthesize and electrochemically address dual stimuli responsive core–shell microgels, where the temperature-responsiveness modulates not only the internal structure, but also the microgel electroactivity both on an internal and on a global scale. In detail, a facile one-step precipitation polymerization results in architecturally advanced poly(N-isopropylacrylamide-co-vinylferrocene) P(NIPAM-co-VFc) microgels with a ferrocene (Fc)-enriched (collapsed/hard) core and a NIPAM-rich shell. While the remaining Fc units in the shell are electrochemically accessible, the electrochemical activity of Fc in the core is limited due to the restricted mobility of redox active sites and therefore restricted electron transfer in the compact core domain. Still, prolonged electrochemical action and/or chemical oxidation enable a reversible adjustment of the internal microgel structure from core–shell microgels with a dense core to completely oxidized microgels with a highly swollen core and a denser corona. The combination of thermo-sensitive and redox-responsive units being part of the network allows for efficient amplification of the redox response on the overall microgel dimension, which is mainly governed by the shell. Further, it allows for an electrochemical switching of polarity (hydrophilicity/hydrophobicity) of the microgel, enabling an electrochemically triggered uptake and release of active guest molecules. Hence, bactericidal drugs can be released to effectively kill bacteria. In addition, good biocompatibility of the microgels in cell tests suggests suitability of the new microgel system for future biomedical applications.
Databáze: OpenAIRE