Diverse approaches have allowed the Strassert group to fully control the aggregation of planar coordination compounds and to tune their photophysical properties for phototherapy, functional microscopy, and multimodal bioimaging. They have recently designed a series of photosensitizers able to target, label, and photoinactivate pathogenic and antibiotic resistant bacteria upon irradiation with red light. For this purpose, it was necessary to avoid stacking by diverse supramolecular strategies. Currently, researchers are extending these concepts to targeted, fully water-soluble and biodegradable platforms, a prerequisite for biomedical applications. These approaches include the use of dextrin conjugates and cyclodextrin vesicles that selectively photoinactivate Gram-positive strains. On the other hand, axially decorated dicationic Si(IV) phthalocyanines can kill both Gram-positive and Gram-negative bacteria, despite showing antibiotic resistance. The group has also implemented light-driven arrays for spatiotemporally resolved functional microscopy to monitor in situ the response toward ROS of eukaryotic and prokaryotic cells. Insertion of open-shell transition metal cations and tuning of the macrocycles’ substitution pattern yielded NIR-absorbing sonophores for in vivo photoacoustic imaging. An outlook will be presented regarding the use of Pt(II)-based triplet emitters as multimodal agents for electron microscopy and phosphorescence lifetime imaging without unwanted quenching by dioxygen and related cytotoxicity due to photoproduction of reactive oxygen species. Finally, recent progress in the design and realization of Pt(II) complexes for electroluminescent devices will be discussed, going from bidentate to tridentate and tetradentate luminophores.
Dr. Cristian Strassert serves as Professor for Coordination Chemistry and Molecular Imaging at the Cells in Motion Interfaculty Center within the Institute for Inorganic and Analytical Chemistry at Westfälische Wilhelms-Universität Münster (WWU). Strassert earned his PhD in Organic Chemistry from the University of Buenos Aires under the advisement of Professors Josefina Awruch and Lelia Dicelio before completing his Habilitation in Inorganic Chemistry under the mentorship of Professor Rainer Pöttgen at WWU. His research focuses on photofunctional coordination chemistry, molecular photophysics, functional microscopy, nanomaterials, and photobiology.