Fluorescent Convertible Polymer Capsules with Various Dyes as Tracking Labels for Macrophages
Zhanna V. Kozyreva1, Polina A. Demina2, Anastasiia Yu. Sapach1, Daria A. Terentyeva1, Olga I. Gusliakova1,2, Anna M. Abramova2, Irina Yu. Goryacheva2, Gleb B. Sukhorukov1,3, and Olga A. Sindeeva1
1 Skolkovo Institute of Science and Technology, Moscow, Russia;
2 Saratov State University, Saratov, Russia;
3 Queen Mary University of London, London, UK.
Abstract
The study of mobile cell pathways within large populations is important to understand the interactions, migration, and fate of individual cells. Traditionally, GFP-like proteins are used to solve these tasks; however, they require cell transfection for the generation of photoconvertible proteins. The application of photoconvertible microcapsules works as an alternative to genetic modifications, which are unacceptable for some cell types, for example, macrophages. We explored various dyes, namely rhodamine B, rhodamine 6G, pyronin B, fluorescein, acridine yellow, acridine orange, and thiazine red, as potential convertible labels in capsules that underwent hydrothermal synthesis. To facilitate the scaled-up production of polymeric capsules, we propose the use of PVA gel as a medium for capsule synthesis, which resulted in a 250-fold increase in microcapsule production from a single synthesis cycle. Capsules containing various dyes were analyzed for fluorescence brightness, photostability, and ability to photoconversion. Based on chemical and optical studies, microcapsules containing rhodamine B and rhodamine 6G were chosen as the most promising candidates for macrophage labeling. Additionally, through mass spectrometry analysis, we verified the photoconversion mechanism of both the rhodamine dyes. Successful labelling of RAW 264.7 and bone marrow-derived macrophage cell lines was demonstrated using our capsule-based labels, exhibiting minimal cytotoxicity and negligible impact on cell mobility. In addition, we performed photoconversion of the capsules inside the cells, while ensuring high cell viability. This approach opens new possibilities for nontoxic macrophage labeling and facilitates high-resolution tracking studies in diverse cellular environments.
This research was supported by the Russian Science Foundation (project no. 22-15-00292).
Speaker
Zhanna Kozyreva
Skolkovo Institute of Science and Technology
Russia
Discussion
Ask question
