Polymeric Encapsulation of a Ruthenium Polypyridine Complex for Tumor Targeted 1- and 2-Photon Photodynamic Therapy

08 June 2020, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Photodynamic therapy is a medical technique, which is gaining increasing attention to treat various types of cancer. Among the investigated classes of photosensitizers, the use of Ru(II) polypyridine complexes is gaining momentum. However, the currently investigated compounds generally show poor cancer cell selectivity. As a consequence, high drug doses are needed, which can cause side effects. To overcome this limitation, there is a need for the development of a suitable drug delivery system to increase the amount of PS delivered to the tumor. Herein, we report on the encapsulation of a promising Ru(II) polypyridyl complex into polymeric nanoparticles with terminal biotin groups. Thanks to this design, the particles showed much higher selectivity for cancer cells in comparison to non-cancerous cells in a 2D monolayer and 3D multicellular tumor spheroid model. As a highlight, upon intravenous injection of an identical amount of the Ru(II) polypyridine complex, an improved accumulation inside an adenocarcinomic human alveolar basal epithelial tumor of a mouse by a factor of 8.7 compared to the Ru complex itself was determined. The nanoparticles were found to have a high phototoxic effect upon 1-photon (500 nm) or 2-photon (800 nm) excitation with an eradication of an adenocarcinomic human alveolar basal epithelial tumor inside a mouse. Overall, this work describes, to the best of our knowledge, the first in vivo study demonstrating the cancer cell selectivity of a very promising Ru(II)-based PDT photosensitizer encapsulated into polymeric nanoparticles with terminal biotin groups.


Bioinorganic Chemistry
Medicinal Inorganic Chemistry
Metals in Medicine
Photodynamic Therapy

Supplementary materials



Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.