Heteroleptic Ruthenium Polypyridyl Complex Had Differential Effects on the Production of Pro-inflammatory Cytokines TNFα, IL1β, and IL6 by the Mammalian Macrophages In Vitro

Modulation of the immune system has gathered more attention in the field of medicine due to the immense potential that it presents. Our immune system has important roles against cancer to infectious diseases, as well as in the development of autoimmune disorders. Therefore, being able to manipulate our immune system cells would enable us to determine the type and strength of the immune response to certain danger stimuli. Macrophages play an important role in the regulation of the immune system by producing cytokines, chemokines and by presenting antigens to other immune system cells to enable their activation; in our study, we focused on their in vitro activity in terms of pro-inflammatory cytokine production. In order to screen new immunomodulatory or immunostimulatory drug candidates, we examined the effect of ruthenium polypyridyl-based complex K30 that is used in solar cells as photosensitizer. Due to its electron transfer capacity, this material has potential to change the electron transfer reactions therefore could alter the function of the cells through metabolic changes at a cellular level. Our results suggest that K30 was differentially regulating the secretion levels of the pro-inflammatory cytokines by the LPS-activated mammalian macrophages, while it did not stimulate the macrophages by itself. K30 has an anti-inflammatory potential while lacking the immunostimulatory effect in our in vitro results and has potential to be used as anti-inflammatory drug molecule in metallic implants of the fractured bones to prevent damaging inflammatory environment and enable more efficient transplant and healing.