Evaluation of the Toxic Activity of the Graphene Oxide in the Ex Vivo Model of Human PBMC Infection with Mycobacterium tuberculosis

Abstract

Graphene Oxide has been proposed as a potential adjuvant to develop improved anti-TB treatment, thanks to its activity in entrapping mycobacteria in the extracellular compartment limiting their entry in macrophages. Indeed, when administered together with linezolid, Graphene Oxide significantly enhanced bacterial killing due to the increased production of Reactive Oxygen Species. In this work, we evaluated Graphene Oxide toxicity and its anti-mycobacterial activity on human peripheral blood mononuclear cells. Our data show that Graphene Oxide, different to what is observed in macrophages, does not support the clearance of Mycobacterium tuberculosis in human immune primary cells, probably due to the toxic effects of the nano-material on monocytes and CD4+ lymphocytes, which we measured by cytometry. These findings highlight the need to test GO and other carbon-based nanomaterials in relevant in vitro models to assess the cytotoxic activity while measuring antimicrobial potential.

Unraveling the potential of graphene quantum dots against Mycobacterium tuberculosis infection

“…We have recently demonstrated that GO exerts a generalized toxic effect on human PBMCs ( Salustri et al, 2023 ), hence we aimed to investigate whether GQDs have any toxicity in similar settings. We assessed cellular viability 1 h post treatment measuring 7AAD PC5.5-A signal (7AAD PC5.5-A binds DNA with high affinity and it is efficiently excluded by viable cells resulting an optimal marker for dead cells which have damaged nuclear membranes).…”

“…We have demonstrated that GO can entrap extracellular mycobacteria ( De Maio et al, 2019 ) and, depending on its surface-exposed functional groups, enhances the anti- Mtb activity of LZD, but not of INH and AMK ( De Maio et al, 2020 ). However, GO exerts a toxic effect on immune cells reducing monocytes viability and prompting an early activation of CD4 lymphocytes ( Salustri et al, 2023 ).…”

“…However, interaction of GO sheets with isoniazid or amikacin interfered and hindered antibiotic activity ( De Maio et al, 2020 ). Moreover, when GO was used in a Mtb infection model based on peripheral blood mononuclear cells, we observed a failure in controlling mycobacterial replication, largely due to the toxicity of GO against monocytes and CD4 T cells ( Salustri et al, 2023 ).…”

Recent Advances in Two-Dimensional Nanomaterials for Healthcare Monitoring

“…191 Graphene oxide showed promising anti-TB potential by trapping mycobacteria, but it exhibited toxicity to human immune cells, impairing Mycobacterium tuberculosis clearance. 192 MoS 2 nanosheets (NSs) were found to activate the KLF4-signaling pathway in both in vitro 3D Caco-2 spheroids and in vivo mouse intestines. Exposure to MoS 2 NSs led to decreased body weight, altered organ coefficients, increased Mo elements, and morphological changes in intestines, including villi shortening and decreased crypt depth.…”

“…In C. elegans , it affected organ function, transcription factor nuclear accumulation, neuronal health, and antioxidant defense mechanisms . Graphene oxide showed promising anti-TB potential by trapping mycobacteria, but it exhibited toxicity to human immune cells, impairing Mycobacterium tuberculosis clearance . MoS 2 nanosheets (NSs) were found to activate the KLF4-signaling pathway in both in vitro 3D Caco-2 spheroids and in vivo mouse intestines.…”