Industrial multi-walled carbon nanotubes (ig-MWCNTs) make up the majority of carbon nanomaterials, and human contact with them is the most probable. At the same time, the biodegradation of ig-MWCNTs by phagocytes has not been studied—existing articles consider mainly laboratory-grade/functionalized MWCNTs (l-MWCNTs), in contrast to which ig-MWCNTs are a highly heterogeneous nanomaterial in terms of morphological and physicochemical characteristics. The aim of the present study was to analyze ig-MWCNTs’ biodegradation by proinflammatory macrophages. We focused on both extra- and intracellular ig-MWCNTs’ degradation. We analyzed biodegradation of two different types of ig-MWCNTs by human (THP-1) and murine (RAW264.7) macrophages. After 10 days of incubation, we studied nanoparticle localization within cells; isolated intra- and extracellular ig-MWCNTs were used for quantitative analysis. Ultrastructural and morphometric analysis were performed using transmission electron microscopy; electron diffraction was used for nanotube identification. To estimate chemical alterations, energy-dispersive X-ray spectroscopy and Raman spectroscopy were used. The study showed that both intra- and extracellular ig-MWCNTs undergo almost complete biodegradation, but in different ways: intracellular nanotubes become perforated and reduce to graphene flakes, while extracellular become thinner. We believe that the demonstrated variability in the destruction of ig-MWCNTs by cells suggests the possibility of creating nanomaterials with controlled biodegradation properties.

Accurate normalization of qRT-PCR data in pulmonary tuberculosis (TB) research requires reference genes whose expression is invariant across clinically relevant matrices, yet no studies have addressed this in lesion tissue and blood concurrently. We assessed the expression stability of eight popular housekeeping genes—ACTB, B2M, GAPDH, HPRT1, PPIA, RPL13A, UBC and YWHAZ—in lung tuberculomas and peripheral blood mononuclear cells (PBMCs) from TB patients. Standardized extraction and amplification yielded Cq values that were ranked by geNorm, NormFinder, BestKeeper and comparative Delta CT, with consensus scores generated in RefFinder; and correlation analysis was conducted in order to select the most suitable genes to work collectively for future normalization. The consensus analysis placed PPIA, YWHAZ and HPRT1 at the top, while GAPDH and UBC were the least stable. Our findings endorse a three-gene panel (PPIA, YWHAZ, HPRT1) for robust normalization of host gene-expression studies in both lesion tissue and PBMCs in pulmonary TB and highlight the necessity of context-specific reference-gene validation.

The problem of reduced effectiveness of antituberculosis drugs is currently associated not only with the development of drug resistance in the pathogen but

Nanodiamonds modified with functional groups are obtained for targeted drug delivery. A set of methods for identifying nanodiamonds in biological material is determined and their localization in human macrophages and mouse lung cells is identified. It is shown that seven days after introduction into the mouse lungs, nanodiamonds are internalized by endotheliocytes and interstitial macrophages. Both in the human macrophage culture and in the lung cells, nanodiamonds are localized in phagosomes/phagolysosomes. The nanodiamonds do not cause pathological changes in human macrophages and mouse lung cells. The results obtained lead us to consider nanodiamonds as a promising carrier platform for drug delivery, first and foremost to macrophages of the interstitium of the respiratory portion of the lung, which is relevant in such a disease as tuberculosis.

Pulmonary surfactant is an essential component of the respiratory system for the implementation of phagocytosis by alveolar macrophages. Pulmonary tubercul

Pulmonary surfactant is an essential component of the respiratory system for the implementation of phagocytosis by alveolar macrophages. Pulmonary tuberculosis is associated with the reduced pulmonary surfactant production and the phagocytic function of macrophages. The transporter protein P-gp ( ABCB1 gene) is overexpressed in lung cells and exports numerous substrates. The incorporation of P-gp into the plasma membrane alters its characteristics. The aim of this study was to analyze the relationship between P-gp and the phagocytic activity of macrophages under the influence of exogenous pulmonary surfactant. The study employed scanning electron microscopy and confocal laser scanning microscopy methods, as well as two models of cultured human cells: (1) pro-inflammatory THP-1 macrophages (P-gp+), infected with M. bovis BCG (this model, when exposed to surfactant, is considered a model of alveolarlike macrophages); and (2) parental myeloblastic leukemia K562 cells (P-gp-) and K562/i-S9 cells (P-gp+) transfected with the ABCB1 gene and induced to adhere. In model 1, it was found that the addition of 1 mg/ml of exogenous pulmonary surfactant for 1 h led to the formation of numerous long filopodia, ruffles, and phagocytic cups, as well as a 1.7-fold increase in the phagocytic index. This demonstrates that the surfactant is an effective activator of phagocytosis in infected macrophages. In model 2, it was shown that in the presence of P-gp, the surface activity of cells significantly increased under the influence of exogenous pulmonary surfactant compared to cells without P-gp. It is hypothesized that due to the interaction between P-gp, ERM complex proteins (ezrin, radixin, moesin) and actin filaments, P-gp+ cells are more potentiated for cell surface activation and phagocytosis than P-gp- cells. Further analysis of the features of infected macrophages’ phagocytosis depending on P-gp activity may contribute to the development of new drugs aimed at regulating the phagocytic activity of macrophages.