Acid-functionalized single-walled carbon nanotubes alter epithelial tight junctions and enhance paracellular permeability

Organ-specific renal tissue damage manifested by single-walled carbon-nanotubes and single-walled carbon-nanotubes-silver-titania nanocomposite: Cellular toxicity at high doses

BACKGROUND

Single-walled (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) can pose risks in biological systems leading to harmful effects, such as, reactive oxygen species (ROS) formation, DNA damage, mitochondrial dysfunction, and ultimately, the cell death through apoptosis.

OBJECTIVES

The study assessed the nephrotoxicity of the SWCNTs and SWCNTs-Ag-TiO2 nanocomposites through in vitro and in vivo experiments, assessing oxidative stress, genotoxicity, and safety for biomedical applications.

METHODOLOGY

In vitro, HK-2 cell lines were utilized to evaluate the effects of nanomaterials on cellular activity, apoptosis, ROS generation, and micronuclei formations. In the in vivo study, twenty male mice were divided into five groups: the first received a control injection of phosphate-buffer saline (PBS), while the second, and third groups received daily intraperitoneal injections of SWCNTs at doses of 50 mg/kg, and 100 mg/kg, respectively, for ten days. The fourth and fifth groups received the SWCNTs-Ag-TiO2 at 50 mg/kg and 100 mg/kg, respectively, for ten days in sequence.

RESULTS

SWCNTs and SWCNTs-Ag-TiO2 significantly promoted the micronuclei formations in HK-2 cells, with rates of 48 % and 79 %, respectively, as compared to the 12.67 % of the control group. The analysis of renal tissues revealed increased levels of ROS, DNA-protein crosslinks (DPC), glutathione (GSH), malondialdehyde (MDA), creatinine, and 8-hydroxy-2'-deoxyguanosine, while the GSH levels decreased. These findings indicated renal tissue injury, and oxidative damages.

CONCLUSIONS

The study demonstrated the cellular toxicity of these nanomaterials, highlighting the need for caution regarding their widespread use, particularly the use of carbon nanotubes and their metallic composites at higher exposure doses in occupational, environmental, or therapeutic contexts.

Magnetic carbon nanotubes modified with proteins and hydrophilic monomers: Cytocompatibility, in-vitro toxicity assays and permeation across biological interfaces

Carbon nanotubes are promising materials for biomedical applications like delivery systems and tissue scaffolds. In this paper, magnetic carbon nanotubes (M-CNTs) covered with bovine serum albumin (M-CNTs-BSA) or functionalized with hydrophilic monomers (M-CNTs-HL) were synthesized, characterized, and evaluated concerning their interaction with Caco-2 cells. There is no comparison between these two types of functionalization, and this study aimed to verify their influence on the material's interaction with the cells. Different concentrations of the nanotubes were applied to investigate cytotoxicity, cell metabolism, oxidative stress, apoptosis, and capability to cross biomimetic barriers. The materials showed cytocompatibility up to 100 μg mL-1 and a hemolysis rate below 2 %. Nanotubes' suspensions were allowed to permeate Caco-2 monolayers for up to 8 h under the effect of the magnetic field. Magnetic nanoparticles associated with the nanotubes allowed estimation of permeation through the monolayers, with values ranging from 0.50 to 7.19 and 0.27 to 9.30 × 10-3 μg (equivalent to 0.43 to 6.22 and 0.23 to 9.54 × 10-2 % of the initially estimated mass of magnetic nanoparticles) for cells exposed and non-exposed to the magnets, respectively. Together, these results support that the developed materials are promising for applications in biomedical and biotechnological fields.

Carboxyl nanodiamonds inhibit melanoma tumor metastases by blocking cellular motility and invasiveness

Carboxyl nanodiamond (cND) nanoparticles are actively internalized by B16F10 melanoma cells in culture. Treatment of B16F10 tumor cells with cNDs in vitro inhibited their ability to (i) migrate and invade through porous membranes in a transwell culture system, (ii) secrete matrix metalloproteinases (MMPs) MMP-2 and MMP-9, and (iii) express selected epithelial-mesenchymal transition markers critical for cell migration and invasion. Administration of luciferase-transfected B16F10-Luc2 melanoma cells resulted in a rapid growth of the tumor and its metastasis to different organs that could be monitored by in vivo bioluminescence imaging as well as by ex vivo BLI of the mouse organs. After tumor cells were administered intravenously in C57Bl/6 mice, administration of cNDs (50 μg i.v. every alternate day) resulted in marked suppression of the tumor growth and metastasis in different organs of mice. Subcutaneous administration of B16F10 cells resulted in robust growth of the primary tumor subcutaneously as well as its metastasis to the lungs, liver, spleen, and kidneys. Intravenous treatment with cNDs did not affect the growth of the primary tumor mass but essentially blocked the metastasis of the tumor to different organs. Histological examination of mouse organs indicated that the administration of cNDs by itself was safe and did not cause toxic changes in mouse organs. These results indicate that the cND treatment may have an antimetastatic effect on the spread of B16F10 melanoma tumor cells in mice. Further exploration of cNDs as a possible antimetastatic therapeutic agent is suggested.

Carbon-Based Nanomaterials as Drug Delivery Agents for Colorectal Cancer: Clinical Preface to Colorectal Cancer Citing Their Markers and Existing Theranostic Approaches

Colorectal cancer (CRC) is one of the universally established cancers with a higher incidence rate. Novel progression toward cancer prevention and cancer care among countries in transition should be considered seriously for controlling CRC. Hence, several cutting edge technologies are ongoing for high performance cancer therapeutics over the past few decades. Several drug-delivery systems of the nanoregime are relatively new in this arena compared to the previous treatment modes such as chemo- or radiotherapy to mitigate cancer. Based on this background, the epidemiology, pathophysiology, clinical presentation, treatment possibilities, and theragnostic markers for CRC were revealed. Since the use of carbon nanotubes (CNTs) for the management of CRC has been less studied, the present review analyzes the preclinical studies on the application of carbon nanotubes for drug delivery and CRC therapy owing to their inherent properties. It also investigates the toxicity of CNTs on normal cells for safety testing and the clinical use of carbon nanoparticles (CNPs) for tumor localization. To conclude, this review recommends the clinical application of carbon-based nanomaterials further for the management of CRC in diagnosis and as carriers or therapeutic adjuvants.

Carbon nanostructures: a comprehensive review of potential applications and toxic effects

There is no doubt that nanotechnology has revolutionized our life since the 1970s when it was first introduced. Nanomaterials have helped us to improve the current products and services we use. Among the different types of nanomaterials, the application of carbon-based nanomaterials in every aspect of our lives has rapidly grown over recent decades. This review discusses recent advances of those applications in distinct categories, including medical, industrial, and environmental applications. The first main section introduces nanomaterials, especially carbon-based nanomaterials. In the first section, we discussed medical applications, including medical biosensors, drug and gene delivery, cell and tissue labeling and imaging, tissue engineering, and the fight against bacterial and fungal infections. The next section discusses industrial applications, including agriculture, plastic, electronic, energy, and food industries. In addition, the environmental applications, including detection of air and water pollutions and removal of environmental pollutants, were vastly reviewed in the last section. In the conclusion section, we discussed challenges and future perspectives.

Non-ionic Surfactants as a P-Glycoprotein(P-gp) Efflux Inhibitor for Optimal Drug Delivery-A Concise Outlook

Significant research efforts have been devoted to unraveling the mystery of P-glycoprotein(P-gp) in drug delivery applications. The efflux membrane transporter P-gp is widely distributed in the body and accountable for restricting drug absorption and bioavailability. For these reasons, it is the primary cause of developing multidrug resistance (MDR) in most drug delivery applications. Therefore, P-gp inhibitors must be explored to address MDR and the low bioavailability of therapeutic substrates. Several experimental models in kinetics and dynamic studies identified the sensitivity of drug molecules and excipients as a P-gp inhibitor. In this review, we aimed to emphasize nonionic surface-active agents for effective reversal of P-gp inhibition. As it is inert, non-toxic, noncharged, and quickly reaching the cytosolic lipid membrane (the point of contact with P-gp efflux protein) enables it to be more efficient as P-gp inhibitors. Moreover, nonionic surfactant improves drug absorption and bioavailability through the various mechanism, involving (i) association of drug with surfactant improves solubilization, facilitating its cell penetration and absorption; (ii) weakening the lateral membrane packing density, facilitating the passive drug influx; and (iii) inhibition of the ATP binding cassette of transporter P-glycoprotein. The application of nonionic surfactant as P-gp inhibitors is well established and supported by various experiments. Altogether, herein, we have primarily focused on various nonionic surfactants and their development strategies to conquer the MDR-causing effects of P-gp efflux protein in drug delivery. Graphical Abstract.

Impact of nanomaterials on the intestinal mucosal barrier and its application in treating intestinal diseases

The intestinal mucosal barrier (IMB) is one of the important barriers to prevent harmful substances and pathogens from entering the body environment and to maintain intestinal homeostasis. The dysfunction of the IMB is associated with intestinal diseases and disorders. Nanomaterials have been widely used in medicine and as drug carriers due to their large specific surface area, strong adsorbability, and good biocompatibility. In this review, we comprehensively discuss the impact of typical nanomaterials on the IMB and summarize the treatment of intestinal diseases by using nanomaterials. The effects of nanomaterials on the IMB are mainly influenced by factors such as the dosage, size, morphology, and surface functional groups of nanomaterials. There is huge potential and a broad prospect for the application of nanomaterials in regulating the IMB for achieving an optimal therapeutic effect for antibiotics, oral vaccines, drug carriers, and so on.

Toxicity of poly-dispersed single-walled carbon nanotubes on bone marrow derived Hematopoietic Stem and Progenitor Cells

This study has explored the effect of acid-functionalized single-walled carbon nanotubes (AF-SWCNTs) on Hematopoietic Stem and Progenitor Cell (HSPCs) in mouse bone marrow. Administration of AF-SWCNTs induced a significant decline in the live-cell recovery from bone marrow. Lin-negative Stem cell enriched HSPCs internalized AF-SWCNTs that remained localized in cytoplasmic areas. Incubation of HSPCs with AF-SWCNTs resulted in induction of cell death, inhibition of cell cycle, and induction of reactive oxygen species (ROS) as well as the expression of Caspase 3, 7 and 9 enzymes. In vitro culture with a cytokine cocktail (SCF, GM-CSF, IL3, IL6, IL7) induced differentiation of HSPCs into lymphocytes and myeloid cells, that was inhibited in presence of AF-SWCNTs. Relative recoveries of lymphocytes specifically B lymphocytes, was significantly reduced by AF-SWCNT-treatment, whereas the relative recovery of myeloid cells remained unaltered. These results suggest that AF-SWCNTs have significant toxic effects on HSPCs and differentially suppress the ontogeny of lymphoid and myeloid cells.

Nanodiamonds inhibit scratch-wound repair in lung epithelial cell monolayers by blocking cell migration and inhibiting cell proliferation

Proliferation and migration of lung epithelial cells following the injury to the epithelial lining of alveoli and airways in the lung are pivotal for remodeling and repair of the wound to restore normal lung function. In the present study, we examined the modulatory effect of carboxylated nanodiamonds (cNDs) on the cell division, migration, and adhesion of epithelial cells in the well-established in vitro model of wound repair and cell migration. Flow cytometry and confocal microscopy results indicated that both LA4 and A549 cells effectively internalized fluorescent carboxylated nanodiamonds (cFNDs) and the internalized nanodiamonds were essentially localized in the cytoplasmic region. Treatment with cNDs blocked the division and migration of cells to fill the scratch wound. Live cell imaging and time-lapse videography of the wound healing process indicated a significant inhibition of cell proliferation activity in cND-treated cells and blocked the wound repair process. Trans-well cell-migration assay results further support the inhibitory effect of cNDs on the cell migration process. Western blotting and immunofluorescence staining indicated that the crucial proteins involved in epithelial-mesenchymal transition (EMT) and cell migration i.e. β-catenin, Vimentin, NM-myosin, and Focal Adhesion Kinase (FAK) were downregulated after treatment with cNDs, while the expression of E-cadherin and Claudin-1, major cell adhesion markers remained unaltered. Taken together, our results indicate that the decline in cell proliferation activity, downregulation in the expression of various crucial protein like β-Catenin, NM-myosin, FAK, and Vimentin involved in the cell migration and unaltered expression of cell adhesion molecules E-cadherin and Claudin-1, may be the factors that contribute to the cND-mediated inhibition of EMT during the wound repair process in the monolayers of lung epithelial cells.

Poly dispersed acid-functionalized single walled carbon nanotubes target activated T and B cells to suppress acute and chronic GVHD in mouse model

Graft versus host disease (GVHD) results from hyper-activation of transplanted lymphocytes against the host antigens. Bone marrow transplantation in humans as well as some cases of blood transfusion and organ transplantation are associated with a strong GVH reaction resulting in GVHD that in many cases may be fatal. We had previously shown that poly-dispersed acid-functionalized single-walled carbon nanotubes (AF-SWCNTs) specifically target activated T and B lymphocytes and kill them. In the present study, efficacy of AF-SWCNTs to suppress the GVH reaction was tested in the mouse model. Acute GVHD was induced in mice by administering intravenously 30 or 60 million spleen cells from a parental strain (C57bl/6 mouse, MHC haplotype H-2^b) to host (C57bl/6 x Balb/c) F1 mice (MHC haplotype H-2^b/d)and waiting for 8-10 days. Chronic GVHD was similarly induced by administration of 30 million parent spleen cells to F1 mice and waiting for a period of 60 days. Our results demonstrate a marked decline in splenomegaly and recovery of spleen T (both CD4 and CD8) and B cells in GVHD mice treated with AF-SWCNTs. AF-SWCNTs treatment also limited T and B cell proliferation by restricting S-phage of cell cycle. Generation of anti-host cytotoxic T cells (CTLs) was also markedly suppressed by AF-SWCNT treatment of acute GVHD mice, and a significant reduction in the generation of anti-host antibodies could also be demonstrated. Taken together, our results suggest that the AF-SWCNTs can be considered as a potential therapeutic agent for treating GVHD.