Therapeutic tattoo

Tattoo of nanoparticles will help in the treatment of autoimmune diseases

Oleg Lischuk, N+1

American scientists have discovered that carbon nanoparticles can selectively suppress the activity of T-lymphocytes and reduce the symptoms of autoimmune diseases. At the same time, it is preferable to inject them under the skin, which leads to its temporary staining, resembling a tattoo. The results of the work are published in the journal Scientific Reports (Huq et al., Preferential uptake of antioxidant carbon nanoparticles by T lymphocytes for immunomodulation).

Autoimmune diseases are a group of heterogeneous manifestations of diseases (such as rheumatoid arthritis, multiple sclerosis, and many others) that have a common mechanism of development: for some reason, the immune system perceives the tissues of its own body as foreign and attacks them, causing chronic inflammation. In most autoimmune diseases, the key role is played by the pathological activation of T-lymphocytes, which damage cells by synthesizing reactive oxygen species, in particular, superoxide radical. Currently, immunosuppressants are used to treat autoimmune diseases, which suppress the immune system non-selectively, which increases the risk of severe infections and malignant neoplasms.

As it was shown in previous works, functionalized carbon nanomaterials, such as fullerenes or nanotubes, effectively neutralize reactive oxygen species, significantly surpassing natural antioxidants in this. However, many of them, when they enter the body, form fibrous aggregates that are toxic to cells.

The staff of Rice University and Baylor College of Medicine used hydrophilic carbon nanoclusters functionalized with polyethylene glycol (PEG-HCC) in their work. Such nanostructures have a powerful antioxidant effect and are non-toxic to cells.

A drawing from the press release of Baylor College of Medicine Tattoo therapy could ease chronic disease; skin-embedded nanoparticles may help control autoimmune diseases – VM.

During the experiment, scientists injected PEG-HCC under the skin of rats and observed the behavior of nanoclusters in the body using antibodies to polyethylene glycol.

It turned out that the nanopreparation is selectively absorbed by T-lymphocytes in the spleen, but not by other immune cells (macrophages, neutrophils, B-lymphocytes and others). It also does not affect the T-lymphocytes in the thymus gland, that is, it does not affect the process of their maturation. The study of cells under an electron microscope showed that PEG-HCC accumulates in cells near mitochondria, which synthesize superoxide radical and its derivatives. At the same time, they do not lead to cell death and are gradually removed from it, having a reversible effect.

Subcutaneous administration of the drug led to its delayed release and, as a result, to a longer and more uniform effect compared to intravenous injection.

Experiments with cultures of rat and human T-lymphocytes treated with PEG-HCC have shown that the drug effectively reduces the intracellular concentration of reactive oxygen species and suppresses the proliferation of antigen-stimulated T-lymphocytes. In addition, it reduced the production of pro–inflammatory cytokines - interleukin-2 and interferon-gamma by about 30 percent. These effects, as in the previous experiment, turned out to be reversible. PEG-HCC did not act on unstimulated cells, that is, its effects are manifested only with increased production of superoxide.

At the next stage of the experiments, the scientists injected PEG-HCC into rats with delayed hypersensitivity (cell-mediated hyperimmune reactions underlying various diseases) and acute autoimmune encephalomyelitis (multiple sclerosis model). Already after the first injection, a decrease in the intensity of inflammation was observed, and subcutaneous administration of the drug every three days significantly reduced the clinical and histological manifestations of encephalomyelitis.

Thus, PEG-HCC has prospects for use in autoimmune diseases, but numerous preclinical and clinical trials are needed for its introduction into medical practice. Scientists note that since the drug causes temporary staining of the skin, it can be administered using microneedles made up in the form of a pattern, so that the injection site will resemble a temporary tattoo. Such an approach can improve the psychological state of patients and reduce discomfort from the administration of medication.

Carbon nanostructures have long been of interest to biomedical researchers. For example, graphene turned out to be a good material for neuroprostheses, nanofilms from it were used to enhance the action of polyethylene glycol in the restoration of spinal cord injuries. Carbon nanoparticles of various shapes were used in experiments on targeted drug delivery. In addition, graphene can also be used in diagnostics: for example, a patch for diabetics was created on its basis, which is able to automatically measure glucose levels and, if necessary, inject a hypoglycemic drug.

Portal "Eternal youth" http://vechnayamolodost.ru  27.09.2016