Introduction: One of the characteristics of nanomaterials is that in one or more of their small dimensions, the movement of electrons is very limited and causes electrons to scatter and collide with network ions, photons, and impurities, which leads to huge changes in the properties of materials. In the past few years, the use of high-tech nanomaterials in the field of medicine has become increasingly common; among all types of nanoparticles, metal nanoparticles have unique characteristics that make them superior to others, and one of these widely used nanoparticles is zinc oxide nanoparticles. According to numerous researches, zinc oxide nanoparticles have been widely used in the advancement and improvement of medical science in the treatment and prevention discussion, and for this reason, they have been given attention.
For this reason, in this research, we examined and categorized the recent applications of zinc oxide nanoparticles in medical science, and of course, we also pointed out the important challenge of its possible toxicity.
Methods: All the materials obtained from the application of zinc oxide nanoparticles were searched in the Google Scholar database and key phrases such as "the use of zinc oxide nanoparticles in medical science", "the effect of zinc oxide nanoparticles in different organs of the body", "the role of zinc oxide nanoparticles in the treatment of diseases such as Cancer, diabetes and skin diseases" and keywords such as "nanoparticles" and "zinc oxide nanoparticles" were searched, but we limited the search to the last 4 years, that is, we reviewed the articles from 2019 to 2023. And we found a series of review and research articles in the period of time and finally 25 related articles categorized each of them based on keywords such as treatment, side effects, toxicity and type of target organ, in terms of different applications in medical science, and finally formed different parts of the article.
Results: Anti-cancer: They show cytotoxic effects in cancer cells and selectively make only these cells undergo apoptosis.
Anti-inflammatory: reduce inflammatory cytokines. Bamboo salt contains zinc and is used to treat inflammation.
Skin care and wound healing: One of the important types of zinc paste bandages contains zinc oxide nanoparticles, which are used for skin care and leg wound treatment.
Treatment of diabetes: After examining mice with type 2 diabetes, it was found that zinc oxide nanoparticles were responsible for increasing insulin levels and reducing glucose levels.
Toxicity: nanoparticles can generally attack the surrounding cells and accumulate inside the blood vessels, or cause more damage to them by migrating to distant tissues or organs;
Toxicity effect on brain tissue: According to the tests conducted, zinc oxide nanoparticles may have a harmful role in brain development, and on the other hand, other tests identified its protective role on the brain.
Toxic effect on liver tissue: Experiments on rats showed that zinc oxide nanoparticles have a toxic pathological effect on liver function and reduce liver enzyme levels.
Effects of toxicity on reproduction: it causes fertility problems through different pathways, including changing the gene expression of proteins involved in the biogenesis and function of mitochondria.
Toxic effects on thyroid tissue and lysosomes: their toxic effects on thyroid gland function or the secretion of thyroid stimulating hormone may cause a decrease in the secretion of these hormones. Also, a sudden increase in the level of free zinc may damage lysosomes.
It is important to note that pathological changes caused by zinc oxide nanoparticles mainly depend on their size and dose.
Conclusion: According to the studies, it was found that zinc oxide nanoparticles are widely used in medical science and are used as a safe candidate for targeted treatment. But on the other hand, it should be noted that zinc oxide nanoparticles can indirectly affect humans and the environment through contact or consumption of water, plants and animals (which previously received these nanoparticles), or directly through skin contact and inhalation.
As a result, it is suggested that in the future, in addition to discovering and investigating the useful applications of zinc nanoparticles in medical science, their side effects and toxicity in different organs should also be investigated in order to reach a scientific balance between application and risk.