Histopathological evaluation of long term dermal administration of poly(lactic-co-glycolic acid) nanoparticles

Abstract

Topical drug delivery is one of the therapeutic methods and has many advantages, including controlled drug release, more patient collaboration and possibility to high absorption rates. Because of the skin's impenetrability to many medications, various chemical and physical technologies have been developed to improve the transfer of medications through the skin. An example of these technologies is the use of nanoparticles, including polymer nanoparticles in drug delivery. It should be remembered that the main function of the skin protects against the entry of foreign substances. As a result, it will be difficult to get nanoparticles into the skin. But by optimizing the formulation of nanoparticles, they can be transmitted to the skin and appropriate drug delivery to the tissues. The success of a new formulation depends on the amount of drug delivery to the desired target tissue, with low complications. In addition to the use of nanoparticles in drug delivery to reduce the side effects of drugs, should be considered the safety of nanocomposites in their long-term use. The purpose of this research is histopathological examination of long-term use of dermal nanoparticles of poly (lactic-co-glycolic acid). In this research after the preparation of nanoparticles it was used locally and daily in the skin rat. Then was studied in different periods of time by optical microscopy and electron microscopy, and oxidative enzymes from tissue samples. Oxidative enzymes and optical and electron microscopic images of cells and cell structures did not show any significant difference compared to control groups. Therefor according to the results of skin evaluation and histological examination of the skin using electron microscopy and staining of hematoxylin-eosin, it is concluded that daily intake of PLGA nanoparticles does not cause significant toxicity to the skin for at least one year.