Perspectives on percutaneous penetration: Silica nanoparticles.

Nanotechnology is a rapidly expanding area of research involved in developing science-based solutions for innovative therapeutics. Silica nanoparticles (SNPs) have received wide attention in several industries and medicine and are being developed for biomedical and biotechnological applications such as drug delivery, DNA transfection, and targeted molecular imaging of cancer. Recently, they are emerging in the fields of cosmetics and dermal preparations. SNP may offer a revolutionized treatment of several skin diseases by controlled and sustained release of drugs to skin, as well as enhanced skin penetration of encapsulated drug ingredients. SNPs are candidates for transcutaneous vaccination and transdermal gene therapy, too. Yet there exist concerns that whilst the properties of SNPs have enabled numerous industrial and medical applications, their toxicological and environmental safety mandates evaluation. The knowledge of passage of SNPs through skin following skin exposure (intentionally or unintentionally) and subsequent effects is limited. This review surveys the key experiments on SNP-based formulations in the fields of dermatology and cosmetics with the goal of rationalizing data and informing public health concerns related to SNPs' toxicity among scientists and manufacturers handling them, while highlights the research gaps in dermal absorption of these compounds.