Aim: We assessed the effects of flexing and massage on human skin penetration and toxicity of topically applied coated and uncoated zinc oxide nanoparticles (˜75 nm) in vivo. Materials & methods: Noninvasive multiphoton tomography with fluorescence lifetime imaging was used to evaluate the penetration of nanoparticles through the skin barrier and cellular apoptosis in the viable epidermis. Results: All nanoparticles applied to skin with flexing and massage were retained in the stratum corneum or skin furrows. No significant penetration into the viable epidermis was seen and no cellular toxicity was detected. Conclusion: Exposure of normal in vivo human skin to these nanoparticles under common in-use conditions of flexing or massage is not associated with significant adverse events.

Vitiligo is an acquired, chronic condition characterised by depigmentation of the epidermis or by destruction/loss of melanin. Skin cells (melanocytes) are responsible for producing melanin, the substance that gives pigmentation to the skin. This review aims to provide a comprehensive overview of the current state of knowledge about vitiligo. Although there is no specific ethnic group, gender, or skin type that is more prone to vitiligo than others, it can affect anyone. The most commonly prescribed treatments for vitiligo are systemic and topical phototherapy and immunomodulators such as corticosteroids, calcineurin inhibitors, and vitamin D analogues, in addition to cosmetics that can camouflage and improve the quality of life. Even though vitiligo is typically thought of as a cosmetic disorder, its effects on the physical and psychosocial health of sufferers cannot be ignored.