4 October 2018

Biodegradable nanoparticles with plant extracts result in UV protection

Utrecht researchers develop technology for safer, more sustainable sunscreens

Researchers at Utrecht University have taken a step towards safer and more environmentally friendly sunscreens. Recently, sunscreens have been strongly linked with coral reef degradation in highly touristic areas such as Hawaii, which was the first US state to pass a bill banning the sale of any sunscreens containing known harmful chemicals. Moreover, these chemicals in direct contact with skin can potentially result in adverse health effects for the sunscreen wearer. Therefore, the researchers have developed a new, bio-based technology with the aim to avoid these issues. The results were published in the scientific journal RSC Advances in July of this year.

The researchers at the Debye Institute for Nanomaterials Science used two types of biopolymers, ethyl cellulose and zein, to prepare bio-based, biodegradable nanoparticles which contain UV-absorbing plant extracts. The replacement of current sunscreen chemicals with plant extracts is potentially safer and more environmentally friendly, whilst the encapsulation of these chemicals into ‘green’ nanoparticles is a method of reducing skin contact.

Transparent coatings

The researchers have shown that the encapsulation of multiple plant extracts can result in UV protection across the entire UV spectrum – an essential property of sunscreens. Moreover, the researchers demonstrated that it is possible to make transparent coatings with this technology, which is desirable for sunscreen formulations because consumers prefer no white cast on their skin.

Further research is required to study the full effects of this technique, but the researchers believe that their research provides a genuine solution to many of the environmental and health issues with current sunscreens. Additionally, they hope to inspire further research into the development of new, greener photoprotection technologies.

Above: the UV-protective particles form a layer that stops UV, but is completely transparent to visible light. Left: a glass plate covered with a transparent, thin layer of particles. Right: an image of this layer made with the electron microscope.

Publication

Fully-biobased UV-absorbing nanoparticles from ethyl cellulose and zein for environmentally friendly photoprotection
D.R. Hayden, H.V.M. Kibbelaar, A. Imhof and K.P. Velikov
RSC Advances 8, 25104-25111 (2018). DOI: 10.1039/c8ra02674b