Zinc oxide (ZnO) is an effective sunscreen with a wide range of uses. In addition to being a sunscreen ingredient, it is also contained in gardenia cream, which has the effects of astringent wounds and accelerated healing. However, the medical profession has not yet determined whether the use of nano zinc oxide particles in sunscreens will be absorbed by the skin.
In recent years, the safety of nano particles used in sunscreens has been a controversial issue, because previous animal exposure studies found that applying zinc oxide (ZnO) sunscreens to the skin from human studies has required skin absorption. Much higher. Some public advocacy groups are concerned that sunscreens containing zinc oxide (ZnO) nanoparticle penetration into the upper layers of the skin can enter living cells in the living epidermis and cause toxicity, including DNA damage.
Australian Cancer Council’s 2017 National Sun Protection Survey found that only 55% of Australians believe that using sunscreen daily is safe, down from 61% in 2014. According to a report in the “Global News on Medicine” about “real exposure studies supporting the use of nano zinc oxide particles in sunscreens”, a recent article in Australia was published in the Journal of Investigative Dermatology Research shows that new risk assessments may help mitigate safety issues.
The study found that intact zinc oxide (ZnO) nano particles did not penetrate human skin, and did not cause cytotoxicity after repeated application to human volunteers under normal use conditions. This is also the first research report to directly confirm that zinc oxide (ZnO) nano particles are not toxic.
Australian researchers study the safety of polymerized ZnO nano particles, repeated application to 5 volunteers (age 20 to 30 years) over 5 days, zinc oxide (ZnO) nano particles suspended in a commercial sunscreen matrix per hour Application to volunteers was continued on the skin for 6 hours for 5 consecutive days.
Afterwards, multiphoton tomography and fluorescent life-cycle microscopic imaging systems were used, and the results showed that the nanoparticle remained only in the superficial layer of the stratum corneum and the skin groove. Even after repeated hourly or daily use, it did not penetrate the epidermis and did not cause cytotoxicity.
The research team pointed out that this study confirms that sunscreens containing zinc oxide (ZnO) nano particles can be repeatedly applied to the skin without any risk of toxicity. People are advised to take good sun protection to reduce skin aging and cancer caused by ultraviolet rays.
Jiang Zhigang, a professor at the Institute of Toxicology and the Secretary-General of the Toxicology Society of Yantai University Medical College, pointed out that zinc oxide (ZnO) is widely used, but if it becomes nano zinc particles, safety considerations must be taken in use.
Jiang Zhigang said that the medical industry is concerned that the particle size of zinc oxide (ZnO) nano particles is too small, so that they may penetrate into the cells or even stay in the cells. Therefore, the related products must consider the exposure risk. At present, it is too early to say whether this related research report alone can be judged harmless, and the relevant results of subsequent studies should be observed.