Photoprotective effects of inclusion complexes of fullerenes with polyvinylpyrrolidone

The outermost surface of the body is covered by the stratum corneum, which is critical for proper skin barrier function. We investigated photoprotective effects of inclusion complexes of fullerenes with polyvinylpyrrolidone (PVP/fullerenes).

To examine the cytoprotective activity of PVP/fullerenes against ultraviolet B (UVB) irradiation, we placed a dish with or without PVP/fullerenes on top of dishes containing cultured keratinocytes with or without PVP/fullerenes. Next, we examined the effects of PVP/fullerenes on the ratio of cells with cornified envelopes and transglutaminase-1 expression by real-time polymerase chain reaction and immunohistochemistry. Finally, we examined the barrier recovery effect of PVP/fullerenes solution by measuring transepidermal water loss after tape stripping in humans.

UVB irradiation at 40 mJ/cm(2) markedly induced inhibition of keratinocyte proliferation. The inhibition of keratinocyte proliferation was restored only when PVP/fullerenes were present before UVB irradiation in the lower dish with the cells. UVB irradiation decreased the ratio of cells with cornified envelopes and transglutaminase-1 expression; however, the application of PVP/fullerenes reversed this phenomenon. PVP/fullerenes solution significantly promoted the recovery of transepidermal water loss on the second and third days after tape stripping.

PVP/fullerenes can be used in cosmetics, especially in those intended to protect photo damage and ameliorate skin barrier perturbations.