Pharmaceuticals and cosmeceuticals based on soft nanotechnology techniques with antioxidative, immunostimulative and other therapeutic activities

The Role of Singlet Oxygen in Photoreactivity and Phototoxicity of Curcumin

Curcumin is a plant-derived yellow-orange compound widely used as a spice, dye and food additive. It is also believed to have therapeutic effects against different disorders. On the other hand, there are data showing its phototoxicity against bacteria, fungi and various mammalian cells. Since the mechanism of its phototoxic action is not fully understood, we investigated here the phototoxic potential of curcumin in liposomal model membranes and in HaCaT cells. First, detection of singlet oxygen (¹ O₂ ) luminescence proved that curcumin generates ¹ O₂ upon blue light irradiation in organic solvent and in liposomes. Then, HPLC-EC(Hg) measurements revealed that liposomal and cellular cholesterol is oxidized by ¹ O₂ photogenerated by curcumin. Enrichment of liposome membranes with curcumin significantly increased the oxygen photo-consumption rate compared to the control liposomes as determined by EPR oximetry. Cytotoxicity measurements, mitochondrial membrane potential analyses and protein hydroperoxides detection confirmed strong phototoxic effects of curcumin in irradiated HaCaT cells. These data show that since curcumin is advertised as a valuable dietary supplement, or a component of cosmetics for topical use, caution should be recommended especially when skin is exposed to light.

Current application of phytocompound-based nanocosmeceuticals for beauty and skin therapy

Phytocompounds have been used in cosmeceuticals for decades and have shown potential for beauty applications, including sunscreen, moisturizing and antiaging, and skin-based therapy. The major concerns in the usage of phyto-based cosmeceuticals are lower penetration and high compound instability of various cosmetic products for sustained and enhanced compound delivery to the beauty-based skin therapy. To overcome these disadvantages, nanosized delivery technologies are currently in use for sustained and enhanced delivery of phyto-derived bioactive compounds in cosmeceutical sectors and products. Nanosizing of phytocompounds enhances the aseptic feel in various cosmeceutical products with sustained delivery and enhanced skin protecting activities. Solid lipid nanoparticles, transfersomes, ethosomes, nanostructured lipid carriers, fullerenes, and carbon nanotubes are some of the emerging nanotechnologies currently in use for their enhanced delivery of phytocompounds in skin care. Aloe vera, curcumin, resveratrol, quercetin, vitamins C and E, genistein, and green tea catechins were successfully nanosized using various delivery technologies and incorporated in various gels, lotions, and creams for skin, lip, and hair care for their sustained effects. However, certain delivery agents such as carbon nanotubes need to be studied for their roles in toxicity. This review broadly focuses on the usage of phytocompounds in various cosmeceutical products, nanodelivery technologies used in the delivery of phytocompounds to various cosmeceuticals, and various nanosized phytocompounds used in the development of novel nanocosmeceuticals to enhance skin-based therapy.

[Biodistribution of nanosilica particles in pregnant mice and the potential risk on the reproductive development]

Nanomaterials acquire revolutionary functions such as anti-inflammatory and anti-viral effects by increasing surface area per unit weight, due to the reduction to nanosize. Such nanomaterials are rapidly put to practical use without safety evaluation. This is because it is widely assumed that nanomaterials are merely of the same molecular composition as existing materials of more than submicron size, and that nanomaterials cannot be absorbed from the digestive tract or skin as is the case with existing materials of more than submicron size. On the other hand, as was the case with thalidomide, evidence shows that fetuses and infants are affected more than adults by a variety of environmental toxins, because of physiological immaturity. Thus, placental or breast milk-mediated exposure to nanomaterials may possibly induce unexpected biological effects. To our knowledge, however, no studies have examined effects of pregnant animal exposure to nanomaterials on transitivity to placenta or infants, or on maintenance of pregnancy. Therefore, using nanosilica particles (nSPs) employed as additives in cosmetics and foods, we will report on the efficiency of transitivity of nSPs of various diameters to the circulation through the placental barrier after nanomaterial exposure and the risks of nSP exposure to pregnant mice. In this review, I will discuss the development of safety in nanomaterials and the maintenance of good health.

Toxicity of zinc oxide (ZnO) nanoparticles on human bronchial epithelial cells (BEAS-2B) is accentuated by oxidative stress

Although several studies reported that cytotoxic effects of various nanoparticles are partially due to induction of oxidative stress, it is unclear how oxidative state of the cell per se could influence its sensitivity to cytotoxic nanoparticles. This is of clinical significance because certain pathological conditions such as inflammation is associated with elevated oxidative stress and this may alter sensitivity of cells and tissues to cytotoxic nanoparticles. Hence, this study investigated how initial exposure of BEAS-2B human bronchial epithelial cells to oxidative stress influences subsequent response to cytotoxic challenge with zinc oxide (ZnO) nanoparticles (approximately 10nm). Oxidative stress was induced by exposing BEAS-2B cells to 5 and 10 microM of H(2)O(2) for 45 min in PBS (with Ca(2+)). Subsequently, the H(2)O(2) solutions were washed off and the cells were exposed to varying concentrations (5-25 microg/ml) of ZnO nanoparticles in culture media for 24h, followed by cell viability assessment with the WST-8 assay. The results demonstrated that initial transient exposure of cells to oxidative stress accentuated cytotoxicity of ZnO nanoparticles. In the negative control unexposed to H(2)O(2), >99% of cells remained viable up to a ZnO nanoparticle concentration of 10 microg/ml, but displayed a steep decrease in viability above 10 microg/ml ZnO. By contrast, cells that were initially exposed to 5 and 10 microM of H(2)O(2), displayed a sharp drop in viability even at concentrations below 10 microg/ml ZnO. At 10 microg/ml ZnO, cells initially exposed to 10 microM H(2)O(2) displayed a viability of 40.6+/-2.0%, which is significantly lower than the corresponding values of 72.8+/-2.0% and 99.9+/-1.1% obtained for initial exposure to 5 microM H(2)O(2) and the negative control, respectively. Hence, initial exposure of BEAS-2B cells to oxidative stress sensitized their subsequent response to cytotoxic challenge with ZnO nanoparticles.