Phototoxic Effects on Skin Biomolecules Induced by a Domestic Nail Polish Dryer Device.

UVA radiation and visible light can lead to indirect damage to DNA, proteins, and lipids through photosensitized reactions, where a molecule undergoes a photochemical alteration by the initial absorption of radiation by another molecular entity called photosensitizer (Sens). The chemical changes undergone by biomolecules in photosensitized reactions can trigger important adverse processes such as photoallergy, phototoxicity, and skin cancer, among others. Despite the knowledge about photosensitized reactions and the fact that many endogenous compounds present in the skin can act as Sens, UVA, and visible light are widely used in several devices for domestic and general use without a thorough evaluation of their possible harmful effects; one prominent example is UV-nail polish dryers.

Alkylation converts riboflavin into an efficient photosensitizer of phospholipid membranes.

A new decyl chain [-(CH)CH] riboflavin conjugate has been synthesized and investigated. A nucleophilic substitution (S2) reaction was used for coupling the alkyl chain to riboflavin (Rf), a model natural photosensitizer. As expected, the alkylated compound (decyl-Rf) is significantly more lipophilic than its precursor and efficiently intercalates within phospholipid bilayers, increasing its fluorescence quantum yield.

Singlet Oxygen Flux, Associated Lipid Photooxidation, and Membrane Expansion Dynamics Visualized on Giant Unilamellar Vesicles.

The physical properties of lipid membranes depend on their lipid composition. Photosensitized singlet oxygen (O) provides a handle to spatiotemporally control the generation of lipid hydroperoxides via the reaction, enabling fundamental studies on membrane dynamics in response to chemical composition changes. Critical to relating the physical properties of the lipid membrane to hydroperoxide formation is the availability of a sensitive reporter to quantify the arrival of O.

Synthesis, Characterization and Photocleavage of Bis-decyl Pteroic Acid: A Folate Derivative with Affinity to Biomembranes.

Here, we provide mechanistic insight to the photocleavage of a compound in the folate family, namely pteroic acid. A bis-decyl chain derivative of pteroic acid was synthesized, structurally characterized and photochemically investigated. We showed that, like folic acid, pteroic acid and the decylated derivative undergo a photocleavage reaction in the presence of H O, while no reaction was observed in methanol solution.

Immobilization of alkyl-pterin photosensitizer on silicon surfaces through in situ S2 reaction as suitable approach for photodynamic inactivation of Staphylococcus aureus.

The tuning of surface properties through functionalization is an important field of research with a broad spectrum of applications. Self-assembled monolayers (SAMs) allow the surface tailoring through the adsorption of molecular layers having the appropriate functional group or precursor group enabling in situ chemical reactions and thus to the incorporation of new functionalities. The latter approach is particularly advantageous when the incorporation of huge groups is needed.