Surfactant Semiconductors as Trojan Horses in Cell-Membranes for On-Demand and Spatial Regulation of Oxidative Stress

Oxidative stress is a cause for numerous diseases and aging processes. Thus, researchers are keen to tune the level of intracellular stress and to learn from that. An unusual approach is presented here. The methodology involves multifunctional surfactants. Although their molecular design is nonbiological—a fullerenol head group attached covalently to pi-conjugated dyes—the surfactants possess superior biocompatibility. Using an intrinsic fluorescence signal as a probe, it is shown that the amphiphiles become incorporated into the Caco-2 cells. There, they are able to exhibit additional functions. The compound reduces cellular stress in dark reaction pathways. The antagonistic property is activated under irradiation, the photocatalytic production of reactive oxygen species (ROS), resulting in cell damage. The feature is activated even by near-infrared light (NIR-light) via a two-photon process. The properties as molecular semiconductors lead to a trojan horse situation and allows the programming of the spatial distribution of cytotoxicity

Micellar (Photo-)Catalysis driven by IR-Active Semiconductor Surfactants

In micellar catalysis, one uses aggregates formed by surfactants as nanoreactors for performing chemical reactions. A special class of tailor-made surfactants containing catalytically active sites opens new perspectives in micellar catalysis. Little is known about the combination of such surfactants with photocatalysis. Molecular semiconductors are presented, which simultaneously have amphiphilic properties and are made of a hydrophilic fullerenol head group attached to dye molecules as the hydrophobic entity. The first generation of those surfactants produces reactive oxygen species (ROS) when exposed to light in the UV/Vis range. The concept of the current paper is that one can drive the photocatalytic process also using low-energy photons in the near-infrared region. For this purpose, NIR-active dye molecules were selected and attached to the fullerenol head. It is shown that a fullerenol - aminostilbene compound representing the second generation of semiconductor surfactants fulfills all requirements. It forms aggregates in water that are catalytically active. Moreover, two-photon experiments with lamda = 780 nm were performed, indicating successful ROS production and, thus, photocatalytic activity

Surfactant Semiconductors as Trojan Horses in Cell‐Membranes for On‐Demand and Spatial Regulation of Oxidative Stress

Oxidative stress is a cause for numerous diseases and aging processes. Thus, researchers are keen to tune the level of intracellular stress and to learn from that. An unusual approach is presented here. The methodology involves multifunctional surfactants. Although their molecular design is nonbiological—a fullerenol head group attached covalently to pi-conjugated dyes—the surfactants possess superior biocompatibility. Using an intrinsic fluorescence signal as a probe, it is shown that the amphiphiles become incorporated into the Caco-2 cells. There, they are able to exhibit additional functions. The compound reduces cellular stress in dark reaction pathways. The antagonistic property is activated under irradiation, the photocatalytic production of reactive oxygen species (ROS), resulting in cell damage. The feature is activated even by near-infrared light (NIR-light) via a two-photon process. The properties as molecular semiconductors lead to a trojan horse situation and allows the programming of the spatial distribution of cytotoxicity.publishe

Photoactive surfactant semiconductors characterized by a dissociative identity disorder integrated into the membranes of living cells as trojan horses for on-demand and spatial regulation of oxidative stress.

Oxidative stress is a cause for numerous diseases and aging processes. Thus, one is keen to tune the level of intracellular stress and to learn from that, and an unusual approach is presented here. The methodology involves multifunctional surfactants. Although their molecular design is non-biological, a fullerenol head group attached covalently to -conjugated dyes, the surfactants possess superior biocompatibility. Using the intrinsic fluorescence signal as a probe it is proven, the amphiphiles become incorporated into the membranes of Caco-2 cells. There, they are able to exhibit additional functions. The compound reduces cellular stress in dark reaction pathways. The antagonistic property is activated under irradiation, the photocatalytic production of ROS, resulting in cell damage and finally to apoptosis. The feature is activated even by NIR-light via a two-photon process. The properties as molecular semiconductors leads to a trojan horse situation and allows programming the spatial distribution of cytotoxicity