Sun block for nanoparticles: Unintentional photorelease triggered by UV light is a problem in photodynamic therapy. Encapsulating upconverting nanoparticles containing photoswitches in a UV-blocking amphiphilic polymer shuts down the one-photon process and only allows two-photon-driven photochemistry. Thus, UV light is blocked while NIR light can reach the nanoparticle core and trigger photorelease.

Scheme 1. Photo-Induced Ring-Opening and Ring-Closing of the Photochromic Spiropyran (1) and Merocyanine (2) Used in These Studies Communication pubs.acs.org/cm

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Sonnenschutz für Nanopartikel: Unbeabsichtigt durch UV‐Licht ausgelöste Freisetzung stört bei der photodynamischen Therapie. Das Einschließen von hochkonvertierenden Nanopartikeln, die Photoschalter enthalten, in ein UV‐Strahlung abblockendes amphiphiles Polymer unterbindet den Einphotonenprozess und lässt nur die zweiphotonengesteuerte Photochemie zu. Nur NIR‐Licht kann daher den Nanopartikelkern noch erreichen und die Photofreisetzung auslösen.

Neolamellarin A, a metabolite isolated from the sponge Dendrilla nigra, was found to inhibit hypoxia-inducible factor-1 (HIF-1) activation by 26% at 10 µM concentration and inhibition of HIF-1 has become a major antitumor molecular target. Herein the first synthesis of neolamellarin A is described. The synthetic strategy features the condensation of vinylogous amide with aminomalonate to construct the 3,4-bis(4-methoxyphenyl)-1H-pyrrole core and the subsequent acylation and deprotection rendered the target compound in 18% over all yield.

Visible light is used to generate heat from gold nanoparticles wrapped in an amphiphilic polymer shell and trigger a reverse Diels-Alder reaction of a ‘caged’ tyrophostin therapeutic agent. The hydrophillic...

In this protocol, we first describe a procedure to synthesize lanthanide doped upconverting nanoparticles (UCNPs). We then demonstrate how to generate amphiphilic polymers in situ, and describe a protocol to encapsulate the prepared UCNPs and different organic dye molecules (porphyrins and diarylethenes) using polymer shells to form stable water-dispersible nanoassemblies. The nanoassembly samples containing both the UCNPs and the diarylethene organic dyes have interesting photochemical and photophysical properties. Upon 365 nm UV irradiation, the diarylethene group undergoes a visual color change. When the samples are irradiated with visible light of another specific wavelength, the color fades and the samples return to the initial colorless state. The samples also emit visible light from the UCNPs upon irradiation with 980 nm near-infrared light. The emission intensity of the samples can be tuned through alternate irradiation with UV and visible light. Modulation of fluorescence can be performed for many cycles without observable degradation of the samples. This versatile encapsulation procedure allows for the transfer of hydrophobic molecules and nanoparticles from an organic solvent to an aqueous medium. The polymer helps to maintain a lipid-like microenvironment for the organic molecules to aid in preservation of their photochemical behavior in water. Thus this method is ideal to prepare water-dispersible photoresponsive systems. The use of near-infrared light to activate upconverting nanoparticles allows for lower energy light to be used to activate photoreactions instead of more harmful ultraviolet light.

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