Near‐Infrared Optogenetic Genome Engineering Based on Photon‐Upconversion Hydrogels

Abstract

Photon upconversion (UC) from near-infrared (NIR) light to visible light has enabled optogenetic manipulations in deep tissues.H owever,m aterials for NIR optogenetics have been limited to inorganic UC nanoparticles.Herein, NIR-light-triggered optogenetics using biocompatible,organic TTA-UC hydrogels is reported. To achieve triplet sensitization even in highly viscous hydrogel matrices,aNIR-absorbing complex is covalently linked with energy-pooling acceptor chromophores,w hichs ignificantly elongates the donor triplet lifetime.T he donor and acceptor are solubilized in hydrogels formed from biocompatible Pluronic F127 micelles,a nd heat treatment endows the excited triplets in the hydrogel with remarkable oxygen tolerance.Combined with photoactivatable Cre recombinase technology,N IR-light stimulation successfully performs genome engineering resulting in the formation of dendritic-spine-like structures of hippocampal neurons.

Multi‐Photon Excitation in Photoredox Catalysis: Concepts, Applications, Methods

“…Pd II and Pt II complexes such as those included in Table (entries 5–7) are typical red‐light absorbers which are frequently used for TTA‐UC . Os II polypyridines represent another attractive option which allow the direct excitation into 3 MLCT states, and this can minimize the energy loss associated with TTA‐UC and maximize achievable anti‐Stokes shifts. Applications of such Os, Pd, or Pt sensitizers in hydrogels are of significant interest in the context of biological applications …”

Multiphotonen‐Anregung in der Photoredoxkatalyse: Konzepte, Anwendungen und Methoden

“…Pd II ‐ und Pt II ‐Komplexe – wie jene in Tabelle (Einträge 5–7) – sind typische Absorber für rotes Licht und werden häufig für TAA‐UC verwendet . Os II ‐Polypyridine bieten eine vielversprechende Alternative für Systeme mit großen Anti‐Stokes‐Verschiebungen, da eine direkte Anregung in 3 MLCT‐Zustände möglich ist und dadurch der Energieverlust bei der TAA‐UC minimiert werden kann. Vor allem für biologische Anwendungen sind diese Pd‐, Pt‐ und Os‐Sensibilisatoren in Hydrogelen interessant …”

In silico prediction of annihilators for triplet–triplet annihilation upconversion via auxiliary-field quantum Monte Carlo

“…biological tissue) accessible only by photons of lower energy. 1,9 A schematic of TTA upconversion is shown in Fig. 1.…”