Two‐Photon‐Triggered Drug Delivery in Cancer Cells Using Nanoimpellers

Abstract

A therapy of cancer cells: Two-photon-triggered camptothecin delivery (see picture) with nanoimpellers was studied in MCF-7 breast cancer cells. A fluorophore with a high two-photon absorption cross-section was first incorporated in the nanoimpellers. Fluorescence resonance energy transfer (FRET) from the fluorophore to the azobenzene moiety was demonstrated.

Photoresponsive nanoparticles for drug delivery

“…In another example, an azobenzene derivative and a two-photon fluorophore were both attached to the pore surface of MSNPs. Upon two-photon excitation in the NIR range, Förster resonance energy transfer (FRET) from the fluorophores to the azobenzenes triggered the reversible isomerization of the azobenzenes, which then acted as impellers [149]. Irradiation with a focused laser beam (760 nm, 900 mW/cm 2 , three scans of 1.57 s duration) triggered the release of camptothecin from the pores by the “impeller” effect, inducing cancer cell death.…”

Ultraviolet light-mediated drug delivery: Principles, applications, and challenges

“…The relatively poor tissue penetration limits the use of UV to organs that can be directly illuminated, such as the skin, or to targets that can be reached by endoscopic techniques. [83] While low energy NIR light is less phototoxic, and has deeper penetration (2 cm), [84] its chemical effects on molecules are limited.…”

Photochromie jenseits des Sichtbaren: Direkte, im biologischen Fenster addressierbare Einphotonen‐NIR‐Photoschalter

“…In den letzten Jahren wurde ein tiefgehendes Verständnis darüber gewonnen, welche Faktoren die thermische Stabilität von Photoschaltern beeinflussen und welche Faktoren eine Rotverschiebung der Anregungswellenlänge,b esonders für Azobenzole,v erursachen. Als alternativer Ansatz wurde die Zwei-Photonen-Anregung verwendet, um Azobenzole entweder direkt oder indirekt (über Sensibilisatoren) mit NIR-Licht zu schalten, [11] aber die erforderlichen, hohen Laserintensitäten machen medizinische Anwendungen unwahrscheinlich. 2.1 eV [6] ), was Photonen des sichtbaren Bereichs (l % 530 nm) entspricht.…”