Multifunctional Tetracene/Pentacene Host/Guest Nanorods for Enhanced Upconversion Photodynamic Tumor Therapy

Abstract

The tissue penetration depth of light and the singlet oxygen ( 1 O 2 ) generation efficiency of photosensitizers (PSs) are the two main factors that determine the effectiveness of photodynamic therapy for tumors. Herein, we report a novel strategy to prepare a multifunctional upconversion photosensitizer (UCPS) based on the host/ guest nanoarchitecture. By a simple reprecipitation method, host/guest tetracene/pentacene nanorods (Tc/Pc NRs) were synthesized for enhancing triplet−triplet annihilation-upconversion (TTA-UC) or two-photon excited emission and 1 O 2 generation efficiency upon 650 or 808 nm excitation. Tc/Pc NRs had higher 1 O 2 quantum yield (74%) than Tc NRs (28%) upon 650 nm laser irradiation. The proposed mechanism is that doping Pc molecules into Tc NRs induces intermediate states between S 0 and S 1 , shortening the energy gap for 1 O 2 generation and resulting in TTA-UC emission. Equally important, with 808 nm fs laser excitation, Tc/Pc NRs showed an enhanced 1 O 2 generation efficiency and two-photon absorption cross section (σ) compared with Tc NRs. In addition, when the tumors in mice were exposed to Tc/Pc NRs with 650 or 808 nm wavelength irradiation, the tumor inhibition rates achieved 99 and 95%, respectively. This work opens new perspectives for exploring novel nano-UCPSs for biomedical applications.

Recent advances in materials for and applications of triplet–triplet annihilation-based upconversion

“…Li and coworkers prepared biocompatible host/guest nanorods for highly effective upconversion photodynamic therapy. 13 Upon 650 or 808 nm laser irradiation, the prepared Tc/Pc (tetracene/pentacene) nanorods generated 1 O 2 . The in vivo antitumor activity was monitored by the tumor volume and the body weight of mice over a period of a few days after the injection of Tc/Pc nanorods under laser irradiation.…”

“…1.Copyrights, 2017 Wiley-Blackwell. (B) Schematic illustration of synthesized nanorod complex's self-delivered TTA-UC and excited photodynamic therapy of tumors with 650 nm and 808 nm laser irradiation 13. Reproduced with permission from ref 13…”

Tuning the edge states in X-type carbon based molecules for applications in nonlinear optics

“…Materials with inherent nonlinear optical (NLO) response and stability, especially conjugated organic compounds, have potential applications in the domain of optical limiting, 1 optical switching, 2,3 data storage, 4 photodynamic therapy, 5,6 etc. Two-dimensional (2D) graphene 7 is passionately explored for potential applications in nonlinear optics, owing to its unique electro-optical properties.…”

Activatable Photodynamic Therapy with Therapeutic Effect Prediction Based on a Self-correction Upconversion Nanoprobe

“…It is urgent to introduce internal standard and prepare a self-correction imaging system for accurate intracellular enzyme imaging and corresponding therapeutic effect prediction. − With the capabilities of deep tissue penetration, multiple luminance emissions, and little autofluorescence, upconversion nanoparticles (UCNPs) turn out to be appropriate self-correction probes. Though widely applied in bioimaging − and biomedicine , such as PDT, − the low upconversion energy transfer efficiencies − and luminance intensities , attenuate their response to macromolecules and proteins. Here, we prepared an enzyme-responsive UCNPs nanoprobe for activatable PDT with the capability of luminance self-correction for simultaneous therapeutic effect prediction.…”