Organic Nanoparticles Based on D-A-D Small Molecule: Self-Assembly, Photophysical Properties, and Synergistic Photodynamic/Photothermal Effects.

Liangliang Yue,Xiaogang Luo,Qi Sun,Fengshou Wu,Haolan Li,Xunjin Zhu

doi:10.3390/ma15020502

Abstract

Cancer is one of the major diseases threatening human health. Traditional cancer treatments have notable side-effects as they can damage the immune system. Recently, phototherapy, as a potential strategy for clinical cancer therapy, has received wide attention due to its minimal invasiveness and high efficiency. Herein, a small organic molecule (PTA) with a D-A-D structure was prepared via a Sonogashira coupling reaction between the electron-withdrawing dibromo-perylenediimide and electron-donating 4-ethynyl-N,N-diphenylaniline. The amphiphilic organic molecule was then transformed into nanoparticles (PTA-NPs) through the self-assembling method. Upon laser irradiation at 635 nm, PTA-NPs displayed a high photothermal conversion efficiency (PCE = 43%) together with efficient reactive oxygen species (ROS) generation. The fluorescence images also indicated the production of ROS in cancer cells with PTA-NPs. In addition, the biocompatibility and photocytotoxicity of PTA-NPs were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and live/dead cell co-staining test. Therefore, the as-prepared organic nanomaterials were demonstrated as promising nanomaterials for cancer phototherapy in the clinic.

Highlights

Because of its high mortality, cancer has always been a great threat to human health [1]
Based on the mechanism of Photodynamic therapy (PDT) and photothermal therapy (PTT), much effort has been dedicated to developing photosensitizers with high reactive oxygen species (ROS) generation or efficient photothermal conversion efficiency (PCE) for effective cancer phototherapy
The photocytotoxicity and intracellular ROS generation of PTA-NPs were verified by MTT assay and fluorescence images. Compared to those reported nanomaterials, the PTA-NPs showed several distinct properties, including (1) organic nanomaterials generated from small molecules (PTA) with a clear structure and accurately determined molecular weight, (2) high photothermal conversion efficiency (43%), and (3) simple fabrication method without the addition of any other reagents

Summary

Introduction

Because of its high mortality, cancer has always been a great threat to human health [1]. Based on the mechanism of PDT and PTT, much effort has been dedicated to developing photosensitizers with high ROS generation or efficient photothermal conversion efficiency (PCE) for effective cancer phototherapy. PTA-NPs exhibited high photothermal conversion efficiency (PCE = 43%) under 635 nm laser, which was comparable to that of reported organic nanomaterials (Table 1). The photocytotoxicity and intracellular ROS generation of PTA-NPs were verified by MTT assay and fluorescence images Compared to those reported nanomaterials, the PTA-NPs showed several distinct properties, including (1) organic nanomaterials generated from small molecules (PTA) with a clear structure and accurately determined molecular weight, (2) high photothermal conversion efficiency (43%), and (3) simple fabrication method without the addition of any other reagents. ESI-MS: m/z calculated for C80H68N4O10 [M + H]+ 1244.5, found 1244.5

Preparation of Perylene Diimide-Based Nanoparticles

Morphology and Particle Size

Photophysical Properties

Findings

MTT Assay