Near-infrared AIE-active phosphorescent iridium(III) complex for mitochondria-targeted photodynamic therapy.

Mitochondria-targeted photodynamic therapy (PDT) has recently been recognized as a promising strategy for effective cancer treatment. In this work, a mitochondria-targeted near-infrared (NIR) aggregation-induced emission (AIE)-active phosphorescent Ir(III) complex (Ir1) is reported with highly favourable mitochondria-targeted bioimaging and cancer PDT properties. Complex Ir1 has strong absorption in the visible light region (∼500 nm) and can effectively produce singlet oxygen (1O2) under green light (525 nm) irradiation. It preferentially accumulates in the mitochondria of human breast cancer MDA-MB-231 cells as revealed by colocalization analysis. Complex Ir1 displays high phototoxicity toward human breast cancer MDA-MB-231 cells and mouse breast cancer 4T1 cells. Complex Ir1 induces reactive oxygen species (ROS) production, mitochondrial dysfunction, and endoplasmic reticulum (ER) stress in MDA-MB-231 cells upon photoirradiation, leading to apoptotic cell death. The favorable PDT performance of Ir1in vivo has been further demonstrated in tumour-bearing mice. Together, the results suggest that Ir1 is a promising photosensitizer for mitochondria-targeted imaging and cancer phototherapy.

Recoding the Cancer Epigenome by Intervening in Metabolism and Iron Homeostasis with Mitochondria-Targeted Rhenium(I) Complexes.

The development and malignancy of cancer cells are closely related to the changes of the epigenome. In this work, a mitochondria-targeted rhenium(I) complex (DFX-Re3), integrating the clinical iron chelating agent deferasirox (DFX), has been designed. By relocating iron to the mitochondria and changing the key metabolic species related to epigenetic modifications, DFX-Re3 can elevate the methylation levels of histone, DNA, and RNA. As a consequence, DFX-Re3 affects the events related to apoptosis, RNA polymerases, and T-cell receptor signaling pathways. Finally, it is shown that DFX-Re3 induces immunogenic apoptotic cell death and exhibits potent antitumor activity in vivo. This study provides a new approach for the design of novel epigenetic drugs that can recode the cancer epigenome by intervening in mitochondrial metabolism and iron homeostasis.

Multifunctional low-temperature photothermal nanodrug with in vivo clearance, ROS-Scavenging and anti-inflammatory abilities.

Harsh photothermal temperatures, long-term body retention of nanoagents, elevated ROS and inflammation induction all threaten the normal tissues, thus hindering the translation of photothermal therapy (PTT) from bench to clinical practice. To resolve these problems, we have developed a disassembled theranostic nanodrug Qu-FeIIP based on the quercetin coordination. Herein, quercetin is not only the heat shock protein (Hsp 70) inhibitor but also the skeleton of Qu-FeIIP, realizing near-infrared light induced low-temperature PTT (45 °C) to ablate tumor completely without heat stress to normal tissues. Owing to the ROS scavenging ability of quercetin, Qu-FeIIP effectively reduces intracellular ROS and in vivo inflammatory factors (TNF-α, IL-6, IFN-γ) levels. Simultaneously, quercetin-Fe coordination is weakened when scavenging ROS, which triggers the Qu-FeIIP disassembling, resulting in effective clearance of nanoparticles from main organs 168 h post intravenous injection. Additionally, the photoacoustic and magnetic resonance dual-imaging capability of Qu-FeIIP offers excellent spatial resolution and imaging depth not only for precise tumor diagnosis but also for monitoring the nanodrug disassembling in vivo. Thus, Qu-FeIIP intrinsically integrates precise diagnosis, excellent low-temperature PTT efficacy, ROS elimination and anti-inflammatory action, dynamic disassembly and renal clearance ability into a single nanodrug, which is very promising for future clinical cancer treatment.

Smart hyaluronidase-actived theranostic micelles for dual-modal imaging guided photodynamic therapy.

We here report smart hyaluronidase-actived theranostic nanoparticles based on hyaluronic acid (HA) coupled with chlorin e6 (Ce6) via adipic dihydrazide (ADH) forming HA-ADH-Ce6 conjugates and self-assembling into HACE NPs. The resulting nanoparticles showed stable nano-structure in aqueous condition with uniform size distribution and can be actively disassembled in the presence of hyaluronidase (over-expressed in tumor cells), exhibiting hyaluronidase-responsive "OFF/ON" behavior of fluorescence signal. The HACE NPs were rapidly taken up to human lung cancer cells A549 via CD44 (the HA receptor on the surface of tumor cells) receptor mediated endocytosis. Upon laser irradiation, the HACE NPs realized good near-infrared fluorescence imaging and photoacoustic imaging in the tumor bearing mice, which showed 5-fold higher fluorescence intensity and 3-fold higher photoacoustic (PA) intensity than free Ce6, respectively. In addition, under low dose of laser power, the HACE NPs presented more effective photodynamic therapy to suppression of tumor growth than free Ce6 in vitro and in vivo. Overall, these results suggest that the well-defined HACE NPs is a biocompatible theranostic nanoplatform for in vivo dual-modal tumor imaging and phototherapy simultaneously.