Heptamethine Cyanine–Based Application for Cancer Theranostics

Abstract

Cancer is the most common life-threatening malignant disease. The future of personalized cancer treatments relies on the development of functional agents that have tumor-targeted anticancer activities and can be detected in tumors through imaging. Cyanines, especially heptamethine cyanine (Cy7), have prospective application because of their excellent tumor-targeting capacity, high quantum yield, low tissue autofluorescence, long absorption wavelength, and low background interference. In this review, the application of Cy7 and its derivatives in tumors is comprehensively explored. Cy7 is enormously acknowledged in the field of non-invasive therapy that can “detect” and “kill” tumor cells via near-infrared fluorescence (NIRF) imaging, photothermal therapy (PTT), and photodynamic therapy (PDT). Furthermore, Cy7 is more available and has excellent properties in cancer theranostics by the presence of multifunctional nanoparticles via fulfilling multimodal imaging and combination therapy simultaneously. This review provides a comprehensive scope of Cy7’s application for cancer NIRF imaging, phototherapy, nanoprobe-based combination therapy in recent years. A deeper understanding of the application of imaging and treatment underlying Cy7 in cancer may provide new strategies for drug development based on cyanine. Thus, the review will lead the way to new types with optical properties and practical transformation to clinical practice.

Heptamethine Cyanine-Loaded Nanomaterials for Cancer Immuno-Photothermal/Photodynamic Therapy: A Review

“…Nanoparticles containing prototypic HC also hold great potential for application in cancer immuno-PTT/PDT due to their improved optical properties (reviewed in detail in [ 10 , 17 , 68 ]). Among these, IR780-loaded nanomaterials have been the most applied, followed by IR820-loaded nanostructures.…”

“…In general, photothermal heating to temperatures around 41–45 °C can induced reversible damage to cells (e.g., affect DNA repair mechanisms or metabolic pathways) or sensitize them to the action of other agents (e.g., chemotherapeutic drugs) [ 16 ]. In turn, hyperthermia of 50 °C (or above) causes irreversible damage in cells in the primary tumor (e.g., mitochondrial/enzymatic dysfunctions, protein denaturation, membrane destruction), culminating in cell death by necrosis—reviewed in detail in [ 16 , 17 ]. Furthermore, the photogenerated ROS are highly reactive and short-lived, inducing oxidative stress and damage to the nearby structures, leading to cell death by apoptosis (most common), necrosis, and autophagy-associated cell death [ 12 , 13 ].…”

“…These nanostructures can be simply prepared by loading the HCs into the hydrophobic reservoirs of the nanomaterials [ 61 , 67 ]. Moreover, HC-loaded nanomaterials also have a multifunctional character due to the HCs’ photothermal, photodynamic, and fluorescent properties—reviewed in detail by us and by Wang’s group [ 10 , 17 , 68 ]. In this regard, the FDA-approval status of the HC Indocyanine Green (ICG) has strongly contributed to the investigation of ICG-loaded nanomaterials for cancer immuno-PTT/PDT [ 69 , 70 ].…”

Recent progress on near‐infrared fluorescence heptamethine cyanine dye‐based molecules and nanoparticles for tumor imaging and treatment

“…Among numerous NIR fluorescent organic dyes based on cyanines, phthalocyanines (Debnath et al, 2022), BODIPYs (Boens et al, 2012), and rhodamine analogs (Liu & Scott, 2021), heptamethine cyanine dyes have secured their place in early tumor diagnosis due to some intriguing features including little side effects, deep tissue infiltration, and low fluorescence background in living organisms (Yuan et al, 2013). Impressively, indocyanine green (ICG), a traditional heptamethine cyanine dye, has been approved by the United States Food and Drug Administration (FDA) for clinical applications (Zhang et al, 2021). Additionally, IRDye800CW is in the process of clinical approval worldwide (Harlaar et al, 2016).…”

A Lysosome-Targeted Near-Infrared Fluorescent Probe with Excellent Water Solubility for Surgery Navigation in Breast Cancer

“…Therefore, it is urgent to develop targeted and safe contrast agents to guide the resection of cancer tumors. Currently, the use of cyanine dyes for cancer imaging and treatment has received increasing attention. − Cyanine 7 (Cy7) is a NIR anthocyanin fluorescent dye, , which has weak background fluorescence and strong penetration characteristics, so Cy7 is often used in vivo imaging of small animals, but the water solubility of ordinary Cy7 is low. In view of the poor water solubility of conventional cyanine dyes, quaternary ammonium groups were modified on each side to provide good water solubility according to a previous report .…”