Biocompatible Semiconductor Quantum Dots as Cancer Imaging Agents

Abstract

Approximately 1.7 million new cases of cancer will be diagnosed this year in the United States leading to 600 000 deaths. Patient survival rates are highly correlated with the stage of cancer diagnosis, with localized and regional remission rates that are much higher than for metastatic cancer. The current standard of care for many solid tumors includes imaging and biopsy with histological assessment. In many cases, after tomographical imaging modalities have identified abnormal morphology consistent with cancer, surgery is performed to remove the primary tumor and evaluate the surrounding lymph nodes. Accurate identification of tumor margins and staging are critical for selecting optimal treatments to minimize recurrence. Visible, fluorescent, and radiolabeled small molecules have been used as contrast agents to improve detection during real-time intraoperative imaging. Unfortunately, current dyes lack the tissue specificity, stability, and signal penetration needed for optimal performance. Quantum dots (QDs) represent an exciting class of fluorescent probes for optical imaging with tunable optical properties, high stability, and the ability to target tumors or lymph nodes based on surface functionalization. Here, state-of-the-art biocompatible QDs are compared with current Food and Drug Administration approved fluorophores used in cancer imaging and a perspective on the pathway to clinical translation is provided.

Anti‐VEGF‐Aptamer Modified C‐Dots—A Hybrid Nanocomposite for Topical Treatment of Ocular Vascular Disorders

“…Nanomedicine represents a rapidly developing research area aiming to apply nanoparticles, such as metallic nanoparticles, semi‐conductive quantum dots or carbonous materials, such as graphene oxide or nanotubes for sensing, imaging, stimuli responsive carriers or therapeutic agents . Carbon dots (C‐dots) have attracted growing interest as a functional nanomaterial due to their unique optical, electronic, and catalytic properties, making them suitable for various applications such as sensing, biosensing, imaging, drug and gene delivery, catalysis, electrocatalysis, and photo‐electrochemistry .…”

Recent Progress in Fluorescence Imaging of the Near‐Infrared II Window

“…QDs and cyanine dyes have been reported to be useful for biological imaging applications . However, these fluorescent materials have broad emission bands, which limit their ability to be easily distinguished from the background fluorescence.…”

“…QDs and cyanine dyes have been reported to be useful for biological imaging applications. [99,100] However,t hese fluorescent materials have broad emission bands,w hich limit their ability to be easily distinguished from the background fluorescence. Cyanine dyes show limited photostabilitya nd QDs exhibit blinkinge mission,w hich make it difficultt om onitor a process or track am oiety.S everal lanthanide cations,w ith emission wavelengths in the NIR-II region, have advantages over semiconductor nanocrystals and organic fluorophores.…”

Designating Vulnerability of Atherosclerotic Plaques

“…Quantum dots (QDs) are used as contrast and therapeutic agents since they have unique properties including strong fluorescence intensity with excellent light stability, low toxicity, and changing emission wavelength with QD size, ranging from 10 to 100 Å in radius [46]. Therefore, they possess great potential in the fields of biological imaging, molecular markers [47][48][49], and drug delivery [50][51][52]. QDs are useful in tumor detection [53], cardiovascular imaging [54], and cancer targeting [55].…”