Quaternary Zn–Ag–In–Se Quantum Dots for Biomedical Optical Imaging of RGD-Modified Micelles

Abstract

Exploring the synthesis of new biocompatible quantum dots (QDs) helps in overcoming the intrinsic toxicity of the existing QDs composed of highly toxic heavy metals (e.g., Cd, Hg, Pb, etc.) and is particularly interesting for the future practical application of QDs in biomedical imaging. Hence, in this report, a new one-pot approach to oil-soluble (highly toxic heavy metal-free) highly luminescent quaternary Zn-Ag-In-Se (ZAISe) QDs was designed. Their photoluminescence (PL) emission could be systematically tuned from 660 to 800 nm by controlling the Ag/Zn feed ratio, and their highest PL quantum yield is close to 50% after detailed optimization. Next, by using biodegradable RGD peptide (arginine-glycine-aspartic acid)-modified N-succinyl-N'-octyl-chitosan (RGD-SOC) micelles as a water transfer agent, the versatility of these quaternary ZAISe QDs for multiscale bioimaging of micelles (namely, in vitro and in vivo evaluating the tumor targeting of drug carriers) was further explored, as a promising alternative for Cd- and Pb-based QDs.

Near‐infrared fluorescent peptide probes for imaging of tumor in vivo and their biotoxicity evaluation

“…These formulations works very well on targeting the integrin positive of tumor models and these functionalized nanoparticles are suitable for long‐term imaging due to their long circulation time in blood. For example, Deng et al performed successful imaging of MDA‐MB‐231 tumor in vivo by using quaternary ZnAgInSe QDs packaged within RGD‐modified micelles . However, some of these nanoparticle formulations are found to be accumulated in the liver and spleen and more importantly, they may degrade in these organs and causing local toxicity to the tissues.…”

Design, fabrication, and biomedical applications of bioinspired peptide–inorganic nanomaterial hybrids

“…In addition, many high-quality QDs obtained from nonpolar organic media have a hydrophobic surface, which requires part of hydrophobic amino acids to form hydrophobic interaction. 38 Moreover, many multifunctional peptides also contain typical amino-terminal fragments. For example, biological aromatic polypeptides like Fmoc-FF that can fold into amyloid fibrils with β-sheet structures were observed blue and green photon emission.…”

“…For example, chitosan that was modified with RGD peptide sequence was used as surface ligand of Zn-Ag-In-Se QDs. 38 As a result, the oil-soluble QDs became water-soluble and kept the initial shape, crystal structure, and optical properties. Similarly, His 6 peptide was used to modify PEG and stabilized the QDs.…”

Studies on the Conformations and Hydrogen-Bonding Interactions of RGD Tri-peptide in Aqueous Solutions by Molecular Dynamics Simulations and 2D-NOESY Spectroscopy

“…The RGD peptide also represents a new class of radiotracers that target both tumor cells and activated endothelial cells of the neovasculature during tumor growth, invasion, and metastasis. RGD-based anticancer strategies are very useful in cancer therapy and diagnosis [6][7][8][9][10]. RGD and RGD containing conjugates are effective antithrombotics.…”