High quantum yield Ag₂S quantum dot@polypeptide-engineered hybrid nanogels for targeted second near-infrared fluorescence/photoacoustic imaging and photothermal therapy

Abstract

A high quantum yield (4.3%) hybrid nanogel system based on engineered polypeptides and AgS quantum dots has been developed as a multifunctional diagnostic and therapeutic agent for targeted second near-infrared fluorescence, photoacoustic imaging, and photothermal therapy.

Recent Advances of Optical Imaging in the Second Near‐Infrared Window

“…Other than polymer and metal coating, some biomolecules such as DNA, proteins and enzymes have also been demonstrated as potential matrix to enhance the colloidal stability and moderate the toxicity of inorganic nanomaterials. [11e,f,13b,28d,g,31] For instance, human serum albumin (HSA) has been applied to encapsulate Ag 2 S and rare‐earth nanoparticles to ensure their aqueous dispersibility and stability. [13b] Using tumor‐targeted fluorescence imaging as an example, the biodistribution of 100 nm HSA‐coated rare‐earth‐doped sodium yttrium fluoride (NaYF 4 ) core‐shell nanoparticles can be modulated and optimized through fine‐tune the coating thickness of the HSA shell.…”

“…From the nanomaterial design perspective, biocompatible inorganic NIR‐II emissive contrast agents have also found their usage in pharmaceutical research and development to leverage on the diagnostic function. [28f,31–32] Great efforts have been devoted to developing theranostic nanoplatforms, which can assist clinicians in real‐time visualization of therapeutic effect. Therefore, in addition to developing NIR‐II emissive inorganic nanomaterials with a simple targeting function, other therapeutic and imaging modalities have been integrated into a single nanoformulation.…”

“…Therefore, in addition to developing NIR‐II emissive inorganic nanomaterials with a simple targeting function, other therapeutic and imaging modalities have been integrated into a single nanoformulation. [28f,31,32b] Ag 2 S quantum dots have been reported to function as a potential theranostic nanoplatform. By a single component, Ag 2 S displays NIR‐II fluorescence and photothermal characteristics, which has been used for image‐guided tumor therapy (Figure b).…”

“…By a single component, Ag 2 S displays NIR‐II fluorescence and photothermal characteristics, which has been used for image‐guided tumor therapy (Figure b). [28f,31] The controlled growth of Ag 2 S quantum dots of different sizes, ranging from 4 to 10 nm, display distinct optical properties, where larger quantum dots were found to show stronger fluorescence and photothermal effect. [28f] When Ag 2 S quantum dots were coupled with platinum (Pt) decorated gold nanorods, the multifunctional nanocomposites showed NIR‐II/Computed Tomography/PA (NIR‐II/CT/PA) trimodal imaging with photothermal therapeutic effect.…”

An Injectable Self‐Healing Multifluorescent Hydrogel Formed by Engineered Coiled‐Coil Polypeptide and Quantum Dots

“…Hydrogels that contain both hydrophobic region and hydrophilic region will address this problem due to little effect on the microenvironment of hydrophobic QDs. We have previously reported that the QY of Ag 2 S QDs have not changed significantly by using encapsulation with PC 10 A polypeptide …”