Ag_2–3xBi_xS Quantum Dots as Single-Component Theranostic Agents for Second Near-Infrared Fluorescence Imaging-Guided Photothermal Therapy

Abstract

Silver sulfide (Ag 2 S) nanomaterials are being researched increasingly because of their multifunctional potential in the second near-infrared (NIR-II) region (1000−1500 nm). Here, we report Ag 2−3x Bi x S quantum dots (Ag 2−3x Bi x S QDs) as single-component theranostic nanomaterials for NIR-II fluorescence imaging and synchronous photothermal therapy. Bismuth doping in Ag 2 S QDs leads to a fluorescence red shift to the NIR-II region and simultaneously enhances the photothermal conversion efficiency to 58.9%, which can be ascribed to the altered band gap introduced by bismuth doping. This Ag 2 S-based NIR-II theranostic agent can be synthesized in a controlled manner by an albumin biomineralization method under mild conditions. The encapsulation of the biomacromolecular albumin endowed Ag 2−3x Bi x S QDs with greatly strengthened biocompatibility and stability. The survival rate of cancer cells was only 13% after irradiation with an 808 nm laser at a density of 1.2 W cm −2 for 10 min. Meanwhile, in vivo experiments have confirmed the desirable NIR-II fluorescence imaging capability of Ag 2−3x Bi x S QDs. Thus, this study provides a highly efficient single-component theranostic agent with great promise for application in the field of precision theranostics.

Protein-guided biomimetic nanomaterials: a versatile theranostic nanoplatform for biomedical applications

“…75 However, these materials suffer from disadvantages such as poor stability and poor biocompatibility. Some inorganic nanomaterials with fluorescence characteristics can be produced through biomineralization and biomimetic mineralization strategies on the basis of protein, such as Ag 2 S NCs, 76,77 CdNCs, 78 and AuNCs. 79 These materials offer relatively good biocompatibility and in vivo stability.…”

Advancements in semiconductor quantum dots: expanding frontiers in optoelectronics, analytical sensing, biomedicine, and catalysis

“…After 10 minutes of irradiation with an 808 nm laser at a density of 1.2 W cm −2 , the survival rate of cancer cells was only 13%. 286 Sonodynamic treatment (SDT), which applies particular ultrasonic frequencies to stimulate sonosensitizers inside tumors, is another therapeutic method to treat cancer. Reactive oxygen species (ROS) produced by this activation cause tumor cells to die using processes such as pyroptosis and sonoluminescence.…”

Multiwalled Carbon Nanotubes Decorated with Mn0.5Zn0.5Fe2O4 Nanoparticles for Magneto-Photothermal Cancer Therapy

“…Two types of hyperthermia depending on the stimulus used as a trigger, i.e ., optical or magnetic properties activated nanoheating agents. Magnetic hyperthermia (MHT) utilizes heat dissipation by MNPs to kill tumor cells when under an alternating magnetic field (AMF), − while photothermal therapy (PTT) employs photothermal agents that are activated by near-infrared laser (NIR) irradiation. − However, both magnetic hyperthermia and photothermal therapy have their limitations. , For instance, highly concentrated intratumoral injections of magnetic nanoparticles are required to compensate the low specific loss power (SLP) under low magnetic field intensity for the MHT, the real-time temperature monitoring is invasive thermometry, and the nanoparticles distribute non-uniformly within the tumor . Therefore, enhancing SLP value through modifications in the material properties, size, shape, and aggregation state of magnetic nanoparticles emerges as the pivotal factor for augmenting the effectiveness of magnetic hyperthermia. − In PTT, high-power laser exposure can damage surrounding healthy tissue, and some nanoparticles (gold and silver) used are not FDA-approved materials and may not meet biosafety requirements .…”