Quantum dot therapeutics: a new class of radical therapies

Abstract

Traditional therapeutics and vaccines represent the bedrock of modern medicine, where isolated biochemical molecules or designed proteins have led to success in treating and preventing diseases. However, several adaptive pathogens, such as multidrug-resistant (MDR) superbugs, and rapidly evolving diseases, such as cancer, can evade such molecules very effectively. This poses an important problem since the rapid emergence of multidrug-resistance among microbes is one of the most pressing public health crises of our time—one that could claim more than 10 million lives and 100 trillion dollars annually by 2050. Several non-traditional antibiotics are now being developed that can survive in the face of adaptive drug resistance. One such versatile strategy is redox perturbation using quantum dot (QD) therapeutics. While redox molecules are nominally used by cells for intracellular signaling and other functions, specific generation of such species exogenously, using an electromagnetic stimulus (light, sound, magnetic field), can specifically kill the cells most vulnerable to such species. For example, recently QD therapeutics have shown tremendous promise by specifically generating superoxide intracellularly (using light as a trigger) to selectively eliminate a wide range of MDR pathogens. While the efficacy of such QD therapeutics was shown using in vitro studies, several apparent contradictions exist regarding QD safety and potential for clinical applications. In this review, we outline the design rules for creating specific QD therapies for redox perturbation; summarize the parameters for choosing appropriate materials, size, and capping ligands to ensure their facile clearance; and highlight a potential path forward towards developing this new class of radical QD therapeutics.

Photo/electrocatalysis and photosensitization using metal nanoclusters for green energy and medical applications

“…21). 123 Yang et al fabricated titanium dioxide NP-Au NCs-graphene heterogeneous nanocomposites to induce a large production of HOc and O 2 c À radicals, which could serve as Type I PDT for B16F1 melanoma cells. 125 3.3.6.…”

Near‐Infrared‐Light‐Triggered Antimicrobial Indium Phosphide Quantum Dots

“…As such, an effective and scalable alternative to conventional drugs is urgently needed. Nanoparticle‐based therapeutics have demonstrated facile transport, excellent stability, and efficacy as a low‐cost alternative to typical small‐molecule drugs, especially for Gram‐negative multidrug‐resistant (MDR) pathogens. The use of light in treating infections with nanoparticles offers greater control over dosing and spatiotemporal release of therapeutic superoxide.…”

“…Previous studies have used QDs in combination with visible light to eliminate bacteria, including 45 MDR strains, many of which are resistant to almost all known and last‐resort antibiotics . Upon illumination, absorbed light triggers the photo‐electrochemical reduction of oxygen to generate therapeutic superoxide intracellularly . The bottom‐up design of QD nanotherapeutics involves optimizing several aspects: material selection, reduction and oxidation potentials, biocompatibility, and surface chemistry.…”

“…The bottom‐up design of QD nanotherapeutics involves optimizing several aspects: material selection, reduction and oxidation potentials, biocompatibility, and surface chemistry. These variables tightly control the desired phototherapeutic effect, eliminate undesired material toxicity, can modulate the innate host immune response, and ensure efficient QD transport . While cadmium telluride (CdTe) QDs demonstrate selective bacterial killing (even of MDR superbugs), its green‐light absorbing band gap and cadmium content present some concerns.…”

Gold nanoclusters cause selective light-driven biochemical catalysis in living nano-biohybrid organisms

“…[19][20][21][22] We focused on Au NCs capped with the zwitterionic ligand, glutathione (GSH), due to their demonstrated low hydrodynamic radius for cellular uptake. [23][24][25] These atomically-precise Au NCs can be synthesized using simple wet-chemistry, with tunable optoelectronic properties ( Fig. 1a), hydrodynamic size ( Fig.…”