Photoactivated Indium Phosphide Quantum Dots Treat Multidrug-Resistant Bacterial Abscesses In Vivo

Abstract

The increasing prevalence of drug-resistant bacterial strains is causing illness and death in an unprecedented number of people around the globe. Currently implemented small-molecule antibiotics are both increasingly less efficacious and perpetuating the evolution of resistance. Here, we propose a new treatment for drug-resistant bacterial infection in the form of indium phosphide quantum dots (InP QDs), semiconductor nanoparticles that are activated by light to produce superoxide. We show that the superoxide generated by InP QDs is able to effectively kill drug-resistant bacteria in vivo to reduce subcutaneous abscess infection in mice without being toxic to the animal. Our InP QDs are activated by near-infrared wavelengths with high transmission through skin and tissues and are composed of biocompatible materials. Body weight and organ tissue histology show that the QDs are nontoxic at a macroscale. Inflammation and oxidative stress markers in serum demonstrate that the InP QD treatment did not result in measurable effects on mouse health at concentrations that reduce drug-resistant bacterial viability in subcutaneous abscesses. The InP QD treatment decreased bacterial viability by over 3 orders of magnitude in subcutaneous abscesses formed in mice. These InP QDs thus provide a promising alternative to traditional small-molecule antibiotics, with the potential to be applied to a wide variety of infection types, including wound, respiratory, and urinary tract infections.

Antimicrobial Photodynamic Therapy: Latest Developments with a Focus on Combinatory Strategies

“…Consequently, not only can these nano building blocks carry PS molecules and alter the integrity of microbial walls/membranes or gene expression, but they may as well act as PSs; when coupled with other PSs, synergistic interactions in the QD-PS edifices might occur resulting from mechanisms such as Förster resonance energy transfer (FRET, non-radiative energy transfer from QD donors to PS acceptors) to generate free radicals and ROS. Among examples of such QDs and metal chalcogenide aPDT systems can be cited CdTe QDs and related CdTe-PS conjugates, CdSe/ZnS QDs combined with PSs, InP and InP-PS, Mn-doped ZnS, MoS 2 , but also CuS and CdS nanocrystals, with ultimately hybrid systems involving for instance CoZnO/MoS 2 or AgBiS 2 -TiO 2 composites [123,[183][184][185][186][187][188][189][190][191][192][193][194][195][196].…”

Sulfide-Capped InP/ZnS Quantum Dot Nanoassemblies for a Photoactive Antibacterial Surface

“…7 They also demonstrated the effectiveness of these QDs against drug-resistant bacteria for an in vivo model. 32 Similarly, Lee et al explored the antibacterial effects of the same QD solutions (InP/ZnS and InP/ZnSe) modified with MPA utilizing blue light irradiation. 31 In addition, Khan et al showed the antibacterial activity of sulfide-capped InP/ZnO core/shell QDs with type-II band alignment.…”

“…The enhanced charge carrier extraction and faster transfer of photogenerated electrons are the consequences of surface functioning. − Cadmium-based QDs have shown significant antibacterial activity via ROS generation under illumination. ,− However, the release of cadmium ions into the cells and tissues is a major concern. Alternatively, cadmium-free QDs such as AgBiS 2 , CuInS/ZnS, InP, ,− and ZnO QDs have shown antibacterial activity. In the previous reports, Cd-free QDs operate in suspensions, but their application on medical surfaces (e.g., catheters) requires their transformation on solid surfaces.…”

Bright Semiconductor Quantum Dots Shed New Light on Precision Nanomedicine for Various Diseases

“…Therefore, these InP QDs appear to be a promising alternative to conventional antibiotics. [ 116 ] In the subsequent studies, the group further demonstrated that CdTe QDs with a 2.4 eV bandgap can also be activated by blue light to produce the toxic ROS, thereby treating the subcutaneous infection of mice [13a] . By employing a similar design concept, Zhang et al developed CuInS/ZnS QDs to eliminate the pathogenic, multidrug‐resistant P. aeruginosa .…”