Real-Time In Vivo Detection and Monitoring of Bacterial Infection Based on NIR-II Imaging

Abstract

Treatment according to the dynamic changes of bacterial load in vivo is critical for preventing progression of bacterial infections. Here, we present a lead sulfide quantum dots (PbS QDs) based second near-infrared (NIR-II) fluorescence imaging strategy for bacteria detection and real-time in vivo monitoring. Four strains of bacteria were labeled with synthesized PbS QDs which showed high bacteria labeling efficiency in vitro. Then bacteria at different concentrations were injected subcutaneously on the back of male nude mice for in vivo imaging. A series of NIR-II images taken at a predetermined time manner demonstrated changing patterns of photoluminescence (PL) intensity of infected sites, dynamically imaging a changing bacterial load in real-time. A detection limit around 102–104 CFU/ml was also achieved in vivo. Furthermore, analysis of pathology of infected sites were performed, which showed high biocompatibility of PbS QDs. Therefore, under the guidance of our developed NIR-II imaging system, real-time detection and spatiotemporal monitoring of bacterial infection in vivo can be achieved, thus facilitating anti-infection treatment under the guidance of the dynamic imaging of bacterial load in future.

Diagnostic value of lncRNA NORAD in pulmonary tuberculosis and its regulatory role in Mycobacterium tuberculosis infection of macrophages

“…As some patients are asymptomatic in the early stages, it progresses slowly and is infectious, and can cause severe tissue damage and necrosis upon progressing to the middle and late stages. In some cases, PTB directly threatens the life of even healthy patients 17 . Although a common symptom in some, cough is not specific to PTB 18 .…”

“…In some cases, PTB directly threatens the life of even healthy patients. 17 Although a common symptom in some, cough is not specific to PTB. 18 Acid-fast staining has high specificity but has sensitivity less than 30%.…”

Nanoparticle formulations for therapeutic delivery, pathogen imaging and theranostic applications in bacterial infections

“…A NIR-II surveillance technique based on fluorescent PbS QDs for real-time diagnosis of bacterial infection in vitro and in vivo was developed by Feng et al . 178 . The imaging potential of PbS QDs was investigated in a bacteria-infected nude mouse.…”

“…In subsequent validation experiments, they found that CdTe-2.4 (non-excited state) showed no phototoxic effect in co-cultures of E. coli and HEK293T; instead, under light, CdTe-2.4 suppressed E. coli growth without causing damage to HEK293T cells, giving evidence of concept regarding the application of bacteria-specific phototoxic nanomaterials in therapeutic strategies. for real-time diagnosis of bacterial infection in vitro and in vivo was developed by Feng et al [178]. The imaging potential of PbS QDs was investigated in a bacteria-infected nude mouse.…”

Organic Fluorophores for 1064 nm Excited NIR-II Fluorescence Imaging

“…Until now, different kinds of NIR-II fluorescence probes have been developed for disease diagnosis, including carbon nanotubes ( Zhao et al, 2018 ) ( Antaris et al, 2016 ), small molecule dyes ( Zhang et al, 2021 ) ( Zhou et al, 2020c ) ( Chen et al, 2021b ), semiconducting polymers (SPs), and quantum dots( Feng et al, 2021 ) ( Kong et al, 2016 ) ( Li et al, 2015 ) ( Zhang et al, 2019 ) ( Chen et al, 2021c ). Among these materials, organic fluorophores including small molecule dyes and SPs have shown great potential owing to their good biocompatibility and high absorption coefficient( Hu et al, 2021 ) ( Tian et al, 2020 ) ( Wang et al, 2020 ) ( Xie et al, 2020 ) ( Yang et al, 2020b ) ( Zhou et al, 2021 ) ( Ou et al, 2021 ).…”