Imaging techniques and agents articles within Nature Communications

Monitoring the status of blood-brain barrier (BBB) and inhibiting reactive oxygen species (ROS)-mediated oxidative damage are key issues in the treatment of traumatic brain injury (TBI). Here, the authors design a near-infrared-IIb emitting Mn single-atom catalyst for imaging-guided therapy to alleviate ROS mediated neuroinflammation in the brain and simultaneously obtain timely feedback of therapeutic effect, promoting the reconstruction of BBB and recovery of neurological function after TBI in mice.

Magnetic resonance imaging (MRI) is a well-established non-invasive medical imaging technology. Here, to improve the performance of the technique, the authors describe the design of a pH-responsive T1-T2 dual-modal MRI contrast agent, showing enhanced imaging sensitivity in preclinical cancer models.

Sensitive, biocompatible and stable contrast agents for MRI are in demand. Here, the authors combine gadolinium ions with amorphous calcium carbonate to make stable paramagnetic amorphous carbonate nanoclusters with high MRI contrast and significantly improved biocompatibility over commercial gadolinium-based agents.

Metal organic frameworks (MOF) coated with mammalian cell membranes have good biocompatibility. Here, the authors develop a cobalt based hydrogen sulphide producing MOF cloaked with a macrophage membrane and show that the subsequent system can reduce tumour growth in mice.

The first step during skin colonization by is its adhesion to corneocytes. Da Costa et al. show that the cell wall-anchored fibronectin binding protein B (FnBPB) of S. aureus binds to loricrin. Applying single cell force spectroscopy, they demonstrate that this interaction promotes adhesion of S. aureus to human corneocytes.

Hypoxia and immunosuppression contribute to tumor resistance to radiotherapy (RT). Here the authors design a nanoprobe based on NIR-IIb emitting quantum dots for image-guided RT and modified with catalase to relieve hypoxia in the tumor microenvironment, enhancing the precision and efficacy of RT and promoting anti-tumor immune responses.

The authors demonstrate a colourimetric imaging method using plasmonic nanoparticles for visualisation of heterochromatin histone markers. Based on the distance-dependent coupling effect, resulting in spectral shifts, they observe reorganisation of histone markers caused by oncogene-induced senescence.

Ultra-high-field (UHF) magnetic resonance imaging (MRI) has potential for imaging disease including cancer metastasis. Here, the authors develop an ultra-sensitive antiferromagnetic nanoparticle probe with a small magnetisation for use in UHF MRI and demonstrate the ability to detect small primary tumours and micrometastases in mice.

Quantification of intratumoral nanoparticles internalisation in vivo is crucial but challenging. Here, the authors develop a binary ratiometric nanoreporter that can quantify internalisation and predict nanotherapeutic responses based on intracellular nanoparticle exposure.

Fast and specific detection of pathogenic bacteria is needed to combat infections. Here the authors generate an array of near-infrared biosensors based on carbon nanotubes to detect released metabolites and virulence factors and use them to distinguish pathogens such as S. aureus and P. aeruginosa.

Infiltration of immune cells to the pancreatic islets precedes clinical symptoms of type 1 diabetes, and lack of methods to detect this insulitis impedes early interventions. Here the authors report a contrast enhanced ultrasound method that can detect early insulitis in mouse models of type 1 diabetes, based on increased microvascular permeability.

Nanoparticles that can change shape have attracted attention for improved circulation and tumor penetration. Here, the authors report on a size changeable nanoparticle that responds to near-infrared light and can be used for photothermal therapy, photodynamic therapy, and drug delivery applications.

There is a balance between the fluorescence and photothermal properties of fluorescent molecules. Here, the authors report on an NIR-II fluorophore which binds with human serum albumin changing the equilibrium, increasing the photothermal efficiency, and demonstrate application of this for tumour ablation.

Reactive oxygen (ROS) and nitrogen (RNS) species are involved in key physiological processes and their balance is altered in various human diseases. Here the authors develop near-infrared upconversion nanoprobes to screen ROS/RNS dynamics simultaneously by multispectral optoacoustic imaging in vivo.

Nanoparticle applications are limited by insufficient understanding of physiochemical properties on in vivo disposition. Here, the authors explore the influence of size, surface chemistry and administration on the biodisposition of mesoporous silica nanoparticles using image-based pharmacokinetics.

Polymer nanoparticles that have an in-built capacity to elicit an output during drug delivery are highly desirable. Here the authors describe the self-assembly of an amphiphilic tri-block co-polymer that shows particle fluorescence in response to temperature, surface adsorption and cellular uptake.

Conjugated polymer nanoparticles have been applied for biological fluorescence imaging in cell culture and in small animals, but cannot readily be excreted through the renal system. Here the authors show fully conjugated polymer nanoparticles based on imidazole units that can be bio-degraded by activated macrophages.

The effective detection ofHelicobacter pylori has been a challenge clinically. Here, the authors demonstrate the potential of magnetic nanoparticles for non-invasive diagnosis of H. pylori using magnetic resonance imaging in vivo.

Liquid metals are excellent candidate materials for biomedicine, owing to their intriguing optical properties and chemical stability. Here, the authors design multifunctional theranostic liquid metal nanocapsules that, upon irradiation, generate heat and reactive oxygen species and change shape to release drugs.

The signal detected in magnetic resonance imaging comes from the relaxation of proton nuclear magnetization. Here, Zhouet al. introduce magnetic field inhomogeneity as a parameter to design iron oxide nanoparticle clusters to enhance the relaxation rate of nearby protons, thereby increasing image contrast.

Tissue autofluorescence can lead to considerable noise in fluorescence imaging of biological tissues. Here Gu et al.demonstrate that the use of photoluminescent silicon nanoparticles with long emission lifetimes enable a late time-gated imaging technique where autofluorescence effects are avoided.

Spherical superparamagnetic iron oxide nanoparticles are potentially attractive MRI contrast agents, but their low transverse relaxivity has hindered their application. Here, the authors report size and shape control of octapod iron oxide nanoparticles with extremely high transverse relaxivity.