Hypersensitive MR angiography based on interlocking stratagem for diagnosis of cardiac-cerebral vascular diseases

Nanomaterial technologies for precision diagnosis and treatment of brain hemorrhage

Brain hemorrhage events present complex clinical challenges due to their rapid progression and the intricate interplay of oxidative stress, inflammation, and neuronal damage. Traditional diagnostic and therapeutic approaches often struggle to meet the demands for timely and effective intervention. This review explores the cutting-edge role of nanomaterials in transforming cerebral hemorrhage management, focusing on both diagnostic and therapeutic advancements. Nanomaterial-enabled imaging techniques, such as optical imaging, magnetic resonance imaging, and magnetic particle imaging, significantly enhance the accuracy of hemorrhage detection by providing real-time, high-resolution assessments of blood-brain barrier (BBB) integrity, cerebral perfusion, and hemorrhage progression, which is critical for guiding intervention strategies. On the therapeutic front, nanomaterial-based systems enable the precise delivery of drugs and bioactive molecules, fostering neural repair and functional recovery while minimizing systemic side effects. Furthermore, multifunctional nanomaterials not only address the primary injury but also offer precise control over secondary injuries, such as edema and oxidative stress. Their ability to enhance neuroprotection, prevent re-bleeding, and stimulate brain tissue regeneration provides a holistic approach and marks a significant advancement in brain hemorrhage therapy. As the field continues to advance, nanotechnology is set to fundamentally reshape the clinical management and long-term outcomes of brain hemorrhages, presenting a paradigm shift towards personalized and highly effective neurological care.

Cross-sectional study of lipoprotein(a) and the severity of coronary artery disease, cerebrovascular disease, and peripheral vascular disease in a group of South Asian patients

Background

Atherosclerotic cardiovascular diseases (ASCVD), including coronary artery disease (CAD), cerebrovascular disease (CVD), and peripheral vascular disease (PVD), remain the leading cause of death globally. South Asians exhibit a higher incidence of cardiovascular diseases than other ethnicities, attributed to a range of genetic, environmental, and lifestyle factors. Lipoprotein(a) [Lp(a)] with a unique apolipoprotein(a) component, has emerged as a marker of atherosclerosis and ASCVD risk, with evidence to promote arterial plaque formation and thrombogenesis.

Objective

The aim of this study was to explore the associations between Lp(a) levels and the severity of CAD, CVD, and PVD in a group of South Asian patients.

Methods

Following ethical approval, 60 consecutive patients who underwent coronary angiography for any indication were reviewed. There were 51 eligible participants who were evaluated for Lp(a) level, Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score, and severity of CVD and PVD. The SYNTAX-I score was calculated using two-observer consensus on coronary angiograms. Assessment of CVD was by ultrasound/Doppler, and PVD by estimating ankle-brachial index using Doppler. The multisite arterial disease score 2 (MADS2) and SYNTAX score tertiles were used to group the patients. Statistical analysis was performed using the SPSS software.

Results and discussion

In this group, we identified a statistically significant difference with higher Lp(a) levels being associated with more severe coronary disease (SYNTAX tertile 2,3). Despite a numerical trend, statistical significance was not confirmed for Lp(a) levels in relation to MADS2-CVD or MADS2-PVD scores. A larger study may be required to assess these aspects.

Vascular magnifier for ultrahigh-resolution visualization of cerebral vessels in vivo

High-resolution vascular imaging at tens of micrometers in deep tissues in vivo remains a critical challenge. Ultrahigh field susceptibility-weighted imaging (SWI) holds promise but lacking compatible high-sensitivity imaging probes. Herein, we show a holmium (Ho)-based nanoprobe-enhanced SWI strategy for ultrahigh-resolution imaging of cerebral microvessels at 9.4 T. The polyethylene glycol (PEG)-NaHoF4 nanoparticles (NPs) fabricated via coprecipitation synthesis combined with PEG modification possess uniform size, appropriate hydrodynamic size (20 nm), good biocompatibility, and long circulation half-life (710 min). Notably, the PEG-NaHoF4 NPs exhibit high r2/r1 (742.7) and T2∗ relaxivity (r2∗, 73.16 s-1 mM-1) under 9.4 T due to the large magnetic moment (∼10.6 μB) and short electronic relaxation time (∼10-13 s) of Ho3+. The high susceptibility of PEG-NaHoF4 NPs in blood vessels induces a significant blooming effect, resulting in a magnified vascular appearance on SWI. In vivo high-resolution imaging of cerebral microvessels with diameters as small as 10 μm is achieved using PEG-NaHoF4 NPs-enhanced SWI under 9.4 T. In two representative brain disease models, glioma and stroke, this nanoprobe enables high-resolution visualization of tumor vasculature and post-stroke collateral circulation, respectively. Our study offers a new paradigm for precise diagnosis of vascular-related diseases, providing a robust tool for their diagnosis, treatment, and prognosis assessment.

Super-multiplexed imaging and coding in the range of radio frequency

The era of the Internet has led to an information explosion, creating significant challenges for current techniques in information storage and access. High-performance strategies that expand existing methods offer a promising solution. Imaging-based approaches are vital for information perception but remain underexplored for information processing due to limited multiplexity. Here, we introduce 19F magnetic resonance imaging-Empowered information Assess and Storage Technique (FEAST), enabled by 22 fluorinated quaternary ammonium derivatives with distinct 19F chemical shifts. We developed three coding platforms for FEAST: fluorinated choline analog solutions, fluorinated deep eutectic solvents, and fluorinated ionogels. These platforms allow 2-spatial-dimensional applications, such as 16-bit encoding, "dual-color" watermarking, multiplexed Colorcodes, and encrypted QR codes, as well as 3-spatial-dimensional applications like "cubic" information storage, implanted anti-counterfeit labels, and FEAST-guided encryption. This work highlights FEAST's potential for advanced information storage and access, which is inspiring for further developments with versatile and robust coding platforms.

Application of Nanomaterials in Early Imaging and Advanced Treatment of Atherosclerosis

Atherosclerosis (AS) is a serious disease that poses a significant threat to the global population. In this review, we analyze the development of AS from multiple perspectives, aiming to elucidate its molecular mechanisms. We also focus on imaging techniques and therapeutic approaches, highlighting the crucial role of nanomaterials in both imaging and therapy for AS. By leveraging their compatibility and targeting capabilities, nanomaterials can be integrated with traditional medical imaging and therapeutic agents to achieve targeted drug delivery, controlled release, and precise localization and imaging of atherosclerotic plaques.

Neuroinflammation-targeted magnetic resonance imaging nanoprobes for the early diagnosis of Alzheimer's disease

Alzheimer's disease (AD) that is an important contributor to dementia, is a chronic and irreversible neurodegenerative disease, with high rates of disability and mortality. Recently, more and more therapeutic methods have been developed to delay the progression of AD, but it remains a great challenge to achieve the early diagnosis of AD. In this work, we developed a magnetic resonance imaging (MRI) nanoprobe (NP@angiopep-2/CD137) based on angiopep-2 peptide and CD137 antibody with a NaGdF4 nanoparticle as the core and realized neuroinflammation-targeted imaging on APP/PS1 model mice using a clinical 7.0 T MRI scanner. CD137 expression was upregulated in neuroglial cells and cerebral vascular endothelial cells in inflammatory state. In the APP/PS1 mouse model, after administration, the nanoprobe-enhanced images showed specific dot-like signals in the susceptibility-weighted imaging (SWI) sequence. In summary, we designed and synthesized NP@angiopep-2/CD137 nanoprobes using the activation-dependent expression of CD137, which were applied to the pathological assessment of AD based on the hypothesis of AD neuroinflammation, and provided a reliable idea for the early molecular imaging diagnosis of AD.

Shedding light on vascular imaging: the revolutionary role of nanotechnology

Vascular dysfunction, characterized by changes in anatomy, hemodynamics, and molecular expressions of vasculatures, is closely linked to the onset and development of diseases, emphasizing the importance of its detection. In clinical practice, medical imaging has been utilized as a significant tool in the assessment of vascular dysfunction, however, traditional imaging techniques still lack sufficient resolution for visualizing the complex microvascular systems. Over the past decade, with the rapid advancement of nanotechnology and the emergence of corresponding detection facilities, engineered nanomaterials offer new alternatives to traditional contrast agents. Compared with conventional small molecule counterparts, nanomaterials possess numerous advantages for vascular imaging, holding the potential to significantly advance related technologies. In this review, the latest developments in nanotechnology-assisted vascular imaging research across different imaging modalities, including contrast-enhanced magnetic resonance (MR) angiography, susceptibility-weighted imaging (SWI), and fluorescence imaging in the second near-infrared window (NIR-II) are summarized. Additionally, the advancements of preclinical and clinical studies related to these nanotechnology-enhanced vascular imaging approaches are outlined, with subsequent discussion on the current challenges and future prospects in both basic research and clinical translation.

Surface Engineering Enhances Vanadium Carbide MXene-Based Nanoplatform Triggered by NIR-II for Cancer Theranostics

Despite the advantages of high tissue penetration depth, selectivity, and non-invasiveness of photothermal therapy for cancer treatment, developing NIR-II photothermal agents with desirable photothermal performance and advanced theranostics ability remains a key challenge. Herein, a universal surface modification strategy is proposed to effectively improve the photothermal performance of vanadium carbide MXene nanosheets (L-V2C) with the removal of surface impurity ions and generation of mesopores. Subsequently, MnOx coating capable of T1-weighted magnetic resonance imaging can be in situ formed through surface redox reaction on L-V2C, and then, stable nanoplatforms (LVM-PEG) under physiological conditions can be obtained after further PEGylation. In the tumor microenvironment irradiated by NIR-II laser, multivalent Mn ions released from LVM-PEG, as a reversible electronic station, can consume the overexpression of glutathione and catalyze a Fenton-like reaction to produce ·OH, resulting in synchronous cellular oxidative damage. Efficient synergistic therapy promotes immunogenic cell death, improving tumor-related immune microenvironment and immunomodulation, and thus, LVM-PEG can demonstrate high accuracy and excellent anticancer efficiency guided by multimodal imaging. As a result, this study provides a new approach for the customization of 2D surface strategies and the study of synergistic therapy mechanisms, highlighting the application of MXene-based materials in the biomedical field.

Shine and darkle the blood vessels: Multiparameter hypersensitive MR angiography for diagnosis of panvascular diseases

Magnetic resonance angiography (MRA) is pivotal for diagnosing panvascular diseases. However, single-modality MRA falls short in diagnosing diverse vascular abnormalities. Thus, contrast agents combining T1 and T2 effects are sought for multiparameter MRA with clinical promise, yet achieving a balance in T1 and T2 contrast enhancement effects remains a scientific challenge. Herein, we developed a hypersensitive multiparameter MRA strategy using dual-modality NaGdF4 nanoparticles. Because of the longer tumbling time (τR), NaGdF4 nanoparticles can improve the longitudinal relaxivity (r1), brightening vessels in T1-weighted sequences. Simultaneously, the regular arrangement of Gd3+ in the crystal induces magnetic anisotropy, creating local static magnetic field heterogeneity and generating negative signals in T2-weighted sequences. Consequently, the efficacy of NaGdF4-enhanced high-resolution multiparameter MRA has been validated in diagnosing ischemic stroke and Alzheimer's disease in rodent models. In addition, the dual-contrast imaging has been realized on swine with a clinical 3.0-T magnetic resonance imaging scanner, highly emphasizing the clinical translation prospect.

High-Resolution Magnetic Resonance Angiography of Tumor Vasculatures with an Interlocking Contrast Agent

The comprehensive evaluation of tumor vasculature that is crucial for the development, expansion, and spread of cancer still remains a great challenge, especially the three-dimensional (3D) evaluation of vasculatures. In this study, we proposed a magnetic resonance (MR) angiography strategy with interlocking stratagem of zwitterionic Gd-chelate contrast agents (PAA-Gd) for continuous monitoring of tumor angiogenesis progression in 3D. Owing to the zwitterionic structure and nanoscale molecular diameter, the longitudinal molar relaxivity (r1) of PAA-Gd was 2.5 times higher than that of individual Gd-chelates on a 7.0 T MRI scanner, resulting in the higher-resolution visualization of tumor vasculatures. More importantly, PAA-Gd has the appropriate blood half-life (69.2 min), emphasizing the extended imaging window compared to the individual Gd-chelates. On this basis, by using PAA-Gd as the contrast agent, the high-resolution, 3D depiction of the spatiotemporal distribution of microvasculature in solid tumors formed by different cell lines over various inoculation times has been obtained. This method offers an effective approach for early tumor diagnosis, development assessment, and prognosis evaluation.

Hypersensitive MR Angiography for Diagnosis of Ischemic Stroke and Reperfusion Subarachnoid Hemorrhage

Stroke is an acute injury of the central nervous system caused by the disorders of cerebral blood circulation, which has become one of the major causes of disability and death. Hemorrhage, particularly subarachnoid hemorrhage (SAH), is one of the poorest prognostic factors in stroke, which is related to the thrombolytic therapy, and has been considered very dangerous. In this context, the MR angiography with high sensitivity and resolution has been developed based on biocompatible paramagnetic ultrasmall NaGdF4 nanoprobes. Owing to the appropriate hydrodynamic diameter, the nanoprobe can be confined inside the blood vessels and it only extravasates at the vascular injury site when the bleeding occurs. Relying on this property, the three-dimensional (3D) anatomic structures of artery occlusion of stroke rat can be precisely visualized; reperfusion-related SAH has been successfully visualized and identified. Benefiting from the long blood half-life of the nanoprobe, the observation window of MR angiography can last for the whole period of reperfusion, thereby monitoring the probable SAH in real time during thrombolytic therapy. More importantly, through reconstruction of multiparametric MRI, the arterial occlusion, cerebral ischemic region, and SAH can be simultaneously visualized in vivo in a 3D manner for the first time. Therefore, the current study provides a novel approach for both noninvasive 3D vascular visualization and hemorrhage alert, which possesses great prospects for clinical translation.

Progress in ultrasmall ferrite nanoparticles enhanced T1 magnetic resonance angiography

Contrast-enhanced magnetic resonance angiography (CE-MRA) plays a critical role in diagnosing and monitoring various vascular diseases. Achieving high-sensitivity detection of vascular abnormalities in CE-MRA depends on the properties of contrast agents. In contrast to clinically used gadolinium-based contrast agents (GBCAs), the new generation of ultrasmall ferrite nanoparticles-based contrast agents have high relaxivity, long blood circulation time, easy surface functionalization, and high biocompatibility, hence showing promising prospects in CE-MRA. This review aims to comprehensively summarize the advancements in ultrasmall ferrite nanoparticles-enhanced MRA for detecting vascular diseases. Additionally, this review also discusses the future clinical translational potential of ultrasmall ferrite nanoparticles-based contrast agents for vascular imaging. By investigating the current status of research and clinical applications, this review attempts to outline the progress, challenges, and future directions of using ultrasmall ferrite nanoparticles to drive the field of CE-MRA into a new frontier of accuracy and diagnostic efficacy.

Ultrasmall catechol-PEG-anchored ferrite nanoparticles for highly sensitive magnetic resonance angiography

Highly sensitive iron oxide nanoparticles with stable, safe and efficient surface functionalization, as potential substitutes for gadolinium-based contrast agents (GBCAs) with increasing biosafety concerns, exhibit great potential for high-performance magnetic resonance angiography (MRA). Herein, we developed ultrasmall catechol-PEG-anchored ferrite nanoparticles (PEG-UMFNPs) for highly sensitive MRA. The obtained nanoprobe has a high T1 relaxivity value (7.2 mM-1 s-1) due to its ultrasmall size and Mn doping. It has a suitable hydrodynamic size of 20 nm, which prevents rapid vascular extravasation and renal clearance and prolongs its blood circulation time. In vivo MRA at 3.0 T using the nanoprobe shows that the arteries and veins of rats, even blood vessels as small as 0.32 mm, are distinctly visible, and the contrast enhancement can last for at least 1 h. In addition, due to the outstanding contrast enhancement and long circulation time, the stenosis and recanalization process of the rat's carotid artery can be continuously monitored with a single injection of the nanoprobe. Our study indicates that PEG-UMFNPs are outstanding MR imaging nanoprobes that can be used to diagnose vascular diseases without the biosafety issues of GBCAs.

Optimizing the ordering of the Hadamard masks of ghost imaging suitable for the efficient face reconstruction using the max-projection method

One crucial component of ghost imaging (GI) is the encoded mask. Higher-quality reconstruction at lower sampling rates is still a major challenge for GI. Inspired by deep learning, max-projection method is proposed in the paper to reorder the Hadamard masks for its efficient and rapid reconstruction. The simulations demonstrated that max-projection ordering with only 20 face training images yielded excellent reconstruction outcomes. In noise-free simulations, at an ultralow sampling rate of 5%, the PSNR of the max-projection ordering was 1.1 dB higher than that of the cake-cutting ordering with the best performance in the reference group. In noisy simulations, at ultralow sampling rates, the retrieved images remained almost identical to their noise-free counterparts. Irrespective of the presence or absence of noise, the max-projection ordering guaranteed the highest fidelity of image reconstruction at ultralow sampling rates. The reconstruction time was reduced to mere milliseconds, thereby enabling swift visualization of dynamic phenomena. Accordingly, the max-projection ordering Hadamard matrix offers a promising solution for real-time GI due to its higher reconstruction quality, stronger noise immunity and millisecond reconstruction time.