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Subjective cognitive decline (SCD) is a high‐risk population in the preclinical stage of Alzheimer's disease (AD), and olfactory dysfunction is a risk factor for dementia progression. The present study aimed to explore the patterns of functional connectivity (FC) changes in the olfactory neural circuits during olfactory stimulation in SCD subjects. A total of 56 SCD subjects and 56 normal controls (NCs) were included. All subjects were assessed with a cognitive scale, an olfactory behavior test, and olfactory task‐based functional magnetic resonance imaging scanning. The FC differences in olfactory neural circuits between the two groups were analyzed by the generalized psychophysiological interaction. Additionally, we calculated and compared the activation of brain regions within the olfactory neural circuits during odor stimulation, the volumetric differences in brain regions showing FC differences between groups, and the correlations between neuroimaging indicators and olfactory behavioral and cognitive scale scores. During odor stimulation, the FC between the bilateral primary olfactory cortex (bPOC) and the right hippocampus in the SCD group was significantly reduced; while the FC between the right hippocampus and the right frontal cortex was significantly increased in the SCD group. The bPOC of all subjects showed significant activation, but no significant difference in activation between groups was found. No significant differences were observed in the volume of the brain regions within the olfactory neural circuits or in olfactory behavior between groups. The volume of the bPOC and right frontal cortex was significantly positively correlated with olfactory identification, and the volume of the right frontal cortex and right hippocampus was significantly correlated with cognitive functions. Furthermore, a significant correlation between the activation of bPOC and the olfactory threshold was found in the whole cohort. These results suggested that while the structure of the olfactory neural circuits and olfactory behavior in SCD subjects remained stable, there were significant changes observed in the FC of the olfactory neural circuits (specifically, the POC‐hippocampus‐frontal cortex neural circuits) during odor stimulation. These findings highlight the potential of FC alterations as sensitive imaging markers for identifying high‐risk individuals in the early stage of AD. [ABSTRACT FROM AUTHOR]

Leukemia is a non-solid cancer which features the malignant proliferation of leukocytes. Excessive leukocytes of lesions in peripheral blood will infiltrate organs, resulting in intumescence and weakening treatment efficiency. In this study, we proposed a novel approach for targeted clearance of the leukocytes in the peripheral blood ex vivo, which employed magnetic nanochains to selectively destroy the leukocytes of the lesions. The nanochains were doxorubicin-loaded nanochains of Fe3O4 nanoparticles which were fabricated by the solvent exchange method combined with magnetic field-directed self-assembly. Firstly, the nanochains were added into the peripheral blood during extracorporeal circulation and subjected to a rotational magnetic field for actuation. The leukocytes of the lesion were then conjugated by the nanochains via folic acid (FA) targeting. Finally, the rotational magnetic field actuated the nanochains to release the drugs and effectively damage the cytomembrane of the leukocytes. This strategy was conceptually shown in vitro (K562 cell line) and the method's safety was evaluated in a rat model. The preliminary results demonstrate that the nanochains are biocompatible and suitable as drug carriers, showing direct lethal action to the leukemic cells combined with a rotational magnetic field. More importantly to note is that the nanochains can be effectively kept from entry into the body. We believe this extracorporeal circulation-based strategy by activating nanochains magnetically could serve as a potential method for leukemia treatment in the future. [ABSTRACT FROM AUTHOR]

Objective: Targeting in vivo has been a spotlight for precise medicine. Multiple strategies have been proposed for this issue. However, the efficiency of solely biochemical strategies currently remains to be improved. It has been thought that external field-guided targeting will be a beneficial supplement for the passive and the active targeting. Methods: Here, we focused on the magnetic field-guided targeting of magnetized erythrocytes, discovering that a focused magnetic field can direct aggregation of magnetic erythrocytes into a specific region in vivo. Results: The systematic investigation about the aggregates in cerebral vessels showed that the aggregates were isotropic and able to stably exist for six hours. The formation of cellular aggregates can alter echoing characteristic of the blood vessels meaning the vascular wall became more rigid. If the erythrocytes were repeatedly directed into aggregation in an identical region, a stable plaque of erythrocytes can form, which can mimic the process of thrombosis. Significance: We believe these results will be beneficial to the development of novel engineered strategy for targeted delivery of drugs and modeling of vascular diseases. [ABSTRACT FROM AUTHOR]

Photodynamic Therapy (PDT) offers a promising minimally invasive treatment for breast cancer, but its efficacy is limited by the hostile tumor microenvironment (TME), including hypoxia and high glutathione (GSH) levels. Although various strategies to improve oxygen concentration or reduce reactive oxygen species (ROS) resistance for enhanced PDT have been explored, they typically require intricate design and complex synthesis of multifunctional nanocarriers. Thus, this study introduces a facile K 2 FeO 4 -induced strategy to enhance PDT efficiency in breast cancer through the tumor in situ synthesis of Fe 2 O 3 and O 2 . Inspired by the successful application of K 2 FeO 4 in ecological remediation and hemostasis, K 2 FeO 4 reacts with GSH, biological system, H 2 O 2 , and water, to generate Fe 2 O 3 and O 2 . Intratumoral injection of K 2 FeO 4 improves the TME, followed by Ce6 administration to enhance PDT through synergistic ferroptosis. This approach boosts PDT efficacy significantly by increasing ROS generation, lipid peroxidation, and inhibiting GSH and GPX4. Proteomic analysis revealed alterations in key pathways, including endocytosis and energy metabolism. This K 2 FeO 4 -PDT strategy creates a positive feedback loop by enhancing oxidative stress, providing an interesting and promising approach to PDT., (© 2024 Wiley‐VCH GmbH.)

Abstract: Mesenchymal stromal cell transplantation Is an effective and promising approach for treating various systemic and diffuse diseases. However, the biological characteristics of transplanted mesenchymal stromal cells in humans remain unclear, including cell viability, distribution, migration, and fate. Conventional cell tracing methods cannot be used in the clinic. The use of superparamagnetic iron oxide nanoparticles as contrast agents allows for the observation of transplanted cells using magnetic resonance imaging. In 2016, the National Medical Products Administration of China approved a new superparamagnetic iron oxide nanoparticle, Ruicun, for use as a contrast agent in clinical trials.In the present study, an acute hemi-transection spinal cord injury model was established in beagle dogs. The injury was then treated by transplantation of Ruicun-labeled mesenchymal stromal cells. The results indicated that Ruicun-labeled mesenchymal stromal cells repaired damaged spinal cord fibers and partially restored neurological function in animals with acute spinal cord injury. T2*-weighted imaging revealed low signal areas on both sides of the injured spinal cord. The results of quantitative susceptibility mapping with ultrashort echo time sequences indicated that Ruicun-labeled mesenchymal stromal cells persisted stably within the injured spinal cord for over 4 weeks. These findings suggest that magnetic resonance imaging has the potential to effectively track the migration of Ruicun-labeled mesenchymal stromal cells and assess their ability to repair spinal cord injury., (Copyright © 2025 Copyright: © 2025 Neural Regeneration Research.)

Rapid development of medical imaging, such as cellular tracking, has increased the demand for "live" contrast agents. This study provides the first experimental evidence demonstrating that transfection of the clMagR/clCry4 gene can impart magnetic resonance imaging (MRI) T 2 -contrast properties to living prokaryotic Escherichia coli ( E. coli ) in the presence of Fe 3+ through the endogenous formation of iron oxide nanoparticles. The transfected clMagR/clCry4 gene markedly promoted uptake of exogenous iron by E. coli , achieving an intracellular co-precipitation condition and formation of iron oxide nanoparticles. This study will stimulate further exploration of the biological applications of clMagR/clCry4 in imaging studies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Xue, Mai, Wang, Zhu, Han, Xie, Wang, Ge, Zhang and Sun.)

Background: Compared with conventional magnetic resonance imaging methods, the quantitative magnetic susceptibility mapping (QSM) technique can quantitatively measure the magnetic susceptibility distribution of tissues, which has an important clinical application value in the investigations of brain micro-bleeds, Parkinson's, and liver iron deposition, etc. However, the quantitative susceptibility mapping algorithm is an ill-posed inverse problem due to the near-zero value in the dipole kernel, and high-quality QSM reconstruction with effective streaking artifact suppression remains a challenge. In recent years, the performance of sparse representation has been well validated in improving magnetic resonance image (MRI) reconstruction., Methods: In this study, by incorporating feature learning into sparse representation, we propose an edge prior guided dictionary learning-based reconstruction method for the dipole inversion in quantitative susceptibility mapping reconstruction. The structure feature dictionary relies on magnitude images for susceptibility maps have similar structures with magnitude images, and this structure feature dictionary and edge prior information are used in the dipole inversion step., Results: The performance of the proposed algorithm is assessed through in vivo human brain clinical data, leading to high-quality susceptibility maps with improved streaking artifact suppression, structural recovery, and quantitative metrics., Conclusions: The proposed edge prior guided dictionary learning method for dipole inversion in QSM achieves improved performance in streaking artifacts suppression, structural recovery and deep gray matter reconstruction., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://dx.doi.org/10.21037/qims-21-243). The authors have no conflicts of interest to declare., (2022 Quantitative Imaging in Medicine and Surgery. All rights reserved.)