Magnetic Labeling Research Articles

Elucidating the Dynamics of Biodegradation and Biosynthesis of Magnetic Nanoparticles in Human Stem Cells.

Iron oxide nanoparticles, due to their magnetic properties, are versatile tools for biomedical applications serving both diagnostic and therapeutic roles. Their performance is intricately intertwined with their fate in the demanding biological environment. Once inside cells, these nanoparticles can be degraded, implying a loss of magnetic efficacy, but also transformed into neo-synthesized magnetic nanoparticles, potentially restoring functionality. This study aims to delineate biological features governing these processes. Magnetic nanoparticles are internalized in human mesenchymal stem cells (hMSCs), and their biotransformations are investigated from nano- to micro-scale using electron microscopy (STEM-HAADF, HRTEM, SAED), a benchtop magnetic sensor, and fine structural characterizations (synchrotron XRD, VSM). Results evidence a delicate equilibrium between the biodegradation and biosynthesis of magnetic nanoparticles, with biotransformation kinetics depending on cell density at magnetic labeling and on spatial cell configuration (monolayers vs spheroids). The biotransformed nanoparticles, composed of magnetite or maghemite, are localized within endosomal/lysosomal compartments and associated with the recruitment of ferritin proteins.

Magnetic augmentation through multi-gradient coupling enables direct and programmable profiling of circulating biomarkers

Conventional magnetic biosensing technologies have reduced analytical capacity for magnetic field dimensionality and require extensive sample processing. To address these challenges, we spatially engineer 3D magnetic response gradients for direct and programmable molecular detection in native biofluids. Named magnetic augmentation through triple-gradient coupling for high-performance detection (MATCH), the technology comprises gradient-distributed magnetic nanoparticles encapsulated within responsive hydrogel pillars and suspended above a magnetic sensor array. This configuration enables multi-gradient matching to achieve optimal magnetic activation, response and transduction, respectively. Through focused activation by target biomarkers, the platform preferentially releases sensor-proximal nanoparticles, generating response gradients that complement the sensor’s intrinsic detection capability. By implementing an upstream module that recognizes different biomarkers and releases universal activation molecules, the technology achieves programmable detection of various circulating biomarkers in native plasma. It bypasses conventional magnetic labeling, completes in <60 minutes and achieves sensitive detection (down to 10 RNA and 1000 protein copies). We apply the MATCH to measure RNAs and proteins directly in patient plasma, achieving accurate cancer classification.

Amorphization of PrDy-FeCo-B microwire surface under nanosecond laser pulse

Micromagnets used in robotic mechanisms, actuators, electromotive devices, micro-engines require protection from chemically destructive factors. Improving micromagnets in the NdFeB family is particularly important. We found that laser-stimulated amorphization of the surface of PrDy-FeCo-B microwires can restore the amorphous structure from polycrystalline microwires under a single laser irradiation pulse of 1 mJ power and 120 ns duration, penetrating to a depth of 1 μm. The thermal exchange in the microwire causes rapid cooling of the laser-irradiated area. We imprinted periodic local magnetic labels of ∼10 μm in length using single laser pulse. Initially crystalline (PrDy)2(FeCo)14B1 microwires were locally transformed to an amorphous phase by laser irradiation. The alternating amorphous magnetic patterns are magnetized perpendicular to the microwire’s main axis.

Comparisons of magnetic resonance imaging, histopathological and Ki-67 labeling index findings in a single myxofibrosarcoma: a case report

BackgroundMyxofibrosarcoma is a myxoid soft tissue sarcoma showing T2 high intensity on magnetic resonance imaging. However, myxofibrosarcoma is a heterogeneous sarcoma with both myxoid and cellular portions. Magnetic resonance imaging findings were obtained MRI findings for comparison with histological and Ki-67 immunohistochemical features, in different portions of one myxofibrosarcoma.Case presentationMagnetic resonance imaging observations were compared with gross pathological and microscopic findings of a myxofibrosarcoma from a 50-year-old Japanese female. The Ki-67 labeling indices of different portions of the tumor, that is, the myxoid, cellular, and histologically confirmed infiltrative margin portions (pathological tail sign), were compared. The T2 low intensity area was more cellular than the T2 high intensity area, while the cellular portion had a significantly higher Ki-67 index than the myxoid portion (p = 0.0313). The portions with the pathological tail sign had a significantly higher Ki-67 labeling index than those without this sign (p = 0.0313).ConclusionsMore cellular portions of a myxofibrosarcoma correspond to more areas of the tumor showing aggressive features. Furthermore, our data also support the hypothesis of high aggressiveness being associated with the pathological tail sign in myxofibrosarcoma. To our knowledge, this is the first case report to describe comparisons among the imaging findings, histological features, and Ki-67 immunohistochemistry results for different portions of one myxofibrosarcoma.

(Digital Presentation) Sorting of Circulating Tumor Cells Based on Phenotypic Separation in Using Magnetic Nanoparticle Labels

Representing a practical criterion for sorting captured circulating tumor cells (CTCs) based on the cancer progression stage is a new approach that recently received traction. High-throughput, rapid, and cost-effective microfluidic systems that allow for high-efficiency separation and continuous inertial focusing are needed. The goal of the present study is to design of such systems via computational modeling and experimental tests. We propose a new microfluidic device that uses magnetic nanoparticles to label surface biomarkers on CTCs to isolate, focus and sort CTCs based on their cancer progression stage. By eliminating sheath flow interference that may result in harming cell survival, the proposed microchip can successfully determine the progression of cancer by arranging cells in one step. Additionally, the proposed device allows for rapid, efficient separation of the blood cells (RBCs and WBCs) and CTCs in the shortest length of the channel.

A high security coding and anti-counterfeiting method based on the nonlinear magnetization response of superparamagnetic nanomaterials

Traditional coding methods based on graphics and digital or magnetic labels have gradually decreased their anti-counterfeiting because of market popularity. This paper presents a new magnetic anti-counterfeiting coding method. This method uses a high-performance coding material, which, along with small changes to the material itself and the particle size of the superparamagnetic nanomaterials, results in a large difference in the nonlinear magnetization response. This method, which adopts 12-site coding and establishes a screening model by measuring the voltage amplitude of 12-site variables, can code different kinds of products, establishing long-term stable coding and decoding means. Through the anti-counterfeiting experiment of wine, the experiment results show that the authenticity of the coded products can be verified using the self-developed magnetic encoding and decoding system. The new coding technology can verify the anti-counterfeiting of 9000 products, with a single detection accuracy of 97% and a detection time of less than one minute. Moreover, this coding method completely depends on the production batch of the superparamagnetic nanomaterials, which is difficult to imitate, and it provides a new coding anti-counterfeiting technology for related industries with a wide range of potential applications.

ATRT-03. PRIMARY DIFFUSE LEPTOMENINGEAL ATYPICAL TERATOID/RHABDOID TUMOR (ATRT) OF CHILDHOOD DEMONSTRATING UNEXPECTED IMPROVEMENT UPON CESSATION OF CONVENTIONAL THERAPY FOR PRESUMED PROGRESSION; A MOLECULARLY CHARACTERIZED CASE REPORT

Abstract BACKGROUND Atypical teratoid/rhabdoid tumors (ATRTs) are malignant tumors of the central nervous system, typically presenting in the posterior fossa of very young children. Prognosis remains poor despite current therapy, while tumorigenesis implicates both genomic and epigenetic dysregulation. Primary diffuse leptomeningeal disease (PDL ATRT), without a defined intraparenchymal lesion, is an extremely rare ATRT variant with only seven cases reported. None of these preceding cases had undergone molecular characterization. We compared our case, who demonstrated an atypical clinical and radiological trajectory, against these seven cases. CASE PRESENTATION We describe a PDL ATRT, with hitherto novel molecular and imaging characteristics, in a pediatric patient who subsequently demonstrated radiological and clinical recovery from radiologically diagnosed metastatic relapse in the absence of conventional ATRT salvage treatment. Our case is the first to utilize Magnetic Resonance Imaging Arterial Spin Labelling perfusion imaging to suggest an underlying malignancy as the responsible etiology for this patient’s complex presentation, and the first to use methylation profiling to establish a tumor molecular subgroup for a PDL ATRT patient (identifying a MYC-subgroup in this case). CONCLUSIONS For this reported case of pediatric MYC-subgroup PDL ATRT, MR perfusional imaging aided in establishing the diagnosis and predicting potential relapse as part of a multi-parametric imaging assessment. We administered upfront intensive multimodal therapy, including high-dose CSRT to the patient, resulting in the longest overall survival for any patient reported with this extremely challenging ATRT variant. His unanticipated clinical and radiological improvement following a subsequent radiological diagnosis of tumor relapse highlights the importance of confirming recurrence by tissue extraction where feasible, but suggests that further evaluation of histone deacetylase inhibition as a potential future therapy in ATRT is warranted.

Cerebrovascular Effects of Sildenafil in Small Vessel Disease: The OxHARP Trial.

Vascular cognitive impairment due to cerebral small vessel disease is associated with cerebral pulsatility, white matter hypoperfusion, and reduced cerebrovascular reactivity (CVR), and is potentially improved by endothelium-targeted drugs such as cilostazol. Whether sildenafil, a phosphodiesterase-5 inhibitor, improves cerebrovascular dysfunction is unknown. OxHARP trial (Oxford Haemodynamic Adaptation to Reduce Pulsatility) was a double-blind, randomized, placebo-controlled, 3-way crossover trial after nonembolic cerebrovascular events with mild-moderate white matter hyperintensities (WMH), the most prevalent manifestation of cerebral small vessel disease. The primary outcome assessed the superiority of 3 weeks of sildenafil 50 mg thrice daily versus placebo (mixed-effect linear models) on middle cerebral artery pulsatility, derived from peak systolic and end-diastolic velocities (transcranial ultrasound), with noninferiority to cilostazol 100 mg twice daily. Secondary end points included the following: cerebrovascular reactivity during inhalation of air, 4% and 6% CO2 on transcranial ultrasound (transcranial ultrasound-CVR); blood oxygen-level dependent-magnetic resonance imaging within WMH (CVR-WMH) and normal-appearing white matter (CVR-normal-appearing white matter); cerebral perfusion by arterial spin labeling (magnetic resonance imaging pseudocontinuous arterial spin labeling); and resistance by cerebrovascular conductance. Adverse effects were compared by Cochran Q. In 65/75 (87%) patients (median, 70 years;79% male) with valid primary outcome data, cerebral pulsatility was unchanged on sildenafil versus placebo (0.02, -0.01 to 0.05; P=0.18), or versus cilostazol (-0.01, -0.04 to 0.02; P=0.36), despite increased blood flow (∆ peak systolic velocity, 6.3 cm/s, 3.5-9.07; P<0.001; ∆ end-diastolic velocity, 1.98, 0.66-3.29; P=0.004). Secondary outcomes improved on sildenafil versus placebo for CVR-transcranial ultrasound (0.83 cm/s per mm Hg, 0.23-1.42; P=0.007), CVR-WMH (0.07, 0-0.14; P=0.043), CVR-normal-appearing white matter (0.06, 0.00-0.12; P=0.048), perfusion (WMH: 1.82 mL/100 g per minute, 0.5-3.15; P=0.008; and normal-appearing white matter, 2.12, 0.66-3.6; P=0.006) and cerebrovascular resistance (sildenafil-placebo: 0.08, 0.05-0.10; P=4.9×10-8; cilostazol-placebo, 0.06, 0.03-0.09; P=5.1×10-5). Both drugs increased headaches (P=1.1×10-4), while cilostazol increased moderate-severe diarrhea (P=0.013). Sildenafil did not reduce pulsatility but increased cerebrovascular reactivity and perfusion. Sildenafil merits further study to determine whether it prevents the clinical sequelae of small vessel disease. URL: https://www.clinicaltrials.gov/study/NCT03855332; Unique identifier: NCT03855332.

Construction and Application of Cerebral Functional Region-Based Cerebral Blood Flow Atlas Using Magnetic Resonance Imaging-Arterial Spin Labeling.

Cerebral conditions often require precise diagnosis and monitoring, necessitating advanced imaging techniques. Current modalities may not adequately detect early signs of reversible tissue damage, underlining the need for innovative diagnostic tools that can quantify changes in cerebral blood flow (CBF) with high specificity and sensitivity.This study integrates three-dimensional arterial spin labeling (3D-ASL) with structural MRI to develop comprehensive CBF atlases that cover all main functional regions of the brain. This innovative magnetic resonance imaging- arterial spin labeling (MRI-ASL) methodology provides a rapid and noninvasive means of quantifying region-specific CBF, offering a detailed view of CBF levels across different functional regions.The comparison between chronic cerebral ischemia (CCI) patients and healthy subjects revealed significantly diminished CBF across the cerebral functional regions in the constructed CBF atlases for the former. This approach not only allows for the efficient identification of CCI by analyzing concurrent decreases in CBF across critical areas relative to healthy distributions but also enables the tracking of treatment responses and rehabilitation progress through longitudinal CBF atlases.The CBF atlas developed using the MRI-ASL technique represents a novel advancement in the field of cerebral diagnostics and patient care. By comparing regional CBF levels against normative standards, this method enhances diagnostic capabilities, enabling clinicians to provide personalized care to patients with cerebral conditions.

Real-time biomolecule detection using GMR chip-based sensor with green-synthesized Fe3O4/rGO nanocomposites as magnetic labels

The availability of a rapid, low-cost, and easy-to-use device to monitor the bovine serum albumin (BSA) level in human blood and urine is vital in early disease detection. This work reports a biosensor system based on a giant magnetoresistance (GMR) chip as a transducer integrated with Fe3O4/rGO magnetic labels for BSA protein detection. The commercial chip AAL024 is utilized as the GMR sensor, combined with an Arduino microcontroller (AM) and a basic differential amplifier to acquire the digital output voltage. The Fe3O4/rGO nanocomposites were synthesized by a hybrid process based on the green synthesis route utilizing plant extracts. The nanocomposites exhibit superparamagnetic behavior, affecting the magnetic label detection quality. In investigating sensor performance, Fe3O4/rGO nanocomposites can generate sufficient stray fields under a 4 Oe of bias magnetic field (HB). A larger net stray field is produced by a higher concentration of magnetic labels, which suggests that there are more Fe3O4 nanoparticles attached to the sensor surface. Further, the effectiveness of the biosensor was evaluated by detecting the BSA protein. As a result, a high sensitivity of 22.98 mV/(mg/mL) and a low limit of detection (LOD) of 0.3 mg/mL were obtained in detecting Fe3O4/rGO(5:1)/BSA with a voltage signal that can be collected in 30 s. Besides its high sensitivity, low LOD, and fast detection, the sensor exhibits remarkable reproducibility and stability, as evidenced by the relative signal deviation (RSD) range of 1.1 – 5.6%. These findings demonstrate that the GMR chip-based sensor integrated with Fe3O4/rGO magnetic labels provides a simple biosensor system with real-time electronic readout.

A novel method for multiple cardiovascular disease biomarker detection using a SERF-based microfluidic platform

As cardiovascular diseases (CVDs) are the leading cause of death worldwide, it is of great importance to realize a rapid and sensitive diagnosis. Multiple CVD biomarker detection, which holds higher accuracy and speed of early CVD diagnosis, is becoming a promising alternative to single biomarker analysis. Cardiac troponin I (cTnI), C-reactive protein (CRP), brain-type natriuretic peptide (BNP), and heart fatty acid binding protein (H-FABP) are four significant diagnostic biomarkers for CVDs. Among the several methods for biomarker detection, such as optical, magnetic, mechanical, and electrical methods, the magnetic method stands out because of its stability, low toxicity, noninvasive detection, facile manipulation with an external magnetic field, and immunity to the interference of background light. At present, the lack of multiplexing capability, the imprecision of magnetic signal localization, and the agglomeration and non-specific adsorption of magnetic nanoparticles all limit the clinical application of magnetic detection. This paper presented a novel method for multiple CVD biomarker detection using a spin exchange relaxation-free (SERF)-based microfluidic platform. One or more SERF atomic magnetometers were used to scan the remanent field of magnetic labels to detect four CVD biomarkers in 70 min, with a detection limit of 1.88 pg/mL (cTnI), 1.58 pg/mL (CRP), 1.45 pg/mL (BNP), and 1.71 pg/mL (H-FABP). The results showed two-dimensional magnetic fields with a resolution of submillimeter level and a sensitivity of pT level. The measurement technique provides a new magnetic methodology for applications in clinical diagnosis.

Long-term effects of an egg-protein hydrolysate on cognitive performance and brain vascular function: a double-blind randomized controlled trial in adults with elevated subjective cognitive failures

PurposeShort-term intake of the egg-protein hydrolysate Newtricious (NWT)-03 improved executive function, but underlying mechanisms and long-term effects, including other cognitive domains, are unknown.MethodsA 36-week randomized controlled trial involving 44 overweight/obese individuals experiencing elevated Subjective Cognitive Failures (SCF; aged 60–75 years) assessed the impact of daily consumption of 5.7 g of NWT-03 or placebo powders on cognitive performance (psychomotor speed, executive function, memory) and Cerebral Blood Flow (CBF), a marker of brain vascular function. Cognitive performance was evaluated using a neurophysiological test battery (CANTAB) and CBF was measured using magnetic resonance imaging perfusion method Arterial Spin Labeling (ASL). Serum samples were collected to determine brain-derived neurotrophic factor (BDNF) concentrations.ResultsAnthropometrics, and energy and nutrient intakes remained stable throughout the trial. NWT-03 was well tolerated, and compliance was excellent (median: 99%; range: 87–103%). No overall intervention effects were observed on cognitive performance or CBF, but post-hoc analyses revealed significant improvements on executive function in women, but not men. Specifically, a reduction of 74 ms in reaction latency on the multitasking task (95% CI: −134 to −15; p = 0.02), a reduction of 9 between errors (95%CI: −14 to −3; p < 0.001), and a reduction of 9 total errors (95%CI: −15 to −3; p < 0.001) on the spatial working memory task were found in women. No intervention effects were observed on serum BDNF concentrations (p = 0.31).ConclusionLong-term consumption of NWT-03 improved multitasking abilities and working memory in women with elevated SCF. Brain vascular function remained unaffected. Sex differences in executive function require additional clarification.

Next-Level Efficiency: StraightFrom Spleen Isolation Kits - Standardizing Isolation of Untouched T cells with Minimal Hands-On Time

Abstract Isolation of T cells from mouse spleen is essential for various research fields. Studies using magnetically separated cells help to understand the immune system, develop new vaccines and advance immunotherapy. Thus, selecting a reliable cell isolation method is critical for consistent experimental results. Simultaneous spleen dissociation and labeling of unwanted cells with an antibody cocktail was performed using the GentleMACS dissociator. Subsequent automated magnetic labeling of cells and isolation of untouched T cells (CD4, CD8 or Pan T) was performed using the autoMACS NEO Separator. Target cell purity, yield, cell activation status and functionality were assessed. Untouched CD4, CD8 or Pan T cells obtained with our StraightFrom Spleen workflow were of the same high purity and yield as conventional more time-consuming protocols, which require preparation of single cell suspension and various centrifugation steps prior to enrichment. Flow cytometric analysis of isolated cells revealed no expression of the activation markers CD25 or CD69 in non-stimulated cells even after overnight cultivation. However, significant upregulation was observed after stimulation. In addition, isolated cells showed excellent proliferation in culture. We have developed a simple and fast cell isolation method that significantly accelerates the isolation of functional cells, providing an attractive alternative to the laborious multi-step protocols used in academic and industrial laboratories.

Abstract TMP53: MR-ASL Imaging Can Predict the Collaterals in Moyamoya Disease

Introduction: Digital subtraction angiography (DSA) is the gold standard investigation for the diagnosis and prognostication of moyamoya disease (MMD). Magnetic resonance arterial spin labelling (MR-ASL) is a newer non-invasive technique that can predict the perfusion reliably. Our study aims at prediction of collaterals with MR-ASL in addition to parenchymal perfusion deficit. Methodology: It is an observational single centre cohort study where consecutive MMD patients with both DSA and MR-ASL done within 3 months of each other were included in the study. Images were reviewed by 2 radiologists independently. MMD severity was graded using Suzuki staging and collaterals were graded using DSA and MR-ASL in 7 different regions [4 areas in basal ganglia level - basal ganglia, M1, A1 and P1], 3 areas at superficial cortical level above basal ganglia [M2, A2, P2]. DSA collateral grading used was: grade 0 - no collaterals visible (absence of any capillary blush) with perfusion deficit, grade 1 - mild to moderate collaterals with some perfusion deficit, grade 2 - extensive collaterals with no perfusion deficit, grade 3 - normal antegrade flow. Collateral grading used on MR-ASL was: grade 0 - no or minimal ASL signal; grade 1 - moderate ASL signal with arterial transit artefact (ATA), grade 2 - high ASL signal with ATA, grade 3 - normal perfusion without ATA. Results: Of the 46 MMD patients (males - 22), 92 hemispheres were included. 4 hemispheres were excluded as the patient underwent revascularisation in the corresponding hemisphere. Among the remaining 88 hemispheres, 7 were normal on angiography. At various Suzuki grades, the degree of collaterals graded on ASL changed according to Suzuki staging (p&lt;0.001). Whether collateral grading using ASL can predict the collaterals graded using DSA was tested using Cohen Kappa’s method, and it was found that MR-ASL can predict collaterals graded by DSA with very good agreement in all the regions studied (p&lt;0.001). Conclusion: MR-ASL is a simple, safe, effective and reproducible alternative for DSA in determining the collaterals and perfusion status in MMD patients without the untoward effects like contrast exposure.

Trifunctional Nanocomposites with Colorimetric Magnetic Catalytic Activities Labels in Sandwich Immunochromatographic Detection of Escherichia coli O157:H7.

The emergence of nanoenzymes has catalyzed the robust advancement of the lateral flow immunoassay (LFIA) in recent years. Among them, multifunctional nanocomposite enzymes with core-shell architectures are considered preferable for promoting the sensing ability due to their good biocompatibility, precise control over size, and surface properties etc. Herein, we developed a dual-channel ensured lateral flow immunoassay (DFLIA) platform utilizing a magnetic, colorimetric, and catalytic multifunctional nanocomposite enzyme (Fe3O4@TCPP@Pd) [TCPP, Tetrakis (4-carboxyphenyl) porphyrin] for the ultrasensitive and highly accurate rapid detection of Escherichia coli O157:H7 (E. coli O157:H7). Fe3O4@TCPP@Pd-mAb exhibits superior performance compared to traditional AuNPs, including enhanced sensitivity and an extended linear detection range, benefiting from its high brightness signal, strong magnetic separation ability, and high peroxidase activity (Vmax = 2.32 μM S1-). Moreover, the Fe3O4@TCPP@Pd-labeled mAb probe exhibited exceptional stability and high affinity toward E. coli O157:H7 (with an affinity constant of approximately 1.723 × 109 M-1), indicating its potential for the efficient capture of the pathogen. Impressively, the developed Fe3O4@TCPP@Pd-DFLIA achieved ultrasensitive detection for E. coli O157:H7 with pre- and postcatalytic naked-eye detection sensitivities of 255 cfu/mL and 77 cfu/mL, respectively, representing an approximately 41-fold improvement over the conventional AuNP-based LFIA and also possessed good specificity and reproducibility [relative standard deviation (RSD) < 10%]. Additionally, the established DFLIA exhibited satisfactory recoveries in detecting pork and milk samples, further validating the reliability of this platform for immunoassays and demonstrating its potential for utilization in bioassays and clinical diagnostics.

Mn-ferrite nanoparticles as promising magnetic tags for radiofrequency inductive detection and quantification in lateral flow assays.

Lateral flow assays are low-cost point-of-care devices that are stable, easy to use, and provide quick results. They are mostly used as qualitative screening tests to detect biomarkers for several diseases. Quantification of the biomarkers is sometimes desirable but challenging to achieve. Magnetic nanoparticles can be used as tags, providing both visual and magnetic signals that can be detected and quantified by magnetic sensors. In the present work, we synthesized superparamagnetic MnFe2O4 nanoparticles using the hydrothermal coprecipitation route. MnFe2O4 presents low magnetic anisotropy and high saturation magnetization, resulting in larger initial magnetic susceptibility, which is crucial for optimizing the signal in inductive sensors. We functionalized the coprecipitated nanoparticles with citric acid to achieve colloidal stability in a neutral pH and to provide carboxyl groups to their surface to bioconjugate with biomolecules, such as proteins and antibodies. The nanomaterials were characterized by several techniques, and we correlated their magnetic properties with their sensitivity and resolution for magnetic detection in radiofrequency inductive sensors. We considered the NeutrAvidin/biotin model of biorecognition to explore their potential as magnetic labels in lateral flow assays. Our results show that MnFe2O4 nanoparticles are more sensitive to inductive detection than magnetite nanoparticles, the most used nanotags in magnetic lateral flow assays. These nanoparticles present high potential as magnetic tags for the development of sensitive lateral flow immunoassays for detecting and quantifying biomarkers.

Millifluidic magnetophoresis-based chip for age-specific fractionation: evaluating the impact of age on metabolomics and gene expression in yeast.

A novel millifluidic process introduces age-based fractionation of S. pastorianus var. carlsbergensis yeast culture through magnetophoresis. Saccharomyces yeast is a model organism for aging research used in various industries. Traditional age-based cell separation methods were labor-intensive, but techniques like magnetic labeling have eased the process by being non-invasive and scalable. Our approach introduces an age-specific fractionation using a 3D-printed millfluidic chip in a two-step process, ensuring efficient cell deflection in the magnetic field and counteracting magnetic induced convection. Among various channel designs, the pinch-shaped channel proved most effective for age differentiation based on magnetically labeled bud scar numbers. Metabolomic analyses revealed changes in certain amino acids and increased NAD+ levels, suggesting metabolic shifts in aging cells. Gene expression studies further underlined these age-related metabolic changes. This innovative platform offers a high-throughput, non-invasive method for age-specific yeast cell fractionation, with potential applications in industries ranging from food and beverages to pharmaceuticals.

Differential diagnostic value of 3.0T MR 3D-ASL technique for recurrence and pseudo-progression of high-grade glioma.

This study aimed to explore the value of 3.0T magnetic resonance three-dimensional arterial spin labeling imaging (3D-ASL) technology in the differential diagnosis of recurrence and pseudo-progression of high-grade gliomas. Fifty patients with high-grade glioma were selected as research objects. All 50 patients were examined by magnetic resonance imaging (MRI), and the lesions were found to be enlarged or abnormally enhanced. All the patients were examined using the 3.0T MR 3D-ASL technique. With targeted biopsy pathology as the gold standard, the diagnostic results of the 3.0T MR 3D-ASL technique were analyzed, and the cerebral blood flow (rCBFmax) ratio was compared between patients with recurrent glioma and patients with pseudo-progression [maximum blood flow value/contralateral mirror area (CBFmax/contralateral mirror area), CBFmax/contralateral white matter, CBFmax/contralateral gray matter]. Among 50 glioma patients, 31 (62.00%) were diagnosed with recurrence through pathological examination, and 19 (38.00%) were diagnosed with pseudo-progression. 30 patients with recurrence (60.00%) and 20 patients with pseudo-progression (40.00%) were diagnosed using 3.0T magnetic resonance 3D-ASL technology. The diagnostic accuracy of 3.0T magnetic resonance 3D-ASL technology was 96.77% (30/31) (p > 0.05). Using pathological results as the "gold standard", the relevant parameters of 3.0T magnetic resonance 3D-ASL technology under different pathological results were analyzed. The results showed that the CBFmax/contralateral mirror area, CBFmax/contralateral white matter, and CBFmax/contralateral gray matter ratios of advanced glioma recurrence patients were significantly higher than those of pseudo-progression (p < 0.05). The application of 3.0T MR 3D-ASL in high-grade glioma can effectively distinguish recurrence and pseudo-progression, with significant diagnostic value.

High-efficiency magnetophoretic labelling of adoptively-transferred T cells for longitudinal in vivo Magnetic Particle Imaging.

While adoptive cell therapies (ACT) have been successful as therapies for blood cancers, they have limited efficacy in treating solid tumours, where the tumour microenvironment excludes and suppresses adoptively transferred tumour-specific immune cells. A major obstacle to improving cell therapies for solid tumours is a lack of accessible and quantitative imaging modalities capable of tracking the migration and immune functional activity of ACT products for an extended duration in vivo. Methods: A high-efficiency magnetophoretic method was developed for facile magnetic labelling of hard-to-label immune cells, which were then injected into tumour-bearing mice and imaged over two weeks with a compact benchtop Magnetic Particle Imager (MPI) design. Results: Labelling efficiency was improved more than 10-fold over prior studies enabling longer-term tracking for at least two weeks in vivo of the labelled immune cells and their biodistribution relative to the tumour. The new imager showed 5-fold improved throughput enabling much larger density of data (up to 20 mice per experiment). Conclusions: Taken together, our innovations enable the convenient and practical use of MPI to visualise the localisation of ACT products in in vivo preclinical models for longitudinal, non-invasive functional evaluation of therapeutic efficacy.

Commercial Chip-based Tunneling Magnetoresistance Sensor for Green-synthesized Magnetic Nanoparticles Assay

Owing to their significant roles in multiple sectors, the demand for high-performance, rapid, user-friendly, and low-cost sensors is crucial for biosensing. This paper reports the performance of a commercial chip-based tunneling magnetoresistance (TMR) sensor for detecting green-synthesized magnetic nanoparticles (MNP) as potential magnetic labels. A Simple and low-cost design consisting of a TMR chip ALT-025 integrated with an Arduino microcontroller and a basic differential amplifier was developed to provide real-time and measurable digital readouts. Three kinds of ferrite MNPs (Fe3O4, CoFe2O4 and MnFe2O4) was synthesized by the coprecipitation method on the green synthesis approach utilizing Moringa Oleifera extracts. All sample have a face-centered cubic inverse spinel structure with average grain size of 10.3 nm, 9.2 nm and 6.1 nm for Fe3O4, CoFe2O4 and MnFe2O4, respectively. Furthermore, soft ferromagnetic behavior is identified for all sample with magnetization saturation of 55.3 emu/g, 37.6 emu/g, 19.3 emu/g for Fe3O4, CoFe2O4 and MnFe2O4, respectively. The sensor showed a promising performance in the detection of MNPs. For the three particles, the sensitivity exhibited a linear function of the MNPs concentration. The sensitivity is related not only to the particle size but also to the magnetization of the nanoparticles in the bias field. The change in the output voltage was proportional to the bias magnetization (MBias), indicating that particles with a higher bias magnetization can produce a stronger magnetic stray field on the TMR sensor surface. The sensor system successfully detected MNPs at different stray field intensities. Furthermore, a low limit of detection was achieved using these methods. Moreover, the remarkable stability and repeatability of the sensor is further validated by the steady signal acquired for 30s with an RSD of 0.5-28.5%. Therefore, the integration of commercial chip-based TMR sensors and green-synthesized MNPs has great potential for advancing the detection of various biomolecules.