Magnetite (Fe3O4) nanoparticles (NPs) are attractive nanomaterials in the field of material science, chemistry, and physics because of their valuable properties, such as soft ferromagnetism, ...half-metallicity, and biocompatibility. Various structures of Fe3O4 NPs with different sizes, geometries, and nanoarchitectures have been synthesized, and the related properties have been studied with targets in multiple fields of applications, including biomedical devices, electronic devices, environmental solutions, and energy applications. Tailoring the sizes, geometries, magnetic properties, and functionalities is an important task that determines the performance of Fe3O4 NPs in many applications. Therefore, this review focuses on the crucial aspects of Fe3O4 NPs, including structures, synthesis, magnetic properties, and strategies for functionalization, which jointly determine the application performance of various Fe3O4 NP-based systems. We first summarize the recent advances in the synthesis of magnetite NPs with different sizes, morphologies, and magnetic properties. We also highlight the importance of synthetic factors in controlling the structures and properties of NPs, such as the uniformity of sizes, morphology, surfaces, and magnetic properties. Moreover, emerging applications using Fe3O4 NPs and their functionalized nanostructures are also highlighted with a focus on applications in biomedical technologies, biosensing, environmental remedies for water treatment, and energy storage and conversion devices.
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► A historical perspective of self-assembled monolayers (SAMs) is provided. ► The use of SAMs as protective coatings for flat substrates and nanoparticles is examined. ► The thermal ...and chemical stabilities of the SAMs are reviewed. ► Various strategies for enhancing the stability of SAMs are described.
This review examines the use of self-assembled monolayers (SAMs) on gold as nanoscale protective coatings for both nominally flat substrates and for nanoparticles. The thermal and chemical stabilities of the SAMs are discussed, and the various strategies used by researchers to generate thin films with enhanced resistance to corrosion and/or decomposition are described. The use of multidentate adsorbates to achieve the desired objectives is emphasized.
Tuning the magnetic properties of nanoparticles Kolhatkar, Arati G; Jamison, Andrew C; Litvinov, Dmitri ...
International Journal of Molecular Sciences,
07/2013, Letnik:
14, Številka:
8
Journal Article, Book Review
Recenzirano
Odprti dostop
The tremendous interest in magnetic nanoparticles (MNPs) is reflected in published research that ranges from novel methods of synthesis of unique nanoparticle shapes and composite structures to a ...large number of MNP characterization techniques, and finally to their use in many biomedical and nanotechnology-based applications. The knowledge gained from this vast body of research can be made more useful if we organize the associated results to correlate key magnetic properties with the parameters that influence them. Tuning these properties of MNPs will allow us to tailor nanoparticles for specific applications, thus increasing their effectiveness. The complex magnetic behavior exhibited by MNPs is governed by many factors; these factors can either improve or adversely affect the desired magnetic properties. In this report, we have outlined a matrix of parameters that can be varied to tune the magnetic properties of nanoparticles. For practical utility, this review focuses on the effect of size, shape, composition, and shell-core structure on saturation magnetization, coercivity, blocking temperature, and relaxation time.
Magnetic particles are widely used as signal labels in a variety of biological sensing applications, such as molecular detection and related strategies that rely on ligand-receptor binding. In this ...review, we explore the fundamental concepts involved in designing magnetic particles for biosensing applications and the techniques used to detect them. First, we briefly describe the magnetic properties that are important for bio-sensing applications and highlight the associated key parameters (such as the starting materials, size, functionalization methods, and bio-conjugation strategies). Subsequently, we focus on magnetic sensing applications that utilize several types of magnetic detection techniques: spintronic sensors, nuclear magnetic resonance (NMR) sensors, superconducting quantum interference devices (SQUIDs), sensors based on the atomic magnetometer (AM), and others. From the studies reported, we note that the size of the MPs is one of the most important factors in choosing a sensing technique.
Aging is a risk factor for heart failure, which is a leading cause of death world-wide. Elderly patients are more likely than young patients to experience a myocardial infarction (MI) and are more ...likely to develop heart failure following MI. The poor clinical outcome of aging in cardiovascular disease is recapitulated on the cellular level. Increase in stress exposure and shifts in signaling pathways with age change the biology of cardiomyocytes. The progressive accumulation of metabolic waste and damaged organelles in cardiomyocytes blocks the intracellular recycling process of autophagy and increases the cell's propensity toward apoptosis. Additionally, the decreased cardiomyocyte renewal capacity in the elderly, due to reduction in cellular division and impaired stem cell function, leads to further cardiac dysfunction and maladaptive responses to disease or stress. We review the cellular and molecular aspects of post-infarction remodeling in the aged heart, and relate them to the clinical problem of post-infarction remodeling in elderly patients.
Biomaterials for the Treatment of Myocardial Infarction
Karen L. Christman, Randall J. Lee
The emerging fields of tissue engineering and biomaterials have recently begun to provide potential ...treatments for myocardial infarction (MI). There are currently 3 biomaterial approaches for the treatment of MI. The first involves polymeric left ventricular restraints in the prevention of heart failure. The second involves in vitro engineered cardiac tissue, which is subsequently implanted in vivo. The final approach involves injection of cells and/or a scaffold into the myocardium to create in situ engineered cardiac tissue. This review gives an overview of the current progress in the growing field of biomaterials for the treatment of MI.
For nearly a decade, researchers have investigated the possibility of cell transplantation for cardiac repair. More recently, the emerging fields of tissue engineering and biomaterials have begun to provide potential treatments. Tissue engineering approaches are designed to repair lost or damaged tissue through the use of growth factors, cellular transplantation, and biomaterial scaffolds. There are currently 3 biomaterial approaches for the treatment of myocardial infarction (MI). The first involves polymeric left ventricular restraints in the prevention of heart failure. The second utilizes in vitro engineered cardiac tissue, which is subsequently implanted in vivo. The final approach entails injecting cells and/or a scaffold into the myocardium to create in situ engineered cardiac tissue. This review gives an overview of the current progress in the growing field of biomaterials for the treatment of MI.
Atrial fibrillation (AF) is a cardiac rhythm disorder associated with increased morbidity and mortality. It is the leading risk factor for cardioembolic stroke and its early detection is crucial in ...both primary and secondary stroke prevention. Continuous monitoring of cardiac rhythm is today possible thanks to consumer-grade wearable devices, enabling transformative diagnostic and patient management tools. Such monitoring is possible using low-cost easy-to-implement optical sensors that today equip the majority of wearables. These sensors record blood volume variations-a technology known as photoplethysmography (PPG)-from which the heart rate and other physiological parameters can be extracted to inform about user activity, fitness, sleep, and health. Recently, new wearable devices were introduced as being capable of AF detection, evidenced by large prospective trials in some cases. Such devices would allow for early screening of AF and initiation of therapy to prevent stroke. This review is a summary of a body of work on AF detection using PPG. A thorough account of the signal processing, machine learning, and deep learning approaches used in these studies is presented, followed by a discussion of their limitations and challenges towards clinical applications.
Left atrial appendage closure (LAAC) with LARIAT offers an alternative to oral anticoagulation (OAC) for patients with atrial fibrillation. The aim of this study was to present long-term clinical ...outcomes of LAAC in these patients (AF).
A prospective, single-center study was performed in 139 patients undergoing LAAC with Lariat. Thromboembolic events, severe bleeding and mortality rate were recorded. The reduction in risk of thromboembolism and bleeding after LAAC was calculated.
The mean CHADS2-score was 1.8 ± 1.0, mean CHA2DS2-VASc score was 2.9 ± 1.6 and HAS-BLED score was 3.1 ± 1.1. After 428.4 patient-years of follow-up (mean 4.2±1.0 years), the thromboembolism rate was 0.6% with a calculated thromboembolism risk reduction of 81%. The severe bleeding rate was 0.8%; calculated bleeding risk reduction was 78%. The overall mortality rate was 1.6%.
Long-term outcomes show that LAAC with Lariat is a safe and effective treatment for stroke prevention and bleeding risk reduction in AF patients with a high level of underlying risk.
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