Synthesis, functionalization, and nanomedical applications of functional magnetic nanoparticles

Synthesis and Characterization of SiO2/nGO/Fe3O4/SeQDs Nanoparticles as Potential Nanocarriers in Drug Delivery Systems

Herein, we constructed the branch-shaped SiO2/nano GO (nGO)/Fe3O4/selenium quantum dots (QDs) (SeQDs) nanoparticles (SGF/SeQDs) embodying magnetism, fluorescence, and microwave stimulus response properties to enhance the performance of releasing drugs. The SGF/SeQDs composite was characterized by technologies including powder X-ray diffraction, transmission electron microscopy, infrared spectroscopy, etc. In the nanoparticles, the branch-shaped SiO2 provides a large specific surface area, nGO as the dielectric loss-style material promotes microwave-absorbing performance, and the Fe3O4 serves as a magnetic targeting agent and microwave absorber. Integrating nGO and Fe3O4 could further strengthen the microwave absorption of the entire composite; selenium features both fluorescence and anticancer effects. The synthesized nanoparticles as carriers exhibited a branch-like mesoporous sphere of ∼260 nm, a specific surface area of 258.57 m2 g-1, a saturation magnetization of 24.59 emu g-1, and good microwave thermal conversion performance that the temperature was elevated from 25 to 70 °C under microwave irradiation. These physical characteristics, including large pore volume (5.30 nm), high specific surface area, and fibrous morphology, are in favor of loading drugs. Meanwhile, the cumulative etoposide (VP16) loading rate of the nanoparticles reached to 21 wt % after 360 min. The noncovalent interaction between the VP16 and SGF/SeQDs was mainly the hydrogen-bonding effect during the loading process. Furthermore, the drug release rates at 180 min were up to 81.46, 61.92, and 56.84 wt % at pH 4, 5, and 7, respectively. At 25, 37, and 50 °C, the rates of drug release reach 25.40, 56.84, and 65.32 wt %, respectively. After microwave stimulation at pH 7, the rate of releasing drug increased distinctly from 56.84 to 71.74 wt % compared to that of nonmicrowave irradiation. Cytotoxicity tests manifested that the carrier had good biocompatibility. Therefore, the nanoparticles are looking forward to paving one platform for further applications in biomedicine and drug delivery systems.

Advances in surface design and biomedical applications of magnetic nanoparticles

Despite significant efforts by scientists in the development of advanced nanotechnology materials for smart diagnosis devices and drug delivery systems, the success of clinical trials remains largely elusive. In order to address this biomedical challenge, magnetic nanoparticles (MNPs) have gained attention as a promising candidate due to their theranostic properties, which allow the simultaneous treatment and diagnosis of a disease. Moreover, MNPs have advantageous characteristics such as a larger surface area, high surface-to-volume ratio, enhanced mobility, mass transference and, more notably, easy manipulation under external magnetic fields. Besides, certain magnetic particle types based on the magnetite (Fe3O4) phase have already been FDA-approved, demonstrating biocompatible and low toxicity. Typically, surface modification and/or functional group conjugation are required to prevent oxidation and particle aggregation. A wide range of inorganic and organic molecules have been utilized to coat the surface of MNPs, including surfactants, antibodies, synthetic and natural polymers, silica, metals, and various other substances. Furthermore, various strategies have been developed for the synthesis and surface functionalization of MNPs to enhance their colloidal stability, biocompatibility, good response to an external magnetic field, etc. Both uncoated MNPs and those coated with inorganic and organic compounds exhibit versatility, making them suitable for a range of applications such as drug delivery systems (DDS), magnetic hyperthermia, fluorescent biological labels, biodetection and magnetic resonance imaging (MRI). Thus, this review provides an update of recently published MNPs works, providing a current discussion regarding their strategies of synthesis and surface modifications, biomedical applications, and perspectives.

Application of magnetism in tissue regeneration: recent progress and future prospects

Tissue regeneration is a hot topic in the field of biomedical research in this century. Material composition, surface topology, light, ultrasonic, electric field and magnetic fields (MFs) all have important effects on the regeneration process. Among them, MFs can provide nearly non-invasive signal transmission within biological tissues, and magnetic materials can convert MFs into a series of signals related to biological processes, such as mechanical force, magnetic heat, drug release, etc. By adjusting the MFs and magnetic materials, desired cellular or molecular-level responses can be achieved to promote better tissue regeneration. This review summarizes the definition, classification and latest progress of MFs and magnetic materials in tissue engineering. It also explores the differences and potential applications of MFs in different tissue cells, aiming to connect the applications of magnetism in various subfields of tissue engineering and provide new insights for the use of magnetism in tissue regeneration.

Inorganic nanoparticles for photothermal treatment of cancer

In recent years, inorganic nanoparticles (NPs) have attracted increasing attention as potential theranostic agents in the field of oncology. Photothermal therapy (PTT) is a minimally invasive technique that uses nanoparticles to produce heat from light to kill cancer cells. PTT requires two essential elements: a photothermal agent (PTA) and near-infrared (NIR) radiation. The role of PTAs is to absorb NIR, which subsequently triggers hyperthermia within cancer cells. By raising the temperature in the tumor microenvironment (TME), PTT causes damage to the cancer cells. Nanoparticles (NPs) are instrumental in PTT given that they facilitate the passive and active targeting of the PTA to the TME, making them crucial for the effectiveness of the treatment. In addition, specific targeting can be achieved through their enhanced permeation and retention effect. Thus, owing to their significant advantages, such as altering the morphology and surface characteristics of nanocarriers comprised of PTA, NPs have been exploited to facilitate tumor regression significantly. This review highlights the properties of PTAs, the mechanism of PTT, and the results obtained from the improved curative efficacy of PTT by utilizing NPs platforms.

A review on magnetic beads-based SELEX technologies: Applications from small to large target molecules

This review summarizes the stepwise strategy and key points for magnetic beads (MBs)-based aptamer selection which is suitable for isolating aptamers against small and large molecules via systematic evolution of ligands by exponential enrichment (SELEX). Particularities, if any, are discussed according to the target size. Examples targeting small molecules (<1000 Da) such as xenobiotics, toxins, pesticides, herbicides, illegal additives, hormones, and large targets such as proteins (biomarkers, pathogens) are discussed and presented in tabular formats. Of special interest are the latest advances in more efficient alternatives, which are based on novel instrumentation, materials or microelectronics, such as fluorescence MBs-SELEX or microfluidic chip system-assisted MBs-SELEX. Limitations and perspectives of MBs-SELEX are also reviewed. Taken together, this review aims to provide practical insights into MBs-SELEX technologies and their ability to screen multiple potential aptamers against targets from small to large molecules.

Stimuli-responsive Biomaterials for Tissue Engineering Applications

The use of ''smart materials,'' or ''stimulus responsive'' materials, has proven useful in a variety of fields, including tissue engineering and medication delivery. Many factors, including temperature, pH, redox state, light, and magnetic fields, are being studied for their potential to affect a material's properties, interactions, structure, and/or dimensions. New tissue engineering and drug delivery methods are made possible by the ability of living systems to respond to both external stimuli and their own internal signals) for example, materials composed of stimuliresponsive polymers that self assemble or undergo phase transitions or morphology transformation. The researcher examines the potential of smart materials as controlled drug release vehicles in tissue engineering, aiming to enable the localized regeneration of injured tissue by delivering precisely dosed drugs at precisely timed intervals.

Effectiveness In Vivo and In Vitro of Polymeric Nanoparticles as a Drug Release System in the Treatment of Leishmaniasis

Leishmaniasis is a neglected disease caused by the parasite of the genus Leishmania. Current treatment regimens are obsolete and cause several side effects, promoting poor patient compliance, in addition to the vast majority already having the potential for resistance. Therefore, polymeric nanoparticles emerge as one of the viable alternatives to overcome existing limitations, through passive or active vectorization. This review aims to summarize the latest studies of polymeric nanoparticles as an alternative treatment for leishmaniasis. In the first section, the main pharmacokinetic and pharmacodynamic challenges of current drugs are reported. The second section details how nanoparticles with and without functionalization are efficient in the treatment of leishmaniasis, discussing the characteristics of the polymer in the formulation. In this way, polymeric nanoparticles can improve the physicochemical properties of leishmanicidal drugs, improving solubility and stability, as well as improve the release of these drugs, directly or indirectly reaching monocytes/macrophages. 64.28% drugs were focused on the treatment of visceral leishmaniasis, and 28.57% on cutaneous leishmaniasis. The most chosen polymers in the literature are chitosan (35.71%) and PLGA (35.71%), the others represented 14.30% drugs, with all able to manage the drug release and increase the in vitro and/or in vivo efficacy of the original molecule. However, there are several barriers for these nanoformulations to cross laboratory research and is necessary more in-depth studies about the metabolites and degradation pathways of the polymers used in the formulations and plasma proteomics studies.

Fe3O4@Au Core-Shell Magnetic Nanoparticles for the Rapid Analysis of E. coli O157:H7 in an Electrochemical Immunoassay

Escherichia coli (E. coli) O157:H7 is a pathogenic bacterium that causes serious toxic effects in the human gastrointestinal tract. In this paper, a method for its effective analytical control in a milk sample was developed. To perform rapid (1 h) and accurate analysis, monodisperse Fe₃O₄@Au magnetic nanoparticles were synthesized and used in an electrochemical sandwich-type magnetic immunoassay. Screen-printed carbon electrodes (SPCE) were used as transducers, and electrochemical detection was performed by chronoamperometry using a secondary horseradish peroxidase-labeled antibody and 3,3',5,5'-tetramethylbenzidine. This magnetic assay was used to determine the E. coli O157:H7 strain in the linear range from 20 to 2 × 10⁶ CFU/mL, with a limit of detection of 20 CFU/mL. The selectivity of the assay was tested using Listeria monocytogenes p60 protein, and the applicability of the assay was assessed by analyzing a commercial milk sample, demonstrating the usefulness of the synthesized nanoparticles in the developed magnetic immunoassay.

Promising photocatalytic and antimicrobial activity of novel capsaicin coated cobalt ferrite nanocatalyst

In this study, CoFe₂O₄ nanoparticles were prepared by the co-precipitation method then surface modified with Capsaicin (Capsicum annuum ssp.). The virgin CoFe₂O₄ NPs and Capsaicin-coated CoFe₂O₄ NPs (CPCF NPs) were characterized by XRD, FTIR, SEM, and TEM. The antimicrobial potential and photocatalytic degradation efficiencies of the prepared samples via Fuchsine basic (FB) were investigated. The results revealed that CoFe₂O₄ NPs have spherical shapes and their diameter varied from 18.0 to 30.0 nm with an average particle size of 25.0 nm. Antimicrobial activity was tested on Gram-positive (S. aureusATCC 52923) and Gram-negative (E. coli ATCC 52922) by disk diffusion and broth dilution methods to determine the zone of inhibition (ZOI) and minimum inhibitory concentration (MIC), respectively. UV-assisted photocatalytic degradation of FB was examined. Various parameters affecting the photocatalytic efficiency such as pH, initial concentration of FB, and dose of nanocatalyst were studied. The in-vitro ZOI and MIC results verified that CPCF NPs were more active upon Gram-Positive S. aureus ATCC 52923 (23.0 mm ZOI and 0.625 μg/ml MIC) than Gram-Negative E. coli ATCC 52922 (17.0 mm ZOI and 1.250 μg/ml MIC). Results obtained from the photocatalytic activity indicated that the maximum FB removal achieving 94.6% in equilibrium was observed using 20.0 mg of CPCF NPS at pH 9.0. The synthesized CPCF NPs were effective in the removal of FB and also as potent antimicrobial agent against both Gram-positive and Gram-negative bacteria with potential medical and environmental applications.

Magnetic Bone Tissue Engineering: Reviewing the Effects of Magnetic Stimulation on Bone Regeneration and Angiogenesis

Bone tissue engineering emerged as a solution to treat critical bone defects, aiding in tissue regeneration and implant integration. Mainly, this field is based on the development of scaffolds and coatings that stimulate cells to proliferate and differentiate in order to create a biologically active bone substitute. In terms of materials, several polymeric and ceramic scaffolds have been developed and their properties tailored with the objective to promote bone regeneration. These scaffolds usually provide physical support for cells to adhere, while giving chemical and physical stimuli for cell proliferation and differentiation. Among the different cells that compose the bone tissue, osteoblasts, osteoclasts, stem cells, and endothelial cells are the most relevant in bone remodeling and regeneration, being the most studied in terms of scaffold-cell interactions. Besides the intrinsic properties of bone substitutes, magnetic stimulation has been recently described as an aid in bone regeneration. External magnetic stimulation induced additional physical stimulation in cells, which in combination with different scaffolds, can lead to a faster regeneration. This can be achieved by external magnetic fields alone, or by their combination with magnetic materials such as nanoparticles, biocomposites, and coatings. Thus, this review is designed to summarize the studies on magnetic stimulation for bone regeneration. While providing information regarding the effects of magnetic fields on cells involved in bone tissue, this review discusses the advances made regarding the combination of magnetic fields with magnetic nanoparticles, magnetic scaffolds, and coatings and their subsequent influence on cells to reach optimal bone regeneration. In conclusion, several research works suggest that magnetic fields may play a role in regulating the growth of blood vessels, which are critical for tissue healing and regeneration. While more research is needed to fully understand the relationship between magnetism, bone cells, and angiogenesis, these findings promise to develop new therapies and treatments for various conditions, from bone fractures to osteoporosis.

EpCAM aptamer activated 5-FU-loaded PLGA nanoparticles in CRC treatment; in vitro and in vivo study

In this study, epithelial cell adhesion molecule (EpCAM) aptamer-activated nanoparticles (Ap-NPs) were synthesised to enhance treatment efficiency in colorectal cancer (CRC). PLGA [poly(d, l-lactide-co-glycolide)] copolymer was fabricated by conjugation of COOH-PEG-NH₂ to PLGA-COOH through an EDC/NHS-mediated chemistry. Afterwards, 5-fluorouracil-loaded (FU) nanoparticles were prepared using the water/oil/water double emulsion solvent evaporation method. The in vitro cytotoxicity of formulations was evaluated using the MTT assay in HCT-116, CT-26 and HEK-293 cell lines. For in vivo study, tumour-bearing BALB/c mice were established by subcutaneous injection of CT-26 cell line. The results indicated that fabricated AP-FU-NPs had 101 nm size with a spherical surface, relatively homogeneously and, satisfactory encapsulation efficiency (83.93%). In vitro experiments revealed that Ap-FU-NPs had a superior in vitro cytotoxicity than both FU-NPs and free 5-FU in CT-26 and HCT-116 cells but, were significantly low toxic against HEK-293 cells relative to free 5-FU. Furthermore, in vivo results showed no significant haemolytic effect, hepatic and renal injury, or weight loss. After treatment of various animal groups with formulations, notable tumour growth delay was observed following the order: Ap-FU-NPs < FU-NPs < 5-FU < PBS. The results suggest that AP-FU-NPs could be an effective and promising carrier for 5-FU delivery to the EpCAM overexpressing CRC cells.

Biomedicine Innovations and Its Nanohydrogel Classifications

As one of the most cutting-edge and promising polymer crosslinked network nanoparticle systems. Polymer nano-sized hydrogels (nanogels) have been a hot topic in the biomedical field over the last few decades. Due to their unique characteristics, which include their relatively high drug encapsulation efficiency, ease of preparation, high tunability, low toxicity, high stability in serum and responsive behavior to a range of stimuli to facilitate drug release. Nanogels are thought to be the next generation of drug delivery systems that can completely change the way that drug delivery systems have an impact on patients' lives. Nanogels have demonstrated significant potential in a variety of fields, including chemotherapy, diagnosis, organ targeting, and delivery of bioactive molecules of different dimensions. However, the lack of substantial clinical data from nanogels becomes one of the major barriers to translating the nanogel concept into a practical therapeutic application for many disease conditions. In addition, nanogel safety profiles have been the major concern that hinders it advancement to the clinical trial phase. This review aims to emphasize the unique properties of nanogels as delivery systems for a variety of bioactive molecules over other nano-delivery systems. Also, this review attempts to give insight into the recent progress in nanogels as a carrier in the field of nanomedicine to overcome complex biological barriers. Relevant scientific data and clinical rationale for the development and the potential use of nanogel as a carrier for targeted therapeutic interventions are discussed. Finally, the concluding points of this review highlight the importance of understanding the long-term toxicity profile of nanogel within the biological system to fully understand their biocompatibility.

Preparation of PEI-modified nanoparticles by dopamine self-polymerization for efficient DNA delivery

Achieving efficient and safe gene delivery is great of significance to promote the development of gene therapy. In this work, a polydopamine (PDA) layer was coated on the surface of Fe₃ O₄ nanoparticles (NPs) by dopamine (DA) self-polymerization, and then magnetic Fe₃ O₄ NPs were prepared by the Michael addition between amino groups in polyethyleneimine (PEI) and PDA. The prepared Fe₃ O₄ NPs (named Fe₃ O₄ @PDA@PEI) were characterized by FTIR, atomic force microscopy (AFM) and scanning electron microscope (SEM). As an efficient and safe gene carrier, the potential of Fe₃ O₄ @PDA@PEI was evaluated by agarose gel electrophoresis, MTT assay, fluorescence microscopy, flow cytometry. The results shows that the Fe₃ O₄ @PDA@PEI NPs is stable hydrophilic nanoparticles with a particle size of 50-150 nm. It can efficiently condense DNA at low N/P ratios and protect it from nuclease degradation. In addition, the Fe₃ O₄ @PDA@PEI NPs has higher safety than PEI. Further, the Fe₃ O₄ @PDA@PEI/DNA polyplexes could be effectively absorbed by cells and successfully transfected, and exhibit higher cellular uptake and gene transfection efficiency than PEI/DNA polyplexes. The findings indicate that the Fe₃ O₄ @PDA@PEI NPs has the potential to be developed into a novel gene vector. This article is protected by copyright. All rights reserved.

Immobilization of Horseradish Peroxidase on Magnetite-Alginate Beads to Enable Effective Strong Binding and Enzyme Recycling during Anthraquinone Dyes’ Degradation

The aim of this study was to investigate covalent immobilization of horseradish peroxidase (HRP) on magnetic nanoparticles (Mag) encapsulated in calcium alginate beads (MABs) for color degradation, combining easy and fast removal of biocatalyst from the reaction mixture due to its magnetic properties and strong binding due to surface alginate functional groups. MABs obtained by extrusion techniques were analyzed by optical microscopy, FEG-SEM and characterized regarding mechanical properties, magnetization and HRP binding. HRP with initial concentration of 10 mg/g_carrier was successfully covalently bonded on MABs (diameter ~1 mm, magnetite/alginate ratio 1:4), with protein loading of 8.9 mg/g_carrier, immobilization yield 96.9% and activity 32.8 U/g. Immobilized HRP on MABs (HRP-MABs) was then used to catalyze degradation of two anthraquinonic dyes, Acid Blue 225 (AB225) and Acid Violet 109 (AV109), as models for wastewater pollutants. HRP-MABs decolorized 77.3% and 76.1% of AV109 and AB225, respectively after 15 min under optimal conditions (0.097 mM H₂O₂, 200 mg of HRP-MABs (8.9 mg/g_carrier), 0.08 and 0.1 g/mg beads/dye ratio for AV109 and AB225, respectively). Biocatalyst was used for 7 repeated cycles retaining 75% and 51% of initial activity for AB225 and AV109, respectively, showing potential for use in large scale applications for colored wastewater treatment.

Metal/Metalloid-Based Nanomaterials for Plant Abiotic Stress Tolerance: An Overview of the Mechanisms

In agriculture, abiotic stress is one of the critical issues impacting the crop productivity and yield. Such stress factors lead to the generation of reactive oxygen species, membrane damage, and other plant metabolic activities. To neutralize the harmful effects of abiotic stress, several strategies have been employed that include the utilization of nanomaterials. Nanomaterials are now gaining attention worldwide to protect plant growth against abiotic stresses such as drought, salinity, heavy metals, extreme temperatures, flooding, etc. However, their behavior is significantly impacted by the dose in which they are being used in agriculture. Furthermore, the action of nanomaterials in plants under various stresses still require understanding. Hence, with this background, the present review envisages to highlight beneficial role of nanomaterials in plants, their mode of action, and their mechanism in overcoming various abiotic stresses. It also emphasizes upon antioxidant activities of different nanomaterials and their dose-dependent variability in plants' growth under stress. Nevertheless, limitations of using nanomaterials in agriculture are also presented in this review.

A Comprehensive Updated Review on Magnetic Nanoparticles in Diagnostics

Magnetic nanoparticles (MNPs) have been studied for diagnostic purposes for decades. Their high surface-to-volume ratio, dispersibility, ability to interact with various molecules and superparamagnetic properties are at the core of what makes MNPs so promising. They have been applied in a multitude of areas in medicine, particularly Magnetic Resonance Imaging (MRI). Iron oxide nanoparticles (IONPs) are the most well-accepted based on their excellent superparamagnetic properties and low toxicity. Nevertheless, IONPs are facing many challenges that make their entry into the market difficult. To overcome these challenges, research has focused on developing MNPs with better safety profiles and enhanced magnetic properties. One particularly important strategy includes doping MNPs (particularly IONPs) with other metallic elements, such as cobalt (Co) and manganese (Mn), to reduce the iron (Fe) content released into the body resulting in the creation of multimodal nanoparticles with unique properties. Another approach includes the development of MNPs using other metals besides Fe, that possess great magnetic or other imaging properties. The future of this field seems to be the production of MNPs which can be used as multipurpose platforms that can combine different uses of MRI or different imaging techniques to design more effective and complete diagnostic tests.

The cytotoxicity of zinc oxide nanoparticles to 3D brain organoids results from excessive intracellular zinc ions and defective autophagy

Although the neurotoxicity of ZnO nanoparticles (NPs) has been evaluated in animal and nerve cell culture models, these models cannot accurately mimic human brains. Three-dimensional (3D) brain organoids based on human-induced pluripotent stem cells have been developed to study the human brains, but this model has rarely been used to evaluate NP neurotoxicity. We used 3D brain organoids that express cortical layer proteins to investigate the mechanisms of ZnO NP-induced neurotoxicity. Cytotoxicity caused by high levels of ZnO NPs (64 μg/mL) correlated with high intracellular Zn ion levels but not superoxide levels. Exposure to a non-cytotoxic concentration of ZnO NPs (16 μg/mL) increased the autophagy-marker proteins LC3B-II/I but decreased p62 accumulation, whereas a cytotoxic concentration of ZnO NPs (64 μg/mL) decreased LC3B-II/I proteins but did not affect p62 accumulation. Fluorescence micro-optical sectioning tomography revealed that 64 μg/mL ZnO NPs led to decreases in LC3B proteins that were more obvious at the outer layers of the organoids, which were directly exposed to the ZnO NPs. In addition to reducing LC3B proteins in the outer layers, ZnO NPs increased the number of micronuclei in the outer layers but not the inner layers (where LC3B proteins were still expressed). Adding the autophagy flux inhibitor bafilomycin A1 to ZnO NPs increased cytotoxicity and intracellular Zn ion levels, but adding the autophagy inducer rapamycin only slightly decreased cellular Zn ion levels. We conclude that high concentrations of ZnO NPs are cytotoxic to 3D brain organoids via defective autophagy and intracellular accumulation of Zn ions.

Magnetic Nanoparticles Used in Oncology

Recently, magnetic nanoparticles (MNPs) have more and more often been used in experimental studies on cancer treatments, which have become one of the biggest challenges in medical research. The main goal of this research is to treat and to cure advanced or metastatic cancer with minimal side effects through nanotechnology. Drug delivery approaches take into account the fact that MNPs can be bonded to chemotherapeutical drugs, nucleic acids, synthetized antibodies or radionuclide substances. MNPs can be guided, and different treatment therapies can be applied, under the influence of an external magnetic field. This paper reviews the main MNPs’ synthesis methods, functionalization with different materials and highlight the applications in cancer therapy. In this review, we describe cancer cell monitorization based on different types of magnetic nanoparticles, chemotherapy, immunotherapy, magnetic hyperthermia, gene therapy and ferroptosis. Examples of applied treatments on murine models or humans are analyzed, and glioblastoma cancer therapy is detailed in the review. MNPs have an important contribution to diagnostics, investigation, and therapy in the so called theranostics domain. The main conclusion of this paper is that MNPs are very useful in different cancer therapies, with limited side effects, and they can increase the life expectancy of patients with cancer drug resistance.

Magnetic Molecularly Imprinted Polymers: Synthesis and Applications in the Selective Extraction of Antibiotics

Recently, magnetic molecularly imprinted polymers (MMIPs) have integrated molecular imprinting technology (MIT) and magnetic separation technology and become a novel material with specific recognition and effective separation of target molecules. Based on their special function, they can be widely used to detect contaminants such as antibiotics. The antibiotic residues in the environment not only cause harm to the balance of the ecosystem but also induce bacterial resistance to specific antibiotics. Given the above consideration, it is especially important to develop sensitive and selective methods for measuring antibiotics in the complex matrix. The combination of MMIPs and conventional analytical methods provides a rapid approach to separate and determine antibiotics residues. This article gives a systematic overview of synthetic approaches of the novel MMIPs materials, briefly introduces their use in sample pretreatment prior to antibiotic detection, and provides a perspective for future research.

Design and operation of magnetophoretic systems at microscale: Device and particle approaches

Combining both device and particle designs are the essential concepts to be considered in magnetophoretic system development. Researcher efforts are often dedicated to only one of these design aspects and neglecting the interplay between them. Herein, to bring out importance of the idea of integration between device and particle, we reviewed the working principle of magnetophoretic system (includes both device and particle design concepts). Since, the magnetophoretic force is influenced by both field gradient and magnetization volume, hence, accurate prediction of the magnetophoretic force is relying on the availability of information on both parameters. In device design, we focus on the different strategies used to create localized high-field gradient. For particle design, we emphasize on the scaling between hydrodynamic size and magnetization volume. Moreover, we also briefly discussed the importance of magnetoshape anisotropy related to particle design aspect of magnetophoretic systems. Next, we illustrated the need for integration between device and particle design using microscale applications of magnetophoretic systems, include magnetic tweezers and microfluidic systems, as our working example. On the basis of our discussion, we highlighted several promising examples of microscale magnetophoretic systems which greatly utilized the interplay between device and particle design. Further, we concluded the review with several factors that possibly resulted in the lack of research efforts related to device and particle design integration.

Synergetic delivery of triptolide and Ce6 with light-activatable liposomes for efficient hepatocellular carcinoma therapy

Hepatocellular carcinoma (HCC) has been known as the second common leading cancer worldwide, as it responds poorly to both chemotherapy and medication. Triptolide (TP), a diterpenoid triepoxide, is a promising treatment agent for its effective anticancer effect on multiple cancers including HCC. However, its clinical application has been limited owing to its severe systemic toxicities, low solubility, and fast elimination in the body. Therefore, to overcome the above obstacles, photo-activatable liposomes (LP) integrated with both photosensitizer Ce6 and chemotherapeutic drug TP (TP/Ce6-LP) was designed in the pursuit of controlled drug release and synergetic photodynamic therapy in HCC therapy. The TP encapsulated in liposomes accumulated to the tumor site due to the enhanced permeability and retention (EPR) effect. Under laser irradiation, the photosensitizer Ce6 generated reactive oxygen species (ROS) and further oxidized the unsaturated phospholipids. In this way, the liposomes were destroyed to release TP. TP/Ce6-LP with NIR laser irradiation (TP/Ce6-LP+L) showed the best anti-tumor effect both in vitro and in vivo on a patient derived tumor xenograft of HCC (PDXHCC). TP/Ce6-LP significantly reduced the side effects of TP. Furthermore, TP/Ce6-LP+L induced apoptosis through a caspase-3/PARP signaling pathway. Overall, TP/Ce6-LP+L is a novel potential treatment option in halting HCC progression with attenuated toxicity.

An Efficient Uranium Adsorption Magnetic Platform Based on Amidoxime-Functionalized Flower-like Fe3O4@TiO2 Core-Shell Microspheres

Efficient removal of uranium (U) from aqueous solutions is crucial for ecological safety. Functionalized magnetic nanoparticles provide a promising strategy for radionuclide recovery and separation. However, designing and synthesizing magnetic adsorbents with high sorption capacity and selectivity, accompanied by excellent stability and reusability, remain a challenge. In this work, novel amidoxime-functionalized flower-like magnetic Fe₃O₄@TiO₂ core-shell microspheres are designed and synthesized to efficiently remove U(VI) from aqueous solutions and actual seawater. The magnetic Fe₃O₄ core facilitates easy separation by an external magnetic field, and flower-like TiO₂ nanosheets provide abundant specific surface areas and functionalization sites. The grafted amidoxime (AO) groups could function as a claw for catching uranium. The maximum adsorption capacity on U(VI) of the designed nanospheres reaches 313.6 mg·g^-1 at pH 6.0, and the adsorption efficiency is maintained at 97% after 10 cycles. In addition, the excellent selectivity of the magnetic recyclable AO-functioning Fe₃O₄@TiO₂ microspheres endows the potential of uranium extraction from seawater. The designed material provides an effective and applicable diagram for radioactive element elimination and enrichment.

Potential roles of Kruppel-like factors in mediating adverse vascular effects of nanomaterials: A review

The development of nanotechnology leads to the exposure of human beings to nanomaterials (NMs), and there is a health concern about the adverse vascular effects of NMs. Current data from epidemiology, controlled human exposure, and animal studies suggested that exposure to NMs could induce cardiopulmonary effects. In support of in vivo findings, in vitro studies showed that direct contact of vascular cells with NMs could induce endothelial cell (EC) activation and promote macrophage foam cell formation, although only limited studies showed that NMs could damage vascular smooth muscle cells and promote their phenotypic switch. It has been proposed that NMs induced adverse vascular effects via different mechanisms, but it is still necessary to understand the upstream events. Kruppel-like factors (KLFs) are a set of C2H2 zinc finger transcription factors (TFs) that can regulate various aspects of vascular biology, but currently, the roles of KLF2 in mediating the adverse vascular effects of NMs have gained little attention by toxicologists. This review summarized current knowledge about the adverse vascular effects of NMs and proposed the potential roles of KLFs in mediating these effects based on available data from toxicological studies as well as the current understanding about KLFs in vascular biology. Finally, the challenges in investigating the role of KLFs in vascular toxicology were also summarized. Considering the important roles of KLFs in vascular biology, further studies are needed to understand the influence of NMs on KLFs and the downstream events.

Magnetic nanoparticles applied in targeted therapy and magnetic resonance imaging: crucial preparation parameters, indispensable pre-treatments, updated research advancements and future perspectives

Magnetic nanoparticles (MNPs) have attracted much attention in cancer treatment as carriers for drug delivery and imaging contrast agents due to their distinctive performances based on their magnetic properties and nanoscale structure. In this review, we aim to comprehensively dissect how the applications of MNPs in targeted therapy and magnetic resonance imaging are achieved and their specificities by focusing on the following aspects: (1) several important preparation parameters (pH, temperature, ratio of the reactive substances, etc.) that have crucial effects on the properties of MNPs, (2) indispensable treatments to improve the biocompatibility, stability, and targeting ability of MNPs and prolong their circulation time for biomedical applications, (3) the mechanism for MNPs to deliver and release medicine to the desired sites and be applied in magnetic hyperthermia as well as related updated research advancements, (4) comparatively promising research directions of MNPs in magnetic resonance imaging, and (5) perspectives in the further optimization of their preparations, pre-treatments and applications in cancer diagnosis and therapy.

Synthesis and applications of surface-modified magnetic nanoparticles: progress and future prospects

The growing use of magnetic nanoparticles (MNPs) demands cost-effective methods for their synthesis that allow proper control of particle size and size distribution. The unique properties of MNPs include high specific surface area, ease of functionalization, chemical stability and superparamagnetic behavior, with applications in catalysis, data and energy storage, environmental remediation and biomedicine. This review highlights breakthroughs in the use of MNPs since their initial introduction in biomedicine to the latest challenging applications; special attention is paid to the importance of proper coating and functionalization of the particle surface, which dictates the specific properties for each application. Starting from the first report following LaMer’s theory in 1950, this review discusses and analyzes methods of synthesizing MNPs, with an emphasis on functionality and applications. However, several hurdles, such as the design of reactors with suitable geometries, appropriate control of operating conditions and, in particular, reproducibility and scalability, continue to prevent many applications from reaching the market. The most recent strategy, the use of microfluidics to achieve continuous and controlled synthesis of MNPs, is therefore thoroughly analyzed. This review is the first to survey continuous microfluidic coating or functionalization of particles, including challenging properties and applications.

Copper based on diaminonaphthalene-coated magnetic nanoparticles as robust catalysts for catalytic oxidation reactions and C-S cross-coupling reactions

In this work, the immobilization of copper(ii) on the surface of 1,8-diaminonaphthalene (DAN)-coated magnetic nanoparticles provides a highly active catalyst for the oxidation reaction of sulfides to sulfoxides and the oxidative coupling of thiols to disulfides using hydrogen peroxide (H2O2). This catalyst was also applied for the one-pot synthesis of symmetrical sulfides via the reaction of aryl halides with thiourea as the sulfur source in the presence of NaOH instead of former strongly basic and harsh reaction conditions. Under optimum conditions, the synthesis yields of sulfoxides, symmetrical sulfides, and disulfides were about 99%, 95%, and 96% respectively with highest selectivity. The heterogeneous copper-based catalyst has advantages such as the easy recyclability of the catalyst, the easy separation of the product and the less wastage of products during the separation of the catalyst. This heterogeneous nanocatalyst was characterized by FESEM, FT-IR, VSM, XRD, EDX, ICP and TGA. Furthermore, the recycled catalyst can be reused for several runs and is economically effective.

Smart Synthesis of Trimethyl Ethoxysilane (TMS) Functionalized Core-Shell Magnetic Nanosorbents Fe3O4@SiO2: Process Optimization and Application for Extraction of Pesticides

In the current study, a smart approach for synthesizing trimethyl ethoxysilane–decorated magnetic-core silica-nanoparticles (TMS-mcSNPs) and its effectiveness as nanosorbents have been exploited. While the magnetite core was synthesized using the modified Mössbauer method, Stöber method was employed to coat the magnetic particles. The objective of this work is to maximize the magnetic properties and to minimize both particle size (PS) and particle size distribution (PSD). Using a full factorial design (2^k-FFD), the influences of four factors on the coating process was assessed by optimizing the three responses (magnetic properties, PS, and PSD). These four factors were: (1) concentration of tetraethyl-orthosilicate (TEOS); (2) concentration of ammonia; (3) dose of magnetite (Fe₃O₄); and (4) addition mode. Magnetic properties were calculated as the attraction weight. Scanning electron microscopy (SEM) was used to determine PS, and standard deviation (±SD) was calculated to determine the PSD. Composite desirability function (D) was used to consolidate the multiple responses into a single performance characteristic. Pareto chart of standardized effects together with analysis of variance (ANOVA) at 95.0 confidence interval (CI) were used to determine statistically significant variable(s). Trimethyl ethoxysilane–functionalized mcSNPs were further applied as nanosorbents for magnetic solid phase extraction (TMS-MSPE) of organophosphorus and carbamate pesticides.

Stimuli-Responsive Materials for Tissue Engineering and Drug Delivery

Smart or stimuli-responsive materials are an emerging class of materials used for tissue engineering and drug delivery. A variety of stimuli (including temperature, pH, redox-state, light, and magnet fields) are being investigated for their potential to change a material's properties, interactions, structure, and/or dimensions. The specificity of stimuli response, and ability to respond to endogenous cues inherently present in living systems provide possibilities to develop novel tissue engineering and drug delivery strategies (for example materials composed of stimuli responsive polymers that self-assemble or undergo phase transitions or morphology transformations). Herein, smart materials as controlled drug release vehicles for tissue engineering are described, highlighting their potential for the delivery of precise quantities of drugs at specific locations and times promoting the controlled repair or remodeling of tissues.

Intelligent Bimetallic Nanoagents as Reactive Oxygen Species Initiator System for Effective Combination Phototherapy

Phototherapy is a promising oncotherapy method. However, there are various factors greatly restricted phototherapy development, including poor tumor-specific accumulation, the hypoxia in solid tumor, and the systemic phototoxicity of photosensitizer. Herein, a tumor microenvironment (TME)-responsive intelligent bimetallic nanoagents (HSA-Pd-Fe-Ce6 NAs) composed of human serum albumin (HSA), palladium-iron (Pd-Fe) bimetallic particles, and chlorin e6 (Ce6) was designed for effective combination phototherapy. The Pd-Fe part in the HSA-Pd-Fe-Ce6 NAs would react with the endogenous hydrogen peroxide (H₂O₂) in an acidic ambiance within tumor to generate cytotoxic superoxide anion free radical through the “Fenton-like reaction.” H₂O₂, coupled with highly toxic singlet oxygen (¹O₂) caused by the Ce6 component under the irradiation of 660 nm laser, resulted in synergistic cancer therapy effects in hypoxia surroundings. Besides, this nanoagents could result in hyperpyrexia-induced cell apoptosis because of superior absorption performance in near-infrared wavelength window bringing about excellent photothermal conversion efficiency. The cell cytotoxicity results showed that the survival rate after treated by 40 μg mL^–1 nanoagents was only 17%, which reveals that the HSA-Pd-Fe-Ce6 NAs had the advantage of efficient and controllable phototherapy. In short, it exhibited excellent hypoxia-resistant combination phototherapy efficacy in vitro. Therefore, the multifunctional nanoagents are powerful and provide a new avenue for effective combination phototherapy.

Magnetism in drug delivery: The marvels of iron oxides and substituted ferrites nanoparticles

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The conventional utilization of drugs is characterized by poor biodistribution, limited effectiveness, and lack of selectivity, besides undesirable side effects on multiple body systems.

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Seeking a DDS with a modifiable skeleton to customize drug targeting is of extreme importance for successful therapy of many diseases.

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Among the different synthesis strategies for MNPs, chemical methods are the most common, and on top of the pyramid, is the co-precipitation method.

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MNPs have customizable properties, where applying a hydrophilic coating protects the particles from opsonization and human-immunity recognition, which increases their circulation time.

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The route MNPs usually follow in the body starts with magnetic guidance to the target, immobilization for drug release, and finally clearance.

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Interestingly, multifunctional nanocomplexes with conjugated SPIONS and PEI presented enhanced transfection while decreased PEI toxicity.

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Theranostic applications of MNPs are limitless, whether it is a dual function of diagnosis and therapy simultaneously, or a multimodal imaging system.

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IONPs participate in the production of oxidative stress that leads to cell damage.

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Metal ferrite NPs can overcome the drawbacks of IONPs provided that the substituting metal in use is less toxic.

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Metal ferrite NPs present unique properties of high saturation magnetization, enhanced encapsulation efficacy, as well as enzyme-mimetic activities.

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Magnesium ferrite NPs (MFNPs) were found to exhibit greater magnetic heating capacity compared to other ferrites. MFNPs also show safe metabolism and high biocompatibility, making them a promising system for cancer applications.

In modern drug delivery, seeking a drug delivery system (DDS) with a modifiable skeleton for proper targeting of loaded actives to specific sites in the body is of extreme importance for a successful therapy. Magnetically guided nanosystems, where particles such as iron oxides are guided to specific regions using an external magnetic field, can provide magnetic resonance imaging (MRI) while delivering a therapeutic payload at the same time, which represents a breakthrough in disease therapy and make MNPs excellent candidates for several biomedical applications. In this review, magnetic nanoparticles (MNPs) along with their distinguishable properties, including pharmacokinetics and toxicity, especially in cancer therapy will be discussed. The potential perspective of using other elements within the MNP system to reduce toxicity, improve pharmacokinetics, increase the magnetization ability, improve physical targeting precision and/or widen the scope of its biomedical application will be also discussed.