Recent progress of magnetic nanoparticles in biomedical applications: A review

Pharmaceutical cocrystals: a rising star in drug delivery applications

Pharmaceutical cocrystals, owing to their manifold applications, are acting as bridge between drug discovery and pharmaceutical product development. The ability to scale up pharmaceutical cocrystals through continuous manufacturing approaches offers superior and economic pharmaceutical products. Moreover, cocrystals can be an aid for the nanoparticulate systems to solve the issues related to scale-up and cost. Cocrystals grabbed attention of academic researchers and pharmaceutical scientist due to their potential to target various diseases like cancer. The present review is mainly focussed on the diverse and comprehensive applications of pharmaceutical cocrystals in drug delivery including solubility and dissolution enhancement, improvement of bioavailability of drug, mechanical and flow properties of active pharmaceutical ingredients, controlled/sustained release and colour tuning of API. Besides, phytochemical based cocrystals, multi-drug cocrystals and cocrystals for tumour therapy have been discussed in this review. Additionally, recent progress pertinent to pharmaceutical cocrystals is also included, which may provide future directions to manufacturing and scale-up of cocrystals.

Magnetic nanosystem a tool for targeted delivery and diagnostic application: Current challenges and recent advancement

Over the last two decades, researchers have paid more attention to magnetic nanosystems due to their wide application in diverse fields. The metal nanomaterials' antimicrobial and biocidal properties make them an essential nanosystem for biomedical applications. Moreover, the magnetic nanosystems could have also been used for diagnosis and treatment because of their magnetic, optical, and fluorescence properties. Superparamagnetic iron oxide nanoparticles (SPIONs) and quantum dots (QDs) are the most widely used magnetic nanosystems prepared by a simple process. By surface modification, researchers have recently been working on conjugating metals like silica, copper, and gold with magnetic nanosystems. This hybridization of the nanosystems modifies the structural characteristics of the nanomaterials and helps to improve their efficacy for targeted drug and gene delivery. The hybridization of metals with various nanomaterials like micelles, cubosomes, liposomes, and polymeric nanomaterials is gaining more interest due to their nanometer size range and nontoxic, biocompatible nature. Moreover, they have good injectability and higher targeting ability by accumulation at the target site by application of an external magnetic field. The present article discussed the magnetic nanosystem in more detail regarding their structure, properties, interaction with the biological system, and diagnostic applications.

Porphyrin-Based Self-Assembled Nanoparticles for PET/MR Imaging of Sentinel Lymph Node Metastasis

Diagnosing of lymph node metastasis is challenging sometimes, and multimodal imaging offers a promising method to improve the accuracy. This work developed porphyrin-based nanoparticles (68Ga-F127-TAPP/TCPP(Mn) NPs) as PET/MR dual-modal probes for lymph node metastasis imaging by a simple self-assembly method. Compared with F127-TCPP(Mn) NPs, F127-TAPP/TCPP(Mn) NPs synthesized by amino-porphyrins (TAPP) doping can not only construct PET/MR bimodal probes but also improve the T1 relaxivity (up to 456%). Moreover, T1 relaxivity can be adjusted by altering the molar ratio of TAPP/TCPP(Mn) and the concentration of F127. However, a similar increase in T1 relaxivity was not observed in the F127-TCPP/TCPP(Mn) NPs, which were synthesized using carboxy-porphyrins (TCPP) doping. In a breast cancer lymph node metastasis mice model, subcutaneous injection of 68Ga-F127-TAPP/TCPP(Mn) NPs through the hind foot pad, the normal lymph nodes and metastatic lymph nodes were successfully distinguished based on the difference of PET standard uptake values and MR signal intensities. Furthermore, the dark brown F127-TAPP/TCPP(Mn) NPs demonstrated the potential for staining and mapping lymph nodes. This study provides valuable insights into developing and applying PET/MR probes for lymph node metastasis imaging.

Synthesis, modifications, and applications of iron-based nanoparticles

Magnetic nanoparticles (MNPs) are appealing materials as assistant to resolve environmental pollution issues and as recyclable catalysts for the oxidative degradation of resistant contaminants. Moreover, they can significantly influence the advancement of medical applications for imaging, diagnostics, medication administration, and biosensing. On the other hand, due to unique features, excellent biocompatibility, high curie temperatures and low cytotoxicity of the Iron-based nanoparticles, they have received increasing attention in recent years. Using an external magnetic field, in which the ferrite magnetic nanoparticles (FMNPs) in the reaction mixtures can be easily removed, make them more efficient approach than the conventional method for separating the catalyst particles by centrifugation or filtration. Ferrite magnetic nanoparticles (FMNPs) provide various advantages in food processing, environmental issues, pharmaceutical industry, sample preparation, wastewater management, water purification, illness therapy, identification of disease, tissue engineering, and biosensor creation for healthcare monitoring. Modification of FMNPs with the proper functional groups and surface modification techniques play a significant role in boosting their capability. Due to flexibility of FMNPs in functionalization and synthesis, it is possible to make customized FMNPs that can be utilized in variety of applications. This review focuses on synthesis, modifications, and applications of Iron-based nanoparticles.

Emerging Trends of Gold Nanostructures for Point-of-Care Biosensor-Based Detection of COVID-19

In 2019, a worldwide pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged. SARS-CoV-2 is the deadly microorganism responsible for coronavirus disease 2019 (COVID-19), which has caused millions of deaths and irreversible health problems worldwide. To restrict the spread of SARS-CoV-2, accurate detection of COVID-19 is essential for the identification and control of infected cases. Although recent detection technologies such as the real-time polymerase chain reaction delivers an accurate diagnosis of SARS-CoV-2, they require a long processing duration, expensive equipment, and highly skilled personnel. Therefore, a rapid diagnosis with accurate results is indispensable to offer effective disease suppression. Nanotechnology is the backbone of current science and technology developments including nanoparticles (NPs) that can biomimic the corona and develop deep interaction with its proteins because of their identical structures on the nanoscale. Various NPs have been extensively applied in numerous medical applications, including implants, biosensors, drug delivery, and bioimaging. Among them, point-of-care biosensors mediated with gold nanoparticles (GNPSs) have received great attention due to their accurate sensing characteristics, which are widely used in the detection of amino acids, enzymes, DNA, and RNA in samples. GNPS have reconstructed the biomedical application of biosensors because of its outstanding physicochemical characteristics. This review provides an overview of emerging trends in GNP-mediated point-of-care biosensor strategies for diagnosing various mutated forms of human coronaviruses that incorporate different transducers and biomarkers. The review also specifically highlights trends in gold nanobiosensors for coronavirus detection, ranging from the initial COVID-19 outbreak to its subsequent evolution into a pandemic.

Fe3O4 nanoparticles impregnated eggshell as an efficient biocatalyst for eco-friendly synthesis of 2-amino thiophene derivatives

In this study, a biodegradable and eco-friendly biocatalyst (eggshell/Fe3O4) was synthesized utilizing eggshell impregnated with Fe3O4 nanoparticles. The characterization of prepared catalyst was carried out by Fourier transform infrared radiation (FT-IR), scanning electron microscopy (SEM), X-ray Diffraction (XRD), energy-dispersive X-ray (EDX), thermal gravimetric analysis-differential thermogravimetry (TGA-DTG), vibrating sample magnometer (VSM), and atomic force microscopy (AFM). The eggshell/Fe3O4 biocatalyst was served in multi-component reactions (MCRs) for the synthesis of 2-amino thiophene derivatives from variety aromatic aldehydes, malononitrile, ethyl acetoacetate, and sulfur (S8). To achieve optimal reaction conditions, a thorough examination was conducted on key factors, such as the solvent type, reaction time and temperature, and the ratio of eggshell to Fe3O4. The findings suggest that high yield product can be obtained at microwave temperature (MW) in EtOH solvent within 10 min. Additionally, the eggshell/Fe3O4 biocatalyst exhibited high catalytic activity, which was sustained over the five cycles, without any significant decline in its performance.

Plant-Mediated Synthesis of Magnetite Nanoparticles with Matricaria chamomilla Aqueous Extract

Magnetite nanoparticles (NPs) possess properties that make them suitable for a wide range of applications. In recent years, interest in the synthesis of magnetite NPs and their surface functionalization has increased significantly, especially regarding their application in biomedicine such as for controlled and targeted drug delivery. There are several conventional methods for preparing magnetite NPs, all of which mostly utilize Fe(iii) and Fe(ii) salt precursors. In this study, we present a microwave hydrothermal synthesis for the precipitation of magnetite NPs at temperatures of 200 °C for 20 min and 260 °C for 5 min, with only iron(iii) as a precursor utilizing chamomile flower extract as a stabilizing, capping, and reducing agent. Products were characterized using FTIR, PXRD, SEM, and magnetometry. Our analysis revealed significant differences in the properties of magnetite NPs prepared with this approach, and the conventional two-precursor hydrothermal microwave method (sample MagH). FTIR and PXRD analyses confirmed coated magnetite particles. The temperature and magnetic-field dependence of magnetization indicate their superparamagnetic behavior. Importantly, the results of our study show the noticeable cytotoxicity of coated magnetite NPs-toxic to carcinoma cells but harmless to healthy cells-further emphasizing the potential of these NPs for biomedical applications.

Magnetic Hydroxyapatite Nanoparticles in Regenerative Medicine and Nanomedicine

This review focuses on the latest advancements in magnetic hydroxyapatite (mHA) nanoparticles and their potential applications in nanomedicine and regenerative medicine. mHA nanoparticles have gained significant interest over the last few years for their great potential, offering advanced multi-therapeutic strategies because of their biocompatibility, bioactivity, and unique physicochemical features, enabling on-demand activation and control. The most relevant synthetic methods to obtain magnetic apatite-based materials, either in the form of iron-doped HA nanoparticles showing intrinsic magnetic properties or composite/hybrid compounds between HA and superparamagnetic metal oxide nanoparticles, are described as highlighting structure-property correlations. Following this, this review discusses the application of various magnetic hydroxyapatite nanomaterials in bone regeneration and nanomedicine. Finally, novel perspectives are investigated with respect to the ability of mHA nanoparticles to improve nanocarriers with homogeneous structures to promote multifunctional biological applications, such as cell stimulation and instruction, antimicrobial activity, and drug release with on-demand triggering.

Advances in screening hyperthermic nanomedicines in 3D tumor models

Hyperthermic nanomedicines are particularly relevant for tackling human cancer, providing a valuable alternative to conventional therapeutics. The early-stage preclinical performance evaluation of such anti-cancer treatments is conventionally performed in flat 2D cell cultures that do not mimic the volumetric heat transfer occurring in human tumors. Recently, improvements in bioengineered 3D in vitro models have unlocked the opportunity to recapitulate major tumor microenvironment hallmarks and generate highly informative readouts that can contribute to accelerating the discovery and validation of efficient hyperthermic treatments. Leveraging on this, herein we aim to showcase the potential of engineered physiomimetic 3D tumor models for evaluating the preclinical efficacy of hyperthermic nanomedicines, featuring the main advantages and design considerations under diverse testing scenarios. The most recent applications of 3D tumor models for screening photo- and/or magnetic nanomedicines will be discussed, either as standalone systems or in combinatorial approaches with other anti-cancer therapeutics. We envision that breakthroughs toward developing multi-functional 3D platforms for hyperthermia onset and follow-up will contribute to a more expedited discovery of top-performing hyperthermic therapies in a preclinical setting before their in vivo screening.

SARS-CoV-2 Neutralization by Cell Membrane-Coated Antifouling Nanoparticles

The global outbreak of the COVID-19 pandemic has indisputably wreaked havoc on societies worldwide, compelling the scientific community to seek urgently needed therapeutic agents with low-cost and low-side effect profiles. Numerous approaches have been investigated in the quest to prevent or treat COVID-19, but many of them exhibit unwelcome side effects, such as dysfunctional viral immune responses and inflammation. Herein, we present the preparation of solid natural human pulmonary alveolar epithelial cell (ATII) membrane-coated PLGA NPs (PLGA NPs@ATII-M), which demonstrate remarkable affinity and competitiveness to neutralize the SARS-CoV-2 S1 protein-coated NPs (SCMMA NPs-S1), which are employed as a surrogate for coronavirus particles. In addition, we first considered the antifouling properties of these types of NPs, and we found that this membrane-coated NP formulation boasts excellent antifouling capabilities, which serve to protect their neutralization properties out of shielding by protein coronas in blood circulation. Moreover, this formulation is easily prepared and stored with a low-cost profile and exhibits good specificity, high targeting efficiency, and potentially side effect avoiding, thus making it a highly promising candidate for COVID-19 treatment.

MgFe2O4@Tris magnetic nanoparticles: an effective and powerful catalyst for one-pot synthesis of pyrazolopyranopyrimidine and tetrahydrodipyrazolopyridine derivatives

Magnesium (Mg) as a metal has wide applications, but its use in chemical reactions is rarely reported. Currently, magnesium catalytic processes are being developed to synthesize basic chemical compounds. Therefore, an effective and recyclable nano-catalyst was synthesized using MgFe2O4@Tris in this study. The structure of MgFe2O4@Tris was characterized by various techniques including Fourier-transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM) techniques. Finally, the catalytic activity of this nano-catalyst was evaluated for the synthesis of pyrazolopyranopyrimidine and tetrahydrodipyrazolopyridine derivatives. Among the advantages of this catalyst are its high catalytic activity, high yields, use of environmentally friendly solvents, easy magnetic separation, and the possibility of reusing the catalyst.

Antiaging Strategies and Remedies: A Landscape of Research Progress and Promise

Aging is typified by a gradual loss of physiological fitness and accumulation of cellular damage, leading to deteriorated functions and enhanced vulnerability to diseases. Antiaging research has a long history throughout civilization, with many efforts put forth to understand and prevent the effects of aging. Multiple strategies aiming to promote healthy aging and extend the lifespan have been developed including lifestyle adjustments, medical treatments, and social programs. A multitude of antiaging medicines and remedies have also been explored. Here, we use data from the CAS Content Collection to analyze the publication landscape of recent research related to antiaging strategies and treatments. We review the recent advances and delineate trends in research headway of antiaging knowledge and practice across time, geography, and development pipelines. We further assess the state-of-the-art antiaging approaches and explore their correlations with age-related diseases. The landscape of antiaging drugs has been outlined and explored. Well-recognized and novel, currently evaluated antiaging agents have also been summarized. Finally, we review clinical applications of antiaging products with their development pipelines. The objective of this review is to summarize current knowledge on preventive strategies and treatment remedies in the field of aging, to outline challenges and evaluate growth opportunities, in order to further efforts to solve the problems that remain.

Package delivered: folate receptor-mediated transporters in cancer therapy and diagnosis

Neoplasias pose a significant threat to aging society, underscoring the urgent need to overcome the limitations of traditional chemotherapy through pioneering strategies. Targeted drug delivery is an evolving frontier in cancer therapy, aiming to enhance treatment efficacy while mitigating undesirable side effects. One promising avenue utilizes cell membrane receptors like the folate receptor to guide drug transporters precisely to malignant cells. Based on the cellular folate receptor as a cancer cell hallmark, targeted nanocarriers and small molecule-drug conjugates have been developed that comprise different (bio) chemistries and/or mechanical properties with individual advantages and challenges. Such modern folic acid-conjugated stimuli-responsive drug transporters provide systemic drug delivery and controlled release, enabling reduced dosages, circumvention of drug resistance, and diminished adverse effects. Since the drug transporters' structure-based de novo design is increasingly relevant for precision cancer remediation and diagnosis, this review seeks to collect and debate the recent approaches to deliver therapeutics or diagnostics based on folic acid conjugated Trojan Horses and to facilitate the understanding of the relevant chemistry and biochemical pathways. Focusing exemplarily on brain and breast cancer, recent advances spanning 2017 to 2023 in conjugated nanocarriers and small molecule drug conjugates were considered, evaluating the chemical and biological aspects in order to improve accessibility to the field and to bridge chemical and biomedical points of view ultimately guiding future research in FR-targeted cancer therapy and diagnosis.

Magnetic Nanoparticles: A Review on Synthesis, Characterization, Functionalization, and Biomedical Applications

Nowadays, magnetic nanoparticles (MNPs) are applied in numerous fields, especially in biomedical applications. Since biofluidic samples and biological tissues are nonmagnetic, negligible background signals can interfere with the magnetic signals from MNPs in magnetic biosensing and imaging applications. In addition, the MNPs can be remotely controlled by magnetic fields, which make it possible for magnetic separation and targeted drug delivery. Furthermore, due to the unique dynamic magnetizations of MNPs when subjected to alternating magnetic fields, MNPs are also proposed as a key tool in cancer treatment, an example is magnetic hyperthermia therapy. Due to their distinct surface chemistry, good biocompatibility, and inducible magnetic moments, the material and morphological structure design of MNPs has attracted enormous interest from a variety of scientific domains. Herein, a thorough review of the chemical synthesis strategies of MNPs, the methodologies to modify the MNPs surface for better biocompatibility, the physicochemical characterization techniques for MNPs, as well as some representative applications of MNPs in disease diagnosis and treatment are provided. Further portions of the review go into the diagnostic and therapeutic uses of composite MNPs with core/shell structures as well as a deeper analysis of MNP properties to learn about potential biomedical applications.

A novel Nb2C MXene based aptasensor for rapid and sensitive multi-mode detection of AFB1

Rapid and accurate on-site detection of aflatoxin B1 (AFB1) is of great significance for ensuring food safety. This work developed a dual mode aptasensor and a dual channel artificial neural network (ANN) intelligent sensor detection platform for simple and convenient quantitative detection of AFB1 in food. This sensor was prepared by encoding manganese ion (Mn2+) mediated surface concave niobium carbide MXene nanomaterials (Nb2C-MNs) using fluorescent group labeled aptamers (ssDNA-FAM). Mn2+-mediated Nb2C-MNs exhibited better peroxidase-like and fluorescence quenching properties. Moreover, ssDNA-FAM as a fluorescent probe for the sensor also significantly enhanced the enzyme activity of Nb2C-MNs. When AFB1 existed, ssDNA-FAM preferentially bonded to AFB1, resulting in fluorescence signal recovery and colorimetric signal weakening. Consequently, the multimodal biosensor could achieve fluorescence/colorimetric detection without the need for material and reagent replacement. In on-site detection, both ratio fluorescence and colorimetric signals could be collected using smartphones and analyzed and modeled on the developed ANN platform, achieving visual intelligent sensing. This multimodal biosensor had a detection line as low as 0.0950 ng/mL under optimal conditions, and also had the advantages of simple operation, fast and sensitive, and high specificity, which can meet the real-time on-site detection needs of AFB1 in remote areas.

A molecularly imprinted sensor for single-molecule detection of pesticide metabolite at the amol/L level sensitized by water-soluble luminol derivative encapsulated liposome via click reaction

A novel luminol derivative, 4-[(1,4-dioxo-1,2,3,4-tetrahydrophthalazin-5-yl)amino]-4-oxobut-2-enoic acid (ALD) with electrochemiluminescence intensity and stability characteristics similar to luminol, but higher solubility in near neutral solution, was designed and synthesized in this study. Using this derivative, a molecular imprinted electrochemiluminescence sensor (MIECLS) was prepared for the sensitive and selective determination of 2-amino-5-mercapto-1,3,4-thiadiazole (AMT), a metabolite of bismerthiazol, thiediazole copper, thiazole zinc, and other pesticides. The ALD probes encapsulated in liposomes are immobilized on the molecularly imprinted film by light-triggered click reaction, and the concurrent release of multiple probes allows for highly sensitive detection. In the AMT concentration range of 1.00 × 10-18 - 5.00 × 10-13 mol/L, the relation between ECL response and log AMT concentration is linear. With a detection limit of 5.25 × 10-19 mol/L (about 4 - 6 molecules in 10 μL of the sample), the sensor allows for high sensitivity analysis of ultra-trace amounts of small organic compounds. In general, the ECL-based single-molecule detection technique proposed herein might be a promising alternative to fluorescence single-molecule detection.

Nano-scale drug delivery systems for luteolin: advancements and applications

Luteolin (Lu) is a naturally occurring flavonoid compound with a diverse array of pharmacological activities, including anti-tumor, anti-inflammatory, antibacterial, and neuroprotective properties. However, the therapeutic efficacy and clinical application of Lu are significantly hindered by inherent limitations, such as poor water solubility, short half-life, low bioavailability, and potential off-target toxicity. Recent studies have demonstrated that the utilization of nanocarriers presents a promising strategy to enhance the solubility of Lu, prolong its circulation time, and improve its targeting ability. Despite numerous reviews over the past few decades having focused on the source, pharmacological activities, and molecular mechanisms of Lu, there exists a conspicuous gap in the literature regarding a comprehensive review of Lu-loaded nanoformulations and their applications. To address this gap, we present an exhaustive overview of the advancements and applications of nano-scale drug delivery systems specifically designed for Lu. These platforms encompass micelles, nanocarrier-based systems, emulsified drug delivery systems, and vesicular drug delivery systems. We provide detailed insights into the synthetic materials, preparation methods, physicochemical properties, and significant outcomes associated with these nanoformulations. This systematic review will be particularly valuable to researchers seeking novel avenues in the field of nano-delivery strategies and exploring the potential clinical applications of Lu.

Cyclodextrin based nanoparticles for smart drug delivery in colorectal cancer

The advancement of colorectal cancer (CRC) prevention, detection, and treatment is essential to ensure that survivors live longer and higher-quality lives. The field of cancer detection and therapy has undergone a revolution with the development of nanotechnology for targeted drug delivery. The significant problems with the delivery of cancer drugs are their solubility, stability, and nonspecific distribution. There is a challenge that the acidic and enzymatic environment in the digestive tract will modify or destroy the medication or the active pharmaceutical ingredient. To overcome the problems, nanoparticles have been widely employed during the past several years to increase the specificity, selectivity, and controlled release of drug delivery systems. The site-specific and targeted delivery leads to reduce toxicity and side effects. With respect to the capability and utilization of cyclodextrin-based nanoparticles in different aspects of the tumour microenvironment and gut microbiota, a survey of current research papers was conducted via looking through databases including GoogleScholar, PubMed, Web of Science, and Scopus. This review aims to summarize cutting-edge nanoparticulate-based technologies and therapies for CRC.

High-density Au nanoshells assembled onto Fe3O4 nanoclusters for integrated enrichment and photothermal/colorimetric dual-mode detection of SARS-CoV-2 nucleocapsid protein

Traditional lateral flow immunoassays (LFIA) suffer from insufficient sensitivity, difficulty for quantitation, and susceptibility to complex substrates, limiting their practical application. Herein, we developed a polyethylenimine (PEI)-mediated approach for assembling high-density Au nanoshells onto Fe3O4 nanoclusters (MagAushell) as LFIA labels for integrated enrichment and photothermal/colorimetric dual-mode detection of SARS-CoV-2 nucleocapsid protein (N protein). PEI layer served not only as "binders" to Fe3O4 nanoclusters and Au nanoshells, but also "barriers" to ambient environment. Thus, MagAushell not only combined magnetic and photothermal properties, but also showed good stability. With MagAushell, N protein was first separated and enriched from complex samples, and then loaded to the strip for detection. By observation of the color stripes, qualitative detection was performed with naked eye, and by measuring the temperature change under laser irradiation, quantification was attained free of sophisticated instruments. The introduction of Fe3O4 nanoclusters facilitated target purification and enrichment before LFIA, which greatly improved the anti-interference ability and increased the detection sensitivity by 2 orders compared with those without enrichment. Moreover, the high loading density of Au nanoshells on one Fe3O4 nanocluster enhanced the photothermal signal of the nanoprobe significantly, which could further increase the detection sensitivity. The photothermal detection limit reached 43.64 pg/mL which was 1000 times lower than colloidal gold strips. Moreover, this method was successfully applied to real samples, showing great application potential in practice. We envision that this LFIA could serve not only for SARS-CoV-2 detection but also as a general test platform for other biotargets in clinical samples.

3,4-Dihydroxiphenylacetic Acid-Based Universal Coating Technique for Magnetic Nanoparticles Stabilization for Biomedical Applications

Magnetic nanoparticles based on iron oxide attract researchers' attention due to a wide range of possible applications in biomedicine. As synthesized, most of the magnetic nanoparticles do not form the stable colloidal solutions that are required for the evaluation of their interactions with cells or their efficacy on animal models. For further application in biomedicine, magnetic nanoparticles must be further modified with biocompatible coating. Both the size and shape of magnetic nanoparticles and the chemical composition of the coating have an effect on magnetic nanoparticles' interactions with living objects. Thus, a universal method for magnetic nanoparticles' stabilization in water solutions is needed, regardless of how magnetic nanoparticles were initially synthesized. In this paper, we propose the versatile and highly reproducible ligand exchange technique of coating with 3,4-dihydroxiphenylacetic acid (DOPAC), based on the formation of Fe-O bonds with hydroxyl groups of DOPAC leading to the hydrophilization of the magnetic nanoparticles' surfaces following phase transfer from organic solutions to water. The proposed technique allows for obtaining stable water-colloidal solutions of magnetic nanoparticles with sizes from 21 to 307 nm synthesized by thermal decomposition or coprecipitation techniques. Those stabilized by DOPAC nanoparticles were shown to be efficient in the magnetomechanical actuation of DNA duplexes, drug delivery of doxorubicin to cancer cells, and targeted delivery by conjugation with antibodies. Moreover, the diversity of possible biomedical applications of the resulting nanoparticles was presented. This finding is important in terms of nanoparticle design for various biomedical applications and will reduce nanomedicines manufacturing time, along with difficulties related to comparative studies of magnetic nanoparticles with different magnetic core characteristics.

Therapeutic Copolymer from Salicylic Acid and l-Phenylalanine as a Nanosized Drug Carrier for Orthotopic Breast Cancer with Lung Metastasis

Nanoparticle (NP)-mediated drug delivery systems are promising for treating various diseases. However, clinical translation has been delayed by a variety of limitations, such as weak drug loading, nonspecific drug leakage, lack of bioactivity, and short blood circulation. These issues are in part due to the unsatisfactory function of biomaterials for nanocarriers. In addition, the synthesis procedures of drug carrier materials, especially polymers, were usually complicated and led to high cost. In this report, a bioactive copolymer of hydroxy acid and amino acid, poly(salicylic acid-co-phenylalanine) (PSP), was developed for the first time via a one-step rapid and facile synthesis strategy. The PSP could self-assemble into NPs (PSP-NPs) to co-load relatively hydrophilic sphingosine kinase 1 inhibitor (PF543 in HCl salt format) and highly hydrophobic paclitaxel (PTX) to form PF543/PTX@PSP-NPs with efficient dual drug loading. Encouragingly, PF543/PTX@PSP-NPs showed long blood circulation, good stability, and high tumor accumulation, leading to significantly enhanced therapeutic effects on breast cancer. Furthermore, PF543/PTX@PSP-NPs could additionally suppress the lung metastasis of breast cancer, and more importantly, the PSP-NPs themselves as therapeutic nanocarriers also showed an anti-breast cancer effect. With these combined advantages, this new polymer and corresponding NPs will provide valuable insights into the development of new functional polymers and nanomedicines for important diseases.

SMART RHESINs-Superparamagnetic Magnetite Architecture Made of Phenolic Resin Hollow Spheres Coated with Eu(III) Containing Silica Nanoparticles for Future Quantitative Magnetic Particle Imaging Applications

Magnetic particle imaging (MPI) is a powerful and rapidly growing tomographic imaging technique that allows for the non-invasive visualization of superparamagnetic nanoparticles (NPs) in living matter. Despite its potential for a wide range of applications, the intrinsic quantitative nature of MPI has not been fully exploited in biological environments. In this study, a novel NP architecture that overcomes this limitation by maintaining a virtually unchanged effective relaxation (Brownian plus Néel) even when immobilized is presented. This superparamagnetic magnetite architecture made of phenolic resin hollow spheres coated with Eu(III) containing silica nanoparticles (SMART RHESINs) was synthesized and studied. Magnetic particle spectroscopy (MPS) measurements confirm their suitability for potential MPI applications. Photobleaching studies show an unexpected photodynamic due to the fluorescence emission peak of the europium ion in combination with the phenol formaldehyde resin (PFR). Cell metabolic activity and proliferation behavior are not affected. Colocalization experiments reveal the distinct accumulation of SMART RHESINs near the Golgi apparatus. Overall, SMART RHESINs show superparamagnetic behavior and special luminescent properties without acute cytotoxicity, making them suitable for bimodal imaging probes for medical use like cancer diagnosis and treatment. SMART RHESINs have the potential to enable quantitative MPS and MPI measurements both in mobile and immobilized environments.

A review: hemocompatibility of magnetic nanoparticles and their regenerative medicine, cancer therapy, drug delivery, and bioimaging applications

Nanoparticles have demonstrated noteworthy advancements in the management of various complex medical conditions, particularly cancer. In any case, these particles still harbor the potential to improve medicate conveyance to challenging, hard-to-reach loci. The interactions that occur between nanoparticles and red blood cells during their journey throughout the human body, despite exposure to blood, are still not fully understood. Assessment of the ability of nanoparticles to integrate with blood, characterized as nanoparticle compatibility, has been consistently overlooked and undervalued in its import. This review article investigates the effect of nanoparticles on red blood cells, while examining the compatibility of nanoparticles through the angle of hemolysis. This article discusses the main roles of erythrocytes and also provides an informed interpretation of several mechanisms involved in the interaction of nanoparticles and erythrocytes. Throughout the review, significant emphasis is attributed to the investigation of hemocompatibility studies concerning newly designed nanoparticles to promote their successful translation into clinical application. This review article examines the compatibility of magnetic nanoparticles in various fields, including regenerative medicine, cancer therapy, bioimaging, and drug delivery. Our results show that the chemical composition of the nanoparticle surface is a determining factor in hemocompatibility performance and interaction with blood cells. The surface properties of nanoparticles, namely surface charge, geometry, porosity, and surface functionalities of polymers or specific functional groups, represent key determinants of hemocompatibility.

Recent Advances in the Development of Drug Delivery Applications of Magnetic Nanomaterials

With the predicted rise in the incidence of cancer, there is an ever-growing need for new cancer treatment strategies. Recently, magnetic nanoparticles have stood out as promising nanostructures for imaging and drug delivery systems as they possess unique properties. Moreover, magnetic nanomaterials functionalized with other compounds can lead to multicomponent nanoparticles with innovative structures and synergetic performance. The incorporation of chemotherapeutic drugs or RNA in magnetic drug delivery systems represents a promising alternative that can increase efficiency and reduce the side effects of anticancer therapy. This review presents a critical overview of the recent literature concerning the advancements in the field of magnetic nanoparticles used in drug delivery, with a focus on their classification, characteristics, synthesis and functionalization methods, limitations, and examples of magnetic drug delivery systems incorporating chemotherapeutics or RNA.

k-Carrageenan based magnetic@polyelectrolyte complex composite hydrogel for pH and temperature-responsive curcumin delivery

The dual stimuli-responsive drug delivery system has attracted a lot of interest in controlled drug delivery to specific sites. The magnetic iron oxide nanoparticles integrated polyelectrolyte complex-based hydrogel (MPEC HG) system was developed in this work. First, magnetic nanoparticles were produced in situ in the synthetic polymer polyhexamethylene guanidine (PHMG). Furthermore, the natural biopolymer k-carrageenan (kCG) was employed to form the polyelectrolyte complex (PEC) through charge-balancing interaction between positively charged guanidine units and negatively charged sulfonate groups. Various characterization approaches were used to characterize the developed magnetic polyelectrolyte complex hydrogel (MPEC HG) system. Curcumin (Cur) was employed as a model bioactive agent to examine the drug loading and stimuli-responsive drug release efficiency of the MPEC HG system. Under the combined pH and temperature stimuli conditions (pH 5.0/42 °C), the developed hydrogel system demonstrated great drug loading efficiency (~ 68 %) and enhanced drug release. Furthermore, the MPEC HG system's in vitro cytotoxicity behavior was investigated on a human liver cancer (HepG2) cell line, and the results revealed that the MPEC HG system is biocompatible. As a result, the MPEC HG system might be used for dual pH and temperature stimuli-responsive drug delivery applications in cancer therapy.

Highly efficient carbon supported Co-Ir nanozyme for the determination of total antioxidant capacity in foods

Nanozyme-based colorimetric assays have aroused extensive attention in biosensing due to quick response, low cost and simplicity. However, their practical applications are limited by the unsatisfactory stability and catalytic activity of nanozymes in complex detection environments. Herein, using the one-pot chemical vapor deposition method, we successfully prepare a highly efficient and stable carbon supported Co-Ir nanozyme (termed as Co-Ir/C nanozyme) for the determination of total antioxidant capacity (TAC) in food samples. The Co-Ir/C nanozyme shows excellent durability under extensive pH ranges, high temperature and high salt concentration due to the protection of carbon supporter. It can be recycled by simple magnetic separation, and its catalytic activity remains stable after long-term operation and storage. Taking full advantage of the superior peroxidase-like activity of Co-Ir/C nanozyme, it is used for colorimetric detection of ascorbic acid (or known as vitamin C), an important vitamin to adjust body's normal physiological function, with results showing higher sensitivity (detection limit of 0.27 μM) than most of the recently published works. Moreover, the determination of TAC in vitamin C tablets and fruits are further achieved, which are in good agreement with those of commercial colorimetric test kits. This study helps guide the rational preparation of versatile and highly stable nanozymes, and develops a robust TAC determination platform for future food quality monitoring.

Imaging intracellular metabolite and protein changes in live mammalian cells with bright fluorescent RNA-based genetically encoded sensors

Fluorescent RNA (FR)-based genetically encoded sensors have been engineered to detect various essential metabolites in living systems. However, the unfavorable characteristics of FR impede sensor applications. Here, we describe a strategy for converting Pepper fluorescent RNA into a series of fluorescent sensors to detect their cognate targets both in vitro and in live cells. Compared to previously developed FR-based sensors, Pepper-based sensors exhibited expanded emission of up to 620 nm and markedly improved cellular brightness, allowing robust and real-time monitoring of the pharmacologic-triggered dynamics changes in the intracellular level of S-adenosylmethionine (SAM) and the optogenetic manipulated protein translocation in live mammalian cells. Furthermore, signal amplification in fluorescence imaging of the target was achieved using the CRISPR-display strategy by incorporating a Pepper-based sensor into the sgRNA scaffold. Together, these results demonstrate that Pepper can be readily developed into high-performance FR-based sensors to detect various cellular targets.

High Biocompatibility, MRI Enhancement, and Dual Chemo- and Thermal-Therapy of Curcumin-Encapsulated Alginate/Fe3O4 Nanoparticles

(1) Background: Magnetite (Fe₃O₄) nanoparticles have great potential for biomedical applications, including hyperthermia and magnetic resonance imaging. In this study, we aimed to identify the biological activity of nanoconjugates composed of superparamagnetic Fe₃O₄ nanoparticles coated with alginate and curcumin (Fe₃O₄/Cur@ALG) in cancer cells. (2) Methods: The nanoparticles were evaluated for the biocompatibility and toxicity on mice. The MRI enhancement and hyperthermia capacities of Fe₃O₄/Cur@ALG were determined in both in vitro and in vivo sarcoma models. (3) Results: The results show that the magnetite nanoparticles exhibit high biocompatibility and low toxicity in mice at Fe₃O₄ concentrations up to 120 mg/kg when administered via intravenous injection. The Fe₃O₄/Cur@ALG nanoparticles enhance the magnetic resonance imaging contrast in cell cultures and tumor-bearing Swiss mice. The autofluorescence of curcumin also allowed us to observe the penetration of the nanoparticles into sarcoma 180 cells. In particular, the nanoconjugates synergistically inhibit the growth of sarcoma 180 tumors via magnetic heating and the anticancer effects of curcumin, both in vitro and in vivo. (4) Conclusions: Our study reveals that Fe₃O₄/Cur@ALG has a high potential for medicinal applications and should be further developed for cancer diagnosis and treatment.

Hollow SnO2/CdS QDs/CdCO3 heterostructured nanocubes coupled with hollow PtPd/MnCo-CeO2 nanozyme-mediated synergistic amplification for ultrasensitive PEC immunoanalysis of lung cancer biomarker

Nowadays, lung cancer is one of the most dangerous cancers threatening human life all over the world. As a crucial biomarker, cytokeratin 19 fragment 21-1 (CYFRA 21-1) is extraordinary important for diagnosis of non-small cell lung cancer (NSCLC). In this work, we synthesized hollow SnO₂/CdS QDs/CdCO₃ heterostructured nanocubes with high and stable photocurrents, which applied to construction of a sandwich-typed photoelectrochemical (PEC) immunosensor for detection of CYFRA 21-1, integrated by in-situ catalytic precipitation strategy with home-built PtPd alloy anchored MnCo-CeO₂ (PtPd/MnCo-CeO₂) nanozyme for synergistic amplification. The interfacial electron transfer mechanism upon visible-light irradiation was investigated in details. Further, the PEC responses were seriously quenched by the specific immunoreaction and precipitation catalyzed by the PtPd/MnCo-CeO₂ nanozyme. The established biosensor showed a wider linear range of 0.001-200 ng mL^-1 and a lower limit of detection (LOD = 0.2 pg mL^-1, S/N = 3), coupled by exploring such analysis even in diluted human serum sample. This work opens a constructive avenue to develop ultrasensitive PEC sensing platforms for detecting diverse cancer biomarkers in clinic.

Biomedical applications of biodegradable polycaprolactone-functionalized magnetic iron oxides nanoparticles and their polymer nanocomposites

Magnetic nanoparticles (MNPs) have gained significant attention among several nanoscale materials during the last decade due to their unique properties. These properties make them successful nanofillers for drug delivery and a number of new biomedical applications. MNPs are more useful when combined with biodegradable polymers. In this review, we discussed the synthesis of polycaprolactones (PCL) and the various methods of synthesizing magnetic iron oxide nanoparticles. Then, the synthesis of composites that is made of PCL and magnetic materials (with special focus on iron oxide nanoparticles) were highlighted. In addition, we comprehensively reviewed their application in drug delivery, cancer treatment, wound healing, hyperthermia, and bone tissue engineering. Other biomedical applications of the magnetic PCL such as mitochondria targeting are highlighted. Moreover, biomedical applications of magnetic nanoparticles incorporated into other synthetic polymers apart from PCL are also discussed. Thus, great progress and better outcome with functionalized MNPs enhanced with polycaprolactone has been recorded with the biomedical applications of drug delivery and recovery of bone tissues.

Ultra-sensitive and specific detection of pathogenic nucleic acids using composite-excited hyperfine plasma spectroscopy combs sensitized by Au nanoarrays functionalized with 2D Ta2C-MXene

Accurate and rapid screening techniques on a population scale are crucial for preventing and managing epidemics like COVID-19. The standard gold test for nucleic acids in pathogenic infections is primarily the reverse transcription polymerase chain reaction (RT-PCR). However, this method is not suitable for widespread screening due to its reliance on large-scale equipment and time-consuming extraction and amplification processes. Here, we developed a collaborative system that combines high-load hybridization probes targeting N and OFR1a with Au NPs@Ta₂C-M modified gold-coated tilted fiber Bragg grating (TFBG) sensors to enable direct nucleic acid detection. Multiple activation sites of SARS-CoV-2 were saturable modified on the surface of a homogeneous arrayed AuNPs@Ta₂C-M/Au structure based on a segmental modification approach. The combination of hybrid probe synergy and composite polarisation response in the excitation structure results in highly specific hybridization analysis and excellent signal transduction of trace target sequences. The system demonstrates excellent trace specificity, with a limit of detection of 0.2 pg/mL, and achieves a rapid response time of 1.5 min for clinical samples without amplification. The results showed high agreement with the RT-PCR test (Kappa index = 1). And the gradient-based detection of 10-in-1 mixed samples exhibits high-intensity interference immunity and excellent trace identification. Therefore, the proposed synergistic detection platform has a good tendency to curb the global spread of epidemics such as COVID-19.

Immunocapturing rare cells from blood: A simple and robust microsystem approach

Cell immunocapture microsystems are a fast-emerging field with several potential medical diagnostic applications. Isolation and quantification of circulating rare cells (CRCs) show great importance in the early stages of disease diagnostics and prognostics. Here, we present a simple and robust stop-flow microsystem (fabricated by a combination of glass microblasting and 3D printing) based on a planar antibody-coated surface that is effective in the immunocapture of the model as well as naturally occurring rare cells. A chip with a planar immunocapture channel working in the so-called stop-flow dynamic regime was designed to enable monitoring the efficiency of the cell capture by fluorescence microscopy. Up to 90% immunocapture efficiency of MCF-7 cells spiked into whole blood on CD326 antibody-coated planar surfaces was achieved. We discuss the role of the planar surface modifications, the influence of the set stop-flow dynamic conditions, and medium complexity on the efficiency of cell immunocapture. The presented results could be further employed in the design of microsystems for cell-size-independent isolation and identification of rare cells from blood.

The SpACE-CCM: A facile and versatile cell culture medium-based biosensor for detection of SARS-CoV-2 spike-ACE2 interaction

The COVID-19 pandemic is an ongoing global public health threat. COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and binding of the SARS-CoV-2 spike to its receptor, angiotensin-converting enzyme 2 (ACE2), on host cells is critical for viral infection. Here, we developed a luminescent biosensor that readily detects interactions of the spike receptor-binding domain (RBD) and ACE2 in cell culture medium ('SpACE-CCM'), which was based on bimolecular complementation of the split nanoluciferase-fused spike RBD and ectodomain of ACE2 and further engineered to be efficiently secreted from cells by adding a heterologous secretory signal peptide (SSP). Screening of various SSPs identified 'interferon-α+alanine-aspartate' as the SSP that induced the highest activity. The SpACE-CCM biosensor was validated by observing a marked reduction of the activity caused by interaction-defective mutations or in the presence of neutralizing antibodies, recombinant decoy proteins, or peptides. Importantly, the SpACE-CCM biosensor responded well in assay-validating conditions compared with conventional cell lysate-based NanoLuc Binary Technology, indicating its advantage. We further demonstrated the biosensor's versatility by quantitatively detecting neutralizing activity in blood samples from COVID-19 patients and vaccinated individuals, discovering a small molecule interfering with the spike RBD-ACE2 interaction through high-throughput screening, and assessing the cross-reactivity of neutralizing antibodies against SARS-CoV-2 variants. Because the SpACE-CCM is a facile and rapid one-step reaction biosensor that aptly recapitulates the native spike-ACE2 interaction, it would be advantageous in many experimental and clinical applications associated with this interaction.

Magnetic nanoparticle-based hyperthermia: A prospect in cancer stem cell tracking and therapy

Tumor heterogeneity is a major problem in cancer treatment. Cancer stem cells (CSCs) are a subpopulation of tumor masses that produce proliferating and quiescent cells. Under stress-related conditions, quiescent cells are capable of repopulating tumor masses. Consequently, many attempts have been made to identify, isolate, and eradicate CSCs from various tumors. Research has found that quiescent CSCs are less susceptible to conventional therapy than bulk cancer cells. This could be due to reduced cell cycling and increased DNA repair capacity of these cells. Indeed, disease progression is temporarily suppressed by eliminating fast-proliferating tumor cells and sparing quiescent CSCs lead to cancer relapse. Among all the available therapeutic modalities for cancer treatment, hyperthermia uses moderate heat to kill tumor cells. Nanoparticle-based platforms have the potential to deposit heat locally and selectively with the simultaneous activation of nanoparticles as heat transducers. Over the past few decades, magnetic nanoparticles (MNPs) have been widely investigated in the biomedical field. Magnetic hyperthermia therapy (MHT) is a promising therapeutic approach in which MNPs are delivered directly through targeting (systemic) or by direct injection into a tumor under exposure to an alternating magnetic field (AMF). Heat is generated by the MNPs subjected to AMF at a frequency of 100 kHz. Despite the widespread use of MHT alone or in combination therapies, its effectiveness in targeting CSCs remains unclear. This review discusses various types of MHT and their related mechanisms in cancer therapy, particularly concerning the eradication of CSCs.

Virus-like particle-based nanocarriers as an emerging platform for drug delivery

New nanocarrier technologies are emerging, and they have great potential for improving drug delivery, targeting efficiency, and bioavailability. Virus-like particles (VLPs) are natural nanoparticles from animal and plant viruses and bacteriophages. Hence, VLPs present several great advantages, such as morphological uniformity, biocompatibility, reduced toxicity, and easy functionalisation. VLPs can deliver many active ingredients to the target tissue and have great potential as a nanocarrier to overcome the limitations associated with other nanoparticles. This review will focus primarily on the construction and applications of VLPs, particularly as a novel nanocarrier to deliver active ingredients. Herein, the main methods for the construction, purification, and characterisation of VLPs, as well as various VLP-based materials used in delivery systems are summarised. The biological distribution of VLPs in drug delivery, phagocyte-mediated clearance, and toxicity are also discussed.

MOF/COF heterostructure hybrid composite-based molecularly imprinted photoelectrochemical sensing platform for determination of dibutyl phthalate: A further expansion for MOF/COF application

A novel metal-organic framework (MOF)/covalent-organic framework (COF) heterostructure hybrid composite (NH₂-UiO-66/TpPa-1-COF) with excellent photoactivity was developed, which further acted as the photoelectrochemical sensitized layer of a molecularly imprinted photoelectrochemical (MIP-PEC) sensor for extremely sensitive and selective determination of dibutyl phthalate (DBP). The NH₂-UiO-66/TpPa-1-COF was synthesized using a simple one-step solvothermal method, which showed improved photocurrent response owing to heterojunction formation, favorable energy-band configuration and strong light absorption capacity. To improve the sensing performance, molecularly imprinted polymer (MIP) was developed by sol-gel polymerization method as the recognition component of PEC sensor. The specific binding of imprinting sites towards DBP could block the electron transfer, causing decreased photocurrent response of the MIP-PEC sensor. The MIP-PEC sensor showed a wide detection range from 0.1 nmol L^-1 to 100 μmol L^-1 with a limit of detection of 3.0 × 10^-11 mol L^-1 under optimal conditions. Meanwhile, the proposed MIP-PEC sensor showed good stability, selectivity, reproducibility, and applicability in real samples. This is the first attempt to apply MOF/COF heterostructure hybrid composite for MIP-PEC sensor construction, providing new insight into the potential applications of microporous crystalline framework heterostructure hybrid composite in the sensing field.

pH-Responsible Doxorubicin-Loaded Fe3O4@CaCO3 Nanocomposites for Cancer Treatment

A magnetic nanocomposite (MNC) is an integrated nanoplatform that combines a set of functions of two types of materials. A successful combination can give rise to a completely new material with unique physical, chemical, and biological properties. The magnetic core of MNC provides the possibility of magnetic resonance or magnetic particle imaging, magnetic field-influenced targeted delivery, hyperthermia, and other outstanding applications. Recently, MNC gained attention for external magnetic field-guided specific delivery to cancer tissue. Further, drug loading enhancement, construction stability, and biocompatibility improvement may lead to high progress in the area. Herein, the novel method for nanoscale Fe3O4@CaCO3 composites synthesis was proposed. For the procedure, oleic acid-modified Fe3O4 nanoparticles were coated with porous CaCO3 using an ion coprecipitation technique. PEG-2000, Tween 20, and DMEM cell media was successfully used as a stabilization agent and template for Fe3O4@CaCO3 synthesis. Transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) data were used for the Fe3O4@CaCO3 MNC’s characterization. To improve the nanocomposite properties, the concentration of the magnetic core was varied, yielding optimal size, polydispersity, and aggregation ability. The resulting Fe3O4@CaCO3 had a size of 135 nm with narrow size distributions, which is suitable for biomedical applications. The stability experiment in various pH, cell media, and fetal bovine serum was also evaluated. The material showed low cytotoxicity and high biocompatibility. An excellent anticancer drug doxorubicin (DOX) loading of up to 1900 µg/mg (DOX/MNC) was demonstrated. The Fe3O4@CaCO3/DOX displayed high stability at neutral pH and efficient acid-responsive drug release. The series of DOX-loaded Fe3O4@CaCO3 MNCs indicated effective inhibition of Hela and MCF-7 cell lines, and the IC 50 values were calculated. Moreover, 1.5 μg of the DOX-loaded Fe3O4@CaCO3 nanocomposite is sufficient to inhibit 50% of Hela cells, which shows a high prospect for cancer treatment. The stability experiments for DOX-loaded Fe3O4@CaCO3 in human serum albumin solution indicated the drug release due to the formation of a protein corona. The presented experiment showed the “pitfalls” of DOX-loaded nanocomposites and provided step-by-step guidance on efficient, smart, anticancer nanoconstruction fabrication. Thus, the Fe3O4@CaCO3 nanoplatform exhibits good performance in the cancer treatment area.

Harnessing enhanced CRISPR/Cas12a trans-cleavage activity with extended reporters and reductants for early diagnosis of Helicobacter pylori, the causative agent of peptic ulcers and stomach cancer

Developing rapid and non-invasive diagnostics for Helicobacter pylori (HP) is imperative to prevent associated diseases such as stomach gastritis, ulcers, and cancers. Owing to HP strain heterogeneity, not all HP-infected individuals incur side effects. Cytotoxin-associated gene A (CagA), and vacuolating cytotoxin A (VacA) genes predominantly drive HP pathogenicity. Therefore, diagnosing CagA and VacA genotypes could alert active infection and decide suitable therapeutics. We report an enhanced LbCas12a trans-cleavage activity with extended reporters and reductants (CEXTRAR) for early detection of HP. We demonstrate that extended ssDNA reporter acts as an excellent signal amplifier, making it a potential alternative substrate for LbCas12a collateral activity. Through a systematic investigation of various buffer components, we demonstrate that reductants improve LbCas12a trans-cleavage activity. Overall, our novel reporter and optimal buffer increased the trans-cleavage activity to an order of 16-fold, achieving picomolar sensitivity (171 pM) without target pre-amplification. Integrated with loop-mediated isothermal amplification (LAMP), CEXTRAR successfully attained attomolar sensitivity for HP detection using real-time fluorescence (43 and 96 aM), in-tube fluorescence readouts (430 and 960 aM), and lateral flow (4.3 and 9.6 aM) for CagA and VacA, respectively. We also demonstrate a rapid 2-min Triton X-100 lysis for clinical sample analysis, which could provide clinicians with actionable information for rapid diagnosis. CEXTRAR could potentially spot the ¹³C urea breath test false-negatives. For the first time, our study unveils an experimental outlook to manipulate reporters and reconsider precise cysteine substitution via protein engineering for Cas variants with enhanced catalytic activities for use in diagnostics and genetic engineering.

Magnetic nanoparticles: multifunctional tool for cancer therapy

INTRODUCTION

Cancer has one of the highest mortality rates globally. The traditional therapies used to treat cancer have harmful adverse effects. Considering these facts, researchers have explored new therapeutic possibilities with enhanced benefits. Nanoparticle development for cancer detection, in addition to therapy, has shown substantial progress over the past few years.

AREA COVERED

Herein, the latest research regarding cancer treatment employing magnetic nanoparticles (MNPs) in chemo-, immuno-, gene-, and radiotherapy along with hyperthermia is summarized, in addition to their physio-chemical features, advantages, and limitations for clinical translation have also been discussed.

EXPERT OPINION

MNPs are being extensively investigated and developed into effective modules for cancer therapy. They are highly functional tools aimed at cancer therapy owing to their excellent superparamagnetic, chemical, biocompatible, physical, and biodegradable properties.

Targeted delivery and anticancer effects of Chrysin-loaded chitosan-folic acid coated solid lipid nanoparticles in pancreatic malignant cells

The aim of this survey was to load Chrysin (CHY) on solid lipid nanoparticles (SLNs) and decorate the nanoparticles with folate-bound chitosan to increase the effectiveness of the treatment. CHY-SCF-NPs were synthesized by homogenizing and sonication methods and characterized. FA binding and encapsulation efficiency (HPLC), antioxidant capacity (ABTS and DPPH), cell viability assay (MTT), programmed cell death analysis (fluorescence staining, flow cytometry, and qPCR), and angiogenesis (CAM and molecular analysis) assay were done for assessment of therapeutic efficiency of CHY-SCF-NPs. Increases in size and change in surface charge of CHY-SLNs (PS: 84.3 nm and ZP: -18 mV) were reported after coating with folate-bound chitosan (PS: 125 nm and ZP: +34.9 mV). CHY-SCF-NPs inhibited PANC, MCF-7, A2780, and HepG2 as malignant cells and HFF as normal cells with IC₅₀∼53, 55, 249, and >250 µg/mL, respectively. Also, CHY-SCF-NPs scavenged ABTS (IC₅₀: 123.73 µg/mL), and DPPH (IC₅₀: 108.7 µg/mL) free radicals and suppressed angiogenesis in the CAM and qPCR assays. Up-regulation of Bax and caspase 9 genes as well as the fluorescence staining and cell cycle results confirmed the pro-apoptotic properties of CHY-SCF-NPs. CHY-SCF-NPs can be considered a promising anti-cancer candidate for preclinical and clinical studies of pancreatic cancer.

Different coatings on magnetic nanoparticles dictate their degradation kinetics in vivo for 15 months after intravenous administration in mice

BACKGROUND

The surface coating of iron oxide magnetic nanoparticle (MNPs) drives their intracellular trafficking and degradation in endolysosomes, as well as dictating other cellular outcomes. As such, we assessed whether MNP coatings might influence their biodistribution, their accumulation in certain organs and their turnover therein, processes that must be understood in vivo to optimize the design of nanoformulations for specific therapeutic/diagnostic needs.

RESULTS

In this study, three different MNP coatings were analyzed, each conferring the identical 12 nm iron oxide cores with different physicochemical characteristics: 3-aminopropyl-triethoxysilane (APS), dextran (DEX), and dimercaptosuccinic acid (DMSA). When the biodistribution of these MNPs was analyzed in C57BL/6 mice, they all mainly accumulated in the spleen and liver one week after administration. The coating influenced the proportion of the MNPs in each organ, with more APS-MNPs accumulating in the spleen and more DMSA-MNPs accumulating in the liver, remaining there until they were fully degraded. The changes in the physicochemical properties of the MNPs (core size and magnetic properties) was also assessed during their intracellular degradation when internalized by two murine macrophage cell lines. The decrease in the size of the MNPs iron core was influenced by their coating and the organ in which they accumulated. Finally, MNP degradation was analyzed in the liver and spleen of C57BL/6 mice from 7 days to 15 months after the last intravenous MNP administration.

CONCLUSIONS

The MNPs degraded at different rates depending on the organ and their coating, the former representing the feature that was fundamental in determining the time they persisted. In the liver, the rate of degradation was similar for all three coatings, and it was faster than in the spleen. This information regarding the influence of coatings on the in vivo degradation of MNPs will help to choose the best coating for each biomedical application depending on the specific clinical requirements.

A Detailed Review on Synthesis, Functionalization, Application, Challenges, and Current Status of Magnetic Nanoparticles in the Field of Drug Delivery and Gene Delivery System

For progression of health care system, it has always been a challenge to the researchers for formulation to a type of advanced drug delivery system which will have less toxicity, targeted delivery and will be highly biodegradable. Nano science or nanotechnology has been validated to be a successful method as of targeting the drug to its active site be due to its special physicochemical properties and size thereby reducing the dose of administration, increasing bioavailability, and also reducing toxicity. Magnetic nanoparticles recently in few decades have proved as an effective advanced drug delivery system for its elevated magnetic responsiveness, biocompatibility, elevated targeted drug delivery effectiveness, etc. The drug can be easily targeted to active site by application of external magnetic field. Among the various elements, nanoparticles prepared with magnetically active iron oxide or other iron-based spinel oxide nanoparticles are widely used due to its high electrical resistivity, mechanical hardness, chemical stability, etc. Owing to their easy execution towards drug delivery application, extensive research has been carried out in this area. This review paper has summarized all recent modifications of iron-based magnetically active nanoparticle based drug delivery system along with their synthesis, characterization, and applications.

Structural, optical, magnetic, and enhanced antibacterial properties of hydrothermally synthesized Sm-incorporating α-MoO3 2D-layered nanoplates

In this study, we have synthesized pristine and [0.5,1.5, and 2.5] M% samarium (Sm)-incorporating α-MoO₃ 2D-layered nanoplates utilizing a facile hydrothermal process, and investigated the physical properties along with antibacterial effectiveness. X-ray diffraction (XRD) patterns confirmed the single-phase, stable orthorhombic polycrystalline structure of the as-prepared samples. The crystallite size, lattice strain, and dislocation density were measured using both Debye-Scherrer (D-S) and Williamson-Hall (W-H) techniques. Both pristine and Sm-incorporating α-MoO₃ samples showed two-dimensional (2D) layered nanoplate-type surface morphology, revealed by field emission scanning electron microscopy (FE-SEM) images. Energy dispersive X-ray spectroscopy (EDS) confirmed the presence of Sm contents in the α-MoO₃ matrix. After Sm incorporation in α-MoO₃, the different functional groups as well as vibrational groups were observed by Fourier-transform infrared (FTIR) spectroscopy and Raman spectroscopy analyses, respectively. The optical band gaps were measured from UV-vis diffuse reflectance spectroscopy (DRS) by employing the Kubelka-Munk formula and interestingly it is found that the bandgap energy (E _g) gradually decreased from 2.96 to 2.83 eV with the increment of Sm content. When compared to pristine α-MoO₃, the Sm-incorporating samples experienced a steady improvement in room temperature ferromagnetic (RTFM) behavior as Sm content increased, as measured by hysteresis loops. The antibacterial activities of both samples were assessed against Gram-positive: Staphylococcus aureus (S. aureus), and Gram-negative: Escherichia coli (E. coli) and Salmonella enteritidis (S. enteritidis) bacteria by the agar well diffusion method and enhanced antibacterial activity was observed as the Sm concentration increased, compared to pristine nanoplates. The obtained results suggest that the synthesized Sm-incorporating α-MoO₃ 2D-layered nanoplate could be a potential antibacterial agent.

Hyperthermia of Magnetically Soft-Soft Core-Shell Ferrite Nanoparticles

Magnetically soft-soft MnFe₂O₄-Fe₃O₄ core-shell nanoparticles were synthesized through a seed-mediated method using the organometallic decomposition of metal acetyl acetonates. Two sets of core-shell nanoparticles (S1 and S2) of similar core sizes of 5.0 nm and different shell thicknesses (4.1 nm for S1 and 5.7 nm for S2) were obtained by changing the number of nucleating sites. Magnetic measurements were conducted on the nanoparticles at low and room temperatures to study the shell thickness and temperature dependence of the magnetic properties. Interestingly, both core-shell nanoparticles showed similar saturation magnetization, revealing the ineffective role of the shell thickness. In addition, the coercivity in both samples displayed similar temperature dependencies and magnitudes. Signatures of spin glass (SG) like behavior were observed from the field-cooled temperature-dependent magnetization measurements. It was suggested to be due to interface spin freezing. We observed a slight and non-monotonic temperature-dependent exchange bias in both samples with slightly higher values for S2. The effective magnetic anisotropy constant was calculated to be slightly larger in S2 than that in S1. The magnetothermal efficiency of the chitosan-coated nanoparticles was determined by measuring the specific absorption rate (SAR) under an alternating magnetic field (AMF) at 200-350 G field strengths and frequencies (495.25-167.30 kHz). The S2 nanoparticles displayed larger SAR values than the S1 nanoparticles at all field parameters. A maximum SAR value of 356.5 W/g was obtained for S2 at 495.25 kHz and 350 G for the 1 mg/mL nanoparticle concentration of ferrogel. We attributed this behavior to the larger interface SG regions in S2, which mediated the interaction between the core and shell and thus provided indirect exchange coupling between the core and shell phases. The SAR values of the core-shell nanoparticles roughly agreed with the predictions of the linear response theory. The concentration of the nanoparticles was found to affect heat conversion to a great extent. The in vitro treatment of the MDA-MB-231 human breast cancer cell line and HT-29 human colorectal cancer cell was conducted at selected frequencies and field strengths to evaluate the efficiency of the nanoparticles in killing cancer cells. The cellular cytotoxicity was estimated using flow cytometry and an MTT assay at 0 and 24 h after treatment with the AMF. The cells subjected to a 45 min treatment of the AMF (384.50 kHz and 350 G) showed a remarkable decrease in cell viability. The enhanced SAR values of the core-shell nanoparticles compared to the seeds with the most enhancement in S2 is an indication of the potential for tailoring nanoparticle structures and hence their magnetic properties for effective heat generation.

Study of Phase Transformations and Hyperfine Interactions in Fe3O4 and Fe3O4@Au Nanoparticles

The paper presents the results of a study of iron oxide nanoparticles obtained by chemical coprecipitation, coated (Fe₃O₄@Au) and not coated (Fe₃O₄) with gold, which were subjected to thermal annealing. To characterize the nanoparticles under study, scanning and transmission electron microscopy, X-ray diffraction, and Mössbauer spectroscopy on ⁵⁷Fe nuclei were used, the combination of which made it possible to establish a sequence of phase transformations, changes in morphological and structural characteristics, as well as parameters of hyperfine interactions. During the studies, it was found that thermal annealing of nanoparticles leads to phase transformation processes in the following sequence: nonstoichiometric magnetite (Fe_3-γO₄) → maghemite (γ-Fe₂O₃) → hematite (α-Fe₂O₃), followed by structural ordering and coarsening of nanoparticles. It is shown that nanoparticles of nonstoichiometric magnetite with and without gold coating are in the superparamagnetic state with a slow relaxation rate. The magnetic anisotropy energy of nonstoichiometric magnetite is determined as a function of the annealing temperature. An estimate was made of the average size of the region of magnetic ordering of Fe atoms in nonstoichiometric magnetite, which is in good agreement with the data on the average sizes of nanoparticles determined by scanning electron microscopy.

Magnetic nanomaterials for wireless thermal and mechanical neuromodulation

Magnetic fields are very attractive for non-invasive neuromodulation because they easily penetrate trough the skull and tissue. Cell specific neuromodulation requires the magnetic field energy to be converted by an actuator to a biologically relevant signal. Miniaturized actuators available today range from small, isotropic magnetic nanoparticles to larger, submicron anisotropic magnetic nanomaterials. Depending on the parameters of external magnetic fields and the properties of the nanoactuators, they create either a thermal or a mechanical stimulus. Ferromagnetic nanomaterials generate heat in response to high frequency alternating magnetic fields associated with dissipative losses. Anisotropic nanomaterials with large magnetic moments are capable of exerting forces at stationary or slowly varying magnetic fields. These tools allow exploiting thermosensitive or mechanosensitive neurons in circuit or cell specific tetherless neuromodulation schemes. This review will address assortment of available magnetic nanomaterial-based neuromodulation techniques that rely on application of external magnetic fields.

Iron Oxide-Au Magneto-Plasmonic Heterostructures: Advances in Their Eco-Friendly Synthesis

In recent years, nanotechnologies have attracted considerable interest, especially in the biomedical field. Among the most investigated particles, magnetic based on iron oxides and Au nanoparticles gained huge interest for their magnetic and plasmonic properties, respectively. These nanoparticles are usually produced starting from processes and reagents that can be the cause of potential human health and environmental concerns. For this reason, there is a need to develop simple, green, low-cost, and non-toxic synthesis methods and reagents. This review aims at providing an overview of the most recently developed processes to produce iron oxide magnetic nanoparticles, Au nanoparticles, and their magneto-plasmonic heterostructures using eco-friendly approaches, focusing the attention on the microorganisms and plant-assisted syntheses and showing the first results of the development of magneto-plasmonic heterostructures.

Biosensors and Drug Delivery in Oncotheranostics Using Inorganic Synthetic and Biogenic Magnetic Nanoparticles

Magnetic nanocarriers have attracted attention in translational oncology due to their ability to be employed both for tumor diagnostics and therapy. This review summarizes data on applications of synthetic and biogenic magnetic nanoparticles (MNPs) in oncological theranostics and related areas. The basics of both types of MNPs including synthesis approaches, structure, and physicochemical properties are discussed. The properties of synthetic MNPs and biogenic MNPs are compared with regard to their antitumor therapeutic efficiency, diagnostic potential, biocompatibility, and cellular toxicity. The comparative analysis demonstrates that both synthetic and biogenic MNPs could be efficiently used for cancer theranostics, including biosensorics and drug delivery. At the same time, reduced toxicity of biogenic particles was noted, which makes them advantageous for in vivo applications, such as drug delivery, or MRI imaging of tumors. Adaptability to surface modification based on natural biochemical processes is also noted, as well as good compatibility with tumor cells and proliferation in them. Advances in the bionanotechnology field should lead to the implementation of MNPs in clinical trials.