Size-isolation of superparamagnetic iron oxide nanoparticles improves MRI, MPI and hyperthermia performance

Improving MPI and hyperthermia performance of superparamagnetic iron oxide nanoparticles through fractional factorial design of experiments

Superparamagnetic iron oxide nanoparticles (SPIONs) are widely used for biomedical applications, including magnetic particle imaging (MPI) and magnetic hyperthermia. The co-precipitation method is one of the most common synthetic routes to obtain SPIONs, since it is simple and does not require extreme conditions, such as high temperatures. Despite its prevalence, however, the co-precipitation synthesis presents some challenges, most notably the high batch-to-batch variability, as multiple factors can influence nanoparticle growth. In this study, we utilized a fractional factorial design of experiments to identify key factors influencing SPION growth, properties, and performance in MPI and magnetic hyperthermia, namely Fe3+ content, pH, temperature, stirring, and atmosphere. Notably, our study unveiled secondary interactions, particularly between temperature and Fe3+ content, as well as pH and Fe3+ content, for which simultaneous changes of both parameters promoted greater effects than the sum of each factor effect alone, emphasizing the impact of synergistic effects on SPION growth and performance. These findings provide a deeper understanding of the growth mechanism of SPIONs, reconcile discrepancies in the existing literature, and underscore the importance of characterizing secondary interactions to improve the performance of SPIONs for biomedical applications.

The toxicity of superparamagnetic iron oxide nanoparticles induced on the testicular cells: In vitro study

Superparamagnetic iron oxide nanoparticles (SPIONs) have gained significant attention in biomedical research due to their potential applications. However, little is known about their impact and toxicity on testicular cells. To address this issue, we conducted an in vitro study using primary mouse testicular cells, testis fragments, and sperm to investigate the cytotoxic effects of sodium citrate-coated SPIONs (Cit_SPIONs). Herein, we synthesized and physiochemically characterized the Cit_SPIONs and observed that the sodium citrate diminished the size and improved the stability of nanoparticles in solution during the experimental time. The sodium citrate (measured by thermogravimetry) was biocompatible with testicular cells at the used concentration (3%). Despite these favorable physicochemical properties, the in vitro experiments demonstrated the cytotoxicity of Cit_SPIONs, particularly towards testicular somatic cells and sperm cells. Transmission electron microscopy analysis confirmed that Leydig cells preferentially internalized Cit_SPIONs in the organotypic culture system, which resulted in alterations in their cytoplasmic size. Additionally, we found that Cit_SPIONs exposure had detrimental effects on various parameters of sperm cells, including motility, viability, DNA integrity, mitochondrial activity, lipid peroxidation (LPO), and ROS production. Our findings suggest that testicular somatic cells and sperm cells are highly sensitive and vulnerable to Cit_SPIONs and induced oxidative stress. This study emphasizes the potential toxicity of SPIONs, indicating significant threats to the male reproductive system. Our findings highlight the need for detailed development of iron oxide nanoparticles to enhance reproductive nanosafety.

Impact of Particle Size on the Nonlinear Magnetic Response of Iron Oxide Nanoparticles during Frequency Mixing Magnetic Detection

Magnetic nanoparticles (MNPs), particularly iron oxide nanoparticles (IONPs), play a pivotal role in biomedical applications ranging from magnetic resonance imaging (MRI) enhancement and cancer hyperthermia treatments to biosensing. This study focuses on the synthesis, characterization, and application of IONPs with two different size distributions for frequency mixing magnetic detection (FMMD), a technique that leverages the nonlinear magnetization properties of MNPs for sensitive biosensing. IONPs are synthesized through thermal decomposition and subsequent growth steps. Our findings highlight the critical influence of IONP size on the FMMD signal, demonstrating that larger particles contribute dominantly to the FMMD signal. This research advances our understanding of IONP behavior, underscoring the importance of size in their application in advanced diagnostic tools.

Pharmaceutical Quality by Design Approach to Develop High-Performance Nanoparticles for Magnetic Hyperthermia

Magnetic hyperthermia holds significant therapeutic potential, yet its clinical adoption faces challenges. One obstacle is the large-scale synthesis of high-quality superparamagnetic iron oxide nanoparticles (SPIONs) required for inducing hyperthermia. Robust and scalable manufacturing would ensure control over the key quality attributes of SPIONs, and facilitate clinical translation and regulatory approval. Therefore, we implemented a risk-based pharmaceutical quality by design (QbD) approach for SPION production using flame spray pyrolysis (FSP), a scalable technique with excellent batch-to-batch consistency. A design of experiments method enabled precise size control during manufacturing. Subsequent modeling linked the SPION size (6-30 nm) and composition to intrinsic loss power (ILP), a measure of hyperthermia performance. FSP successfully fine-tuned the SPION composition with dopants (Zn, Mn, Mg), at various concentrations. Hyperthermia performance showed a strong nonlinear relationship with SPION size and composition. Moreover, the ILP demonstrated a stronger correlation to coercivity and remanence than to the saturation magnetization of SPIONs. The optimal operating space identified the midsized (15-18 nm) Mn0.25Fe2.75O4 as the most promising nanoparticle for hyperthermia. The production of these nanoparticles on a pilot scale showed the feasibility of large-scale manufacturing, and cytotoxicity investigations in multiple cell lines confirmed their biocompatibility. In vitro hyperthermia studies with Caco-2 cells revealed that Mn0.25Fe2.75O4 nanoparticles induced 80% greater cell death than undoped SPIONs. The systematic QbD approach developed here incorporates process robustness, scalability, and predictability, thus, supporting the clinical translation of high-performance SPIONs for magnetic hyperthermia.

The realization of medical devices for precision surgery - development and implementation of 'stop-and-go' imaging technologies

INTRODUCTION

Surgery and biomedical imaging encompass a big share of the medical-device market. The ever-mounting demand for precision surgery has driven the integration of these two into the field of image-guided surgery. A key-question herein is how imaging modalities can guide the surgical decision-making process. Through performance-based design, chemists, engineers, and doctors need to build a bridge between imaging technologies and surgical challenges.

AREAS-COVERED

This perspective article highlights the complementary nature between the technological design of an image-guidance modality and the type of procedure performed. The specific roles of the involved professionals, imaging technologies, and surgical indications are addressed.

EXPERT-OPINION

Molecular-image-guided surgery has the potential to advance pre-, intra- and post-operative tissue characterization. To achieve this, surgeons need the access to well-designed indication-specific chemical-agents and detection modalities. Hereby, some technologies stimulate exploration ('go'), while others stimulate caution ('stop'). However, failing to adequately address the indication-specific needs rises the risk of incorrect tool employment and sub-optimal surgical performance. Therefore, besides the availability of new technologies, market growth is highly dependent on the practical nature and impact on real-life clinical care. While urology currently takes the lead in the widespread implementation of image-guidance technologies, the topic is generic and its popularity spreads rapidly within surgical oncology.

Advanced Nano-Drug Delivery Systems in the Treatment of Ischemic Stroke

In recent years, the frequency of strokes has been on the rise year by year and has become the second leading cause of death around the world, which is characterized by a high mortality rate, high recurrence rate, and high disability rate. Ischemic strokes account for a large percentage of strokes. A reperfusion injury in ischemic strokes is a complex cascade of oxidative stress, neuroinflammation, immune infiltration, and mitochondrial damage. Conventional treatments are ineffective, and the presence of the blood-brain barrier (BBB) leads to inefficient drug delivery utilization, so researchers are turning their attention to nano-drug delivery systems. Functionalized nano-drug delivery systems have been widely studied and applied to the study of cerebral ischemic diseases due to their favorable biocompatibility, high efficiency, strong specificity, and specific targeting ability. In this paper, we briefly describe the pathological process of reperfusion injuries in strokes and focus on the therapeutic research progress of nano-drug delivery systems in ischemic strokes, aiming to provide certain references to understand the progress of research on nano-drug delivery systems (NDDSs).

Influence of SPION Surface Coating on Magnetic Properties and Theranostic Profile

This study aimed to develop multifunctional nanoplatforms for both cancer imaging and therapy using superparamagnetic iron oxide nanoparticles (SPIONs). Two distinct synthetic methods, reduction-precipitation (MR/P) and co-precipitation at controlled pH (MpH), were explored, including the assessment of the coating's influence, namely dextran and gold, on their magnetic properties. These SPIONs were further functionalized with gadolinium to act as dual T1/T2 contrast agents for magnetic resonance imaging (MRI). Parameters such as size, stability, morphology, and magnetic behavior were evaluated by a detailed characterization analysis. To assess their efficacy in imaging and therapy, relaxivity and hyperthermia experiments were performed, respectively. The results revealed that both synthetic methods lead to SPIONs with similar average size, 9 nm. Mössbauer spectroscopy indicated that samples obtained from MR/P consist of approximately 11-13% of Fe present in magnetite, while samples obtained from MpH have higher contents of 33-45%. Despite coating and functionalization, all samples exhibited superparamagnetic behavior at room temperature. Hyperthermia experiments showed increased SAR values with higher magnetic field intensity and frequency. Moreover, the relaxivity studies suggested potential dual T1/T2 contrast agent capabilities for the coated SPpH-Dx-Au-Gd sample, thus demonstrating its potential in cancer diagnosis.

Magnetic Particle Imaging: From Tracer Design to Biomedical Applications in Vasculature Abnormality

Magnetic particle imaging (MPI) is an emerging non-invasive tomographic technique based on the response of magnetic nanoparticles (MNPs) to oscillating drive fields at the center of a static magnetic gradient. In contrast to magnetic resonance imaging (MRI), which is driven by uniform magnetic fields and projects the anatomic information of the subjects, MPI directly tracks and quantifies MNPs in vivo without background signals. Moreover, it does not require radioactive tracers and has no limitations on imaging depth. This article first introduces the basic principles of MPI and important features of MNPs for imaging sensitivity, spatial resolution, and targeted biodistribution. The latest research aiming to optimize the performance of MPI tracers is reviewed based on their material composition, physical properties, and surface modifications. While the unique advantages of MPI have led to a series of promising biomedical applications, recent development of MPI in investigating vascular abnormalities in cardiovascular and cerebrovascular systems, and cancer are also discussed. Finally, recent progress and challenges in the clinical translation of MPI are discussed to provide possible directions for future research and development.

Comparative studies on the cytotoxic effects induced by iron oxide nanoparticles in cancerous and noncancerous human lung cells subjected to an alternating magnetic field

The cytotoxic effects of water-based ferrofluids composed of iron oxide nanoparticles, including magnetite (Fe3O4) and maghemite (γ-Fe2O3), ranging from 15 to 100 nm, were examined on various lung cancer cells including adenocarcinomic human alveolar basal epithelial cells (A549), nonsmall lung squamous cell carcinoma (H1703), small cell lung cancer cells (DMS 114), and normal bronchial epithelial cells (BEAS-2B). The cytotoxic effect was evaluated both with and without exposure to an alternating magnetic field (AMF). The studies revealed that neither AMF nor iron oxide nanoparticles when tested individually, produced cytotoxic effects on either cancerous or noncancerous cells. However, when applied together, they led to a significant decrease in cell viability and proliferative capacity due to the enhanced effects of magnetic fluid hyperthermia (MFH). The most pronounced effects were found for maghemite (<50 nm) when subjected to an AMF. Notably, A549 cells exhibited the highest resistance to the proposed hyperthermia treatment. BEAS-2B cells demonstrated susceptibility to magnetized iron oxide nanoparticles, similar to the response observed in lung cancer cells. The studies provide evidence that MFH is a promising strategy as a standalone treatment for different types of lung cancer cells. Nevertheless, to prevent any MFH-triggered adverse effects on normal lung cells, targeted magnetic ferrofluids should be designed.

Anti-dengue potential and mosquitocidal effect of marine green algae-stabilized Mn-doped superparamagnetic iron oxide nanoparticles (Mn-SPIONs): an eco-friendly approach

Vector-borne diseases pose a significant public health challenge in economically disadvantaged nations. Malaria, dengue fever, chikungunya, Zika, yellow fever, Japanese encephalitis, and lymphatic filariasis are spread by mosquitoes. Consequently, the most effective method of preventing these diseases is to eliminate the mosquito population. Historically, the majority of control programs have depended on chemical pesticides, including organochlorines, organophosphates, carbamates, and pyrethroids. Synthetic insecticides used to eradicate pests have the potential to contaminate groundwater, surface water, beneficial soil organisms, and non-target species. Nanotechnology is an innovative technology that has the potential to be used in insect control with great precision. The goal of this study was to test the in vitro anti-dengue potential and mosquitocidal activity of Chaetomorpha aerea and C. aerea-synthesized Mn-doped superparamagnetic iron oxide nanoparticles (CA-Mn-SPIONs). The synthesis of CA-Mn-SPIONs using C. aerea extract was verified by the observable alteration in the colour of the reaction mixture, transitioning from a pale green colour to a brown. The study of UV-Vis spectra revealed absorbance peaks at approximately 290 nm, which can be attributed to the surface Plasmon resonance of the CA-Mn-SPIONs. The SEM, TEM, EDX, FTIR, vibrating sample magnetometry, and XRD analyses provided evidence that confirmed the presence of CA-Mn-SPIONs. In the present study, results revealed that C. aerea aqueous extract LC50 values against Ae. aegypti ranged from 222.942 (first instar larvae) to 349.877 ppm in bioassays (pupae). CA-Mn-SPIONs had LC50 ranging from 20.199 (first instar larvae) to 26.918 ppm (pupae). After treatment with 40 ppm CA-Mn-SPIONs and 500 ppm C. aerea extract in ovicidal tests, egg hatchability was lowered by 100%. Oviposition deterrence experiments showed that in Ae. aegypti, oviposition rates were lowered by more than 66% by 100 ppm of green algal extract and by more than 71% by 10 ppm of CA-Mn-SPIONs (oviposition activity index values were 0.50 and 0.55, respectively). Moreover, in vitro anti-dengue activity of CA-Mn-SPIONs has good anti-viral property against dengue viral cell lines. In addition, GC-MS analysis showed that 21 intriguing chemicals were discovered. Two significant phytoconstituents in the methanol extract of C. aerea include butanoic acid and palmitic acid. These two substances were examined using an in silico methodology against the NS5 methyltransferase protein and demonstrated good glide scores and binding affinities. Finally, we looked into the morphological damage and fluorescent emission of third instar Ae. aegypti larvae treated with CA-Mn-SPIONs. Fluorescent emission is consistent with ROS formation of CA-Mn-SPIONs against Ae. aegypti larvae. The present study determines that the key variables for the successful development of new insecticidal agents are rooted in the eco-compatibility and the provision of alternative tool for the pesticide manufacturing sector.

HER2 aptamer-conjugated iron oxide nanoparticles with PDMAEMA-b-PMPC coating for breast cancer cell identification

Aim: To synthesize HER2 aptamer-conjugated iron oxide nanoparticles with a coating of poly(2-(dimethylamino) ethyl methacrylate)-poly(2-methacryloyloxyethylphosphorylcholine) block copolymer (IONPPPs). Methods: Characterization covered molecular structure, chemical composition, thermal stability, magnetic characteristics, aptamer interaction, crystalline nature and microscopic features. Subsequent investigations focused on IONPPPs for in vitro cancer cell identification. Results: Results demonstrated high biocompatibility of the diblock copolymer with no significant toxicity up to 150 μg/ml. The facile coating process yielded the IONPP complex, featuring a 13.27 nm metal core and a 3.10 nm polymer coating. Functionalized with a HER2-targeting DNA aptamer, IONPPP enhanced recognition in HER2-amplified SKBR3 cells via magnetization separation. Conclusion: These findings underscore IONPPP's potential in cancer research and clinical applications, showcasing diagnostic efficacy and HER2 protein targeting in a proof-of-concept approach.

Metallic nanostructure-based aptasensors for robust detection of proteins

There is a significant need for fast, cost-effective, and highly sensitive protein target detection, particularly in the fields of food, environmental monitoring, and healthcare. The integration of high-affinity aptamers with metal-based nanomaterials has played a crucial role in advancing the development of innovative aptasensors tailored for the precise detection of specific proteins. Aptamers offer several advantages over commonly used molecular recognition methods, such as antibodies. Recently, a variety of metal-based aptasensors have been established. These metallic nanomaterials encompass noble metal nanoparticles, metal oxides, metal-carbon nanotubes, carbon quantum dots, graphene-conjugated metallic nanostructures, as well as their nanocomposites, metal-organic frameworks (MOFs), and MXenes. In general, these materials provide enhanced sensitivity through signal amplification and transduction mechanisms. This review primarily focuses on the advancement of aptasensors based on metallic materials for the highly sensitive detection of protein targets, including enzymes and growth factors. Additionally, it sheds light on the challenges encountered in this field and outlines future prospects. We firmly believe that this review will offer a comprehensive overview and fresh insights into metallic nanomaterials-based aptasensors and their capabilities, paving the way for the development of innovative point-of-care (POC) diagnostic devices.

Post-synthesis Oxidation of Superparamagnetic Iron Oxide Nanoparticles to Enhance Magnetic Particle Imaging Performance

This study investigates the impact of post-synthesis oxidation on the performance of superparamagnetic iron oxide nanoparticles (SPIONs) in magnetic particle imaging (MPI), an emerging technology with applications in diagnostic imaging and theranostics. SPIONs synthesized from iron oleate were subjected to a post-synthesis oxidation treatment with a 1% Oxygen in Argon mixture. MPI performance, gauged via signal intensity and resolution using a MOMENTUM™ scanner, was correlated to the nanoparticles' physical and magnetic properties. Post-synthesis oxidation did not alter physical attributes like size and shape, but significantly enhanced magnetic properties. Saturation magnetization increased from 52% to 93% of the bulk value for magnetite, leading to better MPI performance in terms of signal intensity and resolution. However, the observed MPI performance did not fully align with predictions based on the ideal Langevin model, indicating the need for considering factors like relaxation and shape anisotropy. The findings underscore the potential of post-synthesis oxidation as a method to fine-tune magnetic properties of SPIONs and improve MPI performance, and the need for reproducible synthesis methods that afford finely tuned control of nanoparticle size, shape, and magnetic properties.

Quantum Dot-based Bio-conjugates as an Emerging Bioimaging Tool for Cancer Theranostic- A Review

Cancer is the most widely studied disorder in humans, but proper treatment has not yet been developed for it. Conventional therapies, like chemotherapy, radiation therapy, and surgery, have been employed. Such therapies target not only cancerous cells but also harm normal cells. Conventional therapy does not result in specific targeting and hence leads to severe side effects. The main objective of this study is to explore the QDs. QDs are used as nanocarriers for diagnosis and treatment at the same time. They are based on the principle of theranostic approach. QDs can be conjugated with antibodies via various methods that result in targeted therapy. This results in their dual function as a diagnostic and therapeutic tool. Nanotechnology involving such nanocarriers can increase the specificity and reduce the side effects, leaving the normal cells unaffected. This review pays attention to different methods for synthesising QDs. QDs can be obtained using either organic method and synthetic methods. It was found that QDs synthesised naturally are more feasible than the synthetic process. Top or bottom-up approaches have also emerged for the synthesis of QDs. QDs can be conjugated with an antibody via non-covalent and covalent binding. Covalent binding is much more feasible than any other method. Zero-length coupling plays an important role as EDC (1-Ethyl-3-Ethyl dimethylaminopropyl)carbodiimide is a strong crosslinker and is widely used for conjugating molecules. Antibodies work as surface ligands that lead to antigen- antibody interaction, resulting in site-specific targeting and leaving behind the normal cells unaffected. Cellular uptake of the molecule is done by either passive targeting or active targeting. QDs are tiny nanocrystals that are inorganic in nature and vary in size and range. Based on different sizes, they emit light of specific wavelengths. They have their own luminescent and optical properties that lead to the monitoring, imaging, and transport of the therapeutic moiety to a variety of targets in the body. The surface of the QDs is modified to boost their functioning. They act as a tool for diagnosis, imaging, and delivery of therapeutic moieties. For improved therapeutic effects, nanotechnology leads the cellular uptake of nanoparticles via passive targeting or active targeting. It is a crucial platform that not only leads to imaging and diagnosis but also helps to deliver therapeutic moieties to specific sites. Therefore, this review concludes that there are numerous drawbacks to the current cancer treatment options, which ultimately result in treatment failure. Therefore, nanotechnology that involves such a nanocarrier will serve as a tool for overcoming all limitations of the traditional therapeutic approach. This approach helps in reducing the dose of anticancer agents for effective treatment and hence improving the therapeutic index. QDs can not only diagnose a disease but also deliver drugs to the cancerous site.

Nanotechnology translation in vascular diseases: From design to the bench

Atherosclerosis is a systemic pathophysiological condition contributing to the development of majority of polyvascular diseases. Nanomedicine is a novel and rapidly developing science. Due to their small size, nanoparticles are freely transported in vasculature, and have been widely employed as tools in analytical imaging techniques. Furthermore, the application of nanoparticles also allows target intervention, such as drug delivery and tissue engineering regenerative methods, in the management of major vascular diseases. Therefore, by summarizing the physical and chemical characteristics of common nanoparticles used in diagnosis and treatment of vascular diseases, we discuss the details of these applications from cellular, molecular, and in vivo perspectives in this review. Furthermore, we also summarize the status and challenges of the application of nanoparticles in clinical translation. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Emerging Technologies.

In diabetic male Wistar rats, quercetin-conjugated superparamagnetic iron oxide nanoparticles have an effect on the SIRT1/p66Shc-mediated pathway related to cognitive impairment

BACKGROUND

Quercetin (QC) possesses a variety of health-promoting effects in pure and in conjugation with nanoparticles. Since the mRNA-SIRT1/p66Shc pathway and microRNAs (miRNAs) are implicated in the oxidative process, we aimed to compare the effects of QC and QC-conjugated superparamagnetic iron oxide nanoparticles (QCSPIONs) on this pathway.

METHODS

Through the use of the chemical coprecipitation technique (CPT), SPIONs were synthesized, coated with dextran, and conjugated with quercetin. Adult male Wistar rats were given intraperitoneal injections of streptozotocin to look for signs of type 1 diabetes (T1D). The animals were randomized into five groups: the control group got deionized water (DI), free QC solution (25 mg/kg), SPIONs (25 mg/kg), and QCSPIONs (25 mg/kg), and all groups received repeat doses administered orally over 35 days. Real-time quantitative PCR was used to assess the levels of miR-34a, let-7a-p5, SIRT1, p66Shc, CASP3, and PARP1 expression in the hippocampus of diabetic rats.

RESULTS

In silico investigations identified p66Shc, CASP3, and PARP1 as targets of let-7a-5p and miR-34a as possible regulators of SIRT1 genes. The outcomes demonstrated that diabetes elevated miR-34a, p66Shc, CASP3, and PARP1 and downregulated let-7a-5p and SIRT1 expression. In contrast to the diabetic group, QCSPIONs boosted let-7a-5p expression levels and consequently lowered p66Shc, CASP3, and PARP1 expression levels. QCSPIONs also reduced miR-34a expression, which led to an upsurge in SIRT1 expression.

CONCLUSION

Our results suggest that QCSPIONs can regulate the SIRT1/p66Shc-mediated signaling pathway and can be considered a promising candidate for ameliorating the complications of diabetes.

Iron oxide-coupled CRISPR-nCas9-based genome editing assessment in mucopolysaccharidosis IVA mice

Mucopolysaccharidosis (MPS) IVA is a lysosomal storage disorder caused by mutations in the GALNS gene that leads to the lysosomal accumulation of keratan sulfate (KS) and chondroitin 6-sulfate, causing skeletal dysplasia and cardiopulmonary complications. Current enzyme replacement therapy does not impact the bone manifestation of the disease, supporting that new therapeutic alternatives are required. We previously demonstrated the suitability of the CRISPR-nCas9 system to rescue the phenotype of human MPS IVA fibroblasts using iron oxide nanoparticles (IONPs) as non-viral vectors. Here, we have extended this strategy to an MPS IVA mouse model by inserting the human GALNS cDNA into the ROSA26 locus. The results showed increased GALNS activity, mono-KS reduction, partial recovery of the bone pathology, and non-IONPs-related toxicity or antibody-mediated immune response activation. This study provides, for the first time, in vivo evidence of the potential of a CRISPR-nCas9-based gene therapy strategy for treating MPS IVA using non-viral vectors as carriers.

Recent advances of polymeric nanoplatforms for cancer treatment: smart delivery systems (SDS), nanotheranostics and multidrug resistance (MDR) inhibition

Nanotheranostics is a promising field that combines the benefits of diagnostic and treatment into a single nano-platform that not only administers treatment but also allows for real-time monitoring of therapeutic response, decreasing the possibility of under/over-drug dosing. Furthermore, developing smart delivery systems (SDSs) for cancer theranostics that can take advantage of various tumour microenvironment (TME) conditions (such as deformed tumour vasculature, various over-expressed receptor proteins, reduced pH, oxidative stress, and resulting elevated glutathione levels) can aid in achieving improved pharmacokinetics, higher tumour accumulation, enhanced antitumour efficacy, and/or decreased side effects and multidrug resistance (MDR) inhibition. Polymeric nanoparticles (PNPs) are being widely investigated in this regard due to their unique features such as small size, passive/active targeting possibility, better pharmaceutical kinetics and biological distribution, decreased adverse reactions of the established drugs, inherent inhibitory properties to MDR efflux pump proteins, as well as the feasibility of delivering numerous therapeutic substances in just one design. Hence in this review, we have primarily discussed PNPs based targeted and/or controlled SDSs in which we have elaborated upon different TME mediated nanotheranostic platforms (NTPs) including active/passive/magnetic targeting platforms along with pH/ROS/redox-responsive platforms. Besides, we have elucidated different imaging guided cancer therapeutic platforms based on four major cancer imaging techniques i.e., fluorescence/photo-acoustic/radionuclide/magnetic resonance imaging, Furthermore, we have deliberated some of the most recently developed PNPs based multimodal NTPs (by combining two or more imaging or therapy techniques on a single nanoplatform) in cancer theranostics. Moreover, we have provided a brief update on PNPs based NTP which are recently developed to overcome MDR for effective cancer treatment. Additionally, we have briefly discussed about the tissue biodistribution/tumour targeting efficiency of these nanoplatforms along with recent preclinical/clinical studies. Finally, we have elaborated on various limitations associated with PNPs based nanoplatforms.

The important role of miR-1-3p in cancers

Cancer is a malignant tumor that seriously threatens human life and health. At present, the main treatment methods include surgical resection, chemotherapy, radiotherapy, and immunotherapy. However, the mechanism of tumor occurrence and development is complex, and it produces resistance to some traditional treatment methods, leading to treatment failure and a high mortality rate for patients. Therefore, exploring the molecular mechanisms of tumor occurrence, development, and drug resistance is a very important task. MiRNAs are a type of non-coding small RNA that regulate a series of biological effects by binding to the 3'-UTR of the target mRNA, degrading the mRNA, or inhibiting its translation. MiR-1-3p is an important member of them, which is abnormally expressed in various tumors and closely related to the occurrence and development of tumors. This article introduces miR-1-3p from multiple aspects, including its production and regulation, role in tumor occurrence and development, clinical significance, role in drug resistance, and approaches for targeting miR-1-3p. Intended to provide readers with a comprehensive understanding of the important role of miR-1-3p in tumors.

Overcoming barriers: a review on innovations in drug delivery to the middle and inner ear

Despite significant advances in the development of therapeutics for hearing loss, drug delivery to the middle and inner ear remains a challenge. As conventional oral or intravascular administration are ineffective due to poor bioavailability and impermeability of the blood-labyrinth-barrier, localized delivery is becoming a preferable approach for certain drugs. Even then, localized delivery to the ear precludes continual drug delivery due to the invasive and potentially traumatic procedures required to access the middle and inner ear. To address this, the preclinical development of controlled release therapeutics and drug delivery devices have greatly advanced, with some now showing promise clinically. This review will discuss the existing challenges in drug development for treating the most prevalent and damaging hearing disorders, in particular otitis media, perforation of the tympanic membrane, cholesteatoma and sensorineural hearing loss. We will then address novel developments in drug delivery that address these including novel controlled release therapeutics such as hydrogel and nanotechnology and finally, novel device delivery approaches such as microfluidic systems and cochlear prosthesis-mediated delivery. The aim of this review is to investigate how drugs can reach the middle and inner ear more efficiently and how recent innovations could be applied in aiding drug delivery in certain pathologic contexts.

A narrative review of the synthesis, characterization, and applications of iron oxide nanoparticles

The significance of green synthesized nanomaterials with a uniform shape, reduced sizes, superior mechanical capabilities, phase microstructure, magnetic behavior, and superior performance cannot be overemphasized. Iron oxide nanoparticles (IONPs) are found within the size range of 1-100 nm in nanomaterials and have a diverse range of applications in fields such as biomedicine, wastewater purification, and environmental remediation. Nevertheless, the understanding of their fundamental material composition, chemical reactions, toxicological properties, and research methodologies is constrained and extensively elucidated during their practical implementation. The importance of producing IONPs using advanced nanofabrication techniques that exhibit strong potential for disease therapy, microbial pathogen control, and elimination of cancer cells is underscored by the adoption of the green synthesis approach. These IONPs can serve as viable alternatives for soil remediation and the elimination of environmental contaminants. Therefore, this paper presents a comprehensive analysis of the research conducted on different types of IONPs and IONP composite-based materials. It examines the synthesis methods and characterization techniques employed in these studies and also addresses the obstacles encountered in prior investigations with comparable objectives. A green engineering strategy was proposed for the synthesis, characterization, and application of IONPs and their composites with reduced environmental impact. Additionally, the influence of their phase structure, magnetic properties, biocompatibility, toxicity, milling time, nanoparticle size, and shape was also discussed. The study proposes the use of biological and physicochemical methods as a more viable alternative nanofabrication strategy that can mitigate the limitations imposed by the conventional methods of IONP synthesis.

Recent advances in zinc ferrite (ZnFe2O4) based nanostructures for magnetic hyperthermia applications

Spinel ferrite-based magnetic nanomaterials have been investigated for numerous biomedical applications, including targeted drug delivery, magnetic hyperthermia therapy (MHT), magnetic resonance imaging (MRI), and biosensors, among others. Recent studies have found that zinc ferrite-based nanomaterials are favorable candidates for cancer theranostics, particularly for magnetic hyperthermia applications. Zinc ferrite exhibits excellent biocompatibility, minimal toxicity, and more importantly, exciting magnetic properties. In addition, these materials demonstrate a Curie temperature much lower than other transition metal ferrites. By regulating synthesis protocols and/or introducing suitable dopants, the Curie temperature of zinc ferrite-based nanosystems can be tailored to the MHT therapeutic window, i.e., 43-46 °C, a range which is highly beneficial for clinical hyperthermia applications. Furthermore, zinc ferrite-based nanostructures have been extensively used in successful pre-clinical trials on mice models focusing on the synergistic killing of cancer cells involving magnetic hyperthermia and chemotherapy. This review provides a systematic and comprehensive understanding of the recent developments of zinc ferrite-based nanomaterials, including doped particles, shape-modified structures, and composites for magnetic hyperthermia applications. In addition, future research prospects involving pure ZnFe2O4 and its derivative nanostructures have also been proposed.

Bio-Inspired Nanomaterials for Micro/Nanodevices: A New Era in Biomedical Applications

Exploring bio-inspired nanomaterials (BINMs) and incorporating them into micro/nanodevices represent a significant development in biomedical applications. Nanomaterials, engineered to imitate biological structures and processes, exhibit distinctive attributes such as exceptional biocompatibility, multifunctionality, and unparalleled versatility. The utilization of BINMs demonstrates significant potential in diverse domains of biomedical micro/nanodevices, encompassing biosensors, targeted drug delivery systems, and advanced tissue engineering constructs. This article thoroughly examines the development and distinctive attributes of various BINMs, including those originating from proteins, DNA, and biomimetic polymers. Significant attention is directed toward incorporating these entities into micro/nanodevices and the subsequent biomedical ramifications that arise. This review explores biomimicry's structure-function correlations. Synthesis mosaics include bioprocesses, biomolecules, and natural structures. These nanomaterials' interfaces use biomimetic functionalization and geometric adaptations, transforming drug delivery, nanobiosensing, bio-inspired organ-on-chip systems, cancer-on-chip models, wound healing dressing mats, and antimicrobial surfaces. It provides an in-depth analysis of the existing challenges and proposes prospective strategies to improve the efficiency, performance, and reliability of these devices. Furthermore, this study offers a forward-thinking viewpoint highlighting potential avenues for future exploration and advancement. The objective is to effectively utilize and maximize the application of BINMs in the progression of biomedical micro/nanodevices, thereby propelling this rapidly developing field toward its promising future.

Iron Nanoparticles Open Up New Directions for Promoting Healing in Chronic Wounds in the Context of Bacterial Infection

Metal nanoparticles play an outstanding role in the field of wound healing due to their excellent properties, and the significance of iron, one of the most widely used metals globally, cannot be overlooked. The purpose of this review is to determine the importance of iron nanoparticles in wound-healing dressings. Prolonged, poorly healing wounds may induce infections; wound infections are a major cause of chronic wound formation. The primary components of iron nanoparticles are iron oxide nanoparticles, which promote wound healing by being antibacterial, releasing metal ions, and overcoming bacterial resistance. The diameter of iron oxide nanoparticles typically ranges between 1 and 100 nm. Magnetic nanoparticles with a diameter of less than 30 nm are superparamagnetic and are referred to as superparamagnetic iron oxide nanoparticles. This subset of iron oxide nanoparticles can use an external magnetic field for novel functions such as magnetization and functionalization. Iron nanoparticles can serve clinical purposes not only to enhance wound healing through the aforementioned means but also to ameliorate anemia and glucose irregularities, capitalizing on iron's properties. Iron nanoparticles positively impact the healing process of chronic wounds, potentially extending beyond wound management.

Superparamagnetic Nanocrystals Clustered Using Poly(ethylene glycol)-Crosslinked Amphiphilic Copolymers for the Diagnosis of Liver Cancer

Superparamagnetic iron oxide (SPIO) nanocrystals have been extensively studied as theranostic nanoparticles to increase transverse (T2) relaxivity and enhance contrast in magnetic resonance imaging (MRI). To improve the blood circulation time and enhance the diagnostic sensitivity of MRI contrast agents, we developed an amphiphilic copolymer, PCPZL, to effectively encapsulate SPIO nanocrystals. PCPZL was synthesized by crosslinking a polyethylene glycol (PEG)-based homobifunctional linker with a hydrophobic star-like poly(ε-benzyloxycarbonyl-L-lysine) segment. Consequently, it could self-assemble into shell-crosslinked micelles with enhanced colloidal stability in bloodstream circulation. Notably, PCPZL could effectively load SPIO nanocrystals with a high loading capacity of 66.0 ± 0.9%, forming SPIO nanoclusters with a diameter of approximately 100 nm, a high cluster density, and an impressive T2 relaxivity value 5.5 times higher than that of Resovist®. In vivo MRI measurements highlighted the rapid accumulation and contrast effects of SPIO-loaded PCPZL micelles in the livers of both healthy mice and nude mice with an orthotopic hepatocellular carcinoma tumor model. Moreover, the magnetic micelles remarkably enhanced the relative MRI signal difference between the tumor and normal liver tissues. Overall, our findings demonstrate that PCPZL significantly improves the stability and magnetic properties of SPIO nanocrystals, making SPIO-loaded PCPZL micelles promising MRI contrast agents for diagnosing liver diseases and cancers.

Engineered Lipidic Nanomaterials Inspired by Sphingomyelin Metabolism for Cancer Therapy

Sphingomyelin (SM) and its metabolites are crucial regulators of tumor cell growth, differentiation, senescence, and programmed cell death. With the rise in lipid-based nanomaterials, engineered lipidic nanomaterials inspired by SM metabolism, corresponding lipid targeting, and signaling activation have made fascinating advances in cancer therapeutic processes. In this review, we first described the specific pathways of SM metabolism and the roles of their associated bioactive molecules in mediating cell survival or death. We next summarized the advantages and specific applications of SM metabolism-based lipidic nanomaterials in specific cancer therapies. Finally, we discussed the challenges and perspectives of this emerging and promising SM metabolism-based nanomaterials research area.

How Magnetic Composites are Effective Anticancer Therapeutics? A Comprehensive Review of the Literature

Chemotherapy is the most prominent route in cancer therapy for prolonging the lifespan of cancer patients. However, its non-target specificity and the resulting off-target cytotoxicities have been reported. Recent in vitro and in vivo studies using magnetic nanocomposites (MNCs) for magnetothermal chemotherapy may potentially improve the therapeutic outcome by increasing the target selectivity. In this review, magnetic hyperthermia therapy and magnetic targeting using drug-loaded MNCs are revisited, focusing on magnetism, the fabrication and structures of magnetic nanoparticles, surface modifications, biocompatible coating, shape, size, and other important physicochemical properties of MNCs, along with the parameters of the hyperthermia therapy and external magnetic field. Due to the limited drug-loading capacity and low biocompatibility, the use of magnetic nanoparticles (MNPs) as drug delivery system has lost traction. In contrast, MNCs show higher biocompatibility, multifunctional physicochemical properties, high drug encapsulation, and multi-stages of controlled release for localized synergistic chemo-thermotherapy. Further, combining various forms of magnetic cores and pH-sensitive coating agents can generate a more robust pH, magneto, and thermo-responsive drug delivery system. Thus, MNCs are ideal candidate as smart and remotely guided drug delivery system due to a) their magneto effects and guide-ability by the external magnetic fields, b) on-demand drug release performance, and c) thermo-chemosensitization under an applied alternating magnetic field where the tumor is selectively incinerated without harming surrounding non-tumor tissues. Given the important effects of synthesis methods, surface modifications, and coating of MNCs on their anticancer properties, we reviewed the most recent studies on magnetic hyperthermia, targeted drug delivery systems in cancer therapy, and magnetothermal chemotherapy to provide insights on the current development of MNC-based anticancer nanocarrier.

Application of magnetic iron oxide nanoparticles: Thrombotic activity, imaging and cytocompatibility of silica-coated and carboxymethyl dextrane-coated particles

Coated iron oxide nanoparticles (IONs) are promising candidates for various applications in nanomedicine, including imaging, magnetic hyperthermia, and drug delivery. The application of IONs in nanomedicine is influenced by factors such as biocompatibility, surface properties, agglomeration, degradation behavior, and thrombogenicity. Therefore, it is essential to investigate the effects of coating material and thickness on the behavior and performance of IONs in the human body. In this study, IONs with a carboxymethyl dextran (CMD) coating and two thicknesses of silica coating (TEOS0.98, and TEOS3.91) were screened and compared to bare iron oxide nanoparticles (BIONs). All three coated particles showed good cytocompatibility (>70%) when tested with smooth muscle cells over three days. To investigate their potential long term behavior inside the human body, the Fe²⁺ release and hydrodynamic diameters of silica-coated and CMD (carboxymethyl dextrane)-coated IONs were analyzed in simulated body fluids for 72 h at 37 °C. The ION@CMD showed moderate agglomeration of around 100 nm in all four simulated fluids and dissolved faster than the silica-coated particles in artificial exosomal fluid and artificial lysosomal fluid. The particles with silica coating agglomerated in all tested simulated media above 1000 nm. Increased thickness of the silica coating led to decreased degradation of particles. Additionally, CMD coating resulted in nanoparticles with the least prothrombotic activity, and the thick silica coating apparently decreased the prothrombotic properties of nanoparticles compared to BIONs and ION@TEOS0.98. For magnetic resonance applications, ION@CMD and ION@TEOS3.91 showed comparatively high relaxation rates R₂ values. In magnetic particle imaging experiments ION@TEOS3.91 yielded the highest normalized signal to noise ratio values and in magnetic hyperthermia studies, ION@CMD and ION@TEOS0.98 showed similar specific loss power. These findings demonstrate the potential of coated IONs in nanomedicine and emphasize the importance of understanding the effect of coating material and thickness on their behavior and performance in the human body.

Magnetic Nanoparticles Mediated Thrombolysis-A Review

Nanoparticles containing thrombolytic medicines have been developed for thrombolysis applications in response to the increasing demand for effective, targeted treatment of thrombosis disease. In recent years, there has been a great deal of interest in nanoparticles that can be navigated and driven by a magnetic field. However, there are few review publications concerning the application of magnetic nanoparticles in thrombolysis. In this study, we examine the current state of magnetic nanoparticles in the application of in vitro and in vivo thrombolysis under a static or dynamic magnetic field, as well as the combination of magnetic nanoparticles with an acoustic field for dual-mode thrombolysis. We also discuss four primary processes of magnetic nanoparticles mediated thrombolysis, including magnetic nanoparticle targeting, magnetic nanoparticle trapping, magnetic drug release, and magnetic rupture of blood clot fibrin networks. This review will offer unique insights for the future study and clinical development of magnetic nanoparticles mediated thrombolysis approaches.

Electrospun Magnetic Nanofiber Mats for Magnetic Hyperthermia in Cancer Treatment Applications-Technology, Mechanism, and Materials

The number of cancer patients is rapidly increasing worldwide. Among the leading causes of human death, cancer can be regarded as one of the major threats to humans. Although many new cancer treatment procedures such as chemotherapy, radiotherapy, and surgical methods are nowadays being developed and used for testing purposes, results show limited efficiency and high toxicity, even if they have the potential to damage cancer cells in the process. In contrast, magnetic hyperthermia is a field that originated from the use of magnetic nanomaterials, which, due to their magnetic properties and other characteristics, are used in many clinical trials as one of the solutions for cancer treatment. Magnetic nanomaterials can increase the temperature of nanoparticles located in tumor tissue by applying an alternating magnetic field. A very simple, inexpensive, and environmentally friendly method is the fabrication of various types of functional nanostructures by adding magnetic additives to the spinning solution in the electrospinning process, which can overcome the limitations of this challenging treatment process. Here, we review recently developed electrospun magnetic nanofiber mats and magnetic nanomaterials that support magnetic hyperthermia therapy, targeted drug delivery, diagnostic and therapeutic tools, and techniques for cancer treatment.

Sensitive magnetic particle imaging of haemoglobin degradation for the detection and monitoring of intraplaque haemorrhage in atherosclerosis

BACKGROUND

Intraplaque haemorrhage (IPH) drives atherosclerosis progression and is a key imaging biomarker of unstable plaques. Non-invasive and sensitive monitoring of IPH is challenging due to the compositional complexity and dynamic nature of atherosclerotic plaques. Magnetic particle imaging (MPI) is a highly sensitive, radiation-free, and no-tissue-background tomographic technique that detects superparamagnetic nanoparticles. Thus, we aimed to investigate whether MPI can in vivo detect and monitor IPH.

METHODS

Thirty human carotid endarterectomy samples were collected and scanned with MPI. The tandem stenosis (TS) model was employed to establish unstable plaques with IPH in ApoE^-/- mice. MPI and 7 T T1-weighted magnetic resonance imaging (MRI) were performed on TS ApoE^-/- mice. Plaque specimens were analyzed histologically.

FINDINGS

Human carotid endarterectomy samples exhibited endogenous MPI signals, which histologically colocalized with IPH. In vitro experiments identified haemosiderin, a haemoglobin degradation product, as a potential source of MPI signals. Longitudinal MPI of TS ApoE^-/- mice detected IPH at unstable plaques, of which MPI signal-to-noise ratio values increased from 6.43 ± 1.74 (four weeks) to 10.55 ± 2.30 (seven weeks) and reduced to 7.23 ± 1.44 (eleven weeks). In contrast, 7 T T1-weighted MRI did not detect the small-size IPH (329.91 ± 226.82 μm²) at four weeks post-TS. The time-course changes in IPH were shown to correlate with neovessel permeability providing a possible mechanism for signal changes over time.

INTERPRETATION

MPI is a highly sensitive imaging technology that allows the identification of atherosclerotic plaques with IPH and may help detect and monitor unstable plaques in patients.

FUNDING

This work was supported in part by the Beijing Natural Science Foundation under Grant JQ22023; the National Key Research and Development Program of China under Grant 2017YFA0700401; the National Natural Science Foundation of China under Grant 62027901, 81827808, 81730050, 81870178, 81800221, 81527805, and 81671851; the CAS Youth Innovation Promotion Association under Grant Y2022055 and CAS Key Technology Talent Program; and the Project of High-Level Talents Team Introduction in Zhuhai City (Zhuhai HLHPTP201703).

Nanomaterials for Fluorescence and Multimodal Bioimaging

Bioconjugated nanomaterials replace molecular probes in bioanalysis and bioimaging in vitro and in vivo. Nanoparticles of silica, metals, semiconductors, polymers, and supramolecular systems, conjugated with contrast agents and drugs for image-guided (MRI, fluorescence, PET, Raman, SPECT, photodynamic, photothermal, and photoacoustic) therapy infiltrate into preclinical and clinical settings. Small bioactive molecules like peptides, proteins, or DNA conjugated to the surfaces of drugs or probes help us to interface them with cells and tissues. Nevertheless, the toxicity and pharmacokinetics of nanodrugs, nanoprobes, and their components become the clinical barriers, underscoring the significance of developing biocompatible next-generation drugs and contrast agents. This account provides state-of-the-art advancements in the preparation and biological applications of bioconjugated nanomaterials and their molecular, cell, and in vivo applications. It focuses on the preparation, bioimaging, and bioanalytical applications of monomodal and multimodal nanoprobes composed of quantum dots, quantum clusters, iron oxide nanoparticles, and a few rare earth metal ion complexes.

A Spiky Silver-Iron Oxide Nanoparticle for Highly Efficient Targeted Photothermal Therapy and Multimodal Imaging of Thrombosis

Thrombosis and its complications are responsible for 30% of annual deaths. Limitations of methods for diagnosing and treating thrombosis highlight the need for improvements. Agents that provide simultaneous diagnostic and therapeutic activities (theranostics) are paramount for an accurate diagnosis and rapid treatment. In this study, silver-iron oxide nanoparticles (AgIONPs) are developed for highly efficient targeted photothermal therapy and imaging of thrombosis. Small iron oxide nanoparticles are employed as seeding agents for the generation of a new class of spiky silver nanoparticles with strong absorbance in the near-infrared range. The AgIONPs are biofunctionalized with binding ligands for targeting thrombi. Photoacoustic and fluorescence imaging demonstrate the highly specific binding of AgIONPs to the thrombus when functionalized with a single chain antibody targeting activated platelets. Photothermal thrombolysis in vivo shows an increase in the temperature of thrombi and a full restoration of blood flow for targeted group but not in the non-targeted group. Thrombolysis from targeted groups is significantly improved (p < 0.0001) in comparison to the standard thrombolytic used in the clinic. Assays show no apparent side effects of AgIONPs. Altogether, this work suggests that AgIONPs are potential theranostic agents for thrombosis.

Magnetoresponsive fluorescent core-shell nanoclusters for biomedical applications

Nowadays, superparamagnetic iron oxide nanoparticles (SPIONs) have a dominant role in many subfields of biomedicine. Owing to their peculiar properties, they can be employed for magnetic separation, drug delivery, diagnostics, and hyperthermia treatments. However, these magnetic nanoparticles (NPs) suffer from low unit magnetization due to size constraints (up to 20-30 nm) to exhibit superparamagnetic character. In this work, we have designed and synthesized superparamagnetic nanoclusters (SP-NCs) with diameters of up to 400 nm with high unit magnetization for enhanced loading capacity. These were synthesized with conventional or microwave-assisted solvothermal methods, in the presence of either of the two biomolecules (citrate or l-lysine) as the capping agent. Primary particle size, SP-NC size, surface chemistry, and the resultant magnetic properties were observed to be significantly influenced by the choice of synthesis route and capping agent. Selected SP-NCs were then coated with a fluorophore-doped silica shell to provide fluorescence properties, in the near-infrared spectrum region, while silica provided high chemical and colloidal stability. Heating efficiency studies were performed under alternating magnetic field on the synthesized SP-NCs, highlighting their potential in hyperthermia treatment. We envision that their enhanced magnetically-active content, fluorescence, magnetic property, and heating efficiency will pave the way to more effective uses in biomedical applications.

Agglomerated serum albumin adsorbed protocatechuic acid coated superparamagnetic iron oxide nanoparticles as a theranostic agent

Iron oxide nanoparticles have been one of the most widely used nanomaterials in biomedical applications. However, the incomplete understanding of the toxicity mechanisms limits their use in diagnosis and treatment processes. Many parameters are associated with their toxicity such as size, surface modification, solubility, concentration and immunogenicity. Further research needs to be done to address toxicity-related concerns and to increase its effectiveness in various applications. Herein, colloidally stable nanoparticles were prepared by coating magnetic iron oxide nanoparticles (MIONPs) with protocatechuic acid (PCA) which served as a stabilizer and a linkage for a further functional layer. A new perfusion agent with magnetic imaging capability was produced by the adsorption of biocompatible passivating agent macro-aggregated albumin (MAA) on the PCA-coated MIONPs. PCA-coated MIONPs were investigated using infrared spectroscopy, thermogravimetric analysis and dynamic light scattering while adsorption of MAA was analysed by transmission electron microscopy, Fourier-transform infrared spectroscopy and x-ray diffraction methods. Magnetic measurements of samples indicated that all samples showed superparamagnetic behaviour. Cytotoxicity results revealed that the adsorption of MAA onto PCA-coated MIONPs provided an advantage by diminishing their toxicity against the L929 mouse fibroblast cell line compared to bare Fe₃O₄.

Magnetic nanofluids (Ferrofluids): Recent advances, applications, challenges, and future directions

Impelled by the need to find solutions to new challenges of modern technologies new materials with unique properties are being explored. Among various new materials that emerged over the decades, magnetic fluids exhibiting interesting physiochemical properties (optical, thermal, magnetic, rheological, apparent density, etc.) under a magnetic stimulus have been at the forefront of research. In the initial phase, there has been a fervent scientific curiosity to understand the field-induced intriguing properties of such fluids but later a plethora of technological applications emerged. Magnetic nanofluid, popularly known as ferrofluid, is a colloidal suspension of fine magnetic nanoparticles, has been at the forefront of research because of its magnetically tunable physicochemical properties and applications. Due to their stimuli-responsive behaviour, they have been finding more applications in biology and other engineering disciplines in recent years. Therefore, a critical review of this topic highlighting the necessary background, the potential of this material for emerging technologies, and the latest developments is warranted. This review also provides a summary of various applications, along with the key challenges and future research directions. The first part of the review addresses the different types of magnetic fluids, the genesis of magnetic fluids, their synthesis methodologies, properties, and stabilization techniques are discussed in detail. The second part of the review highlights the applications of magnetic nanofluids and nanoemulsions (as model systems) in probing order-disorder transitions, scattering, diffraction, magnetically reconfigurable internal structures, molecular interaction, and weak forces between colloidal particles, conformational changes of macromolecules at interfaces and polymer-surfactant complexation at the oil-water interface. The last part of the review summarizes the interesting applications of magnetic fluids such as heat transfer, sensors (temperature, pH, urea detection, cations, defect detection sensors), tunable optical filters, removal of dyes, dynamic seals, magnetic hyperthermia-based cancer therapy and other biomedical applications. The applications of magnetic nanofluids in diverse disciplines are growing day by day, yet there are challenges in their practical adaptation as field-worthy or packaged products. This review provides a pedagogical description of magnetic fluids, with the necessary background, key concepts, physics, experimental protocols, design of experiments, challenges and future directions.

Specific absorption rate of randomly oriented magnetic nanoparticles in a static magnetic field

Numerical simulations using the stochastic Landau-Lifshitz equation are performed to study magnetization dynamics of dilute assemblies of iron oxide nanoparticles exposed to an alternating (ac) magnetic field with an amplitude H _ac = 200 Oe and a frequency f = 300 kHz and a static (dc) magnetic field in the range H _dc = 0-800 Oe. The specific absorption rate (SAR) of the assemblies is calculated depending on the angle between the directions of the ac and dc magnetic fields. For the case of an inhomogeneous dc magnetic field created by two opposite magnetic fluxes, the spatial distribution of the SAR in the vicinity of the field-free point is obtained for assemblies with different nanoparticle size distributions. The results obtained seem to be helpful for the development of a promising joint application of magnetic nanoparticle imaging and magnetic hyperthermia.

Functional Evaluation of 3D Liver Models Labeled with Polysaccharide Functionalized Magnetic Nanoparticles

Establishing a rapid in vitro evaluation system for drug screening is essential for the development of new drugs. To reproduce tissues/organs with functions closer to living organisms, in vitro three-dimensional (3D) culture evaluation using microfabrication technology has been reported in recent years. Culture on patterned substrates with controlled hydrophilic and hydrophobic regions (Cell-able^TM) can create 3D liver models (miniature livers) with liver-specific Disse luminal structures and functions. MRI contrast agents are widely used as safe and minimally invasive diagnostic methods. We focused on anionic polysaccharide magnetic iron oxide nanoparticles (Resovist^®) and synthesized the four types of nanoparticle derivatives with different properties. Cationic nanoparticles (TMADM) can be used to label target cells in a short time and have been successfully visualized in vivo. In this study, we examined the morphology of various nanoparticles. The morphology of various nanoparticles showed relatively smooth-edged spherical shapes. As 3D liver models, we prepared primary hepatocyte-endothelial cell heterospheroids. The toxicity, CYP3A, and albumin secretory capacity were evaluated in the heterospheroids labeled with various nanoparticles. As the culture period progressed, the heterospheroids labeled with anionic and cationic nanoparticles showed lower liver function than non-labeled heterospheroids. In the future, there is a need to improve the method of creation of artificial 3D liver or to design a low-invasive MRI contrast agent to label the artificial 3D liver.

Magneto-Fluorescent Mesoporous Nanocarriers for the Dual-Delivery of Ofloxacin and Doxorubicin to Tackle Opportunistic Bacterial Infections in Colorectal Cancer

Cancer-related opportunistic bacterial infections are one major barrier for successful clinical therapies, often correlated to the production of genotoxic factors and higher cancer incidence. Although dual anticancer and antimicrobial therapies are a growing therapeutic fashion, they still fall short when it comes to specific delivery and local action in in vivo systems. Nanoparticles are seen as potential therapeutic vectors, be it by means of their intrinsic antibacterial properties and effective delivery capacity, or by means of their repeatedly reported modulation and maneuverability. Herein we report on the production of a biocompatible, antimicrobial magneto-fluorescent nanosystem (NANO3) for the delivery of a dual doxorubicin-ofloxacin formulation against cancer-related bacterial infections. The drug delivery capacity, rendered by its mesoporous silica matrix, is confirmed by the high loading capacity and stimuli-driven release of both drugs, with preference for tumor-like acidic media. The pH-dependent emission of its surface fluorescent SiQDs, provides an insight into NANO3 surface behavior and pore availability, with the SiQDs working as pore gates. Hyperthermia induces heat generation to febrile temperatures, doubling drug release. NANO3-loaded systems demonstrate significant antimicrobial activity, specifically after the application of hyperthermia conditions. NANO3 structure and antimicrobial properties confirm their potential use in a future dual anticancer and antimicrobial therapeutical vector, due to their drug loading capacity and their surface availability for further modification with bioactive, targeting species.

Delivery and assessment of a CRISPR/nCas9-based genome editing system on in vitro models of mucopolysaccharidoses IVA assisted by magnetite-based nanoparticles

Mucopolysaccharidosis IV A (MPS IVA) is a lysosomal disorder caused by mutations in the GALNS gene. Consequently, the glycosaminoglycans (GAGs) keratan sulfate and chondroitin 6-sulfate accumulate in the lysosomal lumen. Although enzyme replacement therapy has shown essential advantages for the patients, several challenges remain to overcome, such as the limited impact on the bone lesion and recovery of oxidative profile. Recently, we validated a CRISPR/nCas9-based gene therapy with promising results in an in vitro MPS IVA model. In this study, we have expanded the use of this CRISPR/nCas9 system to several MPS IVA fibroblasts carrying different GALNS mutations. Considering the latent need to develop more safety vectors for gene therapy, we co-delivered the CRISPR/nCas9 system with a novel non-viral vector based on magnetoliposomes (MLPs). We found that the CRISPR/nCas9 treatment led to an increase in enzyme activity between 5 and 88% of wild-type levels, as well as a reduction in GAGs accumulation, lysosomal mass, and mitochondrial-dependent oxidative stress, in a mutation-dependent manner. Noteworthy, MLPs allowed to obtain similar results to those observed with the conventional transfection agent lipofectamine. Overall, these results confirmed the potential of CRISPR/nCas9 as a genome editing tool for treating MPS IVA. We also demonstrated the potential use of MLPs as a novel delivery system for CRISPR/nCas9-based therapies.

NIR/MRI-Guided Oxygen-Independent Carrier-Free Anti-Tumor Nano-Theranostics

Imaging-guided photothermal therapy (PTT)/photodynamic therapy (PDT) for cancer treatment are beneficial for precise localization of the malignant lesions and combination of multiple cell killing mechanisms in eradicating stubborn thermal-resistant cancer cells. However, overcoming the adverse impact of tumor hypoxia on PDT efficacy remains a challenge. Here, carrier-free nano-theranostic agents are developed (AIBME@IR780-APM NPs) for magnetic resonance imaging (MRI)-guided synergistic PTT/thermodynamic therapy (TDT). Two IR780 derivatives are synthesized as the subject of nanomedicine to confer the advantages for the nanomedicine, which are by feat of amphiphilic IR780-PEG to enhance the sterical stability and reduce the risk from reticuloendothelial system uptake, and IR780-ATU to chelate Mn²⁺ for T₁ -weighted MRI. Dimethyl 2,2'-azobis(2-methylpropionate) (AIBME), acting as thermally decomposable radical initiators, are further introduced into nanosystems with the purpose of generating highly cytotoxic alkyl radicals upon PTT launched by IR780 under 808 nm laser irradiation. Therefore, the sequentially generated heat and alkyl radicals synergistically induce cell death via synergistic PTT/TDT, ignoring tumor hypoxia. Moreover, these carrier-free nano-theranostic agents present satisfactory biocompatibility, which could be employed as a powerful weapon to hit hypoxic tumors via MRI-guided oxygen-independent PTT and photonic TDT.

Nanoparticles in the diagnosis and treatment of vascular aging and related diseases

Aging-induced alternations of vasculature structures, phenotypes, and functions are key in the occurrence and development of vascular aging-related diseases. Multiple molecular and cellular events, such as oxidative stress, mitochondrial dysfunction, vascular inflammation, cellular senescence, and epigenetic alterations are highly associated with vascular aging physiopathology. Advances in nanoparticles and nanotechnology, which can realize sensitive diagnostic modalities, efficient medical treatment, and better prognosis as well as less adverse effects on non-target tissues, provide an amazing window in the field of vascular aging and related diseases. Throughout this review, we presented current knowledge on classification of nanoparticles and the relationship between vascular aging and related diseases. Importantly, we comprehensively summarized the potential of nanoparticles-based diagnostic and therapeutic techniques in vascular aging and related diseases, including cardiovascular diseases, cerebrovascular diseases, as well as chronic kidney diseases, and discussed the advantages and limitations of their clinical applications.

Impact of surface chemistry of ultrasmall superparamagnetic iron oxide nanoparticles on protein corona formation and endothelial cell uptake, toxicity, and barrier function

Ultrasmall superparamagnetic iron oxide nanoparticles (USPION) have been investigated for biomedical applications, including novel contrast agents, magnetic tracers for tumor imaging, targeted drug delivery vehicles, and magneto-mechanical actuators for hyperthermia and thrombolysis. Despite significant progress, recent clinical reports have raised concerns regarding USPION safety related to endothelial cell dysfunction; however, there is limited information on factors contributing to these clinical responses. The influence of USPION surface chemistry on nanoparticle interactions with proteins may impact endothelial cell function leading to adverse responses. Therefore, the goal of this study was to assess the effects of carboxyl-functionalized USPION (CU) or amine-functionalized USPION (AU) (∼30 nm diameter) on biological responses in human coronary artery endothelial cells. Increased protein adsorption was observed for AU compared to CU after exposure to serum proteins. Exposure to CU, but not AU, resulted in a concentration-dependent decrease in cell viability and perinuclear accumulation inside cytoplasmic vesicles. Internalization of CU was correlated with endothelial cell functional changes under non-cytotoxic conditions, as evidenced by a marked decreased expression of endothelial-specific adhesion proteins (e.g., VE-cadherin and PECAM-1) and increased endothelial permeability. Evaluation of downstream signaling indicated endothelial permeability is associated with actin cytoskeleton remodeling, possibly elicited by intracellular events involving reactive oxygen species, calcium ions, and the nanoparticle cellular uptake pathway. This study demonstrated that USPION surface chemistry significantly impacts protein adsorption and endothelial cell uptake, viability, and barrier function. This information will advance the current toxicological profile of USPION and improve development, safety assessment, and clinical outcomes of USPION-enabled medical products.

Intercomparison of radiosensitization induced by gold and iron oxide nanoparticles in human glioblastoma cells irradiated by 6 MV photons

In this work, an intercomparison of sensitization effects produced by gold (GNP) and dextran-coated iron oxide (SPION-DX) nanoparticles in M059J and U87 human glioblastoma cells was performed using 6 MV-photons. Three variables were mapped: the nanoparticle material, treatment concentration, and cell radiosensitivity. For U87, GNP treatments resulted in high sensitization enhancement ratios (SER\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{10\%}$$\end{document}10% up to 2.04). More modest effects were induced by SPION-DX, but still significant reductions in survival were achieved (maximum SER\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{10\%}=1.61$$\end{document}10%=1.61 ). For the radiosensitive M059J, sensitization by both NPs was poor. SER\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{10\%}$$\end{document}10% increased with the degree of elemental uptake in the cells, but not necessarily with treatment concentration. For GNP, where exposure concentration and elemental uptake were found to be proportional, SER\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{10\%}$$\end{document}10% increased linearly with concentration in both cell lines. For SPION-DX, saturation of sensitization enhancement and metal uptake occurred at high exposures. Fold change in the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha /\beta$$\end{document}α/β ratios extracted from survival curves are reduced by the presence of SPION-DX but strongly increased by GNPs , suggesting that sensitization by GNPs occurs mainly via promotion of lethal damage, while for SPION-DX repairable damage dominates. The NPs were more effective in eliminating the radioresistant glioblastoma cells, an interesting finding, as resistant cells are key targets to improve treatment outcome.