Cancer therapy with iron oxide nanoparticles: Agents of thermal and immune therapies

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.

Multiscale Multimodal Investigation of the Intratissural Biodistribution of Iron Nanotherapeutics with Single Cell Resolution Reveals Co-Localization with Endogenous Iron in Splenic Macrophages

Imaging of iron-based nanoparticles (NPs) remains challenging because of the presence of endogenous iron in tissues that is difficult to distinguish from exogenous iron originating from the NPs. Here, an analytical cascade for characterizing the biodistribution of biomedically relevant iron-based NPs from the organ scale to the cellular and subcellular scales is introduced. The biodistribution on an organ level is assessed by elemental analysis and quantification of magnetic iron by electron paramagnetic resonance, which allowed differentiation of exogenous and endogenous iron. Complementary to these bulk analysis techniques, correlative whole-slide optical and electron microscopy provided spatially resolved insight into the biodistribution of endo- and exogenous iron accumulation in macrophages, with single-cell and single-particle resolution, revealing coaccumulation of iron NPs with endogenous iron in splenic macrophages. Subsequent transmission electron microscopy revealed two types of morphologically distinct iron-containing structures (exogenous nanoparticles and endogenous ferritin) within membrane-bound vesicles in the cytoplasm, hinting at an attempt of splenic macrophages to extract and recycle iron from exogenous nanoparticles. Overall, this strategy enables the distinction of endo- and exogenous iron across scales (from cm to nm, based on the analysis of thousands of cells) and illustrates distribution on organ, cell, and organelle levels.

Comparing the Variants of Iron Oxide Nanoparticle-Mediated Delivery of miRNA34a for Efficiency in Silencing of PD-L1 Genes in Cancer Cells

The blocking of programmed death-ligand 1 (PD-L1) in tumor cells represents a powerful strategy in cancer immunotherapy. Using viral vectors to deliver the cargo for inactivating the PD-L1 gene could be associated with host cell genotoxicity and concomitant immune attack. To develop an alternative safe gene delivery method, we designed a unique combination for miRNA34a delivery using a transgene carrier in the form of iron oxide magnetic nanoparticles (IONPs) via magnetofection to downregulate PD-L1 expression in cancer cells. We synthesized IONPs of multiple shapes (IONRs (iron oxide nanorods), IONSs (iron oxide nanospheres), and ITOHs (iron oxide truncated octahedrons)), surface-functionalized with polyethyleneimine (PEI) using the ligand exchange method, as gene delivery systems. Under the guidance of an external magnetic field, PEI@IONPs loaded with plasmid DNA (DNA/PEI@IONPs) encoding GFP showed high transfection efficiency at different weight ratios and time points in A549 and MDA-MB-231 cells. Additionally, the DNA/PEI@IONPs with miRNA34a inserts under a static magnetic field resulted in significant knockdown of the PD-L1 gene, as demonstrated via immunoblotting of the PD-L1 protein. Among the three shapes of IONPs, IONRs showed the highest PD-L1 knockdown efficiency. The genetic expression of miRNA34a was also studied using qPCR and it showed high expression of miRNA in cells treated with PEI@IONRs. Flow cytometry and a live/dead assay confirmed apoptosis after transfection with miRNA34a. To conclude, in this paper, a promising transgene carrier with low cost, negligible cytotoxicity, and high transfection efficiency has been successfully established for miRNA gene delivery in the context of cancer immunotherapy.

Design of a temperature-feedback controlled automated magnetic hyperthermia therapy device

Introduction

Magnetic hyperthermia therapy (MHT) is a minimally invasive adjuvant therapy capable of damaging tumors using magnetic nanoparticles exposed radiofrequency alternating magnetic fields. One of the challenges of MHT is thermal dose control and excessive heating in superficial tissues from off target eddy current heating.

Methods

We report the development of a control system to maintain target temperature during MHT with an automatic safety shutoff feature in adherence to FDA Design Control Guidance. A proportional-integral-derivative (PID) control algorithm was designed and implemented in NI LabVIEW^®. A standard reference material copper wire was used as the heat source to verify the controller performance in gel phantom experiments. Coupled electromagnetic thermal finite element analysis simulations were used to identify the initial controller gains.

Results

Results showed that the PID controller successfully achieved the target temperature control despite significant perturbations.

Discussion and Conclusion

Feasibility of PID control algorithm to improve efficacy and safety of MHT was demonstrated.

Advanced theragnostics for the central nervous system (CNS) and neurological disorders using functional inorganic nanomaterials

Various types of inorganic nanomaterials are capable of diagnostic biomarker detection and the therapeutic delivery of a disease or inflammatory modulating agent. Those multi-functional nanomaterials have been utilized to treat neurodegenerative diseases and central nervous system (CNS) injuries in an effective and personalized manner. Even though many nanomaterials can deliver a payload and detect a biomarker of interest, only a few studies have yet to fully utilize this combined strategy to its full potential. Combining a nanomaterial's ability to facilitate targeted delivery, promote cellular proliferation and differentiation, and carry a large amount of material with various sensing approaches makes it possible to diagnose a patient selectively and sensitively while offering preventative measures or early disease-modifying strategies. By tuning the properties of an inorganic nanomaterial, the dimensionality, hydrophilicity, size, charge, shape, surface chemistry, and many other chemical and physical parameters, different types of cells in the central nervous system can be monitored, modulated, or further studies to elucidate underlying disease mechanisms. Scientists and clinicians have better understood the underlying processes of pathologies for many neurologically related diseases and injuries by implementing multi-dimensional 0D, 1D, and 2D theragnostic nanomaterials. The incorporation of nanomaterials has allowed scientists to better understand how to detect and treat these conditions at an early stage. To this end, having the multi-modal ability to both sense and treat ailments of the central nervous system can lead to favorable outcomes for patients suffering from such injuries and diseases.

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.

Natural resources for sustainable synthesis of nanomaterials with anticancer applications: A move toward green nanomedicine

Today, researchers have focused on the application of environmentally-benign and sustainable micro- and nanosystems for drug delivery and cancer therapy. Compared to conventional chemotherapeutics, advanced micro- and nanosystems designed by applying abundant, natural, and renewable feedstocks have shown biodegradability, biocompatibility, and low toxicity advantages. However, important aspects of toxicological assessments, clinical translational studies, and suitable functionalization/modification still need to be addressed. Herein, the benefits and challenges of green nanomedicine in cancer nanotherapy and targeted drug delivery are cogitated using nanomaterials designed by exploiting natural and renewable resources. The application of nanomaterials accessed from renewable natural resources, comprising metallic nanomaterials, carbon-based nanomaterials, metal-organic frameworks, natural-derived nanomaterials, etc. for targeted anticancer drug delivery and cancer nanotherapy are deliberated, with emphasis on important limitations/challenges and future perspectives.

An Efficient, Short Stimulus PANC-1 Cancer Cell Ablation and Electrothermal Therapy Driven by Hydrophobic Interactions

Promising results in clinical studies have been demonstrated by the utilization of electrothermal agents (ETAs) in cancer therapy. However, a difficulty arises from the balance between facilitating the degradation of ETAs, and at the same time, increasing the electrothermal performance/stability required for highly efficient treatment. In this study, we controlled the thermal signature of the MoS₂ by harnessing MoS₂ nanostructures with M13 phage (MNM) via the structural assembling (hydrophobic interaction) phenomena and developed a combined PANC-1 cancer cell-MNM alternating current (AC)-stimulus framework for cancer cell ablation and electrothermal therapy. A percentage decrease in the cell viability of ~23% was achieved, as well as a degradation time of 2 weeks; a stimulus length of 100 μs was also achieved. Molecular dynamics (MD) simulations revealed the assembling kinetics in integrated M13 phage-cancer cell protein systems and the structural origin of the hydrophobic interaction-enabled increase in thermal conduction. This study not only introduced an 'ideal' agent that avoided the limitations of ETAs but also provided a proof-of-concept application of MoS₂-based materials in efficacious cancer therapy.

A spark to the powder keg: Microneedle-based antitumor nanomedicine targeting reactive oxygen species accumulation for chemodynamic/photothermal/chemotherapy

HYPOTHESIS

Chemodynamic therapy (CDT) can efficiently kill cancer cells by producing hydroxyl radical (•OH), a kind of high-toxic reactive oxygen species (ROS), via Fenton or Fenton-like reactions. This study involved a versatile nanomedicine, MSN@DOX/GA-Fe/PDA (M@DGP), delivered via microneedles, which was expected to combine chemodynamic/photothermal/chemotherapy and efficiently increase ROS accumulation to achieve significant therapeutic efficacy against melanoma.

EXPERIMENTS

The composition of the synthesized nanoparticles was confirmed by a series of characterizations including transmission electron microscopy, Fourier transform infrared spectroscopy, and zeta potential. The photothermal properties of the nanomedicine was evaluated via infrared imaging, and •OH-producing ability was evaluated by UV-Vis and electron spin resonance. The mechanisms of ROS accumulation were studied in B16 cells by detecting intracellular •OH, glutathione, and ROS levels. The drug-loaded microneedles (M@DGP-MNs) were prepared, and their morphology and mechanical strength were characterized. The in vivo antimelanoma effect and biosafety evaluation of the nanomedicine were investigated in tumor-bearing C57 mice.

FINDINGS

M@DGP was successfully prepared and could achieve ROS accumulation through a photothermal-enhanced Fenton reaction, polydopamine-induced glutathione consumption, and doxorubicin-mediated mitochondrial dysfunction which induced oxidative stress and apoptosis of tumor cells. M@DGP-MNs showed superior antitumor efficacy and good biosafety, providing a promising strategy for melanoma treatment.

A Predictive Pharmacokinetic Model for Immune Cell-Mediated Uptake and Retention of Nanoparticles in Tumors

A promise of cancer nanomedicine is the "targeted" delivery of therapeutic agents to tumors by the rational design of nanostructured materials. During the past several decades, a realization that in vitro and in vivo preclinical data are unreliable predictors of successful clinical translation has motivated a reexamination of this approach. Mathematical models of drug pharmacokinetics (PK) and biodistribution (BD) are essential tools for small-molecule drugs development. A key assumption underlying these models is that drug-target binding kinetics dominate blood clearance, hence recognition by host innate immune cells is not explicitly included. Nanoparticles circulating in the blood are conspicuous to phagocytes, and inevitable interactions typically trigger active biological responses to sequester and remove them from circulation. Our recent findings suggest that, instead of referring to nanoparticles as designed for active or passive "tumor targeting", we ought rather to refer to immune cells residing in the tumor microenvironment (TME) as active or passive actors in an essentially "cell-mediated tumor retention" process that competes with active removal by other phagocytes. Indeed, following intravenous injection, nanoparticles induce changes in the immune compartment of the TME because of nanoparticle uptake, irrespective of the nature of tumor targeting moieties. In this study, we propose a 6-compartment PK model as an initial mathematical framework for modeling this tumor-associated immune cell-mediated retention. Published in vivo PK and BD results obtained with bionized nanoferrite® (BNF®) nanoparticles were combined with results from in vitro internalization experiments with murine macrophages to guide simulations. As a preliminary approximation, we assumed that tumor-associated macrophages (TAMs) are solely responsible for active retention in the TME. We model the TAM approximation by relating in vitro macrophage uptake to an effective macrophage avidity term for the BNF® nanoparticles under consideration.

Functionalization and Haemolytic analysis of pure superparamagnetic magnetite nanoparticle for hyperthermia application

Superparamagnetic iron oxide nanoparticles (SPIONPs) are widely used in clinical research. The single domain nanoparticles are used in magnetic fluid hyperthermia (MFH) to treat cancer. When nanoparticles are exposed to an external magnetic field, it generates heat destroying tumour cells. SPIONPs have a large surface area, so the particles tend to aggregate, which leads to the destabilization of the colloidal system. To enhance the stability and biocompatibility of the nanomaterials, it is necessary to coat the surface with biocompatible material. Magnetite (Fe3O4) is a superparamagnetic nanoparticle (SPNPs) that was functionalized with oleic acid (OA) by sol-gel process using ethanol as the solvent. The oleic acid-coated magnetite (OA-Fe3O4) was characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), UV-Visible diffuse reflectance spectroscopy (UV-DRS) and vibrating sample magnetometer (VSM). The haemolysis test has been used to investigate the haemocompatibility properties of nanomaterials. Hyperthermia study shows a high SAR value for the concentration of 1 mg/ml at the field of 600 Oe and frequency of 316 kHz. The OA coating enhanced the haemocompatibility of synthesized magnetite nanoparticles which can be used for magnetic fluid hyperthermia applications.

Superparamagnetic Iron Oxide Nanoparticles for Immunotherapy of Cancers through Macrophages and Magnetic Hyperthermia

Cancer immunotherapy has tremendous promise, but it has yet to be clinically applied in a wider variety of tumor situations. Many therapeutic combinations are envisaged to improve their effectiveness. In this way, strategies capable of inducing immunogenic cell death (e.g., doxorubicin, radiotherapy, hyperthermia) and the reprogramming of the immunosuppressive tumor microenvironment (TME) (e.g., M2-to-M1-like macrophages repolarization of tumor-associated macrophages (TAMs)) are particularly appealing to enhance the efficacy of approved immunotherapies (e.g., immune checkpoint inhibitors, ICIs). Due to their modular construction and versatility, iron oxide-based nanomedicines such as superparamagnetic iron oxide nanoparticles (SPIONs) can combine these different approaches in a single agent. SPIONs have already shown their safety and biocompatibility and possess both drug-delivery (e.g., chemotherapy, ICIs) and magnetic capabilities (e.g., magnetic hyperthermia (MHT), magnetic resonance imaging). In this review, we will discuss the multiple applications of SPIONs in cancer immunotherapy, focusing on their theranostic properties to target TAMs and to generate MHT. The first section of this review will briefly describe immune targets for NPs. The following sections will deal with the overall properties of SPIONs (including MHT). The last section is dedicated to the SPION-induced immune response through its effects on TAMs and MHT.

Synthesis and characterization of magnetic polymeric nanocomposites for pH-sensitive controlled release of methotrexate

As one of the well-known anticancer drugs, methotrexate (MTX) has been limited in clinical application due to its side effects on normal tissues. This study focused on the one-step hydrothermal synthesis and in vitro evaluation of Fe₃O₄/RGO-PEI as MTX carriers for targeted anticancer therapy. In which, the Fe₃O₄ provided magnetic response properties; RGO acted as a stage for Fe₃O₄ loading and improved the dispersion of Fe₃O₄; polyethylenimine (PEI) was used as a surface modifier and a storehouse for MTX. The prepared Fe₃O₄/RGO-PEI nanocomposites exhibited a suitable size, good stability and magnetic responsibility. And the MTX loading content and loading efficiency were calculated to be 26.6% and 90.5%, respectively. What's more, due to the diffusion and dissolution of PEI, the Fe₃O₄/RGO-PEI-MTX exhibited excellent pH-sensitivity, the values of MTX release rate (%) within 48 h at pH 5.8 and 4.0 were 64.3% and 87.4%, respectively. Furthermore, MTT assays in cancer cells (HepG2) and normal cells (HUVEC) demonstrated that Fe₃O₄/RGO-PEI-MTX exhibited high anticancer activity while low toxicity to normal cells, and also the Fe₃O₄/RGO-PEI composites were practically non-toxic. Thus, our results revealed that Fe₃O₄/RGO-PEI-MTX would be a competitive candidate for targeted delivery and controlled release of MTX.

Towards preventing exfoliation glaucoma by targeting and removing fibrillar aggregates associated with exfoliation syndrome

Exfoliation syndrome presents as an accumulation of insoluble fibrillar aggregates that commonly correlates with age and causes ocular complications, most notably open-angle glaucoma. Despite advances in understanding the pathogenesis and risk factors associated with exfoliation syndrome, there has been no significant progress in curative pharmacotherapy of this disease. It is thought that the ability to target the fibrillar aggregates associated with exfoliation may offer a new therapeutic approach, facilitating their direct removal from affected tissues. Phage display techniques yielded two peptides (LPSYNLHPHVPP, IPLLNPGSMQLS) that could differentiate between exfoliative and non-affected regions of the human lens capsule. These peptides were conjugated to magnetic particles using click chemistry to investigate their ability in targeting and removing exfoliation materials from the anterior human lens capsule. The behavior of the fibrillar materials upon binding to these magnetic particles was assessed using magnetic pins and rotating magnetic fields of various strengths. Ex vivo studies showed that the magnetic particle-peptide conjugates could generate enough mechanical force to remove large aggregates of exfoliation materials from the lens capsule when exposed to a low-frequency rotating magnetic field (5000 G, 20 Hz). Biocompatibility of targeting peptides with and without conjugated magnetic particles was confirmed using MTT cell toxicity assay, live/dead cell viability assay, and DNA fragmentation studies on primary cultured human trabecular meshwork cells. This is a novel, minimally invasive, therapeutic approach for the treatment of exfoliation glaucoma via the targeting and removal of exfoliation materials that could be applied to all tissues within the anterior segment of the eye.

Emergent magnetism and exchange bias effect in iron oxide nanocubes with tunable phase and size

We report a systematic investigation of the magnetic properties including the exchange bias (EB) effect in an iron oxide nanocube system with tunable phase and average size (10, 15, 24, 34, and 43 nm). X-ray diffraction and Raman spectroscopy reveal the presence of Fe₃O₄, FeO, andα-Fe₂O₃phases in the nanocubes, in which the volume fraction of each phase varies depending upon particle size. While the Fe₃O₄phase is dominant in all and tends to grow with increasing particle size, the FeO phase appears to coexist with the Fe₃O₄phase in 10, 15, and 24 nm nanocubes but disappears in 34 and 43 nm nanocubes. The nanocubes exposed to air resulted in anα-Fe₂O₃oxidized surface layer whose thickness scaled with particle size resulting in a shell made ofα-Fe₂O₃phase and a core containing Fe₃O₄or a mixture of both Fe₃O₄and FeO phases. Magnetometry indicates that the nanocubes undergo Morin (of theα-Fe₂O₃phase) and Verwey (of the Fe₃O₄phase) transitions at ∼250 K and ∼120 K, respectively. For smaller nanocubes (10, 15, and 24 nm), the EB effect is observed below 200 K, of which the 15 nm nanocubes showed the most prominent EB with optimal antiferromagnetic (AFM) FeO phase. No EB is reported for larger nanocubes (34 and 43 nm). The observed EB effect is ascribed to the strong interfacial coupling between the ferrimagnetic (FiM) Fe₃O₄phase and AFM FeO phase, while its absence is related to the disappearance of the FeO phase. The Fe₃O₄/α-Fe₂O₃(FiM/AFM) interfaces are found to have negligible influence on the EB. Our findings shed light on the complexity of the EB effect in mixed-phase iron oxide nanosystems and pave the way to design exchange-coupled nanomaterials with desirable magnetic properties for biomedical and spintronic applications.

Smart and Multi-Functional Magnetic Nanoparticles for Cancer Treatment Applications: Clinical Challenges and Future Prospects

Iron oxide nanoparticle (IONPs) have become a subject of interest in various biomedical fields due to their magnetism and biocompatibility. They can be utilized as heat mediators in magnetic hyperthermia (MHT) or as contrast media in magnetic resonance imaging (MRI), and ultrasound (US). In addition, their high drug-loading capacity enabled them to be therapeutic agent transporters for malignancy treatment. Hence, smartening them allows for an intelligent controlled drug release (CDR) and targeted drug delivery (TDD). Smart magnetic nanoparticles (SMNPs) can overcome the impediments faced by classical chemo-treatment strategies, since they can be navigated and release drug via external or internal stimuli. Recently, they have been synchronized with other modalities, e.g., MRI, MHT, US, and for dual/multimodal theranostic applications in a single platform. Herein, we provide an overview of the attributes of MNPs for cancer theranostic application, fabrication procedures, surface coatings, targeting approaches, and recent advancement of SMNPs. Even though MNPs feature numerous privileges over chemotherapy agents, obstacles remain in clinical usage. This review in particular covers the clinical predicaments faced by SMNPs and future research scopes in the field of SMNPs for cancer theranostics.

Biochemical changes of macrophages and U87MG cells occurring as a result of the exposure to iron oxide nanoparticles detected with the Raman microspectroscopy

The core size of iron oxide nanoparticles (IONPs) is a crucial factor defining not only their magnetic properties but also toxicological profile and biocompatibility. On the other hand, particular IONPs may induce different biological response depending on the dose, exposure time, but mainly depending on the examined system. New light on this problem may be shed by the information concerning biomolecular anomalies appearing in various cell lines in response to the action of IONPs with different core diameters and this was accomplished in the present study. Using Raman microscopy we studied the abnormalities in the accumulation of proteins, lipids and organic matter within the nucleus, cytoplasm and cellular membrane of macrophages, HEK293T and U87MG cell line occurring as a result of 24-hour long exposure to PEG-coated magnetite IONPs. The examined nanoparticles had 5, 10 and 30 nm cores and were administered in doses 5 and 25 μg Fe/ml. The obtained results showed significant anomalies in biochemical composition of macrophages and the U87MG cells, but not the HEK293T cells, occurring as a result of exposure to all of the examined nanoparticles. However, IONPs with 10 nm core diminished the accumulation of biomolecules in cells only when they were administered at a larger dose. The Raman spectra recorded for the macrophages subjected to 30 nm IONPs and for the U87MG cells exposed to 5 and 10 nm showed the presence of additional bands in the wavenumber range 1700-2400 cm^-1, probably resulting from the appearance of Fe adducts within cells. Our results indicate, moreover, that smaller IONPs may be effectively internalized into the U87MG cells, which points at their diagnostic/therapeutic potential in the case of glioblastoma multiforme.

Engineering nanosystems to overcome barriers to cancer diagnosis and treatment

Over the past two decades, multidisciplinary investigations into the development of nanoparticles for medical applications have continually increased. However, nanoparticles are still subject to biological barriers and biodistribution challenges, which limit their overall clinical potential. This has motivated the implementation of innovational modifications to a range of nanoparticle formulations designed for cancer imaging and/or cancer treatment to overcome specific barriers and shift the accumulation of payloads toward the diseased tissues. In recent years, novel technological and chemical approaches have been employed to modify or functionalize the surface of nanoparticles or manipulate the characteristics of nanoparticles. Combining these approaches with the identification of critical biomarkers provides new strategies for enhancing nanoparticle specificity for both cancer diagnostic and therapeutic applications. This review discusses the most recent advances in the design and engineering of nanoparticles as well as future directions for developing the next generation of nanomedicines.

In Situ Programming of Nanovaccines for Lymph Node-Targeted Delivery and Cancer Immunotherapy

In situ cancer vaccines consisting of antigens and adjuvants are a promising cancer treatment modality; however, the convenient manufacture of vaccines in vivo and their efficient delivery to lymph nodes (LNs) remains a major challenge. Herein, we outline a facile approach to simultaneously achieve the in situ programming of vaccines via two synergetic nanomedicines, Tu-NP_FN and Ln-NP_R848. Tu-NP_FN (∼100 nm) generated a large number of antigens under an alternating magnetic field, and Ln-NP_R848 (∼35 nm) encapsulating adjuvant R848 captured a portion of generated antigens for the manufacture of nanovaccines in situ and LN-targeted delivery, which significantly promoted the uptake and maturation of dendritic cells to initiate potent anticancer immune responses. Notably, combined with an anti-CTLA4 antibody (aCTLA-4), this therapy completely eradicated distant tumors in some mice and exerted a long-term immune memory effect on tumor metastasis. This study provides a generalizable strategy for in situ cancer vaccination.

Greener synthesis of nanostructured iron oxide for medical and sustainable agro-environmental benefits

Nanoscale iron oxide-based nanostructures are among the most apparent metallic nanostructures, having great potential and attracting substantial interest due to their unique superparamagnetic properties. The green production of nanostructures has received abundant attention and been actively explored recently because of their various beneficial applications and properties across different fields. The biosynthesis of the nanostructure using green technology by the manipulation of a wide variety of plant materials has been the focus because it is biocompatible, non-toxic, and does not include any harmful substances. Biological methods using agro-wastes under green synthesis have been found to be simple, environmentally friendly, and cost-effective in generating iron oxide-based nanostructures instead of physical and chemical methods. Polysaccharides and biomolecules in agro-wastes could be utilized as stabilizers and reducing agents for the green production of nanostructured iron oxide towards a wide range of benefits. This review discusses the green production of iron oxide-based nanostructures through a simple and eco-friendly method and its potential applications in medical and sustainable agro-environments. This overview provides different ways to expand the usage of iron oxide nanomaterials in different sectors. Further, provided the options to select an appropriate plant towards the specific applications in agriculture and other sectors with the recommended future directions.

Rapid microwave synthesis of magnetic nanoparticles in physiological serum

Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are more and more used in biomedical applications such as therapy (treatment for certain cancers, hyperthermia), diagnostic (contrast agent for Magnetic Resonance Imaging) or both. For these applications, SPIONs must be stable in an aqueous solution, monodisperse, with a narrow size distribution and without aggregation. To obtain these nanoparticles, a microwave process is carried out in this study as an easy, fast and reproducible synthesis method. Currently, in the literature, most synthesis of SPIONs are in ultra-pure water or another solvent. To consider the use of SPIONs in biomedical applications, it is essential to ensure the preservation of the physico-chemical parameters of the nanoparticles in the physiological medium to validate a synthesis process. With this objective, this study reports a comparison between the SPIONs synthesis in ultra-pure water and the SPIONs direct synthesis in a physiological serum (containing NaCl). To complete this comparison, the dispersion of SPIONs in physiological serum after an elaboration in ultra-pure water is reported. Characterizations of these different SPIONs samples are carried out to determine the physico-chemical parameters and magnetic properties. SPIONs are characterized by Transmission Electronic Microscopy, Dynamic Light Scattering, X-Ray Diffraction, Raman spectroscopy and magnetic measurements. Finally, to check if SPIONs can be used as contrast agent for MRI, a relaxometry measurement is performed.

Proteomics unite traditional toxicological assessment methods to evaluate the toxicity of iron oxide nanoparticles

Iron oxide nanoparticles (IONPs) are the first generation of nanomaterials approved by the Food and Drug Administration for use as imaging agents and for the treatment of iron deficiency in chronic kidney disease. However, several IONPs-based imaging agents have been withdrawn because of toxic effects and the poor understanding of the underlying mechanisms. This study aimed to evaluate IONPs toxicity and to elucidate the underlying mechanism after intravenous administration in rats. Seven-week-old rats were intravenously administered IONPs at doses of 0, 10, 30, and 90 mg/kg body weight for 14 consecutive days. Toxicity and molecular perturbations were evaluated using traditional toxicological assessment methods and proteomics approaches, respectively. The administration of 90 mg/kg IONPs induced mild toxic effects, including abnormal clinical signs, lower body weight gain, changes in serum biochemical and hematological parameters, and increased organ coefficients in the spleen, liver, heart, and kidneys. Toxicokinetics, tissue distribution, histopathological, and transmission electron microscopy analyses revealed that the spleen was the primary organ for IONPs elimination from the systemic circulation and that the macrophage lysosomes were the main organelles of IONPs accumulation after intravenous administration. We identified 197 upregulated and 75 downregulated proteins in the spleen following IONPs administration by proteomics. Mechanically, the AKT/mTOR/TFEB signaling pathway facilitated autophagy and lysosomal activation in splenic macrophages. This is the first study to elucidate the mechanism of IONPs toxicity by combining proteomics with traditional methods for toxicity assessment.

Toxicological effects of the mixed iron oxide nanoparticle (Fe3O4 NP) on murine fibroblasts LA-9

The increase in large-scale production of magnetic nanoparticles (NP) associated with the incomplete comprehensive knowledge regarding the potential risks of their use on environmental and human health makes it necessary to study the biological effects of these particles on organisms at the cellular level. The aim of this study to examine the cellular effects on fibroblast lineage LA-9 after exposure to mixed iron oxide NP (Fe₃O₄ NP). The following analyses were performed: field emission gun-scanning electron microscopy (SEM-FEG), dynamic light scattering (DLS), zeta potential, ultraviolet/visible region spectroscopy (UV/VIS), and attenuated total reactance-Fourier transform infrared (ATR-FTIR) spectroscopy analyses for characterization of the NP. The assays included cell viability, morphology, clonogenic potential, oxidative stress as measurement of reactive oxygen species (ROS) and nitric oxide (NO) levels, cytokines quantification interleukin 6 (IL-6) and tumor necrosis factor (TNF), NP uptake, and cell death. The size of Fe₃O₄ NP was 26.3 nm when evaluated in water through DLS. Fe₃O₄ NP did not reduce fibroblast cell viability until the highest concentration tested (250 µg/ml), which showed a decrease in clonogenic potential as well as small morphological changes after exposure for 48 and 72 hr. The NP concentration of 250 µg/ml induced enhanced ROS and NO production after 24 hr treatment. The uptake assay exhibited time-dependent Fe₃O₄ NP internalization at all concentrations tested with no significant cell death. Hence, exposure of fibroblasts to Fe₃O₄ NP-induced oxidative stress but not reduced cell viability or death. However, the decrease in the clonogenic potential at the highest concentration demonstrates cytotoxic effects attributed to Fe₃O₄ NP which occurred on the 7^th day after exposure.

Current Challenges in Image-Guided Magnetic Hyperthermia Therapy for Liver Cancer

For patients diagnosed with advanced and unresectable hepatocellular carcinoma (HCC), liver transplantation remains the best option to extend life. Challenges with organ supply often preclude liver transplantation, making palliative non-surgical options the default front-line treatments for many patients. Even with imaging guidance, success following treatment remains inconsistent and below expectations, so new approaches are needed. Imaging-guided thermal therapy interventions have emerged as attractive procedures that offer individualized tumor targeting with the potential for the selective targeting of tumor nodules without impairing liver function. Furthermore, imaging-guided thermal therapy with added standard-of-care chemotherapies targeted to the liver tumor can directly reduce the overall dose and limit toxicities commonly seen with systemic administration. Effectiveness of non-ablative thermal therapy (hyperthermia) depends on the achieved thermal dose, defined as time-at-temperature, and leads to molecular dysfunction, cellular disruption, and eventual tissue destruction with vascular collapse. Hyperthermia therapy requires controlled heat transfer to the target either by in situ generation of the energy or its on-target conversion from an external radiative source. Magnetic hyperthermia (MHT) is a nanotechnology-based thermal therapy that exploits energy dissipation (heat) from the forced magnetic hysteresis of a magnetic colloid. MHT with magnetic nanoparticles (MNPs) and alternating magnetic fields (AMFs) requires the targeted deposition of MNPs into the tumor, followed by exposure of the region to an AMF. Emerging modalities such as magnetic particle imaging (MPI) offer additional prospects to develop fully integrated (theranostic) systems that are capable of providing diagnostic imaging, treatment planning, therapy execution, and post-treatment follow-up on a single platform. In this review, we focus on recent advances in image-guided MHT applications specific to liver cancer.

Functionalized Magnetic Nanoparticles for Alternating Magnetic Field- or Near Infrared Light-Induced Cancer Therapies

The multi-faceted nature of functionalized magnetic nanoparticles (fMNPs) is well-suited for cancer therapy. These nanocomposites can also provide a multimodal platform for targeted cancer therapy due to their unique magnetic guidance characteristics. When induced by an alternating magnetic field (AMF), fMNPs can convert the magnetostatic energy to heat for magnetic hyperthermia (MHT), as well as for controlled drug release. Furthermore, with the ability to convert near-infrared (NIR) light energy to heat energy, fMNPs have attracted interest for photothermal therapy (PTT). Other than MHT and PTT, fMNPs also have a place in combination cancer therapies, such as chemo-MHT, chemo-PTT, and chemo-PTT-photodynamic therapy, among others, due to their versatile properties. Thus, this review presents multifunctional nanocomposites based on fMNPs for cancer therapies, induced by an AMF or NIR light. We will first discuss the different fMNPs induced with an AMF for cancer MHT and chemo-MHT. Secondly, we will discuss fMNPs irradiated with NIR lasers for cancer PTT and chemo-PTT. Finally, fMNPs used for dual-mode AMF + NIR-laser-induced magneto-photo-hyperthermia (MPHT) will be discussed.

Iron oxide nanoparticles for biomedical applications: an updated patent review (2015-2021)

INTRODUCTION

Iron oxide nanoparticles (IONPs) hold the edges of great magnetic properties and fine nanoparticle characteristics, making them an attractive therapeutic agent. In the past seven years, more in-depth investigations were devoted to the intrinsic structure, magnetic properties, and biological effects of IONPs, expanding the range of their therapeutic application scenes.

AREAS COVERED

This review focuses on the development of IONPs for biomedical applications from the angle of the patent literature reported during the period 2015-2021.

EXPERT OPINION

While the magnetic properties of IONPs have been extensively explored, the precise control of IONP behavior through external magnetic fields remains a challenge. Further digging into the biological effects of IONPs will facilitate the development of IONP-based immune therapies. Long-term reliable safety evaluations are of necessity and significance to promote the process of clinical translation.

Research Progress of Photothermal Nanomaterials in Multimodal Tumor Therapy

The aggressive growth of cancer cells brings extreme challenges to cancer therapy while triggering the exploration of the application of multimodal therapy methods. Multimodal tumor therapy based on photothermal nanomaterials is a new technology to realize tumor cell thermal ablation through near-infrared light irradiation with a specific wavelength, which has the advantages of high efficiency, less adverse reactions, and effective inhibition of tumor metastasis compared with traditional treatment methods such as surgical resection, chemotherapy, and radiotherapy. Photothermal nanomaterials have gained increasing interest due to their potential applications, remarkable properties, and advantages for tumor therapy. In this review, recent advances and the common applications of photothermal nanomaterials in multimodal tumor therapy are summarized, with a focus on the different types of photothermal nanomaterials and their application in multimodal tumor therapy. Moreover, the challenges and future applications have also been speculated.

LAPONITE® nanodisk-"decorated" Fe3O4 nanoparticles: a biocompatible nano-hybrid with ultrafast magnetic hyperthermia and MRI contrast agent ability

Magnetic Fe₃O₄ nanoparticles "decorated" by LAPONITE® nanodisks have been materialized utilizing the Schikorr reaction following a facile approach and tested as mediators of heat for localized magnetic hyperthermia (MH) and as magnetic resonance imaging (MRI) agents. The synthetic protocol involves the interaction between two layered inorganic compounds, ferrous hydroxide, Fe(OH)₂, and the synthetic smectite LAPONITE® clay Na_0.7⁺[(Si₈Mg_5.5Li_0.3)O₂₀(OH)₄]_0.7^-, towards the formation of superparamagnetic Fe₃O₄ nanoparticles, which are well decorated by the diamagnetic clay nanodisks. The latter imparts high negative ζ-potential values (up to -34.1 mV) to the particles, which provide stability against flocculation and precipitation, resulting in stable water dispersions. The obtained LAPONITE®-"decorated" Fe₃O₄ nanohybrids were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Mössbauer spectroscopy, dynamic light scattering (DLS) and vibrating sample magnetometry (VSM) at room temperature, revealing superior magnetic hyperthermia performance with specific absorption rate (SAR) values reaching 540 W g_Fe^-1 (28 kA m^-1, 150 kHz) for the hybrid material with a magnetic loading of 50 wt% Fe₃O₄/LAPONITE®. Toxicity studies were also performed with human glioblastoma (GBM) cells and human foreskin fibroblasts (HFF), which show negligible to no toxicity. Furthermore, T₂-weighted MR imaging of rodent brain shows that the LAPONITE®-"decorated" Fe₃O₄ nanohybrids predominantly affected the transverse T₂ relaxation time of tissue water, which resulted in a signal drop on the MRI T₂-weighted imaging, allowing for imaging of the magnetic nanoparticles.

Trends in iron oxide nanoparticles: a nano-platform for theranostic application in breast cancer

Breast cancer (BC) is the deadliest malignant disorder globally, with a significant mortality rate. The development of tolerance throughout cancer treatment and non-specific targeting limits the drug's response. Currently, nano therapy provides an interdisciplinary area for imaging, diagnosis, and targeted drug delivery for BC. Several overexpressed biomarkers, proteins, and receptors are identified in BC, which can be potentially targeted by using nanomaterial for drug/gene/immune/photo-responsive therapy and bio-imaging. In recent applications, magnetic iron oxide nanoparticles (IONs) have shown tremendous attention to the researcher because they combine selective drug delivery and imaging functionalities. IONs can be efficaciously functionalised for potential application in BC therapy and diagnosis. In this review, we explored the current application of IONs in chemotherapeutics delivery, gene delivery, immunotherapy, photo-responsive therapy, and bio-imaging for BC based on their molecular mechanism. In addition, we also highlighted the effect of IONs' size, shape, dimension, and functionalization on BC targeting and imaging. To better comprehend the functionalization potential of IONs, this paper provides an outline of BC cellular development. IONs for BC theranostic are also reviewed based on their clinical significance and future aspects.

Highly efficient magnetic ablation and the contrast of various imaging using biocompatible liquid-metal gallium

Background

Although the powerful clinical effects of radiofrequency and microwave ablation have been established, such ablation is associated with several limitations, including a small ablation size, a long ablation time, the few treatment positioning, and biosafety risks. To overcome these limitations, biosafe and efficient magnetic ablation was achieved in this study by using biocompatible liquid gallium as an ablation medium and a contrast medium for imaging.

Results

Magnetic fields with a frequency (f) lower than 200 kHz and an amplitude (H) × f value lower than 5.0 × 10⁹ Am⁻¹ s⁻¹ were generated using the proposed method. These fields could generate an ablation size of 3 cm in rat liver lobes under a temperature of approximately 300 °C and a time of 20 s. The results of this study indicate that biomedical gallium can be used as a contrast medium for the positioning of gallium injections and the evaluation of ablated tissue around a target site. Liquid gallium can be used as an ablation medium and imaging contrast medium because of its stable retention in normal tissue for at least 3 days. Besides, the high anticancer potential of gallium ions was inferred from the self-degradation of 100 µL of liquid gallium after around 21 days of immersion in acidic solutions.

Conclusions

The rapid wireless ablation of large or multiple lesions was achieved through the simple multi-injection of liquid gallium. This approach can replace the currently favoured procedure involving the use of multiple ablation probes, which is associated with limited benefits and several side effects.

Methods

Magnetic ablation was confirmed to be highly efficient by the consistent results obtained in the simulation and in vitro tests of gallium and iron oxide as well as the electromagnetic specifics and thermotherapy performance comparison detailed in this study Ultrasound imaging, X-ray imaging, and magnetic resonance imaging were found to be compatible with the proposed magnetic ablation method. Self-degradation analysis was conducted by mixing liquid gallium in acidic solutions with a pH of approximately 5–7 (to imitate a tumour-containing microenvironment). X-ray diffraction was used to identify the gallium oxides produced by degraded gallium ions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12938-022-01003-9.

Biomedical applications of metallic nanoparticles in cancer: Current status and future perspectives

The current advancements in nanotechnology are as an outcome of the development of engineered nanoparticles. Various metallic nanoparticles have been extensively explored for various biomedical applications. They attract lot of attention in biomedical field due to their significant inert nature, and nanoscale structures, with size similar to many biological molecules. Their intrinsic characteristics which include electronic, optical, physicochemical and, surface plasmon resonance, that can be changed by altering certain particle characteristics such as size, shape, environment, aspect ratio, ease of synthesis and functionalization properties have led to numerous applications in various fields of biomedicine. These include targeted drug delivery, sensing, photothermal and photodynamic therapy, imaging, as well as the modulation of two or three applications. The current article also discusses about the various properties of metallic nanoparticles and their applications in cancer imaging and therapeutics. The associated bottlenecks related to their clinical translation are also discussed.

Recent advances in engineering iron oxide nanoparticles for effective magnetic resonance imaging

Iron oxide nanoparticle (IONP) with unique magnetic property and high biocompatibility have been widely used as magnetic resonance imaging (MRI) contrast agent (CA) for long time. However, a review which comprehensively summarizes the recent development of IONP as traditional T₂ CA and its new application for different modality of MRI, such as T₁ imaging, simultaneous T₂/T₁ or MRI/other imaging modality, and as environment responsive CA is rare. This review starts with an investigation of direction on the development of high-performance MRI CA in both T₂ and T₁ modal based on quantum mechanical outer sphere and Solomon–Bloembergen–Morgan (SBM) theory. Recent rational attempts to increase the MRI contrast of IONP by adjusting the key parameters, including magnetization, size, effective radius, inhomogeneity of surrounding generated magnetic field, crystal phase, coordination number of water, electronic relaxation time, and surface modification are summarized. Besides the strategies to improve r₂ or r₁ values, strategies to increase the in vivo contrast efficiency of IONP have been reviewed from three different aspects, those are introducing second imaging modality to increase the imaging accuracy, endowing IONP with environment response capacity to elevate the signal difference between lesion and normal tissue, and optimizing the interface structure to improve the accumulation amount of IONP in lesion. This detailed review provides a deep understanding of recent researches on the development of high-performance IONP based MRI CAs. It is hoped to trigger deep thinking for design of next generation MRI CAs for early and accurate diagnosis.

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T₂ contrast capacity of iron oxide nanoparticles (IONPs) could be improved based on quantum mechanical outer sphere theory.

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IONPs could be expand to be used as effective T₁ CAs by improving q value, extending τ_s, and optimizing interface structure.

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Environment responsive MRI CAs have been developed to improve the diagnosis accuracy.

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Introducing other imaging contrast moiety into IONPs could increase the contrast efficiency.

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Optimizing in vivo behavior of IONPs have been proved to enlarge the signal difference between normal tissue and lesion.

Synchronous Disintegration of Ferroptosis Defense Axis via Engineered Exosome-Conjugated Magnetic Nanoparticles for Glioblastoma Therapy

Glioblastoma (GBM) is one of the most fatal central nervous system tumors and lacks effective or sufficient therapies. Ferroptosis is a newly discovered method of programmed cell death and opens a new direction for GBM treatment. However, poor blood-brain barrier (BBB) penetration, reduced tumor targeting ability, and potential compensatory mechanisms hinder the effectiveness of ferroptosis agents during GBM treatment. Here, a novel composite therapeutic platform combining the magnetic targeting features and drug delivery properties of magnetic nanoparticles with the BBB penetration abilities and siRNA encapsulation properties of engineered exosomes for GBM therapy is presented. This platform can be enriched in the brain under local magnetic localization and angiopep-2 peptide-modified engineered exosomes can trigger transcytosis, allowing the particles to cross the BBB and target GBM cells by recognizing the LRP-1 receptor. Synergistic ferroptosis therapy of GBM is achieved by the combined triple actions of the disintegration of dihydroorotate dehydrogenase and the glutathione peroxidase 4 ferroptosis defense axis with Fe3 O4 nanoparticle-mediated Fe2+ release. Thus, the present findings show that this system can serve as a promising platform for the treatment of glioblastoma.

Biological interactions of ferromagnetic iron oxide-carbon nanohybrids with alveolar epithelial cells

Iron oxide nanoparticles (IONPs) have been largely investigated in a plethora of biological fields for their interesting physical-chemical properties, which make them suitable for application in cancer therapy, neuroscience, and imaging. Several encouraging results have been reported in these contexts. However, the possible toxic effects of some IONP formulations can limit their applicability. In this work, IONPs were synthesized with a carbon shell (IONP@C), providing enhanced stability both as colloidal dispersion and in the biological environment. We conducted a careful multiparametric evaluation of IONP@C biological interactions in vitro, providing them with an in vivo-like biological identity. Our hybrid nanoformulation showed no cytotoxic effects on a widely employed model of alveolar epithelial cells for a variety of concentrations and exposure times. The IONP@C were efficiently internalized and TEM analysis allowed the protective role of the carbon shell against intracellular degradation to be assessed. Intracellular redistribution of the IONP@C from the lysosomes to the lamellar bodies was also observed after 72 hours.

One-Pot, One-Step Synthesis of Drug-Loaded Magnetic Multimicelle Aggregates

Lipid-based formulations provide a nanotechnology platform that is widely used in a variety of biomedical applications because it has several advantageous properties including biocompatibility, reduced toxicity, relative ease of surface modifications, and the possibility for efficient loading of drugs, biologics, and nanoparticles. A combination of lipid-based formulations with magnetic nanoparticles such as iron oxide was shown to be highly advantageous in a growing number of applications including magnet-mediated drug delivery and image-guided therapy. Currently, lipid-based formulations are prepared by multistep protocols. Simplification of the current multistep procedures can lead to a number of important technological advantages including significantly decreased processing time, higher reaction yield, better product reproducibility, and improved quality. Here, we introduce a one-pot, single-step synthesis of drug-loaded magnetic multimicelle aggregates (MaMAs), which is based on controlled flow infusion of an iron oxide nanoparticle/lipid mixture into an aqueous drug solution under ultrasonication. Furthermore, we prepared molecular-targeted MaMAs by directional antibody conjugation through an Fc moiety using Cu-free click chemistry. Fluorescence imaging and quantification confirmed that antibody-conjugated MaMAs showed high cell-specific targeting that was enhanced by magnetic delivery.

Nanodrugs Detonate Lysosome Bombs

Cancer cell lysosomes contain various hydrolases and non-degraded substrates that are corrosive enough to destroy cancer cells. However, many traditional small molecule drugs targeting lysosomes have strong side effects because they cannot effectively differentiate between normal and cancer cells. Most lysosome-based research has focused on inducing mild lysosomal membrane permeabilization (LMP) to release anticancer drugs from lysosomal traps into the cancer cell cytoplasm. In fact, lysosomes are particularly powerful "bombs". Achieving cancer cell-selective LMP induction may yield high-efficiency anticancer effects and extremely low side effects. Nanodrugs have diverse and combinable properties and can be specifically designed to selectively induce LMP in cancer cells by taking advantage of the differences between cancer cells and normal cells. Although nanodrugs-induced LMP has made great progress recently, related reviews remain rare. Herein, we first comprehensively summarize the advances in nanodrugs-induced LMP. Next, we describe the different nanodrugs-induced LMP strategies, namely nanoparticles aggregation-induced LMP, chemodynamic therapy (CDT)-induced LMP, and magnetic field-induced LMP. Finally, we analyze the prospect of nanodrugs-induced LMP and the challenges to overcome. We believe this review provides a unique perspective and inspiration for designing lysosome-targeting drugs.

Designing the Surface Chemistry of Inorganic Nanocrystals for Cancer Imaging and Therapy

Inorganic nanocrystals, such as gold, iron oxide and semiconductor quantum dots, offer promising prospects for cancer diagnostics, imaging and therapy, due to their specific plasmonic, magnetic or fluorescent properties. The organic coating, or surface ligands, of these nanoparticles ensures their colloidal stability in complex biological fluids and enables their functionalization with targeting functions. It also controls the interactions of the nanoparticle with biomolecules in their environment. It therefore plays a crucial role in determining nanoparticle biodistribution and, ultimately, the imaging or therapeutic efficiency. This review summarizes the various strategies used to develop optimal surface chemistries for the in vivo preclinical and clinical application of inorganic nanocrystals. It discusses the current understanding of the influence of the nanoparticle surface chemistry on its colloidal stability, interaction with proteins, biodistribution and tumor uptake, and the requirements to develop an optimal surface chemistry.

Clinical magnetic hyperthermia requires integrated magnetic particle imaging

Magnetic nanomaterials that respond to clinical magnetic devices have significant potential as cancer nanotheranostics. The complexities of their physics, however, introduce challenges for these applications. Hyperthermia is a heat‐based cancer therapy that improves treatment outcomes and patient survival when controlled energy delivery is combined with accurate thermometry. To date, few technologies have achieved the needed evolution for the demands of the clinic. Magnetic fluid hyperthermia (MFH) offers this potential, but to be successful it requires particle‐imaging technology that provides real‐time thermometry. Presently, the only technology having the potential to meet these requirements is magnetic particle imaging (MPI), for which a proof‐of‐principle demonstration with MFH has been achieved. Successful clinical translation and adoption of integrated MPI/MFH technology will depend on successful resolution of the technological challenges discussed.

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging

Targeted Delivery of DNA Topoisomerase Inhibitor SN38 to Intracranial Tumors of Glioblastoma Using Sub-5 Ultrafine Iron Oxide Nanoparticles

Effectively delivering therapeutics for treating brain tumors is hindered by the physical and biological barriers in the brain. Even with the compromised blood-brain barrier and highly angiogenic blood-tumor barrier seen in glioblastoma (GBM), most drugs, including nanomaterial-based formulations, hardly reach intracranial tumors. This work investigates sub-5 nm ultrafine iron oxide nanoparticles (uIONP) with 3.5 nm core diameter as a carrier for delivering DNA topoisomerase inhibitor 7-ethyl-10-hydroxyl camptothecin (SN38) to treat GBM. Given a higher surface-to-volume ratio, uIONP shows one- or three-folds higher SN38 loading efficiency (48.3 ± 6.1%, mg/mg Fe) than those with core sizes of 10 or 20 nm. SN38 encapsulated in the coating polymer exhibits pH sensitive release with <10% over 48 h at pH 7.4, but 86% at pH 5, thus being protected from converting to inactive glucuronide by UDP-glucuronosyltransferase 1A1. Conjugating α_v β₃ -integrin-targeted cyclo(Arg-Gly-Asp-D-Phe-Cys) (RGD) as ligands, RGD-uIONP/SN38 demonstrates targeted cytotoxicity to α_v β₃ -integrin-overexpressed U87MG GBM cells with a half-maximal inhibitory concentration (IC₅₀ ) of 30.9 ± 2.2 nm. The efficacy study using an orthotopic mouse model of GBM reveals tumor-specific delivery of 11.5% injected RGD-uIONP/SN38 (10 mg Fe kg^-1 ), significantly prolonging the survival in mice by 41%, comparing to those treated with SN38 alone (p < 0.001).

Bionized Nanoferrite Particles Alter the Course of Experimental Cryptococcus neoformans Pneumonia

Cryptococcosis is a devastating fungal disease associated with high morbidity and mortality even when treated with antifungal drugs. Bionized nanoferrite (BNF) nanoparticles are powerful immunomodulators, but their efficacy for infectious diseases has not been investigated. Administration of BNF nanoparticles to mice with experimental cryptococcal pneumonia altered the outcome of infection in a dose response manner as measured by CFU and survival. The protective effects were higher at lower doses, with reductions in IL-2, IL-4, and TNF-α, consistent with immune modulation whereby reductions in inflammation translate into reduced host damage, clearance of infection, and longer survival.

Biomimetic GBM-targeted drug delivery system boosting ferroptosis for immunotherapy of orthotopic drug-resistant GBM

Background

Clinical studies have shown that the efficacy of programmed cell death receptor-1/programmed cell death ligand-1 (PD-1/PD-L1) inhibitors on glioblastoma (GBM) is much lower than what is expected because of the low immunogenicity of GBM. Ferroptosis of cancer cells can induce the maturation of dendritic cells (DC cells) and increase the activity of T cell. The activated T cells release IFN-γ, which subsequently induces the ferroptosis of cancer cells. Thus, the aim of this paper is to set up a new GBM-targeted drug delivery system (Fe₃O₄-siPD-L1@M_-BV2) to boost ferroptosis for immunotherapy of drug-resistant GBM.

Results

Fe₃O₄-siPD-L1@M_-BV2 significantly increased the accumulation of siPD-L1 and Fe²⁺ in orthotopic drug-resistant GBM tissue in mice. Fe₃O₄-siPD-L1@M_-BV2 markedly decreased the protein expression of PD-L1 and increased the ratio between effector T cells and regulatory T cells in orthotopic drug-resistant GBM tissue. Moreover, Fe₃O₄-siPD-L1@M_-BV2 induced ferroptosis of GBM cells and maturation of DC cell, and it also increased the ratio between M1-type microglia and M2-type microglia in orthotopic drug-resistant GBM tissue. Finally, the growth of orthotopic drug-resistant GBM in mice was significantly inhibited by Fe₃O₄-siPD-L1@M_-BV2.

Conclusion

The mutual cascade amplification effect between ferroptosis and immune reactivation induced by Fe₃O₄-siPD-L1@M_-BV2 significantly inhibited the growth of orthotopic drug-resistant GBM and prolonged the survival time of orthotopic drug-resistant GBM mice.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01360-6.

Iron Oxide Nanoparticles: Preparation, Characterization, and Assessment of Antimicrobial and Anticancer Activity

Nanotechnology and nanoparticles (NPs) have increasingly been studied as an alternative for antibiotics because of the feasibility to be used in implantable devices both for bacterial detection and infection prevention. The low rate of resistance development against NPs because of its multiple mode of action has contributed to its increased acceptance in clinical setting. Further development of NPs and their anticancer activity against many human cancer cell lines including breast and ovarian have been documented. Fe2O3-NPs could be used for antibacterial and anticancer activity assessment. Iron oxide, apart from being available extensively and cheap, also plays a role in multiple biological processes, making it an interesting metal for NPs. The aim of the present study revolves around generation and characterization of iron oxide Fe2O3-NPs, followed by assessment of its antimicrobial and anticancer activities. Synthesis of Fe2O3-NPs was performed by hydrothermal approach, and its characterization was done by UV-visible, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) analyses, and transmission electron microscopy (TEM). Antimicrobial activity was checked by agar diffusion assay against Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Candida albicans. Anticancer activity of the NPs was assessed using the human cancer cell lines including cervical carcinoma cell line (HeLa) and MCF7. The developed Fe2O3-NPs exhibited a characteristic absorption curve in the 500-600 nm wavelength range by UV-visible analysis, the XRD peaks were found to index the rhombohedral shape, and the FTIR analysis ascertained the bonds and functional groups at wavenumber from 400 to 4000 cm-1. Antimicrobial assay detected significant effect against Staphylococcus aureus and Bacillus subtilis with zones of inhibition: 21 and 22 mm, respectively. Likewise, Fe2O3-NPs show good activity towards tested fungal strain Candida albicans with zone of inhibition of 24 mm. The 2,5-diphenyl-2H-tetrazolium bromide (MTT) assay identified significant anticancer activity of the NPs against both cell lines. Our study documents the successful generation and characterization of Fe2O3-NPs having excellent antimicrobial and anticancer activities.

Current advances in the imaging of atherosclerotic vulnerable plaque using nanoparticles

Vulnerable atherosclerotic plaques of the artery wall that pose a significant risk of cardio-cerebral vascular accidents remain the global leading cause of morbidity and mortality. Thus, early delineation of vulnerable atherosclerotic plaques is of clinical importance for prevention and treatment. The currently available imaging technologies mainly focus on the structural assessment of the vascular wall. Unfortunately, several disadvantages in these strategies limit the improvement in imaging effect. Nanoparticle technology is a novel diagnostic strategy for targeting and imaging pathological biomarkers. New functionalized nanoparticles that detect hallmarks of vulnerable plaques are promising for advance further control of this critical illness. The review aims to address the current opportunities and challenges for the use of nanoparticle technology in imagining vulnerable plaques.