Biomechanical sensing of in vivo magnetic nanoparticle hyperthermia-treated melanoma using magnetomotive optical coherence elastography

In-situ injectable hydrogel for near-infrared-regulated hyperthermic perfusion therapy of triple-negative breast cancer

Hyperthermic perfusion therapy (HPT) is an emerging and effective treatment for intracavitary tumors, involving circulating a heated solution directly into body cavities such as the peritoneal or pleural spaces, targeting tumors more effectively while minimizing systemic toxicity. However, the clinical application of HPT is currently restricted to intracavitary tumors, and its efficacy is hampered by the up-regulation of thermal stress resistance genes, which enhance the thermal tolerance of cancer cells. Herein, we developed a temperature-sensitive methyl cellulose hydrogel with injectability and removability to enable targeted HPT for the triple-negative breast cancer (TNBC). Using bioinformatics screening, we identified 17-allylamino-17-demethoxygeldanamycin as a potent inhibitor and incorporated it alongside biocompatible cuttlefish ink-derived nanoparticles (CINPs), a natural photothermal agent, into the temperature-sensitive hydrogel. Under near-infrared (NIR) irradiation, CINPs mediate photothermal tumor ablation, while 17-allylamino-17-demethoxygeldanamycin reduces tumor cell resistance to hyperthermia. Moreover, the temperature-responsive phase transition of the hydrogel allows for its complete removal post-treatment, extending the scope of HPT beyond intracavitary tumors and minimizing inflammation at the injection site. This material-engineered HPT approach, achieved remarkable outcomes in both orthotopic and metastatic tumor models, inhibiting breast cancer progression and lung metastasis. These findings highlight the potential of materials-based HPT as an effective treatment for TNBC.

Magnesium‑phosphorus gel containing oxygen vacancy niobium oxide with photothermal property for treating tumor, preventing infection and facilitating bone generation

It is essential to design multifunctional biomaterials for pro-osteogenesis, rooting out residual tumor cells and resisting infection after surgical resection of bone tumors. Herein, niobium oxide with oxygen vacancy (NbOv) was synthesized through a deoxidation reaction, which exhibited photothermal property because of strong light absorption in near-infrared (NIR) region. Subsequently, magnesium‑phosphorus gel composite (MP) containing NbOv (MPNOv) was fabricated, which also possessed photothermal property that effectively ablated tumor cells and eradicated bacteria under NIR irradiation in vitro. The in vitro experiments confirmed that compared with MP, MPNOv significantly boosted bone mesenchymal stem cells responses (e.g., propagation and osteoblastic differentiation) due to the presence of NbOv with bioactivity. The in vivo experiments demonstrate that MPNOv fostered bone generation and prevented tumor recurrence as well as infection. In short, MPNOv with good biocompatibility and photothermal property as well as pro-osteogenesis served as a multiple functional biomaterial conquered the tri-challenges: bone defect, tumor recurrence, and bacterial infection in bone tumor therapy. Accordingly, as a novel photothermal therapeutic platform, MPNOv with tumor cells/bacteria-eradicating and pro-osteogenesis ability would be applicable for treatment of bone tumors.

Optical coherence tomography for noninvasive monitoring of drug delivery

Optical Coherence Tomography (OCT) has revolutionized various medical imaging and diagnostics fields, offering unprecedented insights into the microstructural compositions of biological tissues. In recent years, OCT applications have been extended to noninvasive drug delivery monitoring, which is a critical aspect of many therapeutic procedures and pharmacokinetic studies. Such an extension is strongly enhanced by the inherent combination with 3D anatomical images provided by OCT. This review presents an overview of the principles of OCT technology, its functional extensions for drug delivery systems, and its advancements in monitoring therapeutic interventions. We discuss its advantages over traditional imaging modalities in terms of spatial resolution, depth penetration, and real-time capabilities. The paper highlights significant studies that have utilized OCT for the visualization and quantification of drug delivery processes, including the diffusion of injectable formulations in ocular tissues and the permeation of topical drugs through the skin. In the review, we focused on the latest OCT applications, including OCT-guided drug injection, topical drug delivery monitoring, application of OCT in inhaled drug delivery systems, and the integration of OCT with other imaging modalities.

Extracellular matrix stiffness regulates colorectal cancer progression via HSF4

BACKGROUND

Colorectal cancer (CRC) has high incidence and mortality rates, with severe prognoses during invasion and metastasis stages. Despite advancements in diagnostic and therapeutic technologies, the impact of the tumour microenvironment, particularly extracellular matrix (ECM) stiffness, on CRC progression and metastasis is not fully understood.

METHODS

This study included 107 CRC patients. Tumour stiffness was assessed using magnetic resonance elastography (MRE), and collagen ratio was analysed with Masson staining. CRC cell lines were cultured on matrices of varying stiffness, followed by transcriptome sequencing to identify stiffness-related genes. An HSF4 knockout CRC cell model was cultured in different ECM stiffness to evaluate the effects of HSF4 on cell proliferation, migration, and invasion in vitro and in vivo.

RESULTS

CRC tumour stiffness was significantly higher than normal tissue and positively correlated with collagen content and TNM staging. High-stiffness matrices significantly regulated cell functions and signalling pathways. High HSF4 (heat shock transcriptional factor 4) expression was strongly associated with tumour stiffness and poor prognosis. HSF4 expression increased with higher TNM stages, and its knockout significantly inhibited cell proliferation, migration, and invasion, especially on high-stiffness matrices. In vivo experiments confirmed that HSF4 promoted tumour growth and metastasis, independent of collagen protein increase.

CONCLUSIONS

This study reveals that tumour stiffness promotes the proliferation and metastasis of CRC by regulating EMT-related signalling pathways through HSF4. Tumour stiffness and HSF4 could be valuable targets for prognostic assessment and therapeutic intervention in CRC.

Design of nanosystems for melanoma treatment

Melanoma is a prevalent and concerning form of skin cancer affecting millions of individuals worldwide. Unfortunately, traditional treatments can be invasive and painful, prompting the need for alternative therapies with improved efficacy and patient outcomes. Nanosystems offer a promising solution to these obstacles through the rational design of nanoparticles (NPs) which are structured into nanocomposite forms, offering efficient approaches to cancer treatment procedures. A range of NPs consisting of polymeric, metallic and metal oxide, carbon-based, and virus-like NPs have been studied for their potential in treating skin cancer. This review summarizes the latest developments in functional nanosystems aimed at enhancing melanoma treatment. The fundamentals of these nanosystems, including NPs and the creation of various functional nanosystem types, facilitating melanoma treatment are introduced. Then, the advances in the applications of functional nanosystems for melanoma treatment are summarized, outlining both their benefits and the challenges encountered in implementing nanosystem therapies.

Improved tumour delivery of iron oxide nanoparticles for magnetic hyperthermia therapy of melanoma via ultrasound guidance and 111In SPECT quantification

Magnetic field hyperthermia relies on the intra-tumoural delivery of magnetic nanoparticles by interstitial injection, followed by their heating on exposure to a remotely-applied alternating magnetic field (AMF). This offers a potential sole or adjuvant route to treating drug-resistant tumours for which no alternatives are currently available. However, two challenges in nanoparticle delivery currently hinder the effective clinical translation of this technology: obtaining enough magnetic material within the tumour to enable sufficient heating; and doing this accurately to limit or avoid damage to surrounding healthy tissue. A further complication is the lack of established methods to non-invasively quantify nanoparticle biodistribution, which is necessary to evaluate the performance of improved delivery strategies. Here we employ 111In radiolabelling and single-photon emission computed tomography (SPECT) to non-invasively quantify distribution of a clinical grade iron-oxide-based nanoparticle in a mouse model of melanoma. We show that compared to manual injection, ultrasound guided delivery together with syringe-pump-controlled infusion improves both the nanoparticle concentration within the tumour, and the accuracy of delivery - reducing off-target peri-tumoural delivery. Following AMF heating, injected melanomas shrank significantly compared to non-injected controls, validating therapeutic efficacy. Systemic off-target delivery was quantified and extrapolated to predict off-target energy absorbance within safe limits for the main sites of background accumulation. With many nanoparticle-based therapies currently in development for cancer, this image-guided delivery strategy has wide potential impact beyond the field of magnetic hyperthermia. Future use in representative patient cohorts would also be enabled by the high clinical availability of both SPECT and ultrasound imaging.

Magneto-Acoustic Theranostic Approach: Integration of Magnetomotive Ultrasound Shear Wave Elastography and Magnetic Hyperthermia

OBJECTIVES

Although magnetically induced hyperthermia has shown great efficiency in the treatment of solid tumors, it is still a challenge to avoid incomplete ablation or overtreatment. In this study, we applied magnetomotive ultrasound shear wave elastography (MMUS-SWE) as a tool for real-time image guidance and feedback in the magnetic hyperthermia (MH) process. We called this new method as magneto-acoustic theranostic approach (MATA).

METHODS

In MATA, a ferromagnetic particle (fMP) was simultaneously used as a thermoseed for MH and a shear wave source for MMUS-SWE. The fMP was excited by a high-frequency magnetic field to induce the heating effect for MH. Meanwhile, the fMP was stimulated by a pulsed magnetic field to generate shear wave propagation for MMUS-SWE. Thus, the changes in elastic modulus surrounding fMP can be used to estimate the therapy effect of MH.

RESULTS

The phantom and in vitro experiments were conducted to verify the feasibility of MATA, which has good performance in magnetothermal conversion and treatment efficacy feedback. The shear wave speed of the isolated pork liver changed significantly after the MH process, which varied from about 1.36 to 4.85 m/s.

CONCLUSIONS

Preliminary results proved that changes in elastic modulus could be useful to estimate the therapy effect of MH. We expect that MATA, which is the integration of MMUS-SWE and MH, will be a novel theranostic method for clinical translation.

Green synthesis of biocompatible Fe3O4 magnetic nanoparticles using Citrus Sinensis peels extract for their biological activities and magnetic-hyperthermia applications

Green synthesis of nanoparticles (NPs) is eco-friendly, biocompatible, cost-effective, and highly stable. In the present study, Citrus sinensis peel extract was utilized to the fabrication of superparamagnetic iron oxide nanoparticles (SPIONs). The fabricated SPIONs were first characterized using UV-Visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). The UV-Vis spectra analysis displayed a peak at 259 nm due to the surface plasmon resonance. The FTIR spectrum showed bands at 3306 cm-1, and 1616 cm-1 revealed the protein's involvement in the development and capping of NPs. TEM analysis indicated that green synthesized SPIONs were spherical in shape with particle size of 20-24 nm. Magnetization measurements indicate that the synthesized SPIONs exhibited superparamagnetic behavior at room temperature. The antimicrobial activity, minimum inhibitory concentration (MIC), antioxidant potential, anti-inflammatory effect, and catalytic degradation of methylene blue by SPIONs were investigated in this study. Results demonstrated that SPIONs had variable antimicrobial effect against different pathogenic multi-drug resistant bacteria. At the highest concentration (400 μg/mL), SPIONs showed inhibition zones (14.7-37.3 mm) against all the target isolates. Furthermore, the MIC of synthesized SPIONs against Staphylococcus aureus, Streptococcus mutans, Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, and Candida albicans were 3, 6.5, 6.5, 12.5, 50, 25 μg/mL, respectively. SPIONs exhibited strong antioxidant, anti-inflammatory, and catalytic dye degradation activities. Interestingly, Fe3O4 SPIONs shows optimum magnetic hyperthermia (MHT) techniques under an alternating magnetic field (AMF) measured in specific absorption rate (SAR) of 164, 230, and 286 W/g at concentrations 1, 5, and 10 mg/mL, respectively. Additionally, these newly fabricated SPIONs virtually achieve significant execution under the AMF in fluid MHT and are suitable for biomedical applications.

Green synthesis of biocompatible Fe 3 O 4 magnetic nanoparticles using Citrus Sinensis peels extract for their biological activities and magnetic- hyperthermia applications.. [DOI: 10.21203/rs.3.rs-3010022/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Plants include active chemicals known as phytochemicals and biomolecules that serve as decreasing and biostability factors for nanoparticle (NP) creation. Citrus Sinensis peels are rich in phenolics, flavonoids, antioxidants, and biophysical benefits. Herein, we prepared superparamagnetic iron oxide nanoparticles (SPIONs) by co-precipitation using Citrus Sinensis peel extract as a novel green synthesis method. The antioxidant, anti-inflammatory, dye degradation activities, and antimicrobial activities of Fe3O4 MNPs were investigated. Furthermore, the produced materials were characterized using FTIR, UV, TEM, VSM, and XRD analysis. The Fe3O4 MNPs showed higher antibacterial activities against multi antibiotic resistant bacterial strains: Escherichia coli, Streptococcus mutans, Candida albicans, Staphylococcus aureus, Bacillus subtilis, and Klebsiella pneumonia. The sample has generated a lot of attention in the scientific community for magnetic hyperthermia (MHT) applications. The maximum value of the specific absorption rate (SAR) was evaluated at sample concentrations of 10mg under the magnetic field condition. Additionally, these newly fabricated SPIONs virtually achieve significant execution under the alternating magnetic field (AMF) in fluid HT and are suitable for biomedical applications.

Entropy optimization and response surface methodology of blood hybrid nanofluid flow through composite stenosis artery with magnetized nanoparticles (Au-Ta) for drug delivery application

Entropy creation by a blood-hybrid nanofluid flow with gold-tantalum nanoparticles in a tilted cylindrical artery with composite stenosis under the influence of Joule heating, body acceleration, and thermal radiation is the focus of this research. Using the Sisko fluid model, the non-Newtonian behaviour of blood is investigated. The finite difference (FD) approach is used to solve the equations of motion and entropy for a system subject to certain constraints. The optimal heat transfer rate with respect to radiation, Hartmann number, and nanoparticle volume fraction is calculated using a response surface technique and sensitivity analysis. The impacts of significant parameters such as Hartmann number, angle parameter, nanoparticle volume fraction, body acceleration amplitude, radiation, and Reynolds number on the velocity, temperature, entropy generation, flow rate, shear stress of wall, and heat transfer rate are exhibited via the graphs and tables. Present results disclose that the flow rate profile increase by improving the Womersley number and the opposite nature is noticed in nanoparticle volume fraction. The total entropy generation reduces by improving radiation. The Hartmann number expose a positive sensitivity for all level of nanoparticle volume fraction. The sensitivity analysis revealed that the radiation and nanoparticle volume fraction showed a negative sensitivity for all magnetic field levels. It is seen that the presence of hybrid nanoparticles in the bloodstream leads to a more substantial reduction in the axial velocity of blood compared to Sisko blood. An increase in the volume fraction results in a noticeable decrease in the volumetric flow rate in the axial direction, while higher values of infinite shear rate viscosity lead to a significant reduction in the magnitude of the blood flow pattern. The blood temperature exhibits a linear increase with respect to the volume fraction of hybrid nanoparticles. Specifically, utilizing a hybrid nanofluid with a volume fraction of 3% leads to a 2.01316% higher temperature compared to the base fluid (blood). Similarly, a 5% volume fraction corresponds to a temperature increase of 3.45093%.

Advanced Radio Frequency Applicators for Thermal Magnetic Resonance Theranostics of Brain Tumors

Thermal Magnetic Resonance (ThermalMR) is a theranostic concept that combines diagnostic magnetic resonance imaging (MRI) with targeted thermal therapy in the hyperthermia (HT) range using a radiofrequency (RF) applicator in an integrated system. ThermalMR adds a therapeutic dimension to a diagnostic MRI device. Focused, targeted RF heating of deep-seated brain tumors, accurate non-invasive temperature monitoring and high-resolution MRI are specific requirements of ThermalMR that can be addressed with novel concepts in RF applicator design. This work examines hybrid RF applicator arrays combining loop and self-grounded bow-tie (SGBT) dipole antennas for ThermalMR of brain tumors, at magnetic field strengths of 7.0 T, 9.4 T and 10.5 T. These high-density RF arrays improve the feasible transmission channel count, and provide additional degrees of freedom for RF shimming not afforded by using dipole antennas only, for superior thermal therapy and MRI diagnostics. These improvements are especially relevant for ThermalMR theranostics of deep-seated brain tumors because of the small surface area of the head. ThermalMR RF applicators with the hybrid loop+SGBT dipole design outperformed applicators using dipole-only and loop-only designs, with superior MRI performance and targeted RF heating. Array variants with a horse-shoe configuration covering an arc (270°) around the head avoiding the eyes performed better than designs with 360° coverage, with a 1.3 °C higher temperature rise inside the tumor while sparing healthy tissue. Our EMF and temperature simulations performed on a virtual patient with a clinically realistic intracranial tumor provide a technical foundation for implementation of advanced RF applicators tailored for ThermalMR theranostics of brain tumors.

Protein-Nanoparticle Interactions Govern the Interfacial Behavior of Polymeric Nanogels: Study of Protein Corona Formation at the Air/Water Interface

Biomedical applications of nanoparticles require a fundamental understanding of their interactions and behavior with biological interfaces. Protein corona formation can alter the morphology and properties of nanomaterials, and knowledge of the interfacial behavior of the complexes, using in situ analytical techniques, will impact the development of nanocarriers to maximize uptake and permeability at cellular interfaces. In this study we evaluate the interactions of acrylamide-based nanogels, with neutral, positive, and negative charges, with serum-abundant proteins albumin, fibrinogen, and immunoglobulin G. The formation of a protein corona complex between positively charged nanoparticles and albumin is characterized by dynamic light scattering, circular dichroism, and surface tensiometry; we use neutron reflectometry to resolve the complex structure at the air/water interface and demonstrate the effect of increased protein concentration on the interface. Surface tensiometry data suggest that the structure of the proteins can impact the interfacial properties of the complex formed. These results contribute to the understanding of the factors that influence the bio-nano interface, which will help to design nanomaterials with improved properties for applications in drug delivery.

Recent advances in optical elastography and emerging opportunities in the basic sciences and translational medicine [Invited]

Optical elastography offers a rich body of imaging capabilities that can serve as a bridge between organ-level medical elastography and single-molecule biophysics. We review the methodologies and recent developments in optical coherence elastography, Brillouin microscopy, optical microrheology, and photoacoustic elastography. With an outlook toward maximizing the basic science and translational clinical impact of optical elastography technologies, we discuss potential ways that these techniques can integrate not only with each other, but also with supporting technologies and capabilities in other biomedical fields. By embracing cross-modality and cross-disciplinary interactions with these parallel fields, optical elastography can greatly increase its potential to drive new discoveries in the biomedical sciences as well as the development of novel biomechanics-based clinical diagnostics and therapeutics.

Applications of Metallic Nanoparticles in the Skin Cancer Treatment

Skin cancer is one of leading cancers globally, divided into two major categories including melanoma and nonmelanoma. Skin cancer is a global concern with an increasing trend, hence novel therapies are essential. The local treatment strategies play a key role in skin cancer therapy. Nanoparticles (NPs) exert potential applications in medicine with huge advantages and have the ability to overcome common chemotherapy problems. Recently, NPs have been used in nanomedicine as promising drug delivery systems. They can enhance the solubility of poorly water-soluble drugs, improve pharmacokinetic properties, modify bioavailability, and reduce drug metabolism. The high-efficient, nontoxic, low-cost, and specific cancer therapy is a promising goal, which can be achieved by the development of nanotechnology. Metallic NPs (MNPs) can act as important platforms. MNPs development seeks to enhance the therapeutic efficiency of medicines through site specificity, prevention of multidrug resistance, and effective delivery of therapeutic factors. MNPs are used as potential arms in the case of cancer recognition, such as Magnetic Resonance Imaging (MRI) and colloidal mediators for magnetic hyperthermia of cancer. The applications of MNPs in the cancer treatment studies are mostly due to their potential to carry a large dose of drug, resulting in a high concentration of anticancer drugs at the target site. Therefore, off-target toxicity and suffering side effects caused by high concentration of the drug in other parts of the body are avoided. MNPs have been applied as drug carriers for the of improvement of skin cancer treatment and drug delivery. The development of MNPs improves the results of many cancer treatments. Different types of NPs, such as inorganic and organic NPs have been investigated in vitro and in vivo for the skin cancer therapy. MNPs advantages mostly include biodegradability, electrostatic charge, good biocompatibility, high drug payload, and low toxicity. However, the use of controlled-release systems stimulated by electromagnetic waves, temperature, pH, and light improves the accumulation in tumor tissues and improves therapeutic outcomes. This study (2019-2022) is aimed at reviewing applications of MNPs in the skin cancer therapy.

Functionalized iron oxide nanoparticles: Synthesis through ultrasonic-assisted co-precipitation and performance as hyperthermic agents for biomedical applications

Dual-functional iron oxide nanoparticles (IONPs), displaying self-heating and antibacterial effects are highly desired for biomedical application. This study involved the synthesis of functionalized IONPs coated with 3-aminopropyltriethoxysilane and polyethylene glycol via ultrasonic-assisted co-precipitation technique. The synthesized IONPs were then characterized by using Fourier-transform infrared spectroscopy, X-ray diffraction, dynamic light scattering, scanning electron microscopy, zeta potential, vibrating sample magnetometer and thermogravimetric analysis techniques. In addition, the effect of the synthesized IONPs on bacterial growth (S. aureus and E. coli) was studied. The influence of magnetic field power, as well as the viscous carriers on the heating efficiency of the synthesized IONPs was investigated. The specific absorption rate values increased as the power increased and decreased with the increase in the carrier viscosity. These characteristics render the synthesized iron oxide nanoparticles synthesized in the present study suitable for biomedical application as hyperthermic agents.

Molecular Contrast Optical Coherence Tomography and Its Applications in Medicine

The growing need to understand the molecular mechanisms of diseases has prompted the revolution in molecular imaging techniques along with nanomedicine development. Conventional optical coherence tomography (OCT) is a low-cost in vivo imaging modality that provides unique high spatial and temporal resolution anatomic images but little molecular information. However, given the widespread adoption of OCT in research and clinical practice, its robust molecular imaging extensions are strongly desired to combine with anatomical images. A range of relevant approaches has been reported already. In this article, we review the recent advances of molecular contrast OCT imaging techniques, the corresponding contrast agents, especially the nanoparticle-based ones, and their applications. We also summarize the properties, design criteria, merit, and demerit of those contrast agents. In the end, the prospects and challenges for further research and development in this field are outlined.

Isolation Methods Influence the Protein Corona Composition on Gold-Coated Iron Oxide Nanoparticles

Upon exposure to a biological environment, nanoparticles (NPs) acquire biomolecular coatings, the most studied of which is the protein corona. This protein corona gives NPs a new biological identity that will determine various biological responses including cellular uptake, biodistribution, and toxicity. The standard method to isolate NPs from a biological matrix in order to study their coronas is centrifugation, but more gentle means of retrieval may enable deeper understanding of both irreversibly bound hard coronas and more loosely bound soft coronas. In this study, magnetic gold-coated iron oxide NPs were incubated with rainbow trout gill cell total protein extracts and mass spectrometric proteomic analysis was conducted to determine the composition of the protein coronas isolated by either centrifugation or magnetic retrieval. The number of washes were varied to strip away the soft coronas and isolate the hard corona. Hundreds of proteins were adsorbed to the NPs. Some proteins were common to all isolation methods and many others were particular to the isolation method. Some qualitative trends in protein character were discerned from quantitative proteomic analyses, but more importantly, a new kind of protein corona was identified, mixed corona, in which the labile or inert nature of the protein-NP interaction is dependent upon sample history.

Magnetic particles in motion: magneto-motive imaging and sensing

Superparamagnetic nanoparticles have become an important tool in biomedicine. Their biocompatibility, controllable small size, and magnetic properties allow manipulation with an external magnetic field for a variety of diagnostic and therapeutic applications. Recently, the magnetically-induced motion of superparamagnetic nanoparticles has been investigated as a new source of imaging contrast. In magneto-motive imaging, an external, time-varying magnetic field is applied to move a magnetically labeled subject, such as labeled cells or tissue. Several major imaging modalities such as ultrasound, photoacoustic imaging, optical coherence tomography, and laser speckle tracking can utilize magneto-motive contrast to monitor biological events at smaller scales with enhanced contrast and sensitivity. In this review article, an overview of magneto-motive imaging techniques is presented, including synthesis of superparamagnetic nanoparticles, fundamental principles of magneto-motive force and its utility to excite labeled tissue within a viscoelastic medium, current capabilities of magneto-motive imaging modalities, and a discussion of the challenges and future outlook in the magneto-motive imaging domain.

Design of Magnetic Nanoplatforms for Cancer Theranostics

Cancer is the top cause of death globally. Developing smart nanomedicines that are capable of diagnosis and therapy (theranostics) in one-nanoparticle systems are highly desirable for improving cancer treatment outcomes. The magnetic nanoplatforms are the ideal system for cancer theranostics, because of their diverse physiochemical properties and biological effects. In particular, a biocompatible iron oxide nanoparticle based magnetic nanoplatform can exhibit multiple magnetic-responsive behaviors under an external magnetic field and realize the integration of diagnosis (magnetic resonance imaging, ultrasonic imaging, photoacoustic imaging, etc.) and therapy (magnetic hyperthermia, photothermal therapy, controlled drug delivery and release, etc.) in vivo. Furthermore, due to considerable variation among tumors and individual patients, it is a requirement to design iron oxide nanoplatforms by the coordination of diverse functionalities for efficient and individualized theranostics. In this article, we will present an up-to-date overview on iron oxide nanoplatforms, including both iron oxide nanomaterials and those that can respond to an externally applied magnetic field, with an emphasis on their applications in cancer theranostics.

Magnetic nanoparticles in theranostics of malignant melanoma

Malignant melanoma is an aggressive tumor with a tendency to metastasize early and with an increasing incidence worldwide. Although in early stage, melanoma is well treatable by excision, the chances of cure and thus the survival rate decrease dramatically after metastatic spread. Conventional treatment options for advanced disease include surgical resection of metastases, chemotherapy, radiation, targeted therapy and immunotherapy. Today, targeted kinase inhibitors and immune checkpoint blockers have for the most part replaced less effective chemotherapies. Magnetic nanoparticles as novel agents for theranostic purposes have great potential in the treatment of metastatic melanoma. In the present review, we provide a brief overview of treatment options for malignant melanoma with different magnetic nanocarriers for theranostics. We also discuss current efforts of designing magnetic particles for combined, multimodal therapies (e.g., chemotherapy, immunotherapy) for malignant melanoma.

Phenotypic Switching of B16F10 Melanoma Cells as a Stress Adaptation Response to Fe3O4/Salicylic Acid Nanoparticle Therapy

Melanoma is a melanocyte-derived skin cancer that has a high heterogeneity due to its phenotypic plasticity, a trait that may explain its ability to survive in the case of physical or molecular aggression and to develop resistance to therapy. Therefore, the therapy modulation of phenotypic switching in combination with other treatment modalities could become a common approach in any future therapeutic strategy. In this paper, we used the syngeneic model of B16F10 melanoma implanted in C57BL/6 mice to evaluate the phenotypic changes in melanoma induced by therapy with iron oxide nanoparticles functionalized with salicylic acid (SaIONs). The results of this study showed that the oral administration of the SaIONs aqueous dispersion was followed by phenotypic switching to highly pigmented cells in B16F10 melanoma through a cytotoxicity-induced cell selection mechanism. The hyperpigmentation of melanoma cells by the intra- or extracellular accumulation of melanic pigment deposits was another consequence of the SaIONs therapy. Additional studies are needed to assess the reversibility of SaIONs-induced phenotypic switching and the impact of tumor hyperpigmentation on B16F10 melanoma’s progression and metastasis abilities.