Iron oxide-gold core-shell nano-theranostic for magnetically targeted photothermal therapy under magnetic resonance imaging guidance

Magnetic engineering nanoparticles: Versatile tools revolutionizing biomedical applications

The use of nanoparticles has increased significantly over the past few years in a number of fields, including diagnostics, biomedicine, environmental remediation, and water treatment, generating public interest. Among various types of nanoparticles, magnetic nanoparticles (MNPs) have emerged as an essential tool for biomedical applications due to their distinct physicochemical properties compared to other nanoparticles. This review article focuses on the recent growth of MNPs and comprehensively reviews the advantages, multifunctional approaches, biomedical applications, and latest research on MNPs employed in various biomedical techniques. Biomedical applications of MNPs hold on to their ability to rapidly switch magnetic states under an external field at room temperature. Ideally, these MNPs should be highly susceptible to magnetization when the field is applied and then lose that magnetization just as quickly once the field is removed. This unique property allows MNPs to generate heat when exposed to high-frequency magnetic fields, making them valuable tools in developing treatments for hyperthermia and other heat-related illnesses. This review underscores the role of MNPs as tools that hold immense promise in transforming various aspects of healthcare, from diagnostics and imaging to therapeutic treatments, with discussion on a wide range of peer-reviewed articles published on the subject. At the conclusion of this work, challenges and potential future advances of MNPs in the biomedical field are highlighted.

The nano-revolution in the diagnosis and treatment of endometriosis

Endometriosis is a painful gynecological disease with a high prevalence, affecting millions of women worldwide. Innovative, non-invasive treatments, and new patient follow-up strategies are needed to deal with the harmful social and economic effects. In this scenario, considering the recent, very promising results already reported in the literature, a commitment to new research in the field of nanomedicine is urgently needed. Study findings clearly show the potential of this approach in both the diagnostic and therapeutic phases of endometriosis. Here, we offer a brief review of the recent exciting and effective applications of nanomedicine in both the diagnosis and therapy of endometriosis. Special emphasis will be placed on the emerging theranostic application of nanoproducts, and the combination of phototherapy and nanotechnology as new therapeutic modalities for endometriosis. The review will also provide interested readers with a guide to the selection process and parameters to consider when designing research into this type of approach.

Nanoparticles for imaging-guided photothermal therapy of colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies with a high mortality rate worldwide. While surgery, chemotherapy, and radiotherapy have shown some effectiveness in improving survival rates, they come with drawbacks such as side effects and harm to healthy tissues. The theranostic approach, which integrates the processes of cancer diagnosis and treatment, can minimize biological side effects. Photothermal therapy (PTT) is an emerging treatment method that usages light-sensitive agents to generate heat at the tumor site and induce thermal erosion. The development of nanotechnology for CRC treatment using imaging-guided PTT has garnered significant. Nanoparticles with suitable physical and chemical properties can enhance the efficiency of cancer diagnosis and PTT. This approach enables the monitoring of cancer treatment progress and safeguards healthy tissues. In this article, we concisely introduce the application of metal nanoparticles, polymeric nanoparticles, and carbon nanoparticles in imaging-guided PTT of colorectal cancer.

Radiosensitising effect of iron oxide-gold nanocomplex for electron beam therapy of melanoma in vivo by magnetic targeting

Melanoma is a dangerous type of skin cancer sometimes treated with radiotherapy. However, it induces damage to the surrounding healthy tissue and possibly further away areas. Therefore, it is necessary to give a lower dose to the patient with targeted therapy. In this study, the radio-sensitising effect of gold-coated iron oxide nanoparticles on electron beam radiotherapy of a melanoma tumour with magnetic targeting in a mouse model was investigated. Gold-coated iron oxide nanoparticles were prepared in a steady procedure. The melanoma tumour model was induced in mice. Animals were divided into five groups: (1) normal; (2) melanoma; (3) gold-coated iron oxide nanoparticles alone; (4) electron beam radiotherapy; (5) electron beam radiotherapy plus gold-coated iron oxide nanoparticles. The magnet was placed on the tumour site for 2 h. The tumours were then exposed to 6 MeV electron beam radiotherapy for a dose of 8 Gy. Inductively coupled plasma optical emission spectrometry test, hematoxylin and eosin staining, and enzyme-linked immunosorbent assay blood test were also performed. Gold-coated iron oxide nanoparticles with magnetic targeting before electron beam radiotherapy reduced the growth of the tumour compared to the control group. Blood tests did not show any significant toxicity. Deposition of nanoparticles was more in the tumour and spleen tissue and to a lesser extent in the liver, kidney, and lung tissues. The synergistic effect of nanoparticles administered by the intraperitoneal route and then concentrated into the tumour area by application of an external permanent magnet, before delivery of the electron beam radiotherapy improved the overall cancer treatment outcome and prevented metal distribution side effects.

The Combination of Photothermal Therapy and Chemotherapy using Alginate-Modified Iron Oxide-Gold Nanohybrids Carrying Cisplatin

Background

Chemotherapy is typically the first-line treatment for the advanced stage of cancers. However, there are shortcomings with respect to conventional chemotherapy that limit therapeutic efficiency, including lack of tumor selectivity, systemic toxicity and drug resistance.

Objective

A multifunctional nanoplatform was build using of hydrogel co-loaded containing cisplatin and Iron oxide-gold core-shell nanoparticles. The Au shell comprises the light response and the iron core can be utilized as a negative contrast agent in nanocomplex.

Material and Methods

In this experimental study, KB cells derived from the epithelial cells located in the nasopharynx were exposed to different levels of concentration of hydrogel co-loaded with cisplatin and Iron oxide-gold core-shell nanoparticles. Afterwards, the cytotoxicity was determined using MTT assay.

Results

The cytotoxicity results showed that this nanoplatforms has potent to create higher cytotoxicity in KB cells than free cisplatin, so that Fe-Au@Alg and Fe-Au@Alg with cisplatin mixed with laser irradiation exhibited a significant reduction in cell viability after 5 min.

Conclusion

Hydrogel co-loaded with cisplatin and Iron oxide-gold core-shell nanoparticles are stable construct to combine chemo-photothermal therapy. Therefore, they can be used as a computed tomography-traceable nanocarrie, enabling us to monitor the delivery of therapeutics.

Chemo-radiation therapy of U87-MG glioblastoma cells using SPIO@AuNP-Cisplatin-Alginate nanocomplex

Megavoltage radiotherapy and cisplatin-based chemotherapy are the primary glioblastoma treatments. Novel nanoparticles have been designed to reduce adverse effects and boost therapeutic effectiveness. In the present study, we synthesized the SPIO@AuNP-Cisplatin-Alginate (SACA) nanocomplex, composed of a SPIO core, a gold shell, and an alginate coating. SACA was characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS). U87-MG human glioblastoma cells and the HGF cell line (a healthy primary gingival fibroblast) were treated in multiple groups by a combination of SACA, cisplatin, and 6 MV X-ray. The MTT assay was used to assess the cytotoxicity of cisplatin and SACA (at various concentrations and for 4 h). Following the treatments, apoptosis and cell viability were evaluated in each treatment group using flow cytometry and the MTT assay, respectively. The findings demonstrated that the combination of SACA and 6 MV X-rays (at the doses of 2 and 4 Gy) drastically decreased the viability of U87MG cells, whereas the viability of HGF cells remained unchanged. Moreover, U87MG cells treated with SACA in combination with radiation exhibited a significant increase in apoptosis, demonstrating that this nanocomplex effectively boosted the radiosensitivity of cancer cells. Even though additional in vivo studies are needed, these findings suggest that SACA might be used as a radiosensitizer nanoparticle in the therapy of brain tumors.

Prospects of coupled iron-based nanostructures in preclinical antibacterial therapy

Bacterial infections can threaten human health. Drug-resistant bacteria have become a challenge because of the excessive use of drugs. We summarize the current metallic antibacterial materials, especially Fe-based materials, for efficiently killing bacteria. The possible antibacterial mechanisms of metallic antibacterial agents are classified into interactions with bacterial proteins, iron metabolism, catalytic activity, and combinations of magnetic, photodynamic, and photothermal effects. This review will inspire the development of novel Fe-based antibacterial agents for clinical settings.

Multifunctional plasmonic-magnetic nanoparticles for bioimaging and hyperthermia

Multicompartment nanoparticles have raised great interest for different biomedical applications, thanks to the combined properties of different materials within a single entity. These hybrid systems have opened new avenues toward diagnosis and combination therapies, thus becoming preferred theranostic agents. When hybrid nanoparticles comprise magnetic and plasmonic components, both magnetic and optical properties can be achieved, which are potentially useful for multimodal bioimaging, hyperthermal therapies and magnetically driven selective delivery. Nanostructures comprising iron oxide and gold are usually selected for biomedical applications, as they display size-dependent properties, biocompatibility, and unique physical and chemical characteristics that can be tuned through highly precise synthetic protocols. We provide herein an overview of the most recent synthetic protocols to prepare magnetic-plasmonic nanostructures made of iron oxide and gold, to then highlight the progress made on multifunctional magnetic-plasmonic bioimaging and heating-based therapies. We discuss the advantages and limitations of the various systems in these directions.

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.

Determinants of gold nanoparticle interactions with Proteins: Off-Target effect study

Photothermal therapy is one of the promising approaches toward cancer treatment. To date, several compounds have been developed for this application, among which nanoparticles are attracting ever-increasing attention. One of the obstacles in developing efficient photothermal nanoparticle agents is their off-target effect which is mainly mediated via non-specific interactions with proteins. Such interaction not only reduces the bioavailability of the agent but also will cause protein aggregation that can be lethal. So, gaining knowledge on the mechanisms mediating such interactions will facilitate development of more effective agents. Our last studies showed the mechanism of action of two modified gold nanoparticles, folic acid functionalized gold nanoparticles (FA-AuNPs) and gold shelled Fe₃O₄ nanoparticles (AuFeNPs), as photothermal agents. In the current work, we focus on the interaction of these two NPs with human serum albumin (HSA) and human hemoglobin (Hb) as model proteins. The complex formation between NPs and proteins was investigated by fluorescence spectroscopy, dynamic light scattering and circular dichroism. Our data distinguishes the very distinct mode of interaction of charged and neutral NPs with proteins. While the interaction of neutral AuFeNP to proteins is protein dependent, charged nanoparticles FA-AuNP interact indistinguishably with all proteins via electrostatic interactions. Moreover, complexes obtained from FA-AuNPs with proteins are more stable than that of AuFeNP. However, the secondary structure content of proteins in the presence of NPs indicates the insignificant effect of NPs on the secondary structure of these proteins. Our data propose that the charge functionalization of the NPs is an effective way for modulating the interaction of nanoparticles with proteins.

Theranostic applications of stimulus-responsive systems based on Fe2O3

According to the interaction of nanoparticles with biological systems, enthusiasm for nanotechnology in biomedical applications has been developed in the past decades. Fe2O3 nanoparticles, as the most stable iron oxide, have special merits that make them useful widely for detecting diseases, therapy, drug delivery, and monitoring the therapeutic process. This review presents the fabrication methods of Fe2O3-based materials and their photocatalytic and magnetic properties. Then, we highlight the application of Fe2O3-based nanoparticles in diagnosis and imaging, different therapy methods, and finally, stimulus-responsive systems, such as pH-responsive, magnetic-responsive, redox-responsive, and enzyme-responsive, with an emphasis on cancer treatment. In addition, the potential of Fe2O3 to combine diagnosis and therapy within a single particle called theranostic agent will be discussed.

Label-Free Iron Oxide Nanoparticles as Multimodal Contrast Agents in Cells Using Multi-Photon and Magnetic Resonance Imaging

INTRODUCTION

The inherent fluorescence properties of iron oxide nanoparticles (IONPs) were characterized, and their applicability for multiphoton imaging in cells was tested in combination with their magnetic resonance imaging (MRI) capabilities.

METHODS

Superparamagnetic iron oxide nanoparticles were synthesized and subsequently coated with polyethylene glycol to make them water-dispersible. Further characterization of the particles was performed using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), dynamic light scattering (DLS), superconducting quantum interference device (SQUID) and magnetic resonance relaxivity measurements. MRI and fluorescence properties of bare IONPs were first studied in solution and subsequently in A549-labeled cells.

RESULTS

The particles, with a core size of 11.3 ± 4.5 nm, showed a good negative MRI contrast in tissue-mimicking phantoms. In vitro studies in mammalian A549 cells demonstrate that these IONPs are biocompatible and can also produce significant T2/T2* contrast enhancement in IONPs-labeled cells. Furthermore, excitation-wavelength dependent photoluminescence was observed under one- and two-photon excitation.

DISCUSSION

The obtained results indicated that IONPs could be used for fluorescence label-free bioimaging at multiple wavelengths, which was proven by multiphoton imaging of IONPs internalization in A549 cancer cells.

Recent advances and trends in nanoparticles based photothermal and photodynamic therapy

Light-mediated therapies, including photodynamic therapy (PDT) and photothermal therapy (PTT) have been exploited as minimally invasive techniques for ablation of various tumors., Both modalities may eradicate tumors with minimal side effects to normal tissues and organs. Moreover, developments of light-mediated approaches using nanoparticles (NPs) and photosensitizer (PS) as diagnostic and therapeutic agents may have a crucial role in achieving successful cancer treatment. In recent years, novel nanoplatforms and strategies have been investigated to boost the therapeutic effect.. In this regard, gold, iron oxide, graphene oxide nanoparticles and hybrid nanocomposites have attracted attention.. Moreover, the combination of these materials with PS, in the form of hybrid NPs, reduces in vitro and in vivo normal tissue cytotoxicity, improves their solubility property in the biological environment and enhances the therapeutic effects. In this review, we look into the basic principles of PTT and PDT with their strengths and limitations to treat cancers. We also will discuss light-based nanoparticles and their PTT and PDT applications in the preclinical and clinical translation. Also, recent advances and trends in this field will be discussed along with the clinical challenges of PTT and PDT.

Nonlinear optical response of cancer cells following conventional and nano-technology based treatment strategies: Results of chemo-, thermo- and radiation therapies

BACKGROUND

Although traditional treatments are able to increase cancer survival rate, undesirable impact on off-target tissues are considered a limitation of these approaches. Nanotechnology-based treatments have been proposed as a possible option to enhance targeting., Further,current methods for evaluating cellular damage, are time consuming, highly dependent on the operator skills, and expensive. The aim of this study was to evaluate the capability of nonlinear optical response of cells to determine cellular damages during conventional and nano-technology based treatments.

METHODS

Three different cancer cell lines, CT26, KB, and MCF-7 were used in this study. The alginate hydrogel co-loaded with cisplatin and Au nanoparticle (ACA) nanocomplex and gold-coated iron oxide nanoparticle (Au@IONP) were considered for chemo- and chemo-photothermal therapies, and thermo-radiation therapy, respectively. The sign and value of nonlinear optical absorption coefficient and imaginary part of the third-order nonlinear susceptibility of cells were computed. MTT assay was utilized as a reference method.

RESULTS

The value of nonlinear optical indices increased with increasing cellular damage and cell death. The linear regression analysis indicated high correlation between nonlinear optical indices and MTT results, in all treatments.

CONCLUSION

The nonlinear optical indices are robust from confounding factors, namely treatment approach (traditional and nano-technology based), treatment modality (chemotherapy, thermotherapy, photothermal therapy, and radiation therapy), and cell types. Nonlinear optical properties of cells can be used as a rapid estimation method for cell damage, at the nanoscale level.

Nanoparticle Systems for Cancer Phototherapy: An Overview

Photodynamic therapy (PDT) and photothermal therapy (PTT) are photo-mediated treatments with different mechanisms of action that can be addressed for cancer treatment. Both phototherapies are highly successful and barely or non-invasive types of treatment that have gained attention in the past few years. The death of cancer cells because of the application of these therapies is caused by the formation of reactive oxygen species, that leads to oxidative stress for the case of photodynamic therapy and the generation of heat for the case of photothermal therapies. The advancement of nanotechnology allowed significant benefit to these therapies using nanoparticles, allowing both tuning of the process and an increase of effectiveness. The encapsulation of drugs, development of the most different organic and inorganic nanoparticles as well as the possibility of surfaces' functionalization are some strategies used to combine phototherapy and nanotechnology, with the aim of an effective treatment with minimal side effects. This article presents an overview on the use of nanostructures in association with phototherapy, in the view of cancer treatment.

Online electrophoretic nanoanalysis using miniaturized gel electrophoresis and thermal lens microscopy detection

Online thermal lens microscopy (TLM) coupled with gel electrophoresis (GE) can represent a powerful tool for separating and detecting a wide range of biomaterials. Unlike slab gel electrophoresis (SGE), the proposed method does not require prolonged procedure between separation and detection. In this work, we developed an online monitoring GE system to separate and detect nanosized materials. The design is based on a homemade and cost-effective miniaturized GE chip (MGEC) integrated with real-time TLM detection through microcontroller-based digitization board platform. To validate the feasibility and practicability of the proposed approach, we evaluated its separation capability via employing synthesized Fe₃O₄-Au core-shell nanoparticles (NPs) which served remarkably for the proof-of-concept. The optimum conditions for the separation process were achieved through optimization of the excitation power as 30 mW, detection position at 24 mm, the concentration of agarose gel 0.5 % w/v, and 37.5 V/cm as the effective electric field strength. The findings showed that two populations of Fe₃O₄-Au, core-shell, and uncapped Fe₃O₄ NPs, were effectively separated in less than eleven minutes, demonstrating rapid assessment of the nanomaterial production quality. Moreover, other characterization techniques such as HRTEM and EDX were employed to confirm the presence of the two dissimilar kinds of NPs separated using MGEC-TLM. The sensitivity of the method was demonstrated by determining the limit of detection (23 pM) for 10 nm AuNPs. It is envisaged that our presented system enables rapid, economical, low volume of reagents consumption and high potential analysis for quality test in various bioanalytical and nanotechnological applications.

Nanomagnet-facilitated pharmaco-compatibility for cancer diagnostics: Underlying risks and the emergence of ultrasmall nanomagnets

Cancer therapy is a fast-emerging biomedical paradigm that elevates the diagnostic and therapeutic potential of a nanovector for identification, monitoring, targeting, and post-treatment response analysis. Nanovectors of superparamagnetic iron oxide nanoparticles (SPION) are of tremendous significance in cancer therapy because of their inherited high surface area, high reactivity, biocompatibility, superior contrast, and magnetic and photo-inducibility properties. In addition to a brief introduction, we summarize various progressive aspects of nanomagnets pertaining to their production with an emphasis on sustainable biomimetic approaches. Post-synthesis particulate and surface alterations in terms of pharmaco-affinity, liquid accessibility, and biocompatibility to facilitate cancer therapy are highlighted. SPION parameters including particle contrast, core-fusions, surface area, reactivity, photosensitivity, photodynamics, and photothermal properties, which facilitate diverse cancer diagnostics, are discussed. We also elaborate on the concept of magnetism to selectively focus chemotherapeutics on tumors, cell sorting, purification of bioentities, and elimination of toxins. Finally, while addressing the toxicity of nanomaterials, the advent of ultrasmall nanomagnets as a healthier alternative with superior properties and compatible cellular interactions is reviewed. In summary, these discussions spotlight the versatility and integration of multi-tasking nanomagnets and ultrasmall nanomagnets for diverse cancer theragnostics.

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SPION synthesis with ascribed prominence on sustainable procedures.

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Particulate species, composition, and surface alteration-enabled theragnostics are highlighted.

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Inherent properties of SPIONs facilitating cancer diagnostics are elaborated.

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Magnetism-based “chemotherapeutics,” cell-sorting, and bioentity purification are emphasized.

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Emergence of ultrasmall SPIONs as a healthier option is summarized.

Application of High-Z Gold Nanoparticles in Targeted Cancer Radiotherapy-Pharmacokinetic Modeling, Monte Carlo Simulation and Radiobiological Effect Modeling

High-Z gold nanoparticles (AuNPs) conjugated to a targeting antibody can help to improve tumor control in radiotherapy while simultaneously minimizing radiotoxicity to adjacent healthy tissue. This paper summarizes the main findings of a joint research program which applied AuNP-conjugates in preclinical modeling of radiotherapy at the Klinikum rechts der Isar, Technical University of Munich and Helmholtz Zentrum München. A pharmacokinetic model of superparamagnetic iron oxide nanoparticles was developed in preparation for a model simulating the uptake and distribution of AuNPs in mice. Multi-scale Monte Carlo simulations were performed on a single AuNP and multiple AuNPs in tumor cells at cellular and molecular levels to determine enhancements in the radiation dose and generation of chemical radicals in close proximity to AuNPs. A biologically based mathematical model was developed to predict the biological response of AuNPs in radiation enhancement. Although simulations of a single AuNP demonstrated a clear dose enhancement, simulations relating to the generation of chemical radicals and the induction of DNA strand breaks induced by multiple AuNPs showed only a minor dose enhancement. The differences in the simulated enhancements at molecular and cellular levels indicate that further investigations are necessary to better understand the impact of the physical, chemical, and biological parameters in preclinical experimental settings prior to a translation of these AuNPs models into targeted cancer radiotherapy.

Synergistic anticancer theragnostic study of a core-shell structured galvanic cell

The chemodynamic therapy (CDT) effect is restricted by the neutral pH environment in the tumor, also, the protein corona formed on the surface of the CDT catalyst reduces its activity. Here, we synthesized a core-shell CDT drug consisting of Fe/Fe₃C core and mesoporous graphite carbon shell with biotin modification (denoted FeCNB). The shell and core form a galvanic cells in the physiological electrolyte solution to achieve high-efficiency CDT under physiological pH conditions. The mesoporous in the shell effectively separates the protein corona from the Fe/Fe₃C, avoiding the influence of the protein corona on the catalyst. However, the mesoporous is permeable for the substrate and product of the catalytic reaction. FeCNB also has T2-magnetic resonance imaging (MRI) function and photothermal conversion ability under 808 nm laser irradiation. The tumor heating further improves the CDT effect to achieve a satisfactory synergistic photothermal therapy (PTT)/CDT outcome. In addition, FeCNB degrades in the microenvironment to ensure its excellent biocompatibility. It is the first study of CDT drug design and fabrication based on the mechanism of the galvanic cells.

Supramolecular Tropism Driven Aggregation of Nanoparticles In Situ for Tumor-Specific Bioimaging and Photothermal Therapy

Inorganic nanomedicine has attracted increasing attentions in biomedical sciences due to their excellent biocompatibility and tunable, versatile functionality. However, the relatively poor accumulation and retention of these nanomedicines in targeted tissues have often hindered their clinical translation. Herein, highly efficient, targeted delivery, and in situ aggregation of ferrocene (Fc)-capped Au nanoparticles (NPs) are reported to cucurbit[7]uril (CB[7])-capped Fe₃ O₄ NPs (as an artificial target) that are magnetically deposited into the tumor, driven by strong, multipoint CB[7]-Fc host-guest interactions (here defined as "supramolecular tropism" for the first time), leading to high tumor accumulation and retention of these NPs. The in vitro and in vivo studies demonstrate the precisely controlled, specific accumulation, and retention of Au NPs in the tumor cells and tissue via supramolecular tropism and in situ aggregation, which afford locally enhanced CT imaging of cancer and enable tumor-specific photothermal therapy attributed to the plasmonic coupling effects between adjacent Au NPs within the supramolecular aggregations. This work provides a novel concept of supramolecular tropism, which may drive targeted delivery and enable specific accumulation, retention, and activation of nanomedicine for improved bioimaging and therapy of cancer.

A general in-situ reduction method to prepare core-shell liquid-metal / metal nanoparticles for photothermally enhanced catalytic cancer therapy

Gallium indium (GaIn) alloy as a kind of liquid metal (LM) with unique chemical and physical properties has attracted increasing attention for its potential biomedical applications. Herein, a series of core-shell GaIn@Metal (Metal: Pt, Au, Ag, and Cu) heterogeneous nanoparticles (NPs) are obtained by a simple in-situ reduction method. Take core-shell GaIn@Pt NPs for example, the synthesized GaIn@Pt NPs after Pt growth on their surface showed significantly improved photothermal conversion efficiency (PCE) and thermal stability under near-infrared (NIR) II light irradiation. Moreover, the core-shell GaIn@Pt NPs also exhibited good Fenton-like catalytic effect due to the presence of Pt on their surface, and could convert tumor endogenous H₂O₂ to generate reactive oxygen species (ROS) for cancer cell killing. With biocompatible polyethylene glycol (PEG) modification, such GaIn@Pt-PEG NPs showed efficient tumor homing after intravenous injection, and could lead to effective NIR II triggered photothermal-chemodynamic synergistic therapy of tumors as evidenced in a mouse tumor model. Our work highlights the ingenious use of the chemical properties of metals, providing a rather simple route for the surface engineering of LM-based multifunctional nanoplatforms to achieve a variety of functionalities.

Gold nanoparticles meet medical radionuclides

Thanks to their unique optical and physicochemical properties, gold nanoparticles have gained increased interest as radiosensitizing, photothermal therapy and optical imaging agents to enhance the effectiveness of cancer detection and therapy. Furthermore, their ability to carry multiple medically relevant radionuclides broadens their use to nuclear medicine SPECT and PET imaging as well as targeted radionuclide therapy. In this review, we discuss the radiolabeling process of gold nanoparticles and their use in (multimodal) nuclear medicine imaging to better understand their specific distribution, uptake and retention in different in vivo cancer models. In addition, radiolabeled gold nanoparticles enable image-guided therapy is reviewed as well as the enhancement of targeted radionuclide therapy and nanobrachytherapy through an increased dose deposition and radiosensitization, as demonstrated by multiple Monte Carlo studies and experimental in vitro and in vivo studies.

RGD Peptide and PAD4 Inhibitor-Loaded Gold Nanorods for Chemo-Photothermal Combined Therapy to Inhibit Tumor Growth, Prevent Lung Metastasis and Improve Biosafety

Purpose

A targeted drug delivery system that combines protein-arginine deiminase type-4 (PAD4) inhibitors YW3-56 (356) with PTT of NPs is constructed to both decrease the accumulation of gold in metabolic organs and reduce the dose of chemotherapeutic agents.

Patients and Methods

In vitro cytotoxicity test and in vivo S180 tumor-bearing mice model were used to compare antitumor activity of 356-modified gold nanospheres and nanorods. The A549 tumor-bearing mice model was also exploited in antitumor assessment. In addition, ICP-MS, blood cell analyzer and blood biochemistry analyzer are applied for assessing the biosafety of NPs.

Results

Both 356-modified gold nanospheres and nanorods showed antitumor activity. However, 356-loaded gold nanorods are found to have better tumor inhibitory activity than 356-loaded gold nanospheres in the presence of laser and without laser irradiation. Thus, 356-loaded gold nanorods are selected to be applied for chemo-photothermal combined therapy on in vivo. We find that combination therapy could inhibit tumor growth and reduce lung tumor metastasis and inflammatory infiltration compared with individual therapy. It triggers apoptosis in tumor tissue observed by TUNEL assay and TEM pictures.

Conclusion

Thus, an RGD targeting and PAD4 inhibitor-loaded system are established based on chemo-photothermal combined therapy. It could inhibit tumor growth, prevent lung metastasis and improve biosafety.

Magnetic Nanoparticles for Biomedical Applications: From the Soul of the Earth to the Deep History of Ourselves

Precisely engineered magnetic nanoparticles (MNPs) have been widely explored for applications including theragnostic platforms, drug delivery systems, biomaterial/device coatings, tissue engineering scaffolds, performance-enhanced therapeutic alternatives, and even in SARS-CoV-2 detection strips. Such popularity is due to their unique, challenging, and tailorable physicochemical/magnetic properties. Given the wide biomedical-related potential applications of MNPs, significant achievements have been reached and published (exponentially) in the last five years, both in synthesis and application tailoring. Within this review, and in addition to essential works in this field, we have focused on the latest representative reports regarding the biomedical use of MNPs including characteristics related to their oriented synthesis, tailored geometry, and designed multibiofunctionality. Further, actual trends, needs, and limitations of magnetic-based nanostructures for biomedical applications will also be discussed.

Polyethylene glycol-coated ultrasmall superparamagnetic iron oxide nanoparticles-coupled sialyl Lewis X nanotheranostic platform for nasopharyngeal carcinoma imaging and photothermal therapy

Background

Nasopharyngeal carcinoma (NPC) is a type of head and neck malignant tumor with a high incidence in specific regional distribution, and its traditional therapies face some challenges. It has become an urgent need to seek new therapeutic strategies without or with low toxicity and side effects. At present, more and more researchers has been attracting attention by nanotheranostic platform. Therefore, our team synthesized the polyethylene glycol-coated ultrasmall superparamagnetic iron oxide nanoparticles-coupled sialyl Lewis X (USPIO-PEG-sLe^x) nanotheranostic platform with high temperature pyrolysis.

Results

The USPIO-PEG-sLe^x nanoparticles had excellent photothermal conversion property, and the temperature of USPIO-PEG-sLe^x nanoparticles solution increased with its concentration and power density of near-infrared (NIR) on 808 nm wavelengths. Five USPIO-PEG-sLe^x nanoparticles with different concentrations of 0 mg/ml, 0.025 mg/ml, 0.05 mg/ml, 0.1 mg/ml and 0.2 mg/ml were prepared. The biological toxicity results showed that the viability of NPC 5-8F cells is related to the concentration of USPIO-PEG-sLe^x nanoparticles and the culture time (P < 0.001). The results of photothermal therapy (PTT) in vitro indicated that the viability of 5-8F cells decreased significantly with the concentration of USPIO-PEG-sLe^x nanoparticles increases (P < 0.001), and the viability of NPC 5-8F cells were 91.04% ± 5.20%, 77.83% ± 3.01%, 73.48% ± 5.55%, 59.50% ± 10.98%, 17.11% ± 3.14%, respectively. The USPIO-PEG-sLe^x nanoparticles could target the tumor area, and reduce the T2* value of tumor tissue. The T2* values of tumor pre- and post-injection were 30.870 ± 5.604 and 18.335 ± 4.351, respectively (P < 0.001). In addition, USPIO-PEG-sLe^x nanoparticles as a photothermal agent for PTT could effectively inhibit tumor progression. The ratio of volume change between tail vein injection group, control group, nanoparticles without laser irradiation group and blank group after 5 treatments were 3.04 ± 0.57, 5.80 ± 1.06, 8.09 ± 1.96, 7.89 ± 2.20, respectively (P < 0.001).

Conclusions

Our synthesized USPIO-PEG-sLe^x nanotheranostic platform, and it may be become a new strategy for the treatment of NPC.

Graphic Abstract

Functionalization of Metal and Carbon Nanoparticles with Potential in Cancer Theranostics

Cancer theranostics is a new concept of medical approach that attempts to combine in a unique nanoplatform diagnosis, monitoring and therapy so as to provide eradication of a solid tumor in a non-invasive fashion. There are many available solutions to tackle cancer using theranostic agents such as photothermal therapy (PTT) and photodynamic therapy (PDT) under the guidance of imaging techniques (e.g., magnetic resonance-MRI, photoacoustic-PA or computed tomography-CT imaging). Additionally, there are several potential theranostic nanoplatforms able to combine diagnosis and therapy at once, such as gold nanoparticles (GNPs), graphene oxide (GO), superparamagnetic iron oxide nanoparticles (SPIONs) and carbon nanodots (CDs). Currently, surface functionalization of these nanoplatforms is an extremely useful protocol for effectively tuning their structures, interface features and physicochemical properties. This approach is much more reliable and amenable to fine adjustment, reaching both physicochemical and regulatory requirements as a function of the specific field of application. Here, we summarize and compare the most promising metal- and carbon-based theranostic tools reported as potential candidates in precision cancer theranostics. We focused our review on the latest developments in surface functionalization strategies for these nanosystems, or hybrid nanocomposites consisting of their combination, and discuss their main characteristics and potential applications in precision cancer medicine.

Multifunctional Theranostic Graphene Oxide Nanoflakes as MR Imaging Agents with Enhanced Photothermal and Radiosensitizing Properties

The integration of multiple therapeutic and diagnostic functions into a single nanoplatform for image-guided cancer therapy has been an emerging trend in nanomedicine. We show here that multifunctional theranostic nanostructures consisting of superparamagnetic iron oxide (SPIO) and gold nanoparticles (AuNPs) scaffolded within graphene oxide nanoflakes (GO-SPIO-Au NFs) can be used for dual photo/radiotherapy by virtue of the near-infrared (NIR) absorbance of GO for photothermal therapy (PTT) and the Z element radiosensitization of AuNPs for enhanced radiation therapy (RT). At the same time, this nanoplatform can also be detected by magnetic resonance (MR) imaging because of the presence of SPIO NPs. Using a mouse carcinoma model, GO-SPIO-Au NF-mediated combined PTT/RT exhibited a 1.85-fold and 1.44-fold higher therapeutic efficacy compared to either NF-mediated PTT or RT alone, respectively, resulting in a complete eradication of tumors. As a sensitive multifunctional theranostic platform, GO-SPIO-Au NFs appear to be a promising nanomaterial for enhanced cancer imaging and therapy.

An Updated Review on Implications of Autophagy and Apoptosis in Tumorigenesis: Possible Alterations in Autophagy through Engineered Nanomaterials and Their Importance in Cancer Therapy

Most commonly recognized as a catabolic pathway, autophagy is a perplexing mechanism through which a living cell can free itself of excess cytoplasmic components, i.e., organelles, by means of certain membranous vesicles or lysosomes filled with degrading enzymes. Upon exposure to external insult or internal stimuli, the cell might opt to activate such a pathway, through which it can gain control over the maintenance of intracellular components and thus sustain homeostasis by intercepting the formation of unnecessary structures or eliminating the already present dysfunctional or inutile organelles. Despite such appropriateness, autophagy might also be considered a frailty for the cell, as it has been said to have a rather complicated role in tumorigenesis. A merit in the early stages of tumor formation, autophagy appears to be salutary because of its tumor-suppressing effects. In fact, several investigations on tumorigenesis have reported diminished levels of autophagic activity in tumor cells, which might result in transition to malignancy. On the contrary, autophagy has been suggested to be a seemingly favorable mechanism to progressed malignancies, as it contributes to survival of such cells. Based on the recent literature, this mechanism might also be activated upon the entry of engineered nanomaterials inside a cell, supposedly protecting the host from foreign materials. Accordingly, there is a good chance that therapeutic interventions for modulating autophagy in malignant cells using nanoparticles may sensitize cancerous cells to certain treatment modalities, e.g., radiotherapy. In this review, we will discuss the signaling pathways involved in autophagy and the significance of the mechanism itself in apoptosis and tumorigenesis while shedding light on possible alterations in autophagy through engineered nanomaterials and their potential therapeutic applications in cancer. SIGNIFICANCE STATEMENT: Autophagy has been said to have a complicated role in tumorigenesis. In the early stages of tumor formation, autophagy appears to be salutary because of its tumor-suppressing effects. On the contrary, autophagy has been suggested to be a favorable mechanism to progressed malignancies. This mechanism might be affected upon the entry of nanomaterials inside a cell. Accordingly, therapeutic interventions for modulating autophagy using nanoparticles may sensitize cancerous cells to certain therapies.

Fluorescein-entrapped magnetosomes for magnetically assisted photodynamic therapy

Aim: We investigated the application of fluorescein (FL)-entrapped magnetosomes, in other words, silica-coated iron oxide nanoparticles entrapped within niosomes (SIO/NIO), in magnetically assisted photodynamic therapy (PDT) in vitro. Methods: Panc-1 cells were treated with the magnetosomes, with and without external magnetic guidance, and irradiated with blue light. Results & conclusion: Upon photoactivation, the FL-entrapped magnetosomes can produce higher singlet oxygen in comparison to FL-entrapped micelles, probably due to the higher release tendency of the photosensitizer from the former. In vitro studies in Panc-1 cells revealed magnetically assisted enhancement in the cellular uptake of the magnetosomes. Magnetic assistance also led to enhancement in PDT efficiency in cells treated with the FL-entrapped magnetosomes and light, thus highlighting their potential in PDT.

Recent advances in iron oxide nanoparticles for brain cancer theranostics: from in vitro to clinical applications

Introduction: Today, the development of multifunctional nanoplatforms is more seriously considered in the field of cancer theranostics.Areas covered: In this respect, nanoparticles provide several advantages over the routine, conventional diagnostic methods, and treatments. Due to the expedient properties of iron oxide nanoparticles, such as being readily modified, great payload potential, intrinsic magnetic qualification, considerable biocompatibility, and overwhelming response to targeting strategies, these nanoparticles can be considered good candidates for application as diagnostic contrast agents and drug/gene delivery vehicles, while also being incorporated into hyperthermia-based approaches. Interestingly, these agents are detectable with routine imaging modalities such as magnetic resonance imaging.Expert opinion: Therefore, combining the traditional diagnostics and therapies with nanotechnological approaches may leave a positive impact on the survival rate of patients with cancer. This review summarizes the application of magnetic iron oxide nanoparticles in both in vitro and in vivo models of brain tumors.

Imaging-guided nanomedicine development

Nanomedicine research is an active field that produces thousands of studies every year. However, translation of nanotherapeutics to the clinic has yet to catch up with such a vast output. In recent years, the need to better understand nanomedicines' in vivo behavior has been identified as one of the major challenges for efficient clinical translation. In this context, noninvasive imaging offers attractive solutions to provide valuable information about nanomedicine biodistribution, pharmacokinetics, stability, or therapeutic efficacy. Here, we review the latest imaging approaches used in the development of therapeutic nanomedicines, discuss why these strategies bring added value along the translational pipeline, and give a perspective on future advances in the field.

Iron Oxide-Based Magneto-Optical Nanocomposites for In Vivo Biomedical Applications

Iron oxide nanoparticles (IONPs) have played a pivotal role in the development of nanomedicine owing to their versatile functions at the nanoscale, which facilitates targeted delivery, high contrast imaging, and on-demand therapy. Some biomedical inadequacies of IONPs on their own, such as the poor resolution of IONP-based Magnetic Resonance Imaging (MRI), can be overcome by co-incorporating optical probes onto them, which can be either molecule- or nanoparticulate-based. Optical probe incorporated IONPs, together with two prominent non-ionizing radiation sources (i.e., magnetic field and light), enable a myriad of biomedical applications from early detection to targeted treatment of various diseases. In this context, many research articles are in the public domain on magneto-optical nanoparticles; discussed in detail are fabrication strategies for their application in the biomedical field; however, lacking is a comprehensive review on real-life applications in vivo, their toxicity, and the prospect of bench-to-bedside clinical studies. Therefore, in this review, we focused on selecting such important nanocomposites where IONPs become the magnetic component, conjugated with various types of optical probes; we clearly classified them into class 1 to class 6 categories and present only in vivo studies. In addition, we briefly discuss the potential toxicity of such nanocomposites and their respective challenges for clinical translations.

Inorganic-inorganic nanohybrids for drug delivery, imaging and photo-therapy: recent developments and future scope

Advanced nanotechnology has been emerging rapidly in terms of novel hybrid nanomaterials that have found various applications in day-to-day life for the betterment of the public. Specifically, gold, iron, silica, hydroxy apatite, and layered double hydroxide based nanohybrids have shown tremendous progress in biomedical applications, including bio-imaging, therapeutic delivery and photothermal/dynamic therapy. Moreover, recent progress in up-conversion nanohybrid materials is also notable because they have excellent NIR imaging capability along with therapeutic benefits which would be useful for treating deep-rooted tumor tissues. Our present review highlights recent developments in inorganic-inorganic nanohybrids, and their applications in bio-imaging, drug delivery, and photo-therapy. In addition, their future scope is also discussed in detail.

1H-MRS application in the evaluation of response to photo-thermal therapy using iron oxide-gold core-shell nanoparticles, an in vivo study

BACKGROUND

Photo-thermal therapy (PTT) has been at the center of attention as a new method for cancer treatment in recent years. It is important to predict the response to treatment in the PTT procedure. Using magnetic resonance spectroscopy (MRS) can be considered a novel technique in evaluating changes in metabolites resulted from PTT.

METHODS

In the present project, we conducted an in vivo study to assess the efficacy of ¹H-MRS as a noninvasive technique to evaluate the response to treatment in the early hours following PTT. The BALB/c mice subcutaneously bearing tumor cells (CT26 cell line) were scanned by ¹H-MRS before and after PTT. Iron oxide-gold core-shell (Fe₃O₄@Au) as PTT agent was injected into intra-peritoneal at first and then irradiated by NIR laser. Single-voxel Point RESolved Spectroscopy (PRESS) sequence (TE = 144) was used, and metabolites alternations were evaluated by the non-parametric Wilcoxon test. Besides, Nanoparticle (NP) relaxometry was conducted for negative contrast agents' potentials.

RESULTS

MRS choline (Cho) peak dramatically reduced 24 h post-PTT (p = 0.01) and lipid peak as a marker for necrosis of tumor elevated (p = 0.01) just in group 3 (NPs injection + laser irradiation) 24 h after the procedure.

CONCLUSION

¹H-MRS showed its potential as a method in detecting the changes in metabolites and revealing the outcome accurately. Response to photo-thermal therapy evaluation was achievable only one day after PTT and proved by a 10-day follow-up of the tumor size. Iron oxide-gold core-shell can also be used as a negative contrast agent in MRI images during therapy.

Monitoring of the choline/lipid ratio by 1H-MRS can be helpful for prediction and early detection of tumor response to nano-photo-thermal therapy

Nanotechnology-based photothermal therapy (NPTT) is a new emerging modality of cancer therapy. To have the right prediction and early detection of response to NPTT, it is necessary to get rapid feedback from a tumor treated by NPTT procedure and stay informed of what happens in the tumor site. We performed this study to find if proton magnetic resonance spectroscopy (1H-MRS) can be well responsive to such an imperative requirement. We considered various treatment groups including gold nanoparticles (AuNPs), laser, and the combination of AuNPs and laser (NPTT group). Therapeutic effects on CT26 colon tumor-bearing BALB/c mice were studied by looking at alterations that happened in 1H-MRS signals and tumor size after conducting treatment procedures. In MRS studies, the alterations of choline and lipid concentrations and their ratio were investigated. Having normalized the metabolite peak to water peak, we found a significant decrease in choline concentration post-NPTT (from (1.25 ± 0.05) × 10^-3 to (0.43 ± 0.04) × 10^-3), while the level of lipid concentration in the tumor was slightly increased (from (2.91 ± 0.23) × 10^-3 to (3.52 ± 0.31) × 10^-3). As a result, the choline/lipid ratio was significantly decreased post-NPTT (from 0.41 ± 0.11 to 0.11 ± 0.02). Such alterations appeared just 1 day after NPTT. Tumor shrinkage in all groups was studied and significant changes were significantly detectable on day 7 post-NPTT procedure. In conclusion, the study of choline/lipid ratio using 1H-MRS may help us estimate what happens in a tumor treated by the NPTT method. Such an in vivo assessment is interestingly feasible as soon as just 1 day post-NPTT. This would undoubtedly help the oncologists make a more precise decision about treatment planning strategies. Monitoring of the choline/lipid ratio by ¹H-MRS can be helpful for prediction and early detection of response to nano-photo-thermal therapy.

Gold nanoparticle-mediated bubbles in cancer nanotechnology

Microbubbles (MBs) have been extensively investigated in the field of biomedicine for the past few decades. Ultrasound and laser are the most frequently used sources of energy to produce MBs. Traditional acoustic methods induce MBs with poor localized areas of action. A high energy level is required to generate MBs through the focused continuous laser, which can be harmful to healthy tissues. As an alternative, plasmonic light-responsive nanoparticles, such as gold nanoparticles (AuNPs), are preferably used with continuous laser to decrease the energy threshold and reduce the bubbles area of action. It is also well-known that the utilization of the pulsed lasers instead of the continuous lasers decreases the needed AuNPs doses as well as laser power threshold. When well-confined bubbles are generated in biological environments, they play their own unique mechanical and optical roles. The collapse of a bubble can mechanically affect its surrounding area. Such a capability can be used for cargo delivery to cancer cells and cell surgery, destruction, and transfection. Moreover, the excellent ability of light scattering makes the bubbles suitable for cancer imaging. This review firstly provides an overview of the fundamental aspects of AuNPs-mediated bubbles and then their emerging applications in the field of cancer nanotechnology will be reviewed. Although the pre-clinical studies on the AuNP-mediated bubbles have shown promising data, it seems that this technique would not be applicable to every kind of cancer. The clinical application of this technique may basically be limited to the good accessible lesions like the superficial, intracavity and intraluminal tumors. The other essential challenges against the clinical translation of AuNP-mediated bubbles are also discussed.

Optimal scheduling of the nanoparticle-mediated cancer photo-thermo-radiotherapy

Maximal synergistic effect between photothermal therapy and radiotherapy (RT) may be achieved when the interval between these two modalities is optimal. In this study, we tried to determine the optimal schedule of the combined regime of RT and nano-photothermal therapy (NPTT), based on the cell cycle distribution and kinetics of cell death. To this end, alginate-coated iron oxide-gold core-shell nanoparticles (Fe₃O₄@Au/Alg NPs) were synthesized, characterized, and their photo-radio sensitization potency was evaluated on human nasopharyngeal cancer KB cells. Our results demonstrated that synthesized NPs have a good potential in radiotherapy and near-infrared (NIR) photothermal therapy. However, results from flow cytometry analysis indicated that a major portion of KB cells were accumulated in the most radiosensitive phases of cell cycle (G2/M) 24 h after NPTT. Moreover, the maximal synergistic anticancer efficacy (12.3% cell viability) was observed when RT was applied 24 h following the administration of NPTT (NPs [30 μg/mL, 4 h incubation time] + Laser [808 nm, 1 W/cm², 5 min] + RT [6 Gy]). It is noteworthy that apoptosis was the dominant cell death pathway in the group of cells treated by combination of NPTT and RT. This highly synergistic anticancer efficacy provides a mechanistic basis for Fe₃O₄@Au/Alg NPs-mediated photothermal therapy combined with RT. Knowing such a basis is helpful to promote novel nanotechnology cancer treatment strategies.

Tri-modal imaging of gold-dotted magnetic nanoparticles for magnetic resonance imaging, computed tomography and intravascular ultrasound: an in vitro study

Aim: To examine the multimodal contrasting ability of gold-dotted magnetic nanoparticles (Au*MNPs) for magnetic resonance (MR), computed tomography (CT) and intravascular ultrasound (IVUS) imaging. Materials & methods: Au*MNPs were prepared by adapting an impregnation method, without using surface capping reagents and characterized (transmission electron microscopy, x-ray diffraction and Fourier-transform infrared spectroscopy) with their in vitro cytotoxicity assessed, followed by imaging assessments. Results: The contrast-enhancing ability of Au*MNPs was shown to be concentration-dependent across MR, CT and IVUS imaging. The Au content of the Au*MNP led to evident increases of the IVUS signal. Conclusion: We demonstrated that Au*MNPs showed concentration-dependent contrast-enhancing ability in MRI and CT imaging, and for the first-time in IVUS imaging due to the Au content. These Au*MNPs are promising toward solidifying tri-modal imaging-based theragnostics.

Green and Kilogram-Scale Synthesis of Fe Hydrogel for Photothermal Therapy of Tumors in Vivo

Photothermal agents with good biocompatibility, high tumor accumulation efficiency, large-scale production ability, and low cost are crucial for potential photothermal treatment in clinic. Herein, we proposed a green and highly efficient strategy to fabricate a kilogram-scale alginate-Ca²⁺-Fe powder hydrogel (ALG-Ca²⁺-Fe) by turning commercial Fe powder into hydrogel for enhanced photothermal therapy. The ALG-Ca²⁺-Fe was formed by simply dispersing commercial Fe powder into the preformed alginate-Ca²⁺ hydrogel in a green and energy-/time-saving way. The hydrogel exhibited the advantages of ultrahigh loading capacity of Fe powder (>100 mg mL^-1), excellent large-scale production capacity (>1 kg in lab synthesis), low cost (<1.7 $/kg), and good injectability. More importantly, large size and hydrophobicity endowed Fe powder with excellent tumor retention effect and minimal diffusion to surrounding tissues, greatly benefiting improving treatment efficiency and reducing side effects. In vivo and in vitro studies both proved that the large-scale produced ALG-Ca²⁺-Fe can be used for highly efficient and biosafe tumor treatment in vivo by simple noninvasive injection. The developed ALG-Ca²⁺-Fe with multiple superiors opens up a novel green way to develop efficient and safe photothermal therapeutic agents with great clinic transformation potential.

A New Pharmacokinetic Model Describing the Biodistribution of Intravenously and Intratumorally Administered Superparamagnetic Iron Oxide Nanoparticles (SPIONs) in a GL261 Xenograft Glioblastoma Model

Background

Superparamagnetic iron oxide nanoparticles (SPIONs) have displayed multifunctional applications in cancer theranostics following systemic delivery. In an effort to increase the therapeutic potential of local therapies (including focal hyperthermia), nanoparticles can also be administered intratumorally. Therefore, the development of a reliable pharmacokinetic model for the prediction of nanoparticle distribution for both clinically relevant routes of delivery is of high importance.

Materials and Methods

The biodistribution of SPIONs (of two different sizes – 130 nm and 60 nm) radiolabeled with zirconium-89 or technetium-99m following intratumoral or intravenous injection was investigated in C57/Bl6 mice bearing subcutaneous GL261 glioblastomas. Based on PET/CT biodistribution data, a novel pharmacokinetic model was established for a better understanding of the pharmacokinetics of the SPIONs after both administration routes.

Results

The PET image analysis of the nanoparticles (confirmed by histology) demonstrated the presence of radiolabeled nanoparticles within the glioma site (with low amounts in the liver and spleen) at all investigated time points following intratumoral injection. The mathematical model confirmed the dynamic nanoparticle redistribution in the organism over a period of 72 h with an equilibrium reached after 100 h. Intravenous injection of nanoparticles demonstrated a different distribution pattern with a rapid particle retention in all organs (particularly in liver and spleen) and a subsequent slow release rate.

Conclusion

The mathematical model demonstrated good agreement with experimental data derived from tumor mouse models suggesting the value of this tool to predict the real-time pharmacokinetic features of SPIONs in vivo. In the future, it is planned to adapt our model to other nanoparticle formulations to more precisely describe their biodistribution in in vivo model systems.

Nanoparticles in Colorectal Cancer Therapy: Latest In Vivo Assays, Clinical Trials, and Patents

Colorectal cancer (CRC) is the third most common cancer worldwide. Its poor response to current treatment options in advanced stages and the need for efficient diagnosis in early stages call for the development of new therapeutic and diagnostic strategies. Some of them are based on the use of nanometric materials as carriers and releasers of therapeutic agents and fluorescent molecules, or even on the utilization of magnetic materials that provide very interesting properties. These nanoformulations present several advantages compared with the free molecular cargo, including increased drug solubility, bioavailability, stability, and tumor specificity. Moreover, tumor multidrug resistance has been decreased in some cases, leading to improved treatment effectiveness by reducing drug dose and potential side effects. Here, we present an updated overview of the latest advances in clinical research, in vivo studies, and patents regarding the application of nanoformulations in the treatment of CRC. Based on the information gathered, a wide variety of nanomaterials are being investigated in clinical research, even in advanced phases, i.e., close to reaching the market. In sum, these novel materials can offer remarkable advantages with respect to current therapies, which could be complemented or even replaced by these nanosystems in the near future.

Triple combination of heat, drug and radiation using alginate hydrogel co-loaded with gold nanoparticles and cisplatin for locally synergistic cancer therapy

Although multimodal cancer therapy has shown superior antitumor efficacy in comparison to individual therapy due to the potential generation of synergistic interactions among the treatments, its clinical usage is highly hampered by systemic dose-limiting toxicities. Herein, we developed a multi-responsive nanocomplex constructed from alginate hydrogel co-loaded with cisplatin and gold nanoparticles (AuNPs) (abbreviated as ACA) to combine chemotherapy, radiotherapy (RT) and photothermal therapy. The nanocomplex markedly improved the efficiency of drug delivery where ACA resulted in noticeably higher tumor growth inhibition than free cisplatin. The tumor treated with ACA showed an increased heating rate upon 532 nm laser irradiation, indicating the photothermal conversion ability of the nanocomplex. While RT alone resulted in slight tumor growth inhibition, thermo-chemo therapy, chemoradiation therapy and thermo-radio therapy using ACA dramatically slowed down the rate of tumor growth. Upon 532 nm laser and 6 MV X-ray, the nanocomplex could enable a trimodal thermo-chemo-radio therapy that yielded complete tumor regression with no evidence of relapse during the 90-days follow up period. The results of this study demonstrated that the incorporation of AuNPs and cisplatin into alginate hydrogel network can effectively combine chemotherapy, RT and photothermal therapy to achieve a locally synergistic cancer therapy.