Folic acid decorated magnetic nanosponge: An efficient nanosystem for targeted curcumin delivery and magnetic resonance imaging

Chitosan-modified manganese oxide-conjugated methotrexate nanoparticles delivering 5-aminolevulinic acid as a dual-modal T1-T2* MRI contrast agent in U87MG cell detection

OBJECTIVE

Glioblastoma multiforme is a highly aggressive form of brain cancer, and early diagnosis plays a pivotal role in improving patient survival rates. In this regard, molecular magnetic resonance imaging has emerged as a promising imaging modality due to its exceptional sensitivity to minute tissue changes and the ability to penetrate deep into the brain. This study aimed to assess the efficacy of a novel contrast agent in detecting gliomas during MRI scans.

MATERIALS AND METHODS

The contrast agent utilized modified chitosan coating on manganese oxide nanoparticles. The modification included adding methotrexate and 5-aminolevulinic acid (MnO2/CS@5-ALA-MTX) to target cells with overexpressed folate receptors and breaking down excess hydrogen peroxide in tumor tissue, resulting in enhanced signal intensity in T1-weighted MR images but diminished signal intensity in T2*-weighted MR images.

RESULTS

The nanosystem was characterized and evaluated in MR imaging, safety, and ability to target cells both in vivo and in vitro. MTX-free nanoparticles (MnO2/CS@5-ALA NPs) had no obvious cytotoxicity on cell lines U87MG and NIH3T3 after 24/48 h at a concentration of up to 160 µgr/mL (cell viability more than 80%). In this system, methotrexate enables tumor targeting and the MnO2/5-ALA improves T1-T2*-weighted MRI. In addition, MRI scans of mice with M109 carcinoma indicated significant tumor uptake and NP capacity to improve the positive contrast effect.

CONCLUSION

This developed MnO2/CS@5-ALA-MTX nanoparticle system may exhibit great potential in the accurate diagnosis of folate receptor over-expressing cancers such as glioblastoma.

Controlled Release of the Anticancer Drug Cyclophosphamide from a Superparamagnetic β-Cyclodextrin Nanosponge by Local Hyperthermia Generated by an Alternating Magnetic Field

A β-cyclodextrin (β-CD) nanosponge (NS) was synthesized using diphenyl carbonate (DPC) as a cross-linker to encapsulate the antitumor drug cyclophosphamide (CYC), thus obtaining the NSs-CYC system. The formulation was then associated with magnetite nanoparticles (MNPs) to develop the MNPs-NSs-CYC ternary system. The formulations mentioned above were characterized to confirm the deposition of the MNPs onto the organic matrix and that the superparamagnetic nature of the MNPs was preserved upon association. The association of the MNPs with the NSs-drug complex was confirmed through field emission scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, dynamic light scattering, ζ-potential, atomic absorption spectroscopy, X-ray powder diffraction, selected area electron diffraction, and vibrating-sample magnetometer. The superparamagnetic properties of the ternary system allowed the release of CYC by utilizing magnetic hyperthermia upon the exposure of an alternating magnetic field (AMF). The drug release experiments were carried out at different frequencies and intensities of the magnetic field, complying with the "Atkinson-Brezovich criterion". The assays in AMF showed the feasibility of release by controlling hyperthermia of the drug, finding that the most efficient conditions were F = 280 kHz, H = 15 mT, and a concentration of MNPs of 5 mg/mL. CYC release was temperature-dependent, facilitated by local heat generation through magnetic hyperthermia. This phenomenon was confirmed by DFT calculations. Furthermore, the ternary systems outperformed the formulations without MNPs regarding the amount of released drug. The MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assays demonstrated that including CYC within the magnetic NS cavities reduced the effects on mitochondrial activity compared to those observed with the free drug. Finally, the magnetic hyperthermia assays showed that the tertiary system allows the generation of apoptosis in HeLa cells, demonstrating that the MNPs embedded maintain their properties to generate hyperthermia. These results suggest that using NSs associated with MNPs could be a potential tool for a controlled drug delivery in tumor therapy since the materials are efficient and potentially nontoxic.

Multifunctionality of cyclodextrin-based polymeric nanoparticulate delivery systems for chemotherapeutics, combination therapy, and theranostics

As cancer being the most difficult disease to treat, different kinds of medications and therapeutic approaches have been prominently developed by scientists. For certain families of drugs, such as immuno-therapeutics or antibody-drug conjugates, efficient delivery systems are required during administration to protect the drugs from chemical degradation or biological inactivation. Delivery systems with the ability to carry different therapeutics or diagnostic agents or both, hold promising potential to tackle the abnormalities behind cancer. In this context, this review provides updated insights on how cyclodextrin-based polymeric nanosystems have become an effective treatment approach against cancer. Cyclodextrins (CDs) are natural oligosaccharides that are famously exploited in pharmaceutical research due to their exceptional quality of entrapping water-insoluble molecules inside their hydrophobic core and providing enhanced solubility with the help of their hydrophilic exterior. Combining the properties of CDs with polymeric nanoparticles (PNPs) brings out excellent versatile and tunable profiles, thanks to the submicron-sized PNPs. By introducing the significance of CD as a delivery system, a collective discussion on different binding approaches and release mechanisms of CD-drug complexation, followed by their characterization studies has been done in this review. Further, in light of recent studies, the article majorly focuses on conveying how promoting CD to a polymeric and nanoscale elevates the multifunctional advantages against cancer that can be successfully applied in combination therapy and theranostics. Moreover, CD-based delivery systems including CALAA-01, CRLX101, and CRLX301, have demonstrated improved tumor targeting, reduced side effects, and prolonged drug release in preclinical studies and clinical trials.

Sustainable Routed Mxene-Based Aminolyzed PU/PCL Film for Increased Oxidative Stress and a pH-Sensitive Drug Delivery System for Anticancer Therapy

A remarkable challenge in the anticancer drug delivery system is developing an implantable system that can improve the chemotherapeutic effect. Polyurethane is an excellent implantable substrate, with flaws in hydrophobicity. We modified polyurethane via the chemical aminolysis technique to enhance the wettability and protein interaction. The created pores can release the rutin complex incorporated in the polyurethane matrix. In this work, the hybrid polymer matrix consists of Mxene synthesized via a sustainable and simple method by introducing a toxic-free MAX phase and etchants. The incorporation of Mxene and PCL can enhance physicochemical and biological compatibility. Sustainable Mxene increases oxidative stress, cell death, and antibacterial activity, which also resulted in the Mxene@APU/PCL film. Meanwhile, the drug release with respect to pH sensitivity was demonstrated in which Mxene and Mxene@APU/PCL films showed the highest release at pH 5.2; this indicates that the prepared Mxene and aminolyzed polyurethane can function according to the biological system and release the drug from the polymer matrix on slow degradation and swellability. The Mxene and Mxene@APU/PCL films showed 93.2% drug release with oxidative stress on THP-1 cells, which causes rupturing and apoptosis of cancerous cells. The Mxene@APU/PCL film can show great potential in future implantable anticancer drug delivery systems.

An erythrocyte membrane-camouflaged fluorescent covalent organic framework for starving/nitric oxide/immunotherapy of triple-negative breast cancer

It is a great challenge to effectively treat triple-negative breast cancer (TNBC) due to lack of therapeutic targets and drug resistance of systemic chemotherapy. Rational design of nanomedicine with good hemocompatibility is urgently desirable for combination therapy of TNBC. Herein, an erythrocyte membrane-camouflaged fluorescent covalent organic framework (COF) loaded with an NO donor (hydroxyurea, Hu), glucose oxidase (GOx) and cytosine-phosphate-guanine oligonucleotides (CPG) (COF@HGC) was developed for imaging-guided starving/nitric oxide (NO)/immunization synergistic treatment of TNBC. The substances of HGC are easily co-loaded onto the COF due to the ordered pore structure and large surface area. And a folic acid-modified erythrocyte membrane (FEM) is coated on the surface of COF@HGC to improve targeted therapy and haemocompatibility. When COF@HGC@FEM is internalized into tumor cells, hemoglobin (Hb) on FEM and GOx loaded on the COF can trigger cascade reactions to kill tumor cells due to the simultaneous production of NO and exhaustion of glucose. Meanwhile, the COF with excellent fluorescence properties can be used as a self-reporter for bioimaging. Furthermore, the CPG can reprogram tumor-associated macrophages from tumor-supportive phenotype to anti-tumor phenotype and enhance immunotherapy. Through the "three-in-one" strategy, the biomimetic nanoplatform can effectively inhibit tumor growth and reprogram the tumor immunosuppression microenvironment in the TNBC mouse model.

Folate-mediated magnetic and pH/GSH dual-responsive metal-polymer-coordinated nanocomplexes for joint chemo/chemodynamic anti-breast cancer therapy

It is of great significance to develop a drug carrier that effectively targets chemotherapeutic drugs to the tumor site, improves therapeutic efficacy and reduces side effects associated with high-dose medicines. In the present study, an intelligent drug carrier system, FA-β-CD/DOX@Cu2+@GA@Fe3O4, was synthesized by skillfully introducing metal ions as a bridge base. The performance of the prepared FA-β-CD@Cu2+@GA@Fe3O4 metal-polymer-coordinated nanocomplexes were determined by UV-visible spectroscopy, NMR, FT-IR, XPS, VSM, DLS, and TEM analysis. The data showed that these nanocomplexes had good pH/GSH-responsive drug release behavior, and enabled enhanced magnetic and folic acid-mediated tumor cell targeting. Moreover, the toxicity effects of the FA-β-CD/DOX@Cu2+@GA@Fe3O4 on 3T3 cells and 4T1 cells were measured by the MTT method, and it was found that it displayed low cytotoxicity against 3T3 cells and had a stronger effect on killing 4T1 cells than DOX alone. The results also showed that the Cu2+-based coordination polymers had a significant ability to deplete GSH and generate ROS. It could be concluded that the introduction of Cu2+ not only facilitated the assembly of nanocomplexes, but also successfully enhanced the anti-tumor effect, making FA-β-CD@Cu2+@GA@Fe3O4 a potential nanoplatform for effectively mediating combined chemotherapy and chemokinetic therapy for tumors. All these characteristics verified the great potential of FA-β-CD/DOX@Cu2+@GA@Fe3O4 in multipurpose smart drug delivery systems, accelerating the application range of metal-polymer-coordinated nanocomplexes in biomedical fields.

Preparation of MnO2@poly-(DMAEMA-co-IA)-conjugated methotrexate nano-complex for MRI and radiotherapy of breast cancer application

OBJECTIVE

A novel efficient pH-sensitive targeted magnetic resonance imaging (MRI) contrast agent and innovative radio-sensitizing system were synthesized based on MnO2 NPs coated with biocompatible poly-dimethyl-amino-ethyl methacrylate-Co-itaconic acid, (DMAEMA-Co-IA) and targeted with methotrexate (MTX).

MATERIALS AND METHODS

The as-established NPs were fully characterized and evaluated for MRI signal enhancement, relaxivity, in vitro cell targeting, cell toxicity, blood compatibility, and radiotherapy (RT) efficacy.

RESULTS

The targeted NPs MnO2@Poly(DMAEMA-Co-IA) and MTX-loaded NPs inhibited MCF-7 cell viability more effectively than free MTX after 24 and 48 h, respectively, with no noticeable toxicity. Additionally, the insignificant hemolytic activity demonstrated their proper hemo-compatibility. T1-weighted magnetic resonance imaging was used to distinguish the differential uptake of the produced MnO2@Poly(DMAEMA-Co-IA)-MTX NPs in malignant cells compared to normal ones in the presence of high and low MTX receptor cells (MCF-7 and MCF-10A, respectively). In MRI, the produced theranostic NPs displayed pH-responsive contrast enhancement. As shown by in vitro assays, treatment of cells with MnO2@Poly(DMAEMA-Co-IA)-MTX NPs prior to radiotherapy in hypoxic conditions significantly enhanced therapeutic efficacy.

CONCLUSION

We draw the conclusion that using MnO2@Poly(DMAEMA-Co-IA)-MTX NPs in MR imaging and combination radiotherapy may be a successful method for imaging and radiation therapy of hypoxia cells.

Tannic acid-mediated synthesis of flower-like mesoporous MnO2 nanostructures as T1-T2 dual-modal MRI contrast agents and dual-enzyme mimetic agents

This study introduces a simple method for preparing a new generation of MnO2 nanomaterials (MNMs) using tannic acid as a template. Two shapes of MnO2 NMs, flower-like M1-MnO2 and near-spherical M2-MnO2, were prepared and compared as dual-active nanozymes and contrast agents in magnetic resonance imaging (MRI). Various parameters, including the crystallinity, morphology, magnetic saturation (Ms), surface functionality, surface area, and porosity of the MNMs were investigated. Flower-like M1-MnO2 NMs were biocompatible and exhibited pH-sensitive oxidase and peroxidase mimetic activity, more potent than near-spherical M2-MnO2. Furthermore, the signal intensity and r1 relaxivity strongly depended on the crystallinity, morphology, pore size, and specific surface area of the synthesized MNMs. Our findings suggest that flower-like M1-MnO2 NM with acceptable dual-enzyme mimetic (oxidase-like and peroxidase-like) and T1 MRI contrast activities could be employed as a promising theranostic system for future purposes.

β-Cyclodextrin Nanosponges Inclusion Compounds Associated with Silver Nanoparticles to Increase the Antimicrobial Activity of Quercetin

This work aimed to synthesize and characterize a nanocarrier that consisted of a ternary system, namely β-cyclodextrin-based nanosponge (NS) inclusion compounds (ICs) associated with silver nanoparticles (AgNPs) to increase the antimicrobial activity of quercetin (QRC). The nanosystem was developed to overcome the therapeutical limitations of QRC. The host-guest interaction between NSs and QRC was confirmed by field emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRPD), thermogravimetric analysis (TGA), and proton nuclear magnetic resonance (¹H-NMR). Moreover, the association of AgNPs with the NS-QRC was characterized using FE-SEM, energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), dynamic light scattering (DLS), ζ-potential, and UV-Vis. Finally, the antimicrobial activity of the novel formulations was tested, which depicted that the complexation of QRC inside the supramolecular interstices of NSs increases the inhibitory effects against Escherichia coli ATCC25922, as compared to that observed in the free QRC. In addition, at the same concentrations used to generate an antibacterial effect, the NS-QRC system with AgNPs does not affect the metabolic activity of GES-1 cells. Therefore, these results suggest that the use of NSs associated with AgNPs resulted in an efficient strategy to improve the physicochemical features of QRC.

Cell-Penetrating Peptidic GRP78 Ligand-Conjugated Iron Oxide Magnetic Nanoparticles for Tumor-Targeted Doxorubicin Delivery and Imaging

Although chemotherapy is regarded as an essential option in cancer treatment, it is still far from being perfect. Inadequate tumor drug concentration and systemic toxicity along with broad biodistribution have diminished the utility of chemotherapy. Tumor-targeting peptide-conjugated multifunctional nanoplatforms have emerged as an effective strategy for site-directed tumor tissues in cancer treatment and imaging. Herein, Pep42-targeted iron oxide magnetic nanoparticles (IONPs) functionalized with β-cyclodextrin (ßCD) containing doxorubicin (DOX) (Fe₃O₄-ßCD-Pep42-DOX) were successfully developed. The physical effects of the prepared NPs were characterized by employing various techniques. Transmission electron microscopy (TEM) images disclosed that the developed Fe₃O₄-ßCD-Pep42-DOX nanoplatforms had a spherical morphology and a core-shell structure with a size of nearly 17 nm. Fourier transform infrared (FT-IR) spectroscopy showed that β-cyclodextrin, DOX, and Pep42 molecules were successfully loaded on the IONPs. In vitro cytotoxicity analysis revealed that the fabricated multifunctional Fe₃O₄-ßCD-Pep42 nanoplatforms possessed excellent biosafety toward BT-474, MDA-MB468 (cancerous cells), and MCF10A normal cells, while Fe₃O₄-ßCD-Pep42-DOX exhibited great cancer cell killing ability. The high cellular uptake along with intracellular trafficking of Fe₃O₄-ßCD-Pep42-DOX highlights the usefulness of the Pep42-targeting peptide. In vivo results strongly supported the in vitro results, i.e., significant tumor size reduction was observed by single-dose injection of Fe₃O₄-ßCD-Pep42-DOX into tumor-bearing mice. Interestingly, in vivo MR imaging (MRI) of Fe₃O₄-ßCD-Pep42-DOX revealed T₂ contrast improvement in the tumor cells and therapeutic ability in cancer theranostics. Taken together, these findings provided strong evidence for the potential capability of Fe₃O₄-ßCD-Pep42-DOX as a multifunctional nanoplatform in cancer therapy and imaging and opens up a new avenue of research in this area.

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

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

Lymph Node Metastases Detection Using Gd2O3@PCD as Novel Multifunctional Contrast Imaging Agent in Metabolic Magnetic Resonance Molecular Imaging

Axillary lymph node detection is crucial to staging and prognosis of the lymph node metastatic spread in breast cancer. Currently, lymphoscintigraphy and blue dye, as the conventional methods to localize sentinel lymph nodes (SLNs), are invasive and can only be performed during surgery. This study has had a novel hybrid gadolinium oxide nanoparticle coating with Cyclodextrin-based polyester as a high-relaxivity T₁ magnetic resonance molecular imaging (MRMI) contrast agent (CA). Twelve female BALB/c mice were randomly divided into three groups of four mice; each group was injected with 4T₁ cells to obtain metastasis lymph nodes and diagnosed by using the 3D T₁W (VIBE) MRI (Siemens 3T, Prisma). The synthesized Gd₂O₃@PCD nanoparticles with a suitable particle size range of 20-40 nm have had much higher longitudinal relaxivity (r ₁) for Gd₂O₃@PCD and Gd-DOTA (Dotarem) with the values of 3.98 mM^-1·s^-1 ± 0.003 and 2.71 mM^-1·s^-1 ± 0.005, respectively. Identical MR images in coronal views were subsequently obtained to create time-intensity curves of the right axillary lymph nodes and to measure the contrast ratio (CR). The peak CR and qualitative assessment of axillary lymph nodes at five-time points were evaluated. After subcutaneous injection, the contrast ratio of axillary lymph node and tumor in mice exhibited CR peak of Gd₂O₃@PCD and Dotarem with the values of 2.21 ± 0.06 and 0.40 ± 0.004 for lymph node and 2.54 ± 0.04 and 1.21 ± 0.007 for the tumor, respectively. Furthermore, the lumbar-aortic lymph node is weakly visible in the original coronal image. In conclusion, the use of Gd₂O₃@PCD nanoparticles as novel MRMI CAs enables high resolution for the detection of lymph node metastasis in mice with the potential capability for breast cancer diagnostic imaging.

Multifunctional Gold Helix Phototheranostic Biohybrid That Enables Targeted Image-Guided Photothermal Therapy in Breast Cancer

The preparation of multifunctional smart theranostic systems is commonly achieved through complicated strategies, limiting their biomedical applications. Spirulina platensis (SP) microalgae, as a natural helix with some of the intrinsic theranostic functionalities (e.g., fluorescent and photosensitizer pigments), not only facilitates the fabrication process but also guarantees their biosafety for clinical applications. Herein, the helical architecture of gold nanoparticles (AuNPs) based on a SP biotemplate was engineered as a safe, biodegradable, and tumor-targeted biohybrid for imaging-guided photothermal therapy (PTT) to combat triple-negative breast cancer. The quasi-spherical AuNPs were embedded throughout the SP cell (Au-SP) with minimally involved reagents, only by controlling the original morphological stability of SP through pH adjustment of the synthesis media. SP thiolation increased the localization of AuNPs selectively on the cell wall without using a reducing agent (Au-TSP). SP autofluorescence, along with the high X-ray absorption of AuNPs, was employed for dual-modal fluorescence and computed tomography (FL/CT) imaging. Furthermore, the theranostic efficacy of Au-SP was improved through a targeting process with folic acid (Au-SP@CF). High tumor inhibition effects were obtained by the excellent photothermal performance of Au-SP@CF in both in vitro and in vivo analyses. Of particular note, a comparison of the photothermal effect of Au-SP@CF with the naked SP and calcined form of Au-SP@CF not only indicated the key role of the helical architecture of AuNPs in achieving a high photothermal effect but also led to the formation of new gold microspiral biohybrids (Au-MS) over the calcination process. In short, well-controllable immobilization of AuNPs, appropriate biodegradability, good hemocompatibility, long-term biosafety, accurate imaging, high tumor suppression, and low tumor metastasis effects under laser irradiation are an array of intriguing attributes, making the proposed biohybrid a promising theranostic system for FL/CT-imaging-guided PTT.

Cyclodextrin-Based Nanosponges: Overview and Opportunities

Nanosponges are solid cross-linked polymeric nano-sized porous structures. This broad concept involves, among others, metal organic frameworks and hydrogels. The focus of this manuscript is on cyclodextrin-based nanosponges. Cyclodextrins are cyclic oligomers of glucose derived from starch. The combined external hydrophilicity with the internal hydrophobic surface constitute a unique “microenvironment”, that confers cyclodextrins the peculiar ability to form inclusion host‒guest complexes with many hydrophobic substances. These complexes may impart beneficial modifications of the properties of guest molecules such as solubility enhancement and stabilization of labile guests. These properties complemented with the possibility of using different crosslinkers and high polymeric surface, make these sponges highly suitable for a large range of applications. Despite that, in the last 2 decades, cyclodextrin-based nanosponges have been developed for pharmaceutical and biomedical applications, taking advantage of the nontoxicity of cyclodextrins towards humans. This paper provides a critical and timely compilation of the contributions involving cyclodextrins nanosponges for those areas, but also paves the way for other important applications, including water and soil remediation and catalysis.

Stimuli-responsive cyclodextrin-based supramolecular assemblies as drug carriers

Cyclodextrins (CDs) are widely employed in biomedical applications because of their unique structures. Various biomedical applications can be achieved in a spatiotemporally controlled manner by integrating the host-guest chemistry of CDs with stimuli-responsive functions. In this review, we summarize the recent advances in stimuli-responsive supramolecular assemblies based on the host-guest chemistry of CDs. The stimuli considered in this review include endogenous (pH, redox, and enzymes) and exogenous stimuli (light, temperature, and magnetic field). We mainly discuss the mechanisms of the stimuli-responsive ability and present typical designs of the corresponding supramolecular assemblies for drug delivery and other potential biomedical applications. The limitations and perspectives of CD-based stimuli-responsive supramolecular assemblies are discussed to further promote the translation of laboratory products into clinical applications.

Improved Magneto-Microfluidic Separation of Nanoparticles through Formation of the β-Cyclodextrin-Curcumin Inclusion Complex

Molecular adsorption to the nanoparticle surface may switch the colloidal interactions from repulsive to attractive and promote nanoparticle agglomeration. If the nanoparticles are magnetic, then their agglomerates exhibit a much stronger response to external magnetic fields than individual nanoparticles. Coupling between adsorption, agglomeration, and magnetism allows a synergy between the high specific area of nanoparticles (∼100 m²/g) and their easy guidance or separation by magnetic fields. This yet poorly explored concept is believed to overcome severe restrictions for several biomedical applications of magnetic nanoparticles related to their poor magnetic remote control. In this paper, we test this concept using curcumin (CUR) binding (adsorption) to β-cyclodextrin (βCD)-coated iron oxide nanoparticles (IONP). CUR adsorption is governed by host-guest hydrophobic interactions with βCD through the formation of 1:1 and, possibly, 2:1 βCD:CUR inclusion complexes on the IONP surface. A 2:1 stoichiometry is supposed to promote IONP primary agglomeration, facilitating the formation of the secondary needle-like agglomerates under external magnetic fields and their magneto-microfluidic separation. The efficiency of these field-induced processes increases with CUR concentration and βCD surface density, while their relatively short timescale (<5 min) is compatible with magnetic drug delivery application.

EDTMP ligand-enhanced water interactions endowing iron oxide nanoparticles with dual-modal MRI contrast ability

Single-modal magnetic resonance imaging (MRI) contrast agents sometimes cause signal confusion in clinical diagnosis. Utilizing ligands to endow iron oxide nanoparticles (IO NPs) with excellent dual-modal MRI contrast efficiency might be an effective strategy to improve diagnostic accuracy. This work presents the development of a special ligand-assisted one-pot approach for the preparation of super-hydrophilic magnetic NPs with excellent water dispersion, biocompatibility and T₁-T₂ dual-modal contrast enhancement properties. In addition, the strong binding capacity between the ethylenediamine tetramethylenephosphonic acid (EDTMP) ligand and water molecules induced by the presence of abundant hydrogen bonds significantly improves spin-lattice (T₁) and spin-spin (T₂) imaging of the IO core. After being modified with the EDTMP ligand, the T₂ relaxation rate of the IO core is dramatically increased from 71.78 mM^-1 s^-1 to 452.38 mM^-1 s^-1, and a moderate T₁ relaxation rate (11.61 mM^-1 s^-1) is observed simultaneously, implying that the NPs with an average size of 9.7 nm may be potential candidates as high-efficiency T₁-T₂ MRI contrast agents. This fundamental technique of using super-hydrophilicity ligands to endow IO NPs with dual-modal contrast properties without size change and damage in the T₂ contrast effect may provide a useful strategy to facilitate the application of magnetic NPs in the field of medical diagnosis.

Optimisation of CT scan parameters to increase the accuracy of gross tumour volume identification in brain radiotherapy

Aim:

This study aimed to optimise computed tomography (CT) simulation scan parameters to increase the accuracy for gross tumour volume identification in brain radiotherapy. For this purpose, high-contrast scan protocols were assessed.

Materials and methods:

A CT accreditation phantom (ACR Gammex 464) was used to optimise brain CT scan parameters on a Toshiba Alexion 16-row multislice CT scanner. Dose, tube voltage, tube current–time and CT dose index (CTDI) were varied to create five image quality enhancement (IQE) protocols. They were assessed in terms of contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and noise level and compared with a standard clinical protocol. Finally, the ability of the selected protocols to identify low-contrast objects was examined based on a subjective method.

Results:

Among the five IQE protocols, the one with the highest tube current–time product (250 mA) and lowest tube voltage (100 kVp) showed higher CNR, while another with a tube current–time product of 150 mA and a tube voltage of 135 kVp had improved SNR and lower noise level compared to the standard protocol. In contouring low-contrast objects, the protocol with the highest milliampere and lowest peak kilovoltage exhibited the lowest error rate (1%) compared to the standard protocol (25%).

Findings:

CT image quality should be optimised using the high-dose parameters created in this study to provide better soft tissue contrast. This could lead to an accurate identification of gross tumour volume recognition in the planning of radiotherapy treatment.

Sponge particulates for biomedical applications: Biofunctionalization, multi-drug shielding, and theranostic applications

Sponge particulates have attracted enormous attention in biomedical applications for superior properties, including large porosity, elastic deformation, capillary action, and three-dimensional (3D) reaction environment. Especially, the tiny porous structures make sponge particulates a promising platform for drug delivery, tissue engineering, anti-infection, and wound healing by providing abundant reservoirs of broad surface and internal network for cargo shielding and shuttling. To control the sponge-like morphology and improve the diversity of drug loading, some optimized preparation techniques of sponge particulates have been developed, contributing to the simplified preparation process and improved production reproducibility. Bio-functionalized strategies, including target modification, cell membrane camouflage, and hydrogel of sponge particulates have been applied to modulate the properties, improve the performance, and extend the applications. In this review, we highlight the unique physical properties and functions, current manufacturing techniques, and an overview of spongy particulates in biomedical applications, especially in inhibition of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infectivity. Moreover, the current challenges and prospects of sponge particulates are discussed rationally, providing an insight into developing vibrant fields of sponge particulates-based biomedicine.

A photoluminescent folic acid-derived carbon dot functionalized magnetic dendrimer as a pH-responsive carrier for targeted doxorubicin delivery

A fluorescent folic acid carbon dot-grafted magnetic dendrimer was synthesized as a potential carrier for targeted delivery of DOX drug in an acidic medium (pH 5). The carrier showed biodegradability, high colloidal stability, and good biocompatibility towards A549 cells.

Modular Assembly of Drug and Monodisperse SPIONs for Superior Magnetic and T2-Imaging Performance

Development of superparamagnetic iron oxide nanoparticles (SPIONs) based theranostics has suffered due to its self-contradictory requirements on water dispersity and drug loadings. Generally well-dispersed SPIONs have excellent MRI performance but are insensitive to magnetism mediated delivery. Besides, loading hydrophobic drugs also hampers the stability of SPIONs which is critical for their biomedical applications. Considering these aspects, we employed curcumin as a cross-linking agent to facilitate the modular assembly of drug and monodisperse SPIONs (Cur/ALN-β-CD-SPIONs). Interestingly, the saturation magnetization of Cur/ALN-β-CD-SPIONs is higher than that of ALN-β-CD-SPIONs, and the value of r₂ indicating the negative contrast ability increases to 389.96 mM^-1 s^-1. Furthermore, the Cur/ALN-β-CD-SPIONs are very stable in PBS buffer over 3 weeks. The mice treated with Cur/ALN-β-CD-SPIONs by tail vein injection displayed a better tumor inhibition effect than that of free curcumin. This study provides a simple method for modular assembly of drug and monodisperse SPIONs, which is crucial to the design of SPIONs with superior T₂-imaging performance and drug delivery.

A biocompatible theranostic nanoplatform based on magnetic gadolinium-chelated polycyclodextrin: in vitro and in vivo studies

A novel theranostic nanoplatform was prepared based on Fe₃O₄ nanoparticles (NPs) coated with gadolinium ions decorated-polycyclodextrin (PCD) layer (Fe₃O₄@PCD-Gd) and employed for Curcumin (CUR) loading. The dissolution profile of CUR indicated a pH sensitive release manner. Fe₃O₄@PCD-Gd NPs exhibited no significant toxicity against both normal and cancerous cell lines (MCF 10A and 4T1, respectively); while the CUR-free NPs showed more toxicity against 4T1 than MCF 10A cells. In vivo anticancer study revealed appropriate capability of the system in tumor shrinking with no tissue toxicity and adverse effect on body weight. In vivo MR imaging of BALB/c mouse showed both T₁ and T₂ contrast enhancement on the tumor cells. Fe₃O₄@PCD-Gd/CUR NPs showed significant features as a promising multifunctional system having appropriate T₁-T₂ dual contrast enhancement and therapeutic efficacy in cancer theranostics.

Functionalization of Magnetic Nanoparticles by Folate as Potential MRI Contrast Agent for Breast Cancer Diagnostics

In recent years, the intrinsic magnetic properties of magnetic nanoparticles (MNPs) have made them one of the most promising candidates for magnetic resonance imaging (MRI). This study aims to evaluate the effect of different coating agents (with and without targeting agents) on the magnetic property of MNPs. In detail, iron oxide nanoparticles (IONPs) were prepared by the polyol method. The nanoparticles were then divided into two groups, one of which was coated with silica (SiO2) and hyperbranched polyglycerol (HPG) (SPION@SiO2@HPG); the other was covered by HPG alone (SPION@HPG). In the following section, folic acid (FA), as a targeting agent, was attached on the surface of nanoparticles. Physicochemical properties of nanostructures were characterized using Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and a vibrating sample magnetometer (VSM). TEM results showed that SPION@HPG was monodispersed with the average size of about 20 nm, while SPION@SiO2@HPG had a size of about 25 nm. Moreover, HPG coated nanoparticles had much lower magnetic saturation than the silica coated ones. The MR signal intensity of the nanostructures showed a relation between increasing the nanoparticle concentrations inside the MCF-7 cells and decreasing the signal related to the T2 relaxation time. The comparison of coating showed that SPION@SiO2@HPG (with/without a targeting agent) had significantly higher r2 value in comparison to Fe3O4@HPG. Based on the results of this study, the Fe3O4@SiO2@HPG-FA nanoparticles have shown the best magnetic properties, and can be considered promising contrast agents for magnetic resonance imaging applications.

Theranostics Based on Magnetic Nanoparticles and Polymers: Intelligent Design for Efficient Diagnostics and Therapy

Theranostics is a fast-growing field due to demands for new, efficient therapeutics which could be precisely delivered to the target site using multimodal imaging with enhancing auxiliary actions. In this review article we discuss theranostic nanoplatforms containing polymers and magnetic nanoparticles along with other components. Magnetic nanoparticles allow for both diagnostic and therapeutic (hyperthermia) capabilities, while polymers can be reservoirs for drugs and are easily functionalized for cell targeting. We focus on the most important design strategies to achieve optimal theranostic effects as well as the roles of different components included in theranostics, reviewing the literature from the last 5 years.

History of Cyclodextrin Nanosponges

Nowadays, research in the field of nanotechnology and nanomedicine has become increasingly predominant, focusing on the manipulation and development of materials on a nanometer scale. Polysaccharides have often been used as they are safe, non-toxic, hydrophilic, biodegradable and are low cost. Among them, starch derivatives and, in particular, cyclodextrin-based nanosponges (CD NSs) have recently emerged due to the outstanding properties attributable to their peculiar structure. In fact, alongside the common polysaccharide features, such as the presence of tunable functional groups and their ability to interact with biological tissues, thus giving rise to bioadhesion, which is particularly useful in drug delivery, what makes CD NSs unique is their three-dimensional network made up of crosslinked cyclodextrin units. The name “nanosponge” appeared for the first time in the 1990s due to their nanoporous, sponge-like structure and responded to the need to overcome the limitations of native cyclodextrins (CDs), particularly their water solubility and inability to encapsulate charged and large molecules efficiently. Since CD NSs were introduced, efforts have been made over the years to understand their mechanism of action and their capability to host molecules with low or high molecular weight, charged, hydrophobic or hydrophilic by changing the type of cyclodextrin, crosslinker and degree of crosslinking used. They enabled great advances to be made in various fields such as agroscience, pharmaceutical, biomedical and biotechnological sectors, and NS research is far from reaching its conclusion. This review gives an overview of CD NS research, focusing on the origin and key points of the historical development in the last 50 years, progressing from relatively simple crosslinked networks in the 1960s to today’s multifunctional polymers. The approach adopted in writing the present study consisted in exploring the historical evolution of NSs in order to understand their role today, and imagine their future.

Nanoencapsulated dietary polyphenols for cancer prevention and treatment: successes and challenges

Many dietary polyphenols have been investigated for their therapeutic potential either as single agents or in combinations. Despite the significant anticancer potential of these polyphenols in in vitro cell culture and in vivo animal models, their clinical applications have been limited because of challenges such as ineffective systemic delivery, stability and low bioavailability. Nanoencapsulation of these polyphenols could prolong circulation, improve localization, enhance efficacy and reduce the chances of multidrug resistance. This review summarized the use of various polyphenols especially epigallocatechin gallate, quercetin, curcumin and resveratrol as nanoformulations for cancer prevention and treatment. Despite some success, more research is warranted to design a nanoencapsulated combination of polyphenols, effective in in vitro, in vivo and human systems.

Glucosamine Conjugated Gadolinium (III) Oxide Nanoparticles as a Novel Targeted Contrast Agent for Cancer Diagnosis in MRI

BACKGROUND

Glucose transporter (Glut), a cellular transmembrane receptor, has a key role in the metabolism of cell glucose and is also associated with various human carcinomas.

OBJECTIVE

In this study, we evaluated a magnetic resonance (MR) imaging contrast agent for tumor detection based on paramagnetic gadolinium oxide (Gd₂O₃) coated polycyclodextrin (PCD) and modified with glucose (Gd₂O₃@PCD-Glu) for the targeting of overexpressed glucose receptors.

MATERIAL AND METHODS

In this experimental study, 3T magnetic resonance imaging (MRI) scanner was used to assess the specific interactions between Glut1-overexpressing tumor cells (MDA-MB-231) and Gd₂O₃@PCD-Glu NPs. Furthermore, the capacity of transporting Gd₂O₃@PCD-Glu NPs to tumor cells was evaluated.

RESULTS

It was found that the acquired MRI T₁ signal intensity of MDA-MB-231 cells that were treated with the Gd₂O₃@PCD-Glu NPs increased significantly. Based on the results obtained, Gd₂O₃@PCD-Glu NPs can be applied in targeting Glut1-overexpressing tumor cells in vivo, as well as an MRI-targeted tumor agent to enhance tumor diagnosis.

CONCLUSION

Results have shown that glucose-shell of magnetic nanoparticles has a key role in diagnosing cancer cells of high metabolic activity.

In vitro and in vivo characteristics of doxorubicin-loaded cyclodextrine-based polyester modified gadolinium oxide nanoparticles: a versatile targeted theranostic system for tumour chemotherapy and molecular resonance imaging

β-Cyclodextrine-based polyester was coated on the surface of gadolinium oxide nanoparticles (NPs) and then functionalised with folic acid to produce an efficient pH-sensitive targeted theranostic system (Gd₂O₃@PCD-FA) for doxorubicin delivery and magnetic resonance imaging (MRI). Gd₂O₃@PCD-FA was fully characterised by FTIR, vibrating sample magnetometer, TGA, XRD, SEM and TEM analyses. The dissolution profile of DOX showed a pH sensitive release. No significant toxicity was observed for the targeted NPs (Gd₂O₃@PCD-FA) and DOX-loaded NPs inhibiting M109 cells viability more efficiently than free DOX. Moreover, the negligible hemolytic activity of the targeted NPs showed their appropriate hemocompatibility. The preferential uptake was observed for the developed Gd₂O₃@PCD-FA-DOX NPs in comparison with Dotarem using T₁- and T₂-weighted MRI in the presence of folate receptor-positive and folate receptor-negative cancer cells (M109 and 4T1, respectively). Furthermore, in vivo studies revealed that Gd₂O₃@PCD-FA-DOX not only exhibited considerably relaxivity performance as a contrast agent for MRI, but also improved in vivo anti-tumour efficacy of the system. The results suggest that Gd₂O₃@PCD-FA-DOX improves its therapeutic efficacy in the treatment of solid tumours and also reduces the adverse effects, so it could be proposed as a promising drug delivery system for chemotherapy and molecular imaging diagnosis in MRI.