Recent Advances in Multimodal Molecular Imaging of Cancer Mediated by Hybrid Magnetic Nanoparticles

Magnetic nanoparticles for magnetic particle imaging (MPI): design and applications

Recent advancements in medical imaging have brought forth various techniques such as magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), and ultrasound, each contributing to improved diagnostic capabilities. Most recently, magnetic particle imaging (MPI) has become a rapidly advancing imaging modality with profound implications for medical diagnostics and therapeutics. By directly detecting the magnetization response of magnetic tracers, MPI surpasses conventional imaging modalities in sensitivity and quantifiability, particularly in stem cell tracking applications. Herein, this comprehensive review explores the fundamental principles, instrumentation, magnetic nanoparticle tracer design, and applications of MPI, offering insights into recent advancements and future directions. Novel tracer designs, such as zinc-doped iron oxide nanoparticles (Zn-IONPs), exhibit enhanced performance, broadening MPI's utility. Spatial encoding strategies, scanning trajectories, and instrumentation innovations are elucidated, illuminating the technical underpinnings of MPI's evolution. Moreover, integrating machine learning and deep learning methods enhances MPI's image processing capabilities, paving the way for more efficient segmentation, quantification, and reconstruction. The potential of superferromagnetic iron oxide nanoparticle chains (SFMIOs) as new MPI tracers further advanced the imaging quality and expanded clinical applications, underscoring the promising future of this emerging imaging modality.

Brachytherapy at the nanoscale with protein functionalized and intrinsically radiolabeled [169Yb]Yb2O3 nanoseeds

PURPOSE

Classical brachytherapy of solid malignant tumors is an invasive procedure which often results in an uneven dose distribution, while requiring surgical removal of sealed radioactive seed sources after a certain period of time. To circumvent these issues, we report the synthesis of intrinsically radiolabeled and gum Arabic glycoprotein functionalized [169Yb]Yb2O3 nanoseeds as a novel nanoscale brachytherapy agent, which could directly be administered via intratumoral injection for tumor therapy.

METHODS

169Yb (T½ = 32 days) was produced by neutron irradiation of enriched (15.2% in 168Yb) Yb2O3 target in a nuclear reactor, radiochemically converted to [169Yb]YbCl3 and used for nanoparticle (NP) synthesis. Intrinsically radiolabeled NP were synthesized by controlled hydrolysis of Yb3+ ions in gum Arabic glycoprotein medium. In vivo SPECT/CT imaging, autoradiography, and biodistribution studies were performed after intratumoral injection of radiolabeled NP in B16F10 tumor bearing C57BL/6 mice. Systematic tumor regression studies and histopathological analyses were performed to demonstrate therapeutic efficacy in the same mice model.

RESULTS

The nanoformulation was a clear solution having high colloidal and radiochemical stability. Uniform distribution and retention of the radiolabeled nanoformulation in the tumor mass were observed via SPECT/CT imaging and autoradiography studies. In a tumor regression study, tumor growth was significantly arrested with different doses of radiolabeled NP compared to the control and the best treatment effect was observed with ~ 27.8 MBq dose. In histopathological analysis, loss of mitotic cells was apparent in tumor tissue of treated groups, whereas no significant damage in kidney, lungs, and liver tissue morphology was observed.

CONCLUSIONS

These results hold promise for nanoscale brachytherapy to become a clinically practical treatment modality for unresectable solid cancers.

Nanoparticles for the Treatment of Bone Metastasis in Breast Cancer: Recent Advances and Challenges

Although the frequency of bone metastases from breast cancer has increased, effective treatment is lacking, prompting the development of nanomedicine, which involves the use of nanotechnology for disease diagnosis and treatment. Nanocarrier drug delivery systems offer several advantages over traditional drug delivery methods, such as higher reliability and biological activity, improved penetration and retention, and precise targeting and delivery. Various nanoparticles that can selectively target tumor cells without causing harm to healthy cells or organs have been synthesized. Recent advances in nanotechnology have enabled the diagnosis and prevention of metastatic diseases as well as the ability to deliver complex molecular "cargo" particles to metastatic regions. Nanoparticles can modulate systemic biodistribution and enable the targeted accumulation of therapeutic agents. Several delivery strategies are used to treat bone metastases, including untargeted delivery, bone-targeted delivery, and cancer cell-targeted delivery. Combining targeted agents with nanoparticles enhances the selective delivery of payloads to breast cancer bone metastatic lesions, providing multiple delivery advantages for treatment. In this review, we describe recent advances in nanoparticle development for treating breast cancer bone metastases.

Carbon quantum dots in bioimaging and biomedicines

Carbon quantum dots (CQDs) are gaining a lot more attention than traditional semiconductor quantum dots owing to their intrinsic fluorescence property, chemical inertness, biocompatibility, non-toxicity, and simple and inexpensive synthetic route of preparation. These properties allow CQDs to be utilized for a broad range of applications in various fields of scientific research including biomedical sciences, particularly in bioimaging and biomedicines. CQDs are a promising choice for advanced nanomaterials research for bioimaging and biomedicines owing to their unique chemical, physical, and optical properties. CQDs doped with hetero atom, or polymer composite materials are extremely advantageous for biochemical, biological, and biomedical applications since they are easy to prepare, biocompatible, and have beneficial properties. This type of CQD is highly useful in phototherapy, gene therapy, medication delivery, and bioimaging. This review explores the applications of CQDs in bioimaging and biomedicine, highlighting recent advancements and future possibilities to increase interest in their numerous advantages for therapeutic applications.

Enhancement of Oral Bioavailability of Protein and Peptide by Polysaccharide-based Nanoparticles

Oral drug delivery is a prevalent and cost-effective method due to its advantages, such as increased drug absorption surface area and improved patient compliance. However, delivering proteins and peptides orally remains a challenge due to their vulnerability to degradation by digestive enzymes, stomach acids, and limited intestinal membrane permeability, resulting in poor bioavailability. The use of nanotechnology has emerged as a promising solution to enhance the bioavailability of these vital therapeutic agents. Polymeric NPs, made from natural or synthetic polymers, are commonly used. Natural polysaccharides, such as alginate, chitosan, dextran, starch, pectin, etc., have gained preference due to their biodegradability, biocompatibility, and versatility in encapsulating various drug types. Their hydrophobic-hydrophilic properties can be tailored to suit different drug molecules.

Synergistic Nanomedicine: Photodynamic, Photothermal and Photoimmune Therapy in Hepatocellular Carcinoma: Fulfilling the Myth of Prometheus?

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, with high morbidity and mortality, which seriously threatens the health and life expectancy of patients. The traditional methods of treatment by surgical ablation, radiotherapy, chemotherapy, and more recently immunotherapy have not given the expected results in HCC. New integrative combined therapies, such as photothermal, photodynamic, photoimmune therapy (PTT, PDT, PIT), and smart multifunctional platforms loaded with nanodrugs were studied in this review as viable solutions in the synergistic nanomedicine of the future. The main aim was to reveal the latest findings and open additional avenues for accelerating the adoption of innovative approaches for the multi-target management of HCC. High-tech experimental medical applications in the molecular and cellular research of photosensitizers, novel light and laser energy delivery systems and the features of photomedicine integration via PDT, PTT and PIT in immuno-oncology, from bench to bedside, were introspected. Near-infrared PIT as a treatment of HCC has been developed over the past decade based on novel targeted molecules to selectively suppress cancer cells, overcome immune blocking barriers, initiate a cascade of helpful immune responses, and generate distant autoimmune responses that inhibit metastasis and recurrences, through high-tech and intelligent real-time monitoring. The process of putting into effect new targeted molecules and the intelligent, multifunctional solutions for therapy will bring patients new hope for a longer life or even a cure, and the fulfillment of the myth of Prometheus.

Imaging biomarkers for clinical applications in neuro-oncology: current status and future perspectives

Biomarker discovery and development are popular for detecting the subtle diseases. However, biomarkers are needed to be validated and approved, and even fewer are ever used clinically. Imaging biomarkers have a crucial role in the treatment of cancer patients because they provide objective information on tumor biology, the tumor's habitat, and the tumor's signature in the environment. Tumor changes in response to an intervention complement molecular and genomic translational diagnosis as well as quantitative information. Neuro-oncology has become more prominent in diagnostics and targeted therapies. The classification of tumors has been actively updated, and drug discovery, and delivery in nanoimmunotherapies are advancing in the field of target therapy research. It is important that biomarkers and diagnostic implements be developed and used to assess the prognosis or late effects of long-term survivors. An improved realization of cancer biology has transformed its management with an increasing emphasis on a personalized approach in precision medicine. In the first part, we discuss the biomarker categories in relation to the courses of a disease and specific clinical contexts, including that patients and specimens should both directly reflect the target population and intended use. In the second part, we present the CT perfusion approach that provides quantitative and qualitative data that has been successfully applied to the clinical diagnosis, treatment and application. Furthermore, the novel and promising multiparametric MR imageing approach will provide deeper insights regarding the tumor microenvironment in the immune response. Additionally, we briefly remark new tactics based on MRI and PET for converging on imaging biomarkers combined with applications of bioinformatics in artificial intelligence. In the third part, we briefly address new approaches based on theranostics in precision medicine. These sophisticated techniques merge achievable standardizations into an applicatory apparatus for primarily a diagnostic implementation and tracking radioactive drugs to identify and to deliver therapies in an individualized medicine paradigm. In this article, we describe the critical principles for imaging biomarker characterization and discuss the current status of CT, MRI and PET in finiding imaging biomarkers of early disease.

Shape programmable T1-T2 dual-mode MRI nanoprobes for cancer theranostics

The shape effect is an important parameter in the design of novel nanomaterials. Engineering the shape of nanomaterials is an effective strategy for optimizing their bioactive performance. Nanomaterials with a unique shape are beneficial to blood circulation, tumor targeting, cell uptake, and even improved magnetism properties. Therefore, magnetic resonance imaging (MRI) nanoprobes with different shapes have been extensively focused on in recent years. Different from other multimodal imaging techniques, dual-mode MRI can provide imaging simultaneously by a single instrument, which can avoid differences in penetration depth, and the spatial and temporal resolution of multiple imaging devices, and ensure the accurate matching of spatial and temporal imaging parameters for the precise diagnosis of early tumors. This review summarizes the latest developments of nanomaterials with various shapes for T₁-T₂ dual-mode MRI, and highlights the mechanism of how shape intelligently affects nanomaterials' longitudinal or transverse relaxation, namely sphere, hollow, core-shell, cube, cluster, flower, dumbbell, rod, sheet, and bipyramid shapes. In addition, the combination of T₁-T₂ dual-mode MRI nanoprobes and advanced therapeutic strategies, as well as possible challenges from basic research to clinical transformation, are also systematically discussed. Therefore, this review will help others quickly understand the basic information on dual-mode MRI nanoprobes and gather thought-provoking ideas to advance the subfield of cancer nanomedicine.

Nanoparticles in the diagnosis and treatment of cancer metastases: Current and future perspectives

Metastasis accounts for greater than 90% of cancer-related deaths. Despite recent advancements in conventional chemotherapy, immunotherapy, targeted therapy, and their rational combinations, metastatic cancers remain essentially untreatable. The distinct obstacles to treat metastases include their small size, high multiplicity, redundancy, therapeutic resistance, and dissemination to multiple organs. Recent advancements in nanotechnology provide the numerous applications in the diagnosis and prophylaxis of metastatic diseases, including the small particle size to penetrate cell membrane and blood vessels and their capacity to transport complex molecular 'cargo' particles to various metastatic regions such as bones, brain, liver, lungs, and lymph nodes. Indeed, nanoparticles (NPs) have demonstrated a significant ability to target specific cells within these organs. In this regard, the purpose of this review is to summarize the present state of nanotechnology in terms of its application in the diagnosis and treatment of metastatic cancer. We intensively reviewed applications of NPs in fluorescent imaging, PET scanning, MRI, and photoacoustic imaging to detect metastasis in various cancer models. The use of targeted NPs for cancer ablation in conjunction with chemotherapy, photothermal treatment, immuno therapy, and combination therapy is thoroughly discussed. The current review also highlights the research opportunities and challenges of leveraging engineering technologies with cancer cell biology and pharmacology to fabricate nanoscience-based tools for treating metastases.

Enhanced glypican-3-targeted identification of hepatocellular carcinoma with liver fibrosis by pre-degrading excess fibrotic collagen

Most hepatocellular carcinomas (HCCs) occur in cirrhotic livers, but unequivocal diagnosis of early HCC from the fibrotic microenvironment remains a formidable challenge with conventional imaging strategies, mainly because of the massive fibrotic collagen deposition leading to hepatic nodules formation and dysfunction of contrast agent metabolism. Here, we developed a "sweep-and-illuminate" imaging strategy, pre-degrade hepatic fibrotic collagen with collagenase I conjugated human serum albumin (HSA-C) and then targeting visualize HCC lesion with GPC3 targeting nanoparticles (TSI NPs, TJ2 peptide-superparamagnetic iron oxide-indocyanine green) via fluorescence imaging (FLI) and magnetic particle imaging (MPI). TSI NPs delineated a clear boundary of HCC and normal liver, and the tumor-to-background ratios (TBRs) detected by FLI and MPI were 5.43- and 1.34-fold higher than the non-targeted group, respectively. HSA-C could degrade 24.7% fibrotic collagen, followed by 27.2% reduction of nonspecific NPs retention in mice with liver fibrosis. In a pathological state in which HCC occurs in the fibrotic microenvironment, HSA-C-mediated pre-degradation of fibrotic collagen reduced background signal interference in fibrotic tissues and enhanced the intratumoral uptake of TSI NPs, resulting in the clear demarcation between HCC and liver fibrosis, and the TBR was increased 2.61-fold compared to the group without HSA-C pretreatment. We demonstrated the feasibility of combined pre-degradation of fibrotic collagen and application of a GPC3-targeted FLI/MPI contrast agent for early HCC identification, as well as its clinical value in the management of patients with advanced liver fibrosis. STATEMENT OF SIGNIFICANCE: Given that liver fibrosis hinders early detection and treatment options of hepatocellular carcinomas (HCCs), we report a "sweep-and-illuminate" imaging strategy to enhance the efficiency of HCC identification by modulating the irreversible liver fibrosis. We first "sweep" nonspecific interference of contrast agent by pre-degrading fibrotic collagen with human serum albumin-carried collagenase I (HSA-C); and then specifically "illuminate" HCC lesions with GPC3-targeted-SPIO-ICG nanoparticles (TSI NPs). HSA-C can degrade 24.7% fibrotic collagen, followed by 27.2% reduction of nonspecific NPs retention in mice with liver fibrosis. Furthermore, in HCC models coexisting with liver fibrosis, the combined application of HSA-C and TSI NPs can clarify the demarcation between HCC and liver fibrosis with a 2.61-fold increase in the tumor-to-background ratio. This study may expand the potential of combinatorial biomaterials for early HCC diagnosis.

Molecular and functional imaging in cancer-targeted therapy: current applications and future directions

Targeted anticancer drugs block cancer cell growth by interfering with specific signaling pathways vital to carcinogenesis and tumor growth rather than harming all rapidly dividing cells as in cytotoxic chemotherapy. The Response Evaluation Criteria in Solid Tumor (RECIST) system has been used to assess tumor response to therapy via changes in the size of target lesions as measured by calipers, conventional anatomically based imaging modalities such as computed tomography (CT), and magnetic resonance imaging (MRI), and other imaging methods. However, RECIST is sometimes inaccurate in assessing the efficacy of targeted therapy drugs because of the poor correlation between tumor size and treatment-induced tumor necrosis or shrinkage. This approach might also result in delayed identification of response when the therapy does confer a reduction in tumor size. Innovative molecular imaging techniques have rapidly gained importance in the dawning era of targeted therapy as they can visualize, characterize, and quantify biological processes at the cellular, subcellular, or even molecular level rather than at the anatomical level. This review summarizes different targeted cell signaling pathways, various molecular imaging techniques, and developed probes. Moreover, the application of molecular imaging for evaluating treatment response and related clinical outcome is also systematically outlined. In the future, more attention should be paid to promoting the clinical translation of molecular imaging in evaluating the sensitivity to targeted therapy with biocompatible probes. In particular, multimodal imaging technologies incorporating advanced artificial intelligence should be developed to comprehensively and accurately assess cancer-targeted therapy, in addition to RECIST-based methods.

Fluorescent Single-Core and Multi-Core Nanoprobes as Cell Trackers and Magnetic Nanoheaters

Iron oxide magnetic nanoparticles (MNPs) have been widely studied due to their versatility for diagnosis, tracking (magnetic resonance imaging (MRI)) and therapeutic (magnetic hyperthermia and drug delivery) applications. In this work, iron oxide MNPs with different single-core (8–40 nm) and multi-core (140–200 nm) structures were synthesized and functionalized by organic and inorganic coating materials, highlighting their ability as magnetic nanotools to boost cell biotechnological procedures. Single core Fe3O4@PDA, Fe3O4@SiO2-FITC-SiO2 and Fe3O4@SiO2-RITC-SiO2 MNPs were functionalized with fluorescent components with emission at different wavelengths, 424 nm (polydopamine), 515 (fluorescein) and 583 nm (rhodamine), and their ability as transfection and imaging agents was explored with HeLa cells. Moreover, different multi-core iron oxide MNPs (Fe3O4@CS, Fe3O4@SiO2 and Fe3O4@Citrate) coated with organic (citrate and chitosan, CS) and inorganic (silica, SiO2) shells were tested as efficient nanoheaters for magnetic hyperthermia applications for mild thermal heating procedures as an alternative to simple structures based on single-core MNPs. This work highlights the multiple abilities offered by the synergy of the use of external magnetic fields applied on MNPs and their application in different biomedical approaches.

Progresses in Fluorescence Imaging Guidance for Bone and Soft Tissue Sarcoma Surgery

R0 surgical resection is the preferred treatment for bone and soft tissue sarcoma. However, there is still a lack of precise technology that can visualize bone and soft tissue sarcoma during surgery to assist the surgeon in judging the tumor surgical boundary. Fluorescence imaging technology has been used in the diagnosis of cancer. It is a simple and essentially safe technique that takes no additional time during the operation. Intraoperative fluorescence imaging has potential application prospects in assisting the surgeons in judging the tumor boundary and improving the accuracy of surgical resection. This review mainly starts with clinical studies, animal experimentation, and newly designed probes of intraoperative fluorescence imaging of bone and soft tissue sarcoma, to appraise the application prospects of fluorescence imaging technology in bone and soft tissue sarcoma.

Advances with metal oxide-based nanoparticles as MDR metastatic breast cancer therapeutics and diagnostics

Metal oxide nanoparticles have attracted increased attention due to their emerging applications in cancer detection and therapy. This study envisioned to highlight the great potential of metal oxide NPs due to their interesting properties including high payload, response to magnetic field, affluence of surface modification to overcome biological barriers, and biocompatibility. Mammogram, ultrasound, X-ray computed tomography (CT), MRI, positron emission tomography (PET), optical or fluorescence imaging are used for breast imaging. Drug-loaded metal oxide nanoparticle delivered to the breast cancer cells leads to higher drug uptake. Thus, enhanced the cytotoxicity to target cells compared to free drug. The drug loaded metal oxide nanoparticle formulations hold great promise to enhance efficacy of breast cancer therapy including multidrug resistant (MDR) and metastatic breast cancers. Various metal oxides including magnetic metal oxides and magnetosomes are of current interests to explore cancer drug delivery and diagnostic efficacy especially for metastatic breast cancer. Metal oxide-based nanocarrier formulations are promising for their usage in drug delivery and release to breast cancer cells, cancer diagnosis and their clinical translations.

Biomarker targeted therapy approaches for TNBC using metal oxide-based NPs are highly effective and promising.

Protein-Based Nanoparticles for the Imaging and Treatment of Solid Tumors: The Case of Ferritin Nanocages, a Narrative Review

Protein nanocages have been studied extensively, due to their unique architecture, exceptional biocompatibility and highly customization capabilities. In particular, ferritin nanocages (FNs) have been employed for the delivery of a vast array of molecules, ranging from chemotherapeutics to imaging agents, among others. One of the main favorable characteristics of FNs is their intrinsic targeting efficiency toward the Transferrin Receptor 1, which is overexpressed in many tumors. Furthermore, genetic manipulation can be employed to introduce novel variants that are able to improve the loading capacity, targeting capabilities and bio-availability of this versatile drug delivery system. In this review, we discuss the main characteristics of FN and the most recent applications of this promising nanotechnology in the field of oncology with a particular emphasis on the imaging and treatment of solid tumors.

Low-Dose PET Imaging of Tumors in Lung and Liver Regions Using Internal Motion Estimation

Motion estimation and compensation are necessary for improvement of tumor quantification analysis in positron emission tomography (PET) images. The aim of this study was to propose adaptive PET imaging with internal motion estimation and correction using regional artificial evaluation of tumors injected with low-dose and high-dose radiopharmaceuticals. In order to assess internal motion, molecular sieves imitating tumors were loaded with ¹⁸F and inserted into the lung and liver regions in rats. All models were classified into two groups, based on the injected radiopharmaceutical activity, to compare the effect of tumor intensity. The PET study was performed with injection of F-18 fluorodeoxyglucose (¹⁸F-FDG). Respiratory gating was carried out by external trigger device. Count, signal to noise ratio (SNR), contrast and full width at half maximum (FWHM) were measured in artificial tumors in gated images. Motion correction was executed by affine transformation with estimated internal motion data. Monitoring data were different from estimated motion. Contrast in the low-activity group was 3.57, 4.08 and 6.19, while in the high-activity group it was 10.01, 8.36 and 6.97 for static, 4 bin and 8 bin images, respectively. The results of the lung target in 4 bin and the liver target in 8 bin showed improvement in FWHM and contrast with sufficient SNR. After motion correction, FWHM was improved in both regions (lung: 24.56%, liver: 10.77%). Moreover, with the low dose of radiopharmaceuticals the PET image visualized specific accumulated radiopharmaceutical areas in the liver. Therefore, low activity in PET images should undergo motion correction before quantification analysis using PET data. We could improve quantitative tumor evaluation by considering organ region and tumor intensity.

Ionotropic Gelation-Based Synthesis of Chitosan-Metal Hybrid Nanoparticles Showing Combined Antimicrobial and Tissue Regenerative Activities

The treatment of skin wounds poses significant clinical challenges, including the risk of bacterial infection. In particular due to its antimicrobial and tissue regeneration abilities chitosan (a polymeric biomaterial obtained by the deacetylation of chitin) has received extensive attention for its effectiveness in promoting skin wound repair. On the other hand, due to their intrinsic characteristics, metal nanoparticles (e.g., silver (Ag), gold (Au) or iron oxide (Fe3O4)) have demonstrated therapeutic properties potentially useful in the field of skin care. Therefore, the combination of these two promising materials (chitosan plus metal oxide NPs) could permit the achievement of a promising nanohybrid with enhanced properties that could be applied in advanced skin treatment. In this work, we have optimized the synthesis protocol of chitosan/metal hybrid nanoparticles by means of a straightforward synthetic method, ionotropic gelation, which presents a wide set of advantages. The synthesized hybrid NPs have undergone to a full physicochemical characterization. After that, the in vitro antibacterial and tissue regenerative activities of the achieved hybrids have been assessed in comparison to their individual constituent. As result, we have demonstrated the synergistic antibacterial plus the tissue regeneration enhancement of these nanohybrids as a consequence of the fusion between chitosan and metallic nanoparticles, especially in the case of chitosan/Fe3O4 hybrid nanoparticles.