Harnessing Hafnium-Based Nanomaterials for Cancer Diagnosis and Therapy

Synthesis and X-ray structure analysis of cytotoxic 2-picolylamino-type HfIV-bis-chelated complexes

Eight novel heteroleptic HfIV complexes containing differently substituted 2-picolylamino-bis-phenolate and 2,6-dipicolinic acid (Dipic) groups as chelating ligands were synthesized and characterized with yields higher than 80%. These [ONON] type HfIV complexes have good aqueous stability and potent anti-tumor activity against HeLa S3 (human cervical adenocarcinoma) and Hep G2 (human derived hepatoma) cells. In particular, the complexes demonstrated selective inhibitory activity against Hep G2 cells. The IC50 value of the most cytotoxic complex [L1HfIVDipic4-Cl] (0.9 ± 0.4 μM) was ten-fold higher than that of cisplatin (11.2 ± 2.1 μM) on Hep G2 cells, being the most cytotoxic anti-tumor HfIV complex to date. Furthermore, [L1HfIVDipic4-Cl] could inhibit tumor cell migration, induce reactive oxygen species generation (particularly HO˙), loss of mitochondrial membrane potential and almost exclusive early apoptosis in HeLa S3 cells. [L1HfIVDipic4-Cl] exhibited rapid cellular uptake by HeLa S3 cells, and when in aqueous media, these HfIV complexes slowly hydrolyzed, releasing non-toxic phenolato ligands as the product of hydrolysis. Overall, these rare earth complexes, particularly [L1HfIVDipic4-Cl], show promising potential as novel anticancer agents with significant efficacy against human liver cancer cells and favorable selectivity profiles for further therapeutic development.

Zirconium vs. hafnium: a comparative study of mesoporous MOF stability

A wide range of mesoporous Zr and Hf metal-organic frameworks (MOFs), namely MIP-206, MOF-808, and NU-1000, as well as the microporous UiO-66, were systematically investigated and compared in terms of thermal and chemical stability. The holistic effects of metal type (Zr vs. Hf), linker type (small and rigid vs. large and flexible), and framework topology (2D vs. 3D) on the overall framework stability were investigated.

Nanoscale Metal-Organic Frameworks and Nanoscale Coordination Polymers: From Synthesis to Cancer Therapy and Biomedical Imaging

Recently, there has been significant interest in nanoscale metal-organic frameworks (NMOFs) characterized by ordered crystal structures and nanoscale coordination polymers (NCPs) featuring amorphous structures. These structures arise from the coordination interactions between inorganic metal ions or clusters and organic ligands. Their advantages, such as the ability to tailor composition and structure, efficiently encapsulate diverse therapeutic or imaging agents within porous frameworks, inherent biodegradability, and surface functionalization capability, position them as promising carriers in the biomedical fields. This review provides an overview of the synthesis and surface modification strategies employed for NMOFs and NCPs, along with their applications in cancer treatment and biological imaging. Finally, future directions and challenges associated with the utilization of NMOFs and NCPs in cancer treatment and diagnosis are also discussed.

Nanoparticles and bone microenvironment: a comprehensive review for malignant bone tumor diagnosis and treatment

Malignant bone tumors, which are difficult to treat with current clinical strategies, originate from bone tissues and can be classified into primary and secondary types. Due to the specificity of the bone microenvironment, the results of traditional means of treating bone tumors are often unsatisfactory, so there is an urgent need to develop new treatments for malignant bone tumors. Recently, nanoparticle-based approaches have shown great potential in diagnosis and treatment. Nanoparticles (NPs) have gained significant attention due to their versatility, making them highly suitable for applications in bone tissue engineering, advanced imaging techniques, and targeted drug delivery. For diagnosis, NPs enhance imaging contrast and sensitivity by integrating targeting ligands, which significantly improve the specific recognition and localization of tumor cells for early detection. For treatment, NPs enable targeted drug delivery, increasing drug accumulation at tumor sites while reducing systemic toxicity. In conclusion, understanding bone microenvironment and using the unique properties of NPs holds great promise in improving disease management, enhancing treatment outcomes, and ultimately improving the quality of life for patients with malignant bone tumors. Further research and development will undoubtedly contribute to the advancement of personalized medicine in the field of bone oncology.

Unveiling Advancements: Trends and Hotspots of Metal-Organic Frameworks in Photocatalytic CO2 Reduction

Metal-organic frameworks (MOFs) are robust, crystalline, and porous materials featured by their superior CO2 adsorption capacity, tunable energy band structure, and enhanced photovoltaic conversion efficiency, making them highly promising for photocatalytic CO2 reduction reaction (PCO2RR). This study presents a comprehensive examination of the advancements in MOFs-based PCO2RR field spanning the period from 2011 to 2023. Employing bibliometric analysis, the paper scrutinizes the widely adopted terminology and citation patterns, elucidating trends in publication, leading research entities, and the thematic evolution within the field. The findings highlight a period of rapid expansion and increasing interdisciplinary integration, with extensive international and institutional collaboration. A notable emphasis on significant research clusters and key terminologies identified through co-occurrence network analysis, highlighting predominant research on MOFs such as UiO, MIL, ZIF, porphyrin-based MOFs, their composites, and the hybridization with photosensitizers and molecular catalysts. Furthermore, prospective design approaches for catalysts are explored, encompassing single-atom catalysts (SACs), interfacial interaction enhancement, novel MOF constructions, biocatalysis, etc. It also delves into potential avenues for scaling these materials from the laboratory to industrial applications, underlining the primary technical challenges that need to be overcome to facilitate the broader application and development of MOFs-based PCO2RR technologies.

Metronidazole-modified Au@BSA nanocomposites for dual sensitization of radiotherapy in solid tumors

The hypoxic microenvironment of solid tumors can lead to reduced therapeutic DNA damage to the tumor cells, thus diminishing tumor sensitivity to radiotherapy. Although hypoxic radiosensitizers can improve radiotherapy efficacy by enhancing the role of oxygen, their effects are limited by the uneven distribution of oxygen within solid tumor tissues. In this study, a novel radiosensitizer via leveraging gold complexes and metronidazole (MN) was synthesized to improve radiotherapeutic efficacy. The gold atoms incorporated in the radiosensitizer enabled efficient deposition of high-energy radiation; the hydrophobic metronidazole was reduced to hydrophilic aminoimidazole under hypoxia conditions and further promoted radiotherapy sensitization. The results of CCK-8 assays, Live/Dead assays, γ-H2AX immunofluorescence indicated that metronidazole-modified Au@BSA nanocomposites (NCs) exhibited excellent antitumor effects. The in vivo antitumor tests further showed an inhibition rate of 100%. These results demonstrated that the NCs successfully enhanced radiotherapy efficacy by the dual sensitization strategy. Overall, we believe this multimodal radiosensitizing nanocomplex can significantly inhibit tumor growth and metastasis, with their hypoxia-oriented characteristics ensuring a higher efficacy and safety.

Research trends on nanomaterials in triple negative breast cancer (TNBC): a bibliometric analysis from 2010 to 2024

Breast cancer (BC) is an important cause of cancer-related death in the world. As a subtype of BC with the worst prognosis, triple-negative breast cancer (TNBC) is a serious threat to human life and health. In recent years, there has been an increasing amount of research aimed at designing and developing nanomaterials for the diagnosis and treatment of TNBC. The purpose of this study was to comprehensively evaluate the current status and trend of the application of nanomaterials in TNBC through bibliometric analysis. Studies focusing on nanomaterials and cancer were searched from the Web of Science core collection (WOSCC) database, and relevant literature meeting the inclusion criteria was selected for inclusion in the study. VOSviewer and CiteSpace were used to perform bibliometric and visual analysis of the included publications. A total of 2338 studies were included. Annual publications have increased from 2010 to 2024. China, the United States and India were the leading countries in the field, accounting for 66.1%, 11.5% and 7.2% of publications, respectively. The Chinese Academy of Sciences and Li Yaping were the most influential institutions and authors, respectively. Journal of Controlled Release was considered the most productive journal. Cancer Research was considered to be the most co-cited journal. Drug delivery and anti-cancer mechanisms related to nanomaterials were considered to be the most widely studied aspects, and green synthesis and anti-cancer mechanisms were also recent research hotspots. In this study, the characteristics of publications were summarized, and the most influential countries, institutions, authors, journals, hot spots and trends in the application of nanomaterials in cancer were identified. These findings provide valuable insights into the current state and future direction of this dynamic field.

Oxygen Vacancy-Rich Manganese Nanoflowers as Ferroptosis Inducers for Tumor Radiotherapy

The combination of ferroptosis and innovative tumor therapy methods offers another promising answer to the problem of tumors. In order to generate effective ferroptosis in tumor cells, iron-based nanomaterials are commonly utilized to introduce foreign iron as a trigger for ferroptosis. However, this usually necessitates the injection of larger doses of iron into the body. These exogenous iron increases are likely to create concealed concerns for symptoms such as liver damage and allergy. Herein, an iron-free radiosensitizer is introduced, oxygen-vacancy-rich MnO2 nanoflowers (ovs-MnO2), that promotes ferroptosis and modifies the tumor microenvironment to assist radiotherapy. ovs-MnO2 with enriched oxygen vacancies on the surface induces the release of intracellular free iron (Fe2+), which functions as an activator of Fenton reaction and enhances the accumulation of intracellular reactive oxygen species. On the other hand, Fe2+ also triggers the ferroptosis and promotes the accumulation of lipid peroxides. Subsequently, the depletion of glutathione and accumulation of lipid peroxidation in tumor cells leads to the inactivation of glutathione peroxidase 4 (GPX4) and ferroptosis, thereby enhancing the therapeutic efficacy of radiotherapy. The nanoplatform provides a novel strategy for generating novel nanomedicines for ferroptosis-assisted radiotherapy.

Bibliometric analysis of research on the utilization of nanotechnology in diabetes mellitus and its complications

Aim: To identify hotspots in this field and provide insights into future research directions. Methods: Publications were retrieved from the Web of Science Core Collection database. R Bibliometrix software, VOSviewer and CiteSpace were used to perform the bibliometric and visualization analyses. Results: The analysis comprised 468 publications from 58 countries, with the United States, China and India being the leading contributors. 'Gene therapy', 'nanoparticles' and 'insulin therapy' are the primary focuses. 'Green synthesis', 'cytotoxicity', 'bioavailability' and 'diabetic foot ulcers' have gained prominence, signifying high-intensity areas of interest expected to persist as favored research topics in the future. Conclusion: This study delves into recent frontiers and topical research directions and provides valuable references for further research in this field.

In Vitro and In Vivo Synergetic Radiotherapy with Gold Nanoparticles and Docetaxel for Pancreatic Cancer

This research underscores the potential of combining nanotechnology with conventional therapies in cancer treatment, particularly for challenging cases like pancreatic cancer. We aimed to enhance pancreatic cancer treatment by investigating the synergistic effects of gold nanoparticles (GNPs) and docetaxel (DTX) as potential radiosensitizers in radiotherapy (RT) both in vitro and in vivo, utilizing a MIA PaCa-2 monoculture spheroid model and NRG mice subcutaneously implanted with MIA PaCa-2 cells, respectively. Spheroids were treated with GNPs (7.5 μg/mL), DTX (100 nM), and 2 Gy of RT using a 6 MV linear accelerator. In parallel, mice received treatments of GNPs (2 mg/kg), DTX (6 mg/kg), and 5 Gy of RT (6 MV linear accelerator). In vitro results showed that though RT and DTX reduced spheroid size and increased DNA DSBs, the triple combination of DTX/RT/GNPs led to a significant 48% (p = 0.05) decrease in spheroid size and a 45% (p = 0.05) increase in DNA DSBs. In vivo results showed a 20% (p = 0.05) reduction in tumor growth 20 days post-treatment with (GNPs/RT/DTX) and an increase in mice median survival. The triple combination exhibited a synergistic effect, enhancing anticancer efficacy beyond individual treatments, and thus could be employed to improve radiotherapy and potentially reduce adverse effects.

Radiotherapy-sensitized cancer immunotherapy via cGAS-STING immune pathway by activatable nanocascade reaction

Radiotherapy-induced immune activation holds great promise for optimizing cancer treatment efficacy. Here, we describe a clinically used radiosensitizer hafnium oxide (HfO2) that was core coated with a MnO2 shell followed by a glucose oxidase (GOx) doping nanoplatform (HfO2@MnO2@GOx, HMG) to trigger ferroptosis adjuvant effects by glutathione depletion and reactive oxygen species production. This ferroptosis cascade potentiation further sensitized radiotherapy by enhancing DNA damage in 4T1 breast cancer tumor cells. The combination of HMG nanoparticles and radiotherapy effectively activated the damaged DNA and Mn2+-mediated cGAS-STING immune pathway in vitro and in vivo. This process had significant inhibitory effects on cancer progression and initiating an anticancer systemic immune response to prevent distant tumor recurrence and achieve long-lasting tumor suppression of both primary and distant tumors. Furthermore, the as-prepared HMG nanoparticles "turned on" spectral computed tomography (CT)/magnetic resonance dual-modality imaging signals, and demonstrated favorable contrast enhancement capabilities activated by under the GSH tumor microenvironment. This result highlighted the potential of nanoparticles as a theranostic nanoplatform for achieving molecular imaging guided tumor radiotherapy sensitization induced by synergistic immunotherapy.

Osteogenic and Biomedical Prospects of Hafnium and Its Compounds: A Scoping Review

The direct engagement of hafnium (Hf) in biological processes or its critical function in living things is not well understood as of now. Unlike key elements like oxygen, carbon, hydrogen, and nitrogen, which are necessary for life, Hf is not known to have any biological activities or functions. It is essential to acknowledge that scientific research is ongoing and that new findings may have been made. This systematic review aimed to aggregate and analyze the studies that discuss biomedical applications of Hf metal. This systematic review was conducted following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. The following search strategy was used: two independent researchers conducted electronic searches in databases including PubMed, Embase, Cochrane Database of Systematic Reviews, and Google Scholar. The search was conducted up to August 2023 using the Medical Subject Headings (MeSH) terms "transition elements," "hafnium," and "biomedical research." Boolean operators "AND" and "OR" were used to refine the search. Electronic databases, along with hand searches, identified a total of 38 studies. The various database searches resulted in a total of 38 studies, of which 12 were excluded as duplicates, and five were unavailable for full-text data. The remaining 21 full-text articles were then assessed for their eligibility based on the inclusion and exclusion criteria, and finally, a total of 12 studies were included in the present systematic review. Among the 12 chosen studies, six were on cancer-related targeted radiotherapy or chemoradiotherapy, five were on bone or apatite-forming capabilities, and one was on the treatment of inflammatory bowel disease. The common outcome measures included cell proliferation, osteoblast formation, radiotherapy intensification, and immunotherapy. This review outlines an overall picture of the biomedical uses of Hf metal, a transition element, as a potent biomaterial. In conclusion, this transition element, Hf, has some promising scope in the fields of biomedicine, with a special focus in terms of cancer radiotherapy and osteogenic capabilities.

Nanotechnology-based delivery systems to overcome drug resistance in cancer

Cancer nanomedicine is defined as the application of nanotechnology and nanomaterials for the formulation of cancer therapeutics that can overcome the impediments and restrictions of traditional chemotherapeutics. Multidrug resistance (MDR) in cancer cells can be defined as a decrease or abrogation in the efficacy of anticancer drugs that have different molecular structures and mechanisms of action and is one of the primary causes of therapeutic failure. There have been successes in the development of cancer nanomedicine to overcome MDR; however, relatively few of these formulations have been approved by the United States Food and Drug Administration for the treatment of cancer. This is primarily due to the paucity of knowledge about nanotechnology and the fundamental biology of cancer cells. Here, we discuss the advances, types of nanomedicines, and the challenges regarding the translation of in vitro to in vivo results and their relevance to effective therapies.

Synthesis and Bioapplication of Emerging Nanomaterials of Hafnium

A significant amount of progress in nanotechnology has been made due to the development of engineered nanoparticles. The use of metallic nanoparticles for various biomedical applications has been extensively investigated. Biomedical research is highly focused on them because of their inert nature, nanoscale structure, and similar size to many biological molecules. The intrinsic characteristics of these particles, including electronic, optical, physicochemical, and surface plasmon resonance, that can be altered by altering their size, shape, environment, aspect ratio, ease of synthesis, and functionalization properties, have led to numerous biomedical applications. Targeted drug delivery, sensing, photothermal and photodynamic therapy, and imaging are some of these. The promising clinical results of NBTXR3, a high-Z radiosensitizing nanomaterial derived from hafnium, have demonstrated translational potential of this metal. This radiosensitization approach leverages the dependence of energy attenuation on atomic number to enhance energy-matter interactions conducive to radiation therapy. High-Z nanoparticle localization in tumor issue differentially increases the effect of ionizing radiation on cancer cells versus nearby healthy ones and mitigates adverse effects by reducing the overall radiation burden. This principle enables material multifunctionality as contrast agents in X-ray-based imaging. The physiochemical properties of hafnium (Z = 72) are particularly advantageous for these applications. A well-placed K-edge absorption energy and high mass attenuation coefficient compared to elements in human tissue across clinical energy ranges leads to significant attenuation. Chemical reactivity allows for variety in nanoparticle synthesis, composition, and functionalization. Nanoparticles such as hafnium oxide exhibit excellent biocompatibility due to physiochemical inertness prior to incidence with ionizing radiation. Additionally, the optical and electronic properties are applicable in biosensing, optical component coatings, and semiconductors. The wide interest has prompted extensive research in design and synthesis to facilitate property fine-tuning. This review summarizes synthetic methods for hafnium-based nanomaterials and applications in therapy, imaging, and biosensing with a mechanistic focus. A discussion and future perspective section highlights clinical progress and elaborates on current challenges. By focusing on factors impacting applicational effectiveness and examining limitations this review aims to support researchers and expedite clinical translation of future hafnium-based nanomedicine.

Nanointegrative In Situ Reprogramming of Tumor-Intrinsic Lipid Droplet Biogenesis for Low-Dose Radiation-Activated Ferroptosis Immunotherapy

Low-dose radiotherapy (LDR) has shown significant implications for inflaming the immunosuppressive tumor microenvironment (TME). Surprisingly, we identify that FABP-dependent lipid droplet biogenesis in tumor cells is a key determinant of LDR-evoked cytotoxic and immunostimulatory effects and developed a nanointegrated strategy to promote the antitumor efficacy of LDR through cooperative ferroptosis immunotherapy. Specifically, TCPP-TK-PEG-PAMAM-FA, a nanoscale multicomponent functional polymer with self-assembly capability, was synthesized for cooperatively entrapping hafnium ions (Hf4+) and HIF-1α-inhibiting siRNAs (siHIF-1α). The TCPP@Hf-TK-PEG-PAMAM-FA@siHIF-1α nanoassemblies are specifically taken in by folate receptor-overexpressing tumor cells and activated by the elevated cellular ROS stress. siHIF-1α could readily inhibit the FABP3/7 expression in tumor cells via HIF-1α-FABP3/7 signaling and abolish lipid droplet biogenesis for enhancing the peroxidation susceptibility of membrane lipids, which synergizes with the elevated ROS stress in the context of Hf4+-enhanced radiation exposure and evokes pronounced ferroptotic damage in vital membrane structures. Interestingly, TCPP@Hf-TK-PEG-PAMAM-FA@siHIF-1α-enhanced ferroptotic biomembrane damage also facilitates the exposure of tumor-associated antigens (TAAs) to promote post-LDR immunotherapeutic effects, leading to robust tumor regression in vivo. This study offers a nanointegrative approach to boost the antitumor effects of LDR through the utilization of tumor-intrinsic lipid metabolism.

Advances of hafnium based nanomaterials for cancer theranostics

Hafnium-based nanomaterials (Hf-NMs) have attracted the interest of numerous biomedical researchers by their unique properties. Recent years have witnessed significant advancements in the field of Hafnium-based nanomaterials, particularly in the context of cancer diagnosis and treatment. However, research in this area, especially concerning the clinical application of Hafnium-based nanomaterials, has not been thoroughly reviewed. This review will cover: 1) Classification and synthesis of Hafnium-based nanomaterials including Hafnium oxide nanomaterials, Hafnium Metal-Organic Frameworks/nanoscale coordination polymers (MOFs/NCPs); 2) Hafnium-based nanomaterials act as contrast enhancement agent for cancer imaging, and hafnium-based nanomaterials used for diagnosis in cancer liquid biopsy; 3) hafnium-based nanomaterials for cancer therapy, including hafnium-based nanomaterials for radiotherapy, hafnium-based nanomaterials for photodynamic therapy, hafnium-based nanomaterials for various combined therapy; and 4) Translation, toxicity, and safety for Hf-NMs in human and preclinical animal models. More attention will be given to the clinical translation of Hf-NMs in cancer.

A Facile and Eco-Friendly Hydrothermal Synthesis of High Tetragonal Barium Titanate with Uniform and Controllable Particle Size

The preparation of tetragonal barium titanate (BT) powders with uniform and suitable particle sizes is a significant prerequisite for ultra-thin and highly integrated multilayer ceramic capacitors (MLCCs). However, the balance of high tetragonality and controllable particle size remains a challenge, which limits the practical application of BT powders. Herein, the effects of different proportions of hydrothermal medium composition on the hydroxylation process are explored to obtain high tetragonality. The high tetragonality of BT powders under the optimal solvent condition of water:ethanol:ammonia solution of 2:2:1 is around 1.009 and increases with the particle size. Meanwhile, the good uniformity and dispersion of BT powders with particle sizes of 160, 190, 220, and 250 nm benefit from the inhibition of ethanol on the interfacial activity of BT particles (BTPs). The core-shell structure of BTPs is revealed by different lattice fringe spacings of the core and edge and the crystal structure by reconstructed atomic arrangement, which reasonably explains the trend between tetragonality and average particle size. These findings are instructive for the related research on the hydrothermal process of BT powders.