Nanoceria: an innovative strategy for cancer treatment

Two decades of ceria nanoparticle research: structure, properties and emerging applications

Cerium oxide nanoparticles (CeNPs) are versatile materials with unique and unusual properties that vary depending on their surface chemistry, size, shape, coating, oxidation states, crystallinity, dopant, and structural and surface defects. This review encompasses advances made over the past twenty years in the development of CeNPs and ceria-based nanostructures, the structural determinants affecting their activity, and translation of these distinct features into applications. The two oxidation states of nanosized CeNPs (Ce3+/Ce4+) coexisting at the nanoscale level facilitate the formation of oxygen vacancies and defect states, which confer extremely high reactivity and oxygen buffering capacity and the ability to act as catalysts for oxidation and reduction reactions. However, the method of synthesis, surface functionalization, surface coating and defects are important factors in determining their properties. This review highlights key properties of CeNPs, their synthesis, interactions, and reaction pathways and provides examples of emerging applications. Due to their unique properties, CeNPs have become quintessential candidates for catalysis, chemical mechanical planarization (CMP), sensing, biomedical applications, and environmental remediation, with tremendous potential to create novel products and translational innovations in a wide range of industries. This review highlights the timely relevance and the transformative potential of these materials in addressing societal challenges and driving technological advancements across these fields.

Harnessing cerium-based biomaterials for the treatment of bone diseases

Bone, an actively metabolic organ, undergoes constant remodeling throughout life. Disturbances in the bone microenvironment can be responsible for pathologically bone diseases such as periodontitis, osteoarthritis, rheumatoid arthritis and osteoporosis. Conventional bone tissue biomaterials are not adequately adapted to complex bone microenvironment. Therefore, there is an urgent clinical need to find an effective strategy to improve the status quo. In recent years, nanotechnology has caused a revolution in biomedicine. Cerium(III, IV) oxide, as an important member of metal oxide nanomaterials, has dual redox properties through reversible binding with oxygen atoms, which continuously cycle between Ce(III) and Ce(IV). Due to its special physicochemical properties, cerium(III, IV) oxide has received widespread attention as a versatile nanomaterial, especially in bone diseases. This review describes the characteristics of bone microenvironment. The enzyme-like properties and biosafety of cerium(III, IV) oxide are also emphasized. Meanwhile, we summarizes controllable synthesis of cerium(III, IV) oxide with different nanostructural morphologies. Following resolution of synthetic principles of cerium(III, IV) oxide, a variety of tailored cerium-based biomaterials have been widely developed, including bioactive glasses, scaffolds, nanomembranes, coatings, and nanocomposites. Furthermore, we highlight the latest advances in cerium-based biomaterials for inflammatory and metabolic bone diseases and bone-related tumors. Tailored cerium-based biomaterials have already demonstrated their value in disease prevention, diagnosis (imaging and biosensors) and treatment. Therefore, it is important to assist in bone disease management by clarifying tailored properties of cerium(III, IV) oxide in order to promote the use of cerium-based biomaterials in the future clinical setting. STATEMENT OF SIGNIFICANCE: In this review, we focused on the promising of cerium-based biomaterials for bone diseases. We reviewed the key role of bone microenvironment in bone diseases and the main biological activities of cerium(III, IV) oxide. By setting different synthesis conditions, cerium(III, IV) oxide nanostructures with different morphologies can be controlled. Meanwhile, tailored cerium-based biomaterials can serve as a versatile toolbox (e.g., bioactive glasses, scaffolds, nanofibrous membranes, coatings, and nanocomposites). Then, the latest research advances based on cerium-based biomaterials for the treatment of bone diseases were also highlighted. Most importantly, we analyzed the perspectives and challenges of cerium-based biomaterials. In future perspectives, this insight has given rise to a cascade of cerium-based biomaterial strategies, including disease prevention, diagnosis (imaging and biosensors) and treatment.

Proteome Alterations and Nucleosome Activation in Rat Myoblasts Treated with Cerium Oxide Nanoparticles

Oxidative stress is a widespread causative agent of disease. Together with its general relevance for biomedicine, such a dynamic is recognizably detrimental to space exploration. Among other solutions, cerium oxide nanoparticles (or nanoceria, NC) display a long-lasting, self-renewable antioxidant activity. In a previous experiment, we evaluated oxidative imbalance in rat myoblasts in space, aboard the International Space Station, and unveiled possible protective effects from NC through RNA sequencing. Here, we focus on the myoblast response to NC on land by means of proteomics, defining a list of proteins that putatively react to NC and confirming nucleosomes/histones as likely mediators of its molecular action. The proteomics data set we present here and its counterpart from the space study share four factors. These are coherently either up- (Hist1h4b) or down-regulated (Gnl3, Mtdh, Trip12) upon NC exposure.

Advances in antitumor application of ROS enzyme-mimetic catalysts

The rapid growth of research on enzyme-mimetic catalysts (Enz-Cats) is expected to promote further advances in nanomedicine for biological detection, diagnosis and treatment of disease, especially tumors. ROS-based nanomedicines present fascinating potential in antitumor therapy owing to the rapid development of nanotechnology. In this review, we focus on the applications of Enz-Cats based on ROS in antitumor therapy. Firstly, the definition and category of ROS are introduced, and the key factors enhancing ROS levels are carefully elucidated. Then, the rationally engineered Enz-Cats via different synthetic approaches with high ROS-producing efficiencies are comprehensively discussed. Subsequently, oncotherapy application of Enz-Cats is comprehensively discussed, which integrates diverse synergistic treatment modalities and exhibits high efficiency in ROS generation. Finally, the challenges and future research direction of this field are presented. This review is dedicated to unraveling the enigmas surrounding the interplay of nanomedicine and organisms.

Integrin receptor-targeted, doxorubicin-loaded cerium oxide nanoparticles delivery to combat glioblastoma

Aim: To assess the chemo-immunomodulatory effects of doxorubicin-loaded cerium oxide nanoparticles coated with oleyl amine-linked cyclic RGDfK peptide (CeNP+Dox+RGD) to target both gliomas and its tumor microenvironment (TME) via integrin receptors. Materials & methods: CeNP+Dox+RGD nanoparticles are synthesized by the sequential addition of cerium III chloride heptahydrate, beta-cyclodextrin, oleic acid, and F127 micelle (CeNP). Doxorubicin was then loaded into CeNPs and coated with oleyl amine-linked cyclic RGDfK peptide to form stable CeNP+Dox+RGD nanoparticles. Results: CeNP+Dox+RGD nanoparticles crossed blood-brain barrier (BBB) effectively and demonstrated threefold enhanced survivability in glioma-bearing mice. The IHC profiling of glial tumor cross-sections showed increased CD80 expression (M1 TAMs) and decreased arginase-1 expression (M2 TAMs). Conclusion: CeNP+Dox+RGD can be an immunotherapeutic treatment option to combat glioblastoma.

Advancements in nanomedicine: Precision delivery strategies for male pelvic malignancies - Spotlight on prostate and colorectal cancer

BACKGROUND

Pelvic malignancies consistently pose significant global health challenges, adversely affecting the well-being of the male population. It is anticipated that clinicians will continue to confront these cancers in their practice. Nanomedicine offers promising strategies that revolutionize the treatment of male pelvic malignancies by providing precise delivery methods that aim to improve the efficacy of therapeutic outcomes while minimizing side effects. Nanoparticles are designed to encapsulate therapeutic agents and selectively target cancer cells. They can also be loaded with theragnostic agents, enabling multifunctional capabilities.

OBJECTIVE

This review aims to summarize the latest nanomedicine research into clinical applications, focusing on nanotechnology-based treatment strategies for male pelvic malignancies, encompassing chemotherapy, radiotherapy, immunotherapy, and other cutting-edge therapies. The review is structured to assist physicians, particularly those with limited knowledge of biochemistry and bioengineering, in comprehending the functionalities and applications of nanomaterials.

METHODS

Multiple databases, including PubMed, the National Library of Medicine, and Embase, were utilized to locate and review recently published articles on advancements in nano-drug delivery for prostate and colorectal cancers.

CONCLUSION

Nanomedicine possesses considerable potential in improving therapeutic outcomes and reducing adverse effects for male pelvic malignancies. Through precision delivery methods, this emerging field presents innovative treatment modalities to address these challenging diseases. Nevertheless, the majority of current studies are in the preclinical phase, with a lack of sufficient evidence to fully understand the precise mechanisms of action, absence of comprehensive pharmacotoxicity profiles, and uncertainty surrounding long-term consequences.

Mesenchymal Stem Cell Priming: Potential Benefits of Administration of Molecular Hydrogen

Stem cell therapy has emerged as a promising avenue for regenerative medicine, offering the potential to treat a wide range of debilitating diseases and injuries. Among the various types of stem cells, mesenchymal stem cells (MSCs) have garnered significant attention due to their unique properties and therapeutic potential. In recent years, researchers have been exploring novel approaches to enhance the effectiveness of MSC-based therapies. One such approach that has gained traction is the priming of MSCs with molecular hydrogen (H2). This article delves into the fascinating world of mesenchymal stem cell priming with molecular hydrogen and the potential benefits it holds for regenerative medicine.

Evaluation of Advanced Nanomaterials for Cancer Diagnosis and Treatment

Cancer is a persistent global disease and a threat to the human species, with numerous cases reported every year. Over recent decades, a steady but slowly increasing mortality rate has been observed. While many attempts have been made using conventional methods alone as a theragnostic strategy, they have yielded very little success. Most of the shortcomings of such conventional methods can be attributed to the high demands of industrial growth and ever-increasing environmental pollution. This requires some high-tech biomedical interventions and other solutions. Thus, researchers have been compelled to explore alternative methods. This has brought much attention to nanotechnology applications, specifically magnetic nanomaterials, as the sole or conjugated theragnostic methods. The exponential growth of nanomaterials with overlapping applications in various fields is due to their potential properties, which depend on the type of synthesis route used. Either top-down or bottom-up strategies synthesize various types of NPs. The top-down only branches out to one method, i.e., physical, and the bottom-up has two methods, chemical and biological syntheses. This review highlights some synthesis techniques, the types of nanoparticle properties each technique produces, and their potential use in the biomedical field, more specifically for cancer. Despite the evident drawbacks, the success achieved in furthering nanoparticle applications to more complex cancer stages and locations is unmatched.

Optimizing Oxygen-Production Kinetics of Manganese Dioxide Nanoparticles Improves Hypoxia Reversal and Survival in Mice with Bone Metastases

Persistent hypoxia in bone metastases induces an immunosuppressive environment, limiting the effectiveness of immunotherapies. To address chronic hypoxia, we have developed manganese dioxide (MnO2) nanoparticles with tunable oxygen production kinetics for sustained oxygenation in bone metastases lesions. Using polyethylene glycol (PEG)-stabilized MnO2 or poly(lactic[50]-co-glycolic[50] acid) (50:50 PLGA), poly(lactic[75]-co-glycolic[25] acid) (75:25 PLGA), and polylactic acid (PLA)-encapsulated MnO2 NPs, we demonstrate that polymer hydrophobicity attenuates burst oxygen production and enables tunable oxygen production kinetics. The PEG-MnO2 NPs resulted in rapid hypoxia reduction in spheroids, which was rapidly attenuated, while the PLA-MnO2 NPs exhibited delayed hypoxia control in cancer spheroids. The 50:50 PLGA-MnO2 NPs exhibited the best short- and long-term control of hypoxia in cancer spheroids, resulting in sustained regulation of the expression of HIF-1α and immunosuppressive genes. The sustained control of hypoxia by the 50:50 PLGA-MnO2 NPs enhanced the cytotoxicity of natural killer cells against cancer spheroids. In vivo, 50:50 PLGA-MnO2 showed greater accumulation in the long bones and pelvis, common sites for bone metastases. The NPs decreased hypoxia in bone metastases and decreased regulatory T cell levels, resulting in enhanced survival of mice with established bone metastases.

Single-Component Dual-Functional Autoboost Strategy by Dual Photodynamic and Cyclooxygenase-2 Inhibition for Lung Cancer and Spinal Metastasis

Coloading adjuvant drugs or biomacromolecules with photosensitizers into nanoparticles to enhance the efficiency of photodynamic therapy (PDT) is a common strategy. However, it is difficult to load positively charged photosensitizers and negatively charged adjuvants into the same nanomaterial and further regulate drug release simultaneously. Herein, a single-component dual-functional prodrug strategy is reported for tumor treatment specifically activated by tumor microenvironment (TME)-generated HOCl. A representative prodrug (DHU-CBA2) is constructed using indomethacin grafted with methylene blue (MB). DHU-CBA2 exhibited high sensitivity toward HOCl and achieved simultaneous release of dual drugs in vitro and in vivo. DHU-CBA2 shows effective antitumor activity against lung cancer and spinal metastases via PDT and cyclooxygenase-2 (COX-2) inhibition. Mechanistically, PDT induces immunogenic cell death but stimulates the gene encoding COX-2. Downstream prostaglandins E2 and Indoleamine 2,3 dioxygenase 1 (IDO1) mediate immune escape in the TME, which is rescued by the simultaneous release of indomethacin. DHU-CBA2 promotes infiltration and function of CD8+ T cells, thus inducing a robust antitumor immune response. This work provides an autoboost strategy for a single-component dual-functional prodrug activated by TME-specific HOCl, thereby achieving favorable tumor treatment via the synergistic therapy of PDT and a COX-2 inhibitor.

Melittin kills A549 cells by targeting mitochondria and blocking mitophagy flux

Melittin, a naturally occurring polypeptide found in bee venom, has been recognized for its potential anti-tumor effects, particularly in the context of lung cancer. Our previous study focused on its impact on human lung adenocarcinoma cells A549, revealing that melittin induces intracellular reactive oxygen species (ROS) burst and oxidative damage, resulting in cell death. Considering the significant role of mitochondria in maintaining intracellular redox levels and ROS, we further examined the involvement of mitochondrial damage in melittin-induced apoptosis in lung cancer cells. Our findings demonstrated that melittin caused changes in mitochondrial membrane potential (MMP), triggered mitochondrial ROS burst (Figure 1), and activated the mitochondria-related apoptosis pathway Bax/Bcl-2 by directly targeting mitochondria in A549 cells (Figure 2). Further, we infected A549 cells using a lentivirus that can express melittin-Myc and confirmed that melittin can directly target binding to mitochondria, causing the biological effects described above (Figure 2). Notably, melittin induced mitochondrial damage while inhibiting autophagy, resulting in abnormal degradation of damaged mitochondria (Figure 5). To summarize, our study unveils that melittin targets mitochondria, causing mitochondrial damage, and inhibits the autophagy-lysosomal degradation pathway. This process triggers mitoROS burst and ultimately activates the mitochondria-associated Bax/Bcl-2 apoptotic signaling pathways in A549 cells.

Inorganic Nanoparticles as Radiosensitizers for Cancer Treatment

Nanotechnology has expanded what can be achieved in our approach to cancer treatment. The ability to produce and engineer functional nanoparticle formulations to elicit higher incidences of tumor cell radiolysis has resulted in substantial improvements in cancer cell eradication while also permitting multi-modal biomedical functionalities. These radiosensitive nanomaterials utilize material characteristics, such as radio-blocking/absorbing high-Z atomic number elements, to mediate localized effects from therapeutic irradiation. These materials thereby allow subsequent scattered or emitted radiation to produce direct (e.g., damage to genetic materials) or indirect (e.g., protein oxidation, reactive oxygen species formation) damage to tumor cells. Using nanomaterials that activate under certain physiologic conditions, such as the tumor microenvironment, can selectively target tumor cells. These characteristics, combined with biological interactions that can target the tumor environment, allow for localized radio-sensitization while mitigating damage to healthy cells. This review explores the various nanomaterial formulations utilized in cancer radiosensitivity research. Emphasis on inorganic nanomaterials showcases the specific material characteristics that enable higher incidences of radiation while ensuring localized cancer targeting based on tumor microenvironment activation. The aim of this review is to guide future research in cancer radiosensitization using nanomaterial formulations and to detail common approaches to its treatment, as well as their relations to commonly implemented radiotherapy techniques.

A Bioactive Disintegrable Polymer Nanoparticle for Synergistic Vascular Anticalcification

Although poly(aspartic acid) (PASP), a strong calcium chelating agent, may be potentially effective in inhibition of vascular calcification, its direct administration may lead to side effects. In this study, we employed polysuccinimide, a precursor of PASP, to prepare targeted polysuccinimide-based nanoparticles (PSI NPs) that not only acted as a prodrug but also functioned as a carrier of additional therapeutics to provide powerful synergistic vascular anticalcification effect. This paper shows that chemically modified PSI-NPs can serve as effective nanocarriers for loading of hydrophobic drugs, in addition to anticalcification and antireactive oxygen species (anti-ROS) activities. Curcumin (Cur), with high loading efficiency, was encapsulated into the NPs. The NPs were stable for 16 h in physiological conditions and then slowly dissolved/hydrolyzed to release the therapeutic PASP and the encapsulated drug. The drug release profile was found to be in good agreement with the NP dissolution profile such that complete release occurred after 48 h at physiological conditions. However, under acidic conditions, the NPs were stable, and Cur cumulative release reached only 30% after 1 week. Though highly effective in the prevention of calcium deposition, PSI NPs could not prevent the osteogenic trans-differentiation of vascular smooth muscle cells (VSMCs). The presence of Cur addressed this problem. It not only further reduced ROS level in macrophages but also prevented osteogenic differentiation of VSMCs in vitro. The NPs were examined in vivo in a rat model of vascular calcification induced by kidney failure through an adenine diet. The inclusion of Cur and PSI NPs combined the therapeutic effects of both. Cur-loaded NPs significantly reduced calcium deposition in the aorta without adversely affecting bone integrity or noticeable side effects/toxicity as examined by organ histological and serum biochemistry analyses.

Influence of the Synthesis Scheme of Nanocrystalline Cerium Oxide and Its Concentration on the Biological Activity of Cells Providing Wound Regeneration

In the ongoing search for practical uses of rare-earth metal nanoparticles, cerium dioxide nanoparticles (nanoceria) have received special attention. The purpose of this research was to study the biomedical effects of nanocrystalline forms of cerium oxide obtained by different synthesis schemes and to evaluate the effect of different concentrations of nanoceria (from 10-2 to 10-6 M) on cells involved in the regeneration of skin cell structures such as fibroblasts, mesenchymal stem cells, and keratinocytes. Two different methods of nanoceria preparation were investigated: (1) CeO-NPs-1 by precipitation from aqueous solutions of cerium (III) nitrate hexahydrate and citric acid and (2) CeO-NPs-2 by hydrolysis of ammonium hexanitratocerate (IV) under conditions of thermal autoclaving. According to the X-ray diffraction, transmission electron microscopy, and dynamic light scattering data, CeO2-1 consists of individual particles of cerium dioxide (3-5 nm) and their aggregates with diameters of 60-130 nm. CeO2-2 comprises small aggregates of 8-20 nm in diameter, which consist of particles of 2-3 nm in size. Cell cultures of human fibroblasts, human mesenchymal stem cells, and human keratinocytes were cocultured with different concentrations of nanoceria sols (10-2, 10-3, 10-4, 10-5, and 10-6 mol/L). The metabolic activity of all cell types was investigated by MTT test after 48 and 72 h, whereas proliferative activity and cytotoxicity were determined by quantitative cell culture counting and live/dead test. A dependence of biological effects on the method of nanoceria preparation and concentration was revealed. Data were obtained with respect to the optimal concentration of sol to achieve the highest metabolic effect in the used cell cultures. Hypotheses about the mechanisms of the obtained effects and the structure of a fundamentally new medical device for accelerated healing of skin wounds were formulated. The method of nanoceria synthesis and concentration fundamentally and significantly change the biological activity of cell cultures of different types-from suppression to pronounced stimulation. The best biological activity of cell cultures was determined through cocultivation with sols of citrate nanoceria (CeO-NPs-1) at a concentration of 10-3-10-4 M.

Spiky Silver-Iron Oxide Nanohybrid for Effective Dual-Imaging and Synergistic Thermo-Chemotherapy

Nanophotothermal therapy based on nanoparticles (NPs) that convert near-infrared (NIR) light to generate heat to selectively kill cancer cells has attracted immense interest due to its high efficacy and being free of ionizing radiation damage. Here, for the first time, we have designed a novel nanohybrid, silver-iron oxide NP (AgIONP), which was successfully tuned for strong absorbance at NIR wavelengths to be effective in photothermal treatment and dual-imaging strategy using MRI and photoacoustic imaging (PAI) in a cancer model in vivo and in vitro, respectively. We strategically combine the inherent anticancer activity of silver and photothermal therapy to render excellent therapeutic capability of AgIONPs. In vitro phantoms and in vivo imaging studies displayed preferential uptake of folate-targeted NPs in a cancer mice model, indicating the selective targeting efficiency of NPs. Importantly, a single intravenous injection of NPs in a cancer mice model resulted in significant tumor reduction, and photothermal laser resulted in a further substantial synergistic decrease in tumor size. Additionally, biosafety and biochemical assessment performed in mice displayed no significant difference between NP treatment and control groups. Overall, our folic acid AgIONPs displayed excellent potential in the simultaneous application for safe and successful targeted synergistic photothermal treatment and imaging of a cancer model.

Plant Gel-Mediated Synthesis of Gold-Coated Nanoceria Using Ferula gummosa: Characterization and Estimation of Its Cellular Toxicity toward Breast Cancer Cell Lines

In this study, a novel method using Ferula gummosa gums as a capping agent was used to synthesize the nanoceria for the first time. The method was economical and performed at room temperature. Furthermore, it was coated with gold (Au/nanoceria) and fully characterized using X-ray powder diffraction (XRD), field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDX), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and zeta potential (ζ potential). The crystallite size obtained from the results was 28.09 nm for Au/nanoceria. The energy-dispersive X-ray spectroscopy (EDX) analysis of Au/nanoceria revealed the compositional constituents of the product, which display the purity of the Au/nanoceria. The cell toxicity properties of the non-doped and Au-coated nanoceria were identified by a MTT analysis on a breast cancer cell line (MCF7). Additionally, human foreskin fibroblast cells (HFF) were used as a normal cell line. The cytotoxicity results indicated that the toxicological effect of Au/nanoceria on cancer cells was significant while having little toxic effect on normal cells. The toxicity effect of nanoceria clearly shows the dependence on dose and time, so, with increasing the dose of Au/nanoceria, the death of cancer cells also increases.

Hyaluronic Acid Modified Metal Nanoparticles and Their Derived Substituents for Cancer Therapy: A Review

The use of metal nanoparticles (M-NPs) in cancer therapy has gained significant consideration owing to their exceptional physical and chemical features. However, due to the limitations, such as specificity and toxicity towards healthy cells, their application in clinical translations has been restricted. Hyaluronic acid (HA), a biocompatible and biodegradable polysaccharide, has been extensively used as a targeting moiety, due to its ability to selectively bind to the CD44 receptors overexpressed on cancer cells. The HA-modified M-NPs have demonstrated promising results in improving specificity and efficacy in cancer therapy. This review discusses the significance of nanotechnology, the state of cancers, and the functions of HA-modified M-NPs, and other substituents in cancer therapy applications. Additionally, the role of various types of selected noble and non-noble M-NPs used in cancer therapy are described, along with the mechanisms involved in cancer targeting. Additionally, the purpose of HA, its sources and production processes, as well as its chemical and biological properties are described. In-depth explanations are provided about the contemporary applications of HA-modified noble and non-noble M-NPs and other substituents in cancer therapy. Furthermore, potential obstacles in optimizing HA-modified M-NPs, in terms of clinical translations, are discussed, followed by a conclusion and future prospects.