Preclinical evaluation of platinum-loaded hydroxyapatite nanoparticles in an embryonic zebrafish xenograft model

Modelling bone metastasis in spheroids to study cancer progression and screen cisplatin efficacy

Most bone metastases are caused by primary breast or prostate cancer cells settling in the bone microenvironment, affecting normal bone physiology and function and reducing 5-year survival rates to 10% and 6%, respectively. To expedite clinical availability of novel and effective bone metastases treatments, reliable and predictive in vitro models are urgently required to screen for novel therapies as current in vitro 2D planar mono-culture models do not accurately predict the clinical efficacy. We herein engineered a novel human in vitro 3D co-culture model based on spheroids to study dynamic cellular quantities of (breast or prostate) cancer cells and human bone marrow stromal cells and screen chemotherapeutic efficacy and specificity of the common anticancer drug cisplatin. Bone metastatic spheroids (BMSs) were formed rapidly within 24 h, while the morphology of breast versus prostate cancer BMS differed in terms of size and circularity upon prolonged culture periods. Prestaining cell types prior to BMS formation enabled confocal imaging and quantitative image analysis of in-spheroid cellular dynamics for up to 7 days of BMS culture. We found that cancer cells in BMS proliferated faster and were less susceptible to cisplatin treatment compared to 2D control cultures. Based on these findings and the versatility of our methodology, BMS represent a feasible 3D in vitro model for screening of new bone cancer metastases therapies.

Ultrasmall Gold Nanoparticles Radiolabeled with Iodine-125 as Potential New Radiopharmaceutical

The relatively high linear energy transfer of Auger electrons, which can cause clustered DNA damage and hence efficient cell death, makes Auger emitters excellent candidates for attacking metastasized tumors. Moreover, gammas or positrons are usually emitted along with the Auger electrons, providing the possibility of theragnostic applications. Despite the promising properties of Auger electrons, only a few radiopharmaceuticals employing Auger emitters have been developed so far. This is most likely explained by the short ranges of these electrons, requiring the delivery of the Auger emitters to crucial cell parts such as the cell nucleus. In this work, we combined the Auger emitter 125I and ultrasmall gold nanoparticles to prepare a novel radiopharmaceutical. The 125I labeled gold nanoparticles were shown to accumulate at the cell nucleus, leading to a high tumor-killing efficiency in both 2D and 3D tumor cell models. The results from this work indicate that ultrasmall nanoparticles, which passively accumulate at the cell nucleus, have the potential to be applied in targeted radionuclide therapy. Even better tumor-killing efficiency can be expected if tumor-targeting moieties are conjugated to the nanoparticles.

Hydroxyapatite Biobased Materials for Treatment and Diagnosis of Cancer

Great advances in cancer treatment have been undertaken in the last years as a consequence of the development of new antitumoral drugs able to target cancer cells with decreasing side effects and a better understanding of the behavior of neoplastic cells during invasion and metastasis. Specifically, drug delivery systems (DDS) based on the use of hydroxyapatite nanoparticles (HAp NPs) are gaining attention and merit a comprehensive review focused on their potential applications. These are derived from the intrinsic properties of HAp (e.g., biocompatibility and biodegradability), together with the easy functionalization and easy control of porosity, crystallinity and morphology of HAp NPs. The capacity to tailor the properties of DLS based on HAp NPs has well-recognized advantages for the control of both drug loading and release. Furthermore, the functionalization of NPs allows a targeted uptake in tumoral cells while their rapid elimination by the reticuloendothelial system (RES) can be avoided. Advances in HAp NPs involve not only their use as drug nanocarriers but also their employment as nanosystems for magnetic hyperthermia therapy, gene delivery systems, adjuvants for cancer immunotherapy and nanoparticles for cell imaging.

MiR-4458-loaded gelatin nanospheres target COL11A1 for DDR2/SRC signaling pathway inactivation to suppress the progression of estrogen receptor-positive breast cancer

RNA interference is a promising way to treat cancer and the construction of a stable drug delivery system is critically important for its application. Gelatin nanospheres (GNs) comprise a biodegradable drug vehicle with excellent biocompatibility, but there are limited studies on its delivery and role in the stabilization of miRNA and siRNA. Breast cancer is the most diagnosed type of female cancer worldwide. Abnormal miRNA expression is closely related to the occurrence and progression of estrogen receptor-positive (ER+) breast cancer. In this study, miR-4458 was upregulated in ER+ breast cancer and could inhibit MCF-7 cell viability, colony formation, migration, and invasion. Collagen type XI alpha 1 (COL11A1) was identified as a directly interacting protein of miR-4458 and an important component of the extracellular matrix. High COL11A1 expression was positively correlated with poor prognosis, lower overall survival, disease-free survival, and a late tumor-node-metastasis stage. COL11A1 knockdown could inhibit MCF-7 cell migration and invasion. GNs were used to load a miR-4458 mimic or COL11A1 siRNA (si-COL11A1) to achieve sustained and controlled release in xenograft nude mice. Their tumor volume was decreased, tumor cell apoptosis was promoted, and hepatic metastasis was significantly inhibited. Moreover, the DDR2/SRC signaling pathway was inactivated after transfection with the miR-4458 mimic and si-COL11A1. In conclusion, GNs can be potentially used to deliver siRNA or miRNA, and miR-4458 and COL11A1 can be possible targets for ER+ breast cancer treatment.

Hydroxyapatite nanoparticles promote mitochondrial-based pyroptosis via activating calcium homeostasis and redox imbalance in vascular smooth muscle cells

Hydroxyapatite nanoparticles (HAP) have been widely used in various fields because of their natural biological origin and functional properties. The emerging evidence on their toxicities has attracted research interest. HAP-induced vascular smooth muscle cell (VSMC) damage is a key step in vascular calcification (VC), particularly in patients with chronic kidney disease. However, the injury effects and mechanism of action of HAP on VSMCs have not been extensively investigated. This study comprehensively characterized commercially available HAP and investigated its adverse biological effects in cultured A7R5 cells.In vitroexperiments revealed that internalized HAP was localized in lysosomes, followed by the release of Ca²⁺owing to the low pH microenvironment. Upon Ca²⁺homeostasis, Ca²⁺enters the mitochondria, leading to the simultaneous generation of reactive oxygen species (ROS). ROS subsequently attack mitochondrial transmembrane potentials, promote mitochondrial ROS production, and oxidize mitochondrial DNA (Ox-mtDNA). Mitochondrial permeability-transition pores open, followed by the release of more Ox-mtDNA from the mitochondria into the cytosol due to the redox imbalance. This activates NLRP3/caspase-1/gasdermin D-dependent pyroptosis and finally excretes inflammatory factors to induce VC; an antioxidant could rescue this process. It has been suggested that HAP could induce an imbalance in intracellular Ca²⁺homeostasis in A7R5 cells, followed by the promotion of mitochondrial dysfunction and cell pyroptosis, finally enhancing VC. To detect thein vivotoxicity of HAP, mice were treated with Cy7-labelled HAP NPs for 24 h.In vivoresults also demonstrated that HAP accumulated in the kidneys, accompined with increased Ca concentration, upregulated oxidative stress-related factor and kidney damage. Overall, our research elucidates the mechanism of calcium homeostasis and redox imbalance, providing insights into the prevention of HAP-induced cell death.

Nano-hydroxyapatite as a delivery system: overview and advancements

Nano-hydroxyapatite is being investigated as vital components of implants and dental and tissue engineering devices. It is found as a bone replacement due to its non-toxicity and cytocompatibility with dental tissues and bone. The reality that nanocrystalline hydroxyapatite can be made of porous granules and scaffolds. Additionally, it has a massive loading potential indicating its use as a transporter for drugs or a regulated drug release mechanism in pharmaceutical research. This review aims to present existing nano-hydroxyapatite research developments as a drug carrier employed in bone tissue disorders locally and deliver poorly soluble drugs with reduced bioavailability. We have discussed the nano-hydroxyapatite role in the delivery of drugs (i.e. anti-resorptive, anti-cancer, and antibiotics), proteins, genetic material, and radionuclides.

Zebrafish Models for the Safety and Therapeutic Testing of Nanoparticles with a Focus on Macrophages

New nanoparticles and biomaterials are increasingly being used in biomedical research for drug delivery, diagnostic applications, or vaccines, and they are also present in numerous commercial products, in the environment and workplaces. Thus, the evaluation of the safety and possible therapeutic application of these nanomaterials has become of foremost importance for the proper progress of nanotechnology. Due to economical and ethical issues, in vitro and in vivo methods are encouraged for the testing of new compounds and/or nanoparticles, however in vivo models are still needed. In this scenario, zebrafish (Danio rerio) has demonstrated potential for toxicological and pharmacological screenings. Zebrafish presents an innate immune system, from early developmental stages, with conserved macrophage phenotypes and functions with respect to humans. This fact, combined with the transparency of zebrafish, the availability of models with fluorescently labelled macrophages, as well as a broad variety of disease models offers great possibilities for the testing of new nanoparticles. Thus, with a particular focus on macrophage-nanoparticle interaction in vivo, here, we review the studies using zebrafish for toxicological and biodistribution testing of nanoparticles, and also the possibilities for their preclinical evaluation in various diseases, including cancer and autoimmune, neuroinflammatory, and infectious diseases.

Zebrafish as a Model for Anticancer Nanomedicine Studies

Nanomedicine is a new approach to fight against cancer by the development of anticancer nanoparticles (NPs) that are of high sensitivity, specificity, and targeting ability to detect cancer cells, such as the ability of Silica NPs in targeting epithelial cancer cells. However, these anticancer NPs require preclinical testing, and zebrafish is a useful animal model for preclinical studies of anticancer NPs. This model affords a large sample size, optical imaging, and easy genetic manipulation that aid in nanomedicine studies. This review summarizes the numerous advantages of the zebrafish animal model for such investigation, various techniques for inducing cancer in zebrafish, and discusses the methods to assess cancer development in the model and to test for the toxicity of the anticancer drugs and NPs. In addition, it summarizes the recent studies that used zebrafish as a model to test the efficacy of several different anticancer NPs in treating cancer.

Edelfosine nanoemulsions inhibit tumor growth of triple negative breast cancer in zebrafish xenograft model

Triple negative breast cancer (TNBC) is known for being very aggressive, heterogeneous and highly metastatic. The standard of care treatment is still chemotherapy, with adjacent toxicity and low efficacy, highlighting the need for alternative and more effective therapeutic strategies. Edelfosine, an alkyl-lysophospholipid, has proved to be a promising therapy for several cancer types, upon delivery in lipid nanoparticles. Therefore, the objective of this work was to explore the potential of edelfosine for the treatment of TNBC. Edelfosine nanoemulsions (ET-NEs) composed by edelfosine, Miglyol 812 and phosphatidylcholine as excipients, due to their good safety profile, presented an average size of about 120 nm and a neutral zeta potential, and were stable in biorelevant media. The ability of ET-NEs to interrupt tumor growth in TNBC was demonstrated both in vitro, using a highly aggressive and invasive TNBC cell line, and in vivo, using zebrafish embryos. Importantly, ET-NEs were able to penetrate through the skin barrier of MDA-MB 231 xenografted zebrafish embryos, into the yolk sac, leading to an effective decrease of highly aggressive and invasive tumoral cells' proliferation. Altogether the results demonstrate the potential of ET-NEs for the development of new therapeutic approaches for TNBC.

NMR spectroscopy to study the fate of metallodrugs in cells

Metal-based drugs can modulate various biological processes and exhibit a rich variety of properties that foster their use in biomedicine and chemical biology. On the way to intracellular targets, ligand exchange and redox reactions can take place, thus making metallodrug speciation in vivo a challenging task. Advances in NMR spectroscopy have made it possible to move from solution to live-cell studies and elucidate the transport of metallodrugs and interactions with macromolecular targets in a physiological setting. In turn, the electronic properties and supramolecular chemistry of metal complexes can be exploited to characterize drug delivery nanosystems by NMR. The recent evolution of in-cell NMR methodology is presented with special emphasis on metal-related processes. Applications to paradigmatic cases of platinum and gold drugs are highlighted.

"Fishing" nano-bio interactions at the key biological barriers

Understanding nano-bio interactions is pivotal to the safe implementation of nanotechnology for both biological and environmental applications. Zebrafish as a model organism provides unique opportunities to dissect nano-bio interactions occurring at different biological barriers. In this review, we focus on four key biological barriers, namely cell membrane, blood-brain barrier (BBB), skin and gill epithelia, and gastrointestinal tract (GIT), and highlight recent advancement achieved by using zebrafish to conduct both visualized observations and mechanistic investigations on a diversity of nano-bio interactions.

Application of Animal Models in Cancer Research: Recent Progress and Future Prospects

Animal models refers to the animal experimental objects and related materials that can simulate human body established in medical research. As the second-largest disease in terms of morbidity and mortality after cardiovascular disease, cancer has always been the focus of human attention all over the world, which makes it a research hotspot in the medical field. At the same time, more and more animal models have been constructed and used in cancer research. With the deepening of research, the construction methods of cancer animal models are becoming more and more diverse, including chemical induction, xenotransplantation, gene programming, and so on. In recent years, patient-derived xenotransplantation (PDX) model has become a research hotspot because it can retain the microenvironment of the primary tumor and the basic characteristics of cells. Animal models can be used not only to study the biochemical and physiological processes of the occurrence and development of cancer in objects but also for the screening of cancer drugs and the exploration of gene therapy. In this paper, several main tumor animal models and the application progress of animal models in tumor research are systematically reviewed. Finally, combined with the latest progress and development trend in this field, the future research of tumor animal model was prospected.