Bridging the In Vitro to In Vivo gap: Using the Chick Embryo Model to Accelerate Nanoparticle Validation and Qualification for In Vivo studies

Functionalized Cerium Oxide Nanoparticles Enhance Penetration into Melanoma Spheroids In Vivo through Angiogenesis

Angiogenesis is a crucial step in tumor progression, including melanoma, making anti-angiogenic strategies a widely explored treatment approach. However, both innate and acquired resistance to these therapies suggest that this approach may need re-evaluation. Nanoparticles have gained attention for their potential to enhance drug delivery and retention within tumors via the bloodstream. However, the in vitro screening of nanoparticles is limited by the inability of preclinical models to replicate the complex tumor microenvironment, especially the blood supply. Here, it is demonstrated that melanoma cells embedded in Matrigel spheroids can engraft in and be vascularized by the chorioallantoic membrane (CAM) of fertilized chicken eggs. This model allows for the assessment of nanoparticle toxicity and accumulation in tumor spheroids, as well as functional effects such as angiogenesis. Cerium oxide nanoparticles (nanoceria) and their surface functionalized derivatives are widely explored for biomedical applications due to their ability to modulate oxidative stress and angiogenesis. Here, it is observed that heparin functionalized nanoceria penetrate melanoma spheroids in the CAM and promote spheroid vascularization to a greater extent than nanoceria alone. This study aids in the development of preclinical cancer models for nanoparticle screening and provides new insight into the interplay between nanoparticle surface coatings and biological effects.

The avian embryo as a time-honoured animal model in developmental, biomedical and agricultural research

Avian embryos have been at the core of embryological, morphological, physiological and biochemical/molecular research, especially involving research in three primary areas: developmental, biomedical and agricultural research. As developmental models, the avian embryo-especially that of the chicken-has been the single most used embryo model, perhaps in part from the combination of large size, ease of access and prior knowledge base. Developmental research with avian embryos has included organ system studies of the heart, vasculature, lungs, kidneys, nervous system, etc., as well as integrated physiological processes including gas-exchange, acid-base and ion/water regulation. In terms of translational research, avian embryos have modelled vascular development, based on the easily accessible chorioallantoic membrane under the eggshell. This same respiratory organ has enabled toxicological studies of how pollutants affect vertebrate development. Investigation of the transition to pulmonary breathing and the associated emergence of respiratory control has also relied heavily upon the avian embryo. In addition to developmental and biomedical investigations, the avian embryo has been studied intensively due to the huge importance of domesticated birds as a food source. Consequently, the effects of environment (including temperature, humidity, noise levels and photoperiod) during incubation on subsequent post-hatch phenotype are being actively investigated.This article is part of the theme issue 'The biology of the avian respiratory system'.

A promising role of noble metal NPs@MOFs in chondrosarcoma management

Chondrosarcoma, a challenging and malignant neoplasm originating from cartilage cells, poses significant diagnostic and therapeutic hurdles due to its resistance to conventional treatments and the complexity of its diagnosis. Noble metal nanoparticle-embedded metal-organic frameworks (NPs@MOFs) stand out as a novel approach for the diagnosis and treatment of chondrosarcoma. This review delves into the properties and applications of NPs@MOFs, focusing on their classification by noble metal type and their role in enhancing photothermal therapy (PTT), photodynamic therapy (PDT), targeted drug delivery and chondrosarcoma diagnosis. Despite promising in vitro and in vivo results, challenges such as understanding the mechanisms of action and clinical translation remain, and the therapeutic effect of PTT and PDT on deep chondrosarcoma seems unsatisfactory. Future exploration, such as combined therapy and multiple MOF therapy, could unlock the full potential of noble metal NPs@MOFs in revolutionizing chondrosarcoma management, offering insights into the prospect of these materials in chondrosarcoma management.

Heptamethine cyanine-based polymeric nanoparticles for photothermal therapy in HCT116 human colon cancer model

In this work, we synthesize a quinoline-based heptamethine cyanine, QuCy7, with sulfonate groups to enhance water solubility. This dye demonstrates exceptional near-infrared absorption beyond 750 nm, accompanied by photothermal properties but low photostability. Encapsulating QyCy7 with polyethylene glycol to form nanopolymer, QuCy7@mPEG NPs, addresses the issue of its photoinstability. TEM showed that QuCy7@mPEG NPs possess a spherical morphology, featuring a core-shell structure with a size of around 120 nm in diameter. Upon irradiation with an 808 nm laser for 10 min, a significant increase in temperature up to 24 °C can be achieved with a photothermal conversion (PTC) rate of approximately 35%. QuCy7@mPEG NPs exhibit remarkable photothermal stability as compared to QuCy7. The efficiency of QuCy7@mPEG NPs was demonstrated by the in vitro PTT studies. Finally, the nanoparticles' acute toxicity and effectiveness were assessed using the chick embryo model. The results provide compelling evidence that QuCy7@mPEG NPs are safe without inducing hemolysis, inhibit angiogenesis when exposed to light, and exhibit anti-tumor activity with a 76% reduction in tumor size compared to QuCy7 (40%). Thus suggesting the sulfonate groups can enhance water solubility, and its nanopolymer is biocompatible and possesses superior anti-tumor efficacy.

The Chicken Embryo: An Old but Promising Model for In Vivo Preclinical Research

The chicken embryo has emerged as a valuable model for preclinical studies due to its unique combination of accessibility, affordability, and relevance to human biology. Its rapid development, external growth environment, and clear structural visibility offer distinct advantages over traditional mammalian models. These features facilitate the study of real-time biological processes, including tissue development, tumor growth, angiogenesis, and drug delivery, using various imaging modalities, such as optical imaging, magnetic resonance imaging, positron emission tomography, computed tomography, and ultrasound. The chicken embryo model also minimizes ethical concerns compared to mammalian models, as it allows for early-stage research without the complexity of a fully developed animal. Moreover, its ability to integrate human tumor cells into xenograft models provides a reliable platform for cancer research, enabling high-throughput screening of therapeutic interventions and tracking molecular dynamics in vivo. Advances in molecular imaging techniques further enhance the resolution and depth of data obtained from these studies, offering insights into cellular and molecular mechanisms underlying disease. Given its versatility, cost-effectiveness, and translational potential, the chicken embryo represents a promising tool for advancing preclinical research, particularly in drug development, cancer biology, and regenerative medicine.

Expanding understanding of chick embryo's nervous system development at HH22-HH41 embryonic stages using X-ray microcomputed tomography

Assessing the embryotoxicity and teratogenicity of various substances and processes is crucial due to their complexity and resource intensity. The chicken embryo (CE) serves an ideal model for simulating the first months of mammalian embryonic development. This makes the CE a reliable model for testing teratogenic effects, particularly in relation to the nervous system (NS), which experiences developmental abnormalities second in frequency only to cardiovascular teratogenic disorders. Microcomputed tomography (μCT) is a promising method for studying these processes. The advantages of μCT include relatively high research speed, diagnostic accuracy, high resolution and the ability to visualize the entire internal 3D structure of an object while preserving for other types of research. At the same time, there are practically no available databases of normative μCT data, both qualitative and quantitative, which would act as a starting point for screening detection of abnormalities in the development of the NS. In this study, we present a simple method for obtaining very detailed quantitative sets of 2D and 3D μCT data of NS structures of the CE (Gallus Gallus domesticus) at HH22-HH41 embryonic stages with contrasting by 1% phosphotungstic acid. The results of μCT demonstrate the exact boundaries, high general and differentiated contrast of the main and specific structures of the NS of CE, which are quantitatively and qualitatively similar to results of histological analysis. Calculations of the X-ray density and volume of the main structures of the NS at constant exponential growth are presented. In addition to the increase in linear dimensions, significant changes in the structures of various parts of the brain were identified and visualized during the CE development at HH22 to HH41 embryonic stages. The data presented establish the first methodology for obtaining normative data, including subtle localized differences in the NS in CE embryogenesis. The data obtained open up new opportunities for modern embryology, teratology, pharmacology and toxicology.

Bibliometric study of the application of the chicken embryo chorioallantoic membrane model in cancer research: the top 100 most cited articles

The chicken embryo chorioallantoic membrane (CAM) model has played a crucial role in various aspects of cancer research. The purpose of this study is to help researchers clarify the research direction and prospects of the CAM model. A bibliometric analysis was conducted on the top 100 most cited articles on use of the CAM model in tumour research, retrieved from the Web of Science Core Collection database. Tools such as Bibliometrix, VOSviewer, CiteSpace and Excel were utilized for the visualization network analysis. The 100 articles analysed were mainly from the USA, China and European countries such as Germany and France. Tumour research involving CAM model experiments demonstrated reliability and scientific rigor (average citation count = 156.2). The analysis of keywords, topics and subject areas revealed that the applications of this model ranged from the biological characteristics of tumours to molecular mechanisms and signaling pathways, to recent developments in nanotechnology and clinical applications. Additionally, nude mouse experiments have been more frequently performed in recent years. We conclude that the CAM model is efficient, simple and cost-effective, and has irreplaceable value in various aspects of cancer research. In the future, the CAM model can further contribute to nanotechnology research.

Perspectives on chick embryo models in developmental and reproductive toxicity screening

Teratology, the study of congenital anomalies and their causative factors intersects with developmental and reproductive toxicology, employing innovative methodologies. Evaluating the potential impacts of teratogens on fetal development and assessing human risk is an essential prerequisite in preclinical research. The chicken embryo model has emerged as a powerful tool for understanding human embryonic development due to its remarkable resemblance to humans. This model offers a unique platform for investigating the effects of substances on developing embryos, employing techniques such as ex ovo and in ovo assays, chorioallantoic membrane assays, and embryonic culture techniques. The advantages of chicken embryonic models include their accessibility, cost-effectiveness, and biological relevance to vertebrate development, enabling efficient screening of developmental toxicity. However, these models have limitations, such as the absence of a placenta and maternal metabolism, impacting the study of nutrient exchange and hormone regulation. Despite these limitations, understanding and mitigating the challenges posed by the absence of a placenta and maternal metabolism are critical for maximizing the utility of the chick embryo model in developmental toxicity testing. Indeed, the insights gained from utilizing these assays and their constraints can significantly contribute to our understanding of the developmental impacts of various agents. This review underscores the utilization of chicken embryonic models in developmental toxicity testing, highlighting their advantages and disadvantages by addressing the challenges posed by their physiological differences from mammalian systems.

Advancement in Cancer Vasculogenesis Modeling through 3D Bioprinting Technology

Cancer vasculogenesis is a pivotal focus of cancer research and treatment given its critical role in tumor development, metastasis, and the formation of vasculogenic microenvironments. Traditional approaches to investigating cancer vasculogenesis face significant challenges in accurately modeling intricate microenvironments. Recent advancements in three-dimensional (3D) bioprinting technology present promising solutions to these challenges. This review provides an overview of cancer vasculogenesis and underscores the importance of precise modeling. It juxtaposes traditional techniques with 3D bioprinting technologies, elucidating the advantages of the latter in developing cancer vasculogenesis models. Furthermore, it explores applications in pathological investigations, preclinical medication screening for personalized treatment and cancer diagnostics, and envisages future prospects for 3D bioprinted cancer vasculogenesis models. Despite notable advancements, current 3D bioprinting techniques for cancer vasculogenesis modeling have several limitations. Nonetheless, by overcoming these challenges and with technological advances, 3D bioprinting exhibits immense potential for revolutionizing the understanding of cancer vasculogenesis and augmenting treatment modalities.

The biodistribution of polystyrene nanoparticles administered intravenously in the chicken embryo

Nanoplastics can cause severe malformations in chicken embryos. To improve our understanding of the toxicity of nanoplastics to embryos, we have studied their biodistribution in living chicken embryos. We injected the embryos in the vitelline vein at stages 18-19. We injected polystyrene nanoparticles (PS-NPs) tagged with europium- or fluorescence. Their biodistribution was tracked using inductively-coupled plasma mass spectrometry on tissue lysates, paraffin histology, and vibratome sections analysed by machine learning algorithms. PS-NPs were found at high levels in the heart, liver and kidneys. Furthermore, PS-NPs crossed the endocardium of the heart at sites of epithelial-mesenchymal transformation; they also crossed the liver endothelium. Finally, we detected PS-NPs in the allantoic fluid, consistent with their being excreted by the kidneys. Our study shows the power of the chicken embryo model for analysing the biodistribution of nanoplastics in embryos. Such experiments are difficult or impossible in mammalian embryos. These findings are a major advance in our understanding of the biodistribution and tissue-specific accumulation of PS-NPs in developing animals.

Development of an in vivo system to model breast cancer metastatic organotropism and evaluate treatment response using the chick embryo

Metastatic lesions produced through the process of systemic tumor cell dissemination and growth at distant sites are challenging to treat and the primary cause of patient mortality. Developing in vivo models of metastasis with utility in evaluating molecular targets and therapeutics in a timely manner would expedite the path to therapeutic discovery. Here, we evaluated breast cancer metastasis and metastatic organotropism using the chick embryo. We developed a method to evaluate metastasis using the MDA231 cell line. Then, using cell lines with demonstrated tropism for the bone, brain, and lung, we evaluated organotropism. Rapid and robust organ-specific metastasis was modeled in the chick embryo and, importantly, recapitulated metastatic organotropism congruent to what has been demonstrated in mice. Treatment response in the metastatic setting was also evaluated and quantified. This work establishes the chick embryo as a model for studies aimed at understanding organotropism and therapeutic response in the metastatic setting.

Nanoplastics causes extensive congenital malformations during embryonic development by passively targeting neural crest cells

Nanomaterials are widespread in the human environment as pollutants, and are being actively developed for use in human medicine. We have investigated how the size and dose of polystyrene nanoparticles affects malformations in chicken embryos, and have characterized the mechanisms by which they interfere with normal development. We find that nanoplastics can cross the embryonic gut wall. When injected into the vitelline vein, nanoplastics become distributed in the circulation to multiple organs. We find that the exposure of embryos to polystyrene nanoparticles produces malformations that are far more serious and extensive than has been previously reported. These malformations include major congenital heart defects that impair cardiac function. We show that the mechanism of toxicity is the selective binding of polystyrene nanoplastics nanoparticles to neural crest cells, leading to the death and impaired migration of those cells. Consistent with our new model, most of the malformations seen in this study are in organs that depend for their normal development on neural crest cells. These results are a matter of concern given the large and growing burden of nanoplastics in the environment. Our findings suggest that nanoplastics may pose a health risk to the developing embryo.