Use of Chicken Embryo Model in Toxicity Studies of Endocrine-Disrupting Chemicals and Nanoparticles

Abstract

Lab animals such as mice and rats are widely used in toxicity research of food additive and pharmaceutics, despite the wellrecognized research limitation such as the inability to simulate human neurological diseases, faster absorption of chemicals, big variations among species, and high cost when using a large number of animals. The Society of Toxicology's guidance now focuses on minimizing discomfort and distress of lab animals, finding alternative ways to reduce animal number, replacing animals with in vitro models, and complying to the animal welfare policies. The chicken embryonic model can be a better alternative to mice and rats because of its abundant availability and cost-effectiveness. It can be studied in both laboratory and natural environment, with easy manipulation in ovo or in vivo. The objective of this review paper is to evaluate the use of chicken embryonic model in toxicity evaluation for endocrine-disrupting chemicals (EDCs) and nanoparticles (NPs) by different end points to determine more comprehensive toxic responses. The end points include chicken embryonic mortality and hatchability, developmental malformation analysis, hormonal imbalance, physiological changes in endocrine organs, and antiangiogenesis. Major research methodologies using chicken embryos are also summarized to demonstrate their versatile practice and valuable application in modern toxicity evaluation of EDCs and NPs.

Effects of Particle Size and Surface Charge on Mutagenicity and Chicken Embryonic Toxicity of New Silver Nanoclusters

“… 19 Various toxicity endpoints have been reported by different NPs in chicken embryos, including embryotoxicity and teratogenicity, antiangiogenic or pro-angiogenic activity, neurotoxicity, and brain damage. 22 …”

“…Furthermore, the wider presence of nanomaterials in soil, water, air, and food can result in chicken embryo exposure to these nanomaterials, making this in vivo model a relevant testing system for nanotoxicity . Various toxicity endpoints have been reported by different NPs in chicken embryos, including embryotoxicity and teratogenicity, antiangiogenic or pro-angiogenic activity, neurotoxicity, and brain damage …”

“…19 Various toxicity endpoints have been reported by different NPs in chicken embryos, including embryotoxicity and teratogenicity, antiangiogenic or pro-angiogenic activity, neurotoxicity, and brain damage. 22 Nowadays, in vitro bioassays for genotoxicity have become popular due to fewer ethical concerns and faster turnout. Charles et al 23 systematically reviewed in vitro genotoxicity data for TiO 2 NPs, yet it remained difficult to determine which inherent physicochemical properties (i.e., crystalline form, particle size, and/or surface coating) may explain the reasons for the diverging results observed.…”

Efficient gene delivery into the embryonic chicken brain using neuron-specific promoters and in ovo electroporation

“…The chicken embryo is a preferred animal model for developmental biology, and has also been used to make significant discoveries in cell biology, virology, immunology, cancer biology, epigenetics, and neuroscience [1][2][3][4][5].…”

Live chicken egg embryos as an alternative in vivo tumour model for deep surface enhanced Raman spectroscopy

“…The chicken egg embryo is an alternative in vivo platform which can be used for studying tumour biology, 1 drug distribution, 2 angiogensis 3 and toxicology. 4 The chorioallantoic membrane (CAM) is a highly vascularised membrane that attaches to the eggshell and forms around the chicken embryo. 5 The CAM develops from day 3 until day 14 with embryonic development.…”