Egg-in-Cube: Design and Fabrication of a Novel Artificial Eggshell with Functionalized Surface

Abstract

An eggshell is a porous microstructure that regulates the passage of gases to allow respiration. The chick embryo and its circulatory system enclosed by the eggshell has become an important model for biomedical research such as the control of angiogenesis, cancer therapy, and drug delivery test, because the use of embryo is ethically acceptable and it is inexpensive and small. However, chick embryo and extra-embryonic blood vessels cannot be accessed freely and has poor observability because the eggshell is tough and cannot be seen through, which limits its application. In this study, a novel artificial eggshell with functionalized surface is proposed, which allows the total amount of oxygen to pass into the egg for the chick embryo culturing and has high observability and accessibility for embryo manipulation. First, a 40-mm enclosed cubic-shaped eggshell consisting of a membrane structure and a rigid frame structure is designed, and then the threshold of the membrane thickness suitable for the embryo survival is figured out according to the oxygen-permeability of the membrane structure. The designed artificial eggshell was actually fabricated by using polydimethylsiloxane (PDMS) and polycarbonate (PC) in the current study. Using the fabricated eggshell, chick embryo and extra-embryonic blood vessels can be observed from multiple directions. To test the effectiveness of the design, the cubic eggshells were used to culture chick embryos and survivability was confirmed when PDMS membranes with adequate oxygen permeability were used. Since the surface of the eggshell is transparent, chick embryo tissue development could be observed during the culture period. Additionally, the chick embryo tissues could be accessed and manipulated from outside the cubic eggshell, by using mechanical tools without breakage of the eggshell. The proposed “Egg-in-Cube” with functionalized surface has great potential to serve as a promising platform for biomedical research.

Bioengineered three‐dimensional transparent eggshell as a chicken embryo experimentation platform for biomedical research

“…The selection of PDMS as the eggshell material is based on its proven property of being gas permeable albeit dependent on thickness. 4,30,39,41,44,51 This mimics the porosity of the eggshell which assists in the passage of diffusible substances but yet acts as a barrier to infection. [52][53][54] Moreover, untreated PDMS 40,44 and the surface of eggshell membranes 55,56 possess a hydrophobic surface thus conferring PDMS as a suitable material.…”

“…[33][34][35][36][37] PDMS possesses favorable unique properties as it is permeable to gases, chemically inert, thermally stable, rigid, and optically clear. [38][39][40][41] Lai and Liu 32 and Huang et al 30 have fabricated cubic eggshells made of PDMS with an internal egg-shaped feature in the former model but not in the latter. Huang et al 31 further developed the cubic eggshell to have the ability to direct blood vessel formation.…”

An Experimental Study on Operability of Master-Slave Manipulator System using Human–in–the-Loop Type Simulator

“…Many researchers try new drugs to chick eggs because it is quite cheap and ethically acceptable [1]. A chick egg is covered by hard eggshell, which pass oxygen into the inside of eggshell.…”

Embryo timelapses can be compiled and quantified to understand canonical histone dynamics across multiple cell cycles

“…Quantitative fluorescent microscopy presents challenges compared to cell cultures, including nonuniform cell architecture (variable sizes and shapes), typically short, rapid, often asynchronous, cell cycles (followed by increasingly lengthening cell cycles; Philpott & Yew, 2005), an inability to pause or synchronize cell cycles (due to weak cell cycle checkpoints (Kipreos, 2005) or impermeable eggshells (Huang, Arai, & Kawahara, 2015)), and significant movement of cells/nuclei throughout development (Ishiura, 2010). Quantitative fluorescent microscopy presents challenges compared to cell cultures, including nonuniform cell architecture (variable sizes and shapes), typically short, rapid, often asynchronous, cell cycles (followed by increasingly lengthening cell cycles; Philpott & Yew, 2005), an inability to pause or synchronize cell cycles (due to weak cell cycle checkpoints (Kipreos, 2005) or impermeable eggshells (Huang, Arai, & Kawahara, 2015)), and significant movement of cells/nuclei throughout development (Ishiura, 2010).…”

“…To measure histone dynamics in eukaryotic embryos (or in complex cultures such as organoids), it is essential to accurately measure cell cycle progression. Quantitative fluorescent microscopy presents challenges compared to cell cultures, including nonuniform cell architecture (variable sizes and shapes), typically short, rapid, often asynchronous, cell cycles (followed by increasingly lengthening cell cycles; Philpott & Yew, 2005), an inability to pause or synchronize cell cycles (due to weak cell cycle checkpoints (Kipreos, 2005) or impermeable eggshells (Huang, Arai, & Kawahara, 2015)), and significant movement of cells/nuclei throughout development (Ishiura, 2010). These traits are exemplified even in the simple determined development of C. elegans.…”