Egg-derived Bioinks for Organ Engineering

Chicken eggs are one of the most consumed nutritious foods throughout the world and are one of the highest sources of choline and proteins, essential nutrients which are required for normal body functioning. While the liver has the capacity to produce proteins in small quantities, most of our protein content is supplemented through our diet and eggs play a vital role.

Collagen is the most abundant protein that is found within the human body and is an integral substance that forms a scaffold where cells in our body can reside and are a key component in giving organs strength and structure. However, when an organ in our body is damaged due to disease or trauma, not all of the organs are able to regenerate and restore normal functionality. Tissue engineering is a branch of regenerative medicine that explores materials available in nature  and exploits their use for therapeutic solutions to damaged organs. Recently, a team of researchers from the Vellore Institute of Technology (India),  Shanghai University (China) and the University of Twente (Netherlands) have developed a method to formulate a vascular supportive bioink utilizing the chicken eggs and demonstrated how the tissue or organ structures could be 3D bioprinted into functional tissues.

“Bioprinting is an additive manufacturing process which is adapted for the production of biological products such as human tissues and organs from the combination living cells and biomaterials called a bioink”, pointed out Dr H Zhang, co-corresponding author of the study. Bioink plays a major role in 3D bioprinting of tissues and organs for regenerative medicine applications.

Engineering human organs through 3D bioprinting holds great promise for the development of off-the-shelf and patient-specific tissues and organs, which will also alleviate the shortage of organ donors. The World Health Organization (WHO) estimates that more than a million people worldwide waiting for organ transplantation. Organ transplantation is the medical procedure that can save people with end-stage organ failure, giving them a second lease of life. However, the biggest hurdle for the clinical translation of engineered tissue or organ is the lack of functional vascularization within bioprinted constructs. Vascularisation is an essential function as blood vessels perfuse our tissues and organs with oxygen, essential nutrients, as well as aid in the removal of cellular and biological waste.

The team has developed a new vascular supportive composite bioink using marine algae (alginate) and egg while (albumen), which could be used to 3D print a vascular supportive organ structure. The team has utilized an extrusion-based 3D printing method. They have optimized the conditions necessary of the stable printing of the albumen-rich bioink.

“Albumen is extensively used in food products, especially in edible gels, owing to their high nutritional value and versatile functional properties. Additionally, albumen is a natural source of proteins that is known to have wound healing, anti-bacterial, anti-hypertensive, anti-inflammatory and cell growth stimulatory properties. Therefore, it might be utilized for organ engineering”, pointed out Dr M Ramalingam, co-corresponding author of the study.

The biocompatibility of the printed structure was tested using human umbilical vein endothelial cells. The results showed that the cells were successfully attached to the printed scaffolding system and maintained high viability during the course of study. Interestingly, vascular sprouting and neovascular network formation was also observed in between fibers within the printed scaffold. Hence, egg-based bioinks and 3D bioprinting technology holds a great promise for engineering vascular-supportive organ printing.

The team included Suihong Liu, Haiguang Zhang, Qingxi Hu and Zhipeng Shen from Shanghai University; Deepti Rana from University of Twente and Murugan Ramalingam from Vellore Institute of Technology (VIT).

This article has been republished from the following materials. Note: material may have been edited for length and content. For further information, please contact the cited source.

Reference: Liu et al. (2020). Designing vascular supportive albumen-rich composite bioink for organ 3D printing. Journal of the Mechanical Behavior of Biomedical Materials. https://doi.org/10.1016/j.jmbbm.2020.103642.