Bioprinting and its future

What is bioprinting

In simple words, bioprinting, similar to 3D printing, is a manufacturing method that produces three-dimensional objects by reading digital files. However, 3D printing usually uses metals, resins, ceramics, plastics, etc., as its printing materials, while bioprinting uses a special material called bio-ink. The bio-ink is usually composed of viable cells and biopolymer gel. Biopolymer is very important in protecting the cells and maintaining tissue stability. The bioprinter prints a tissue scaffold with bio-ink, and the viable cells in ink will spread, grow and proliferate on the scaffold.

The process of bioprinting

The bioprinting process usually consists of three steps: pre-bioprinting, bioprinting, and post-bioprinting.

The pre-bioprinting process is mainly to create and export a digital file of the tissue model. First, Researchers usually use computerized tomography (CT) or magnetic resonance imaging (MRI) to obtain images of tissues or organs. And then, they will use computer-aided design (CAD) software to reconstruct the images into three-dimensional tissue structures and export them to a file format that bioprinters can read. Researchers will also choose cells according to the tissue’s structures and functions.

Bioprinting is the process of printing tissues or organs by using a bioprinter. The bioprinter uses the nozzle or needle to deposit the bio-ink layer by layer to create a scaffold similar to the tissue structure and spread the cells evenly on the scaffold.

In the post-bioprinting process, the most important thing is to maintain the stability of the printed tissues. Therefore, researchers typically release physical or chemical stimulations to cells in the tissue, allowing the tissue to live and grow continually.

Applications of bioprinting

The main application of bioprinting is tissue engineering, which can replace damaged tissues in the human body. It will solve the issue of tissue shortage for transplantation and overcome ethical issues related to medical experiments, such as using humans or animals as experimental subjects.

Research teams world-widely have successfully printed tissues, including human skin, ears, bones, cartilage, hearts, kidneys, and livers. For example, in March 2022, a 22-year-old woman with small ears was implanted with ear tissue printed with her cells. It is also the first case of tissue implantation with living cells. Currently, the technologies of bioprinting skin and cartilage are well-developed because these tissues do not employ complex biochemical reactions. However, for organs such as the liver and kidney, bioprinting technologies have only achieved structural similarities so far and have not yet restored the functions of these organs.

In addition to human transplantation, the printed tissue structure has been widely applied in drug screening, toxicology screening, cancer or infectious diseases research, etc. For example, printed tissues have been used to study Covid-19 virus transmission and treatment development. Researchers tested the Covid-19 transmission model on the printed corneal tissue and found that the corneal edge was more susceptible to virus infection than the corneal center.

Bioprinting technology and the future of human beings

Although it is still developing, bioprinting has significantly contributed to tissue manufacturing, drug monitoring, etc. As many people imagine, when bioprinting technology can easily produce every tissue in the human body, it will help to solve problems such as illness and aging and even fulfill the goal of life extension in the future. However, everything has two sides. Some people have also questioned whether this technology will create more trouble while benefiting us. At the very least, many legal and ethical issues need to be established and discussed before clinical use and actual production.

In 2019, artist Hongjie Yang collaborated with the laboratory to create the work semi-human vase II with bioprinting technology. The three vases in this series are printed from biopolymer materials and implanted with human HeLa cells. After that, the artist and researchers painted them blue using a lab-based Coomassie protein dye. This collection will be permanently stored in test tubes containing chemicals. In this work, the artist tries to raise a question: with bioprinting technology developing, will there still be a boundary between people and objects?

Resources:

3D_bioprinting

Ear-transplant-3d-printer.html

S41392-021-00566-8

https://hongjieyang.nl/Semi-human-Vase-I-2015-MK2-Cells-on-PLA-Scaffold-55-x-40-x-20-cm

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7557521/

https://all3dp.com/2/most-promising-3d-printed-organs-for-transplant/

https://all3dp.com/2/for-ricardo-what-is-bioink-simply-explained/