Biofabrication is the use of engineering tools to build living tissue from cells, biomaterials, and controlled growth conditions. It matters because damaged organs and tissues are difficult to replace, and donor tissue is limited. By manufacturing tissue in a controlled way, researchers can study disease, test drugs, and design future implants.
A biofabrication system brings biology, materials science, robotics, and medicine into one workflow.
In a typical device, living cells are mixed with a soft biomaterial to form a bioink that can be printed or shaped into a scaffold. The scaffold supports the cells while they attach, grow, and begin producing their own extracellular matrix. A bioreactor then provides temperature, nutrients, oxygen, fluid flow, and mechanical signals that help the tissue mature.
The final engineered tissue must have the right structure, cell survival, strength, and biological function for its intended use.
Key Facts
- Biofabrication combines cells + biomaterial scaffold + bioreactor conditions to produce engineered tissue.
- Cell viability = living cells / total cells x 100%.
- A scaffold gives cells a 3D structure for attachment, growth, and tissue organization.
- Bioinks often use hydrogels because they contain water and can mimic soft tissue environments.
- Diffusion time increases with distance, so thick tissues need pores, channels, or blood-vessel-like networks.
- Bioreactor variables include temperature, pH, oxygen, nutrients, fluid flow, and mechanical stimulation.
Vocabulary
- Biofabrication
- Biofabrication is the controlled construction of living tissue using cells, biomaterials, and engineering tools.
- Bioink
- Bioink is a printable mixture that usually contains living cells and a supportive biomaterial.
- Scaffold
- A scaffold is a 3D material structure that supports cell attachment, shape, growth, and tissue formation.
- Bioreactor
- A bioreactor is a device that controls the environment around growing tissue, including nutrients, oxygen, temperature, and mechanical forces.
- Cell viability
- Cell viability is the percentage of cells in a sample that are alive after a process such as printing, mixing, or culture.
Common Mistakes to Avoid
- Thinking a printed tissue is immediately a working organ is wrong because cells need time in a bioreactor to organize, mature, and develop function.
- Ignoring oxygen and nutrient transport is wrong because cells inside thick tissue can die if diffusion distances are too large.
- Assuming the stiffest scaffold is always best is wrong because different tissues need different mechanical properties, and overly stiff materials can change cell behavior.
- Treating cells as passive building blocks is wrong because cells respond to chemical signals, surface texture, fluid flow, and forces during tissue development.
Practice Questions
- 1 A bioink sample contains 180,000 living cells and 20,000 dead cells after printing. Calculate the cell viability as a percentage.
- 2 A scaffold is printed as a rectangular slab with dimensions 20 mm by 10 mm by 4 mm. What is its volume in mm^3?
- 3 A research team wants to biofabricate heart tissue. Explain why the bioreactor might need to provide both nutrient flow and mechanical or electrical stimulation.