Basic Funding
A bioprinting system is a type of 3D printer that uses additive manufacturing techniques to produce various types of biological tissue. The 3D structure is typically achieved by the layer-by-layer deposition of bio-inks. Although similar to additive manufacturing of digitally designed 3D models, bioprinting systems use biocompatible solutions or suspensions loaded with living cells instead of the thermoplastics or resins used in traditional 3D printing.
As a result, with the exception of bone tissue engineering, bioprinting tends to focus on the production of softer tissues, which increases the variability of mechanical stability. It also requires sterile and cell-compatible printing conditions to minimise mechanical cell damage (e.g. shear stress from the print head), avoid toxin-induced cell death and maximise cell viability. After bioprinting, the fabricated pre-tissue is transferred to the incubator where it matures into a tissue.
Considering the wide variety of bioinks and loaded cells, the required bioprinting system will provide a sterile environment and enable different types of deposition techniques (e.g. droplet, pneumatic extrusion) and polymerisation methods (e.g. thermal, chemical, photoinduced) for the bioprinting process. It will allow the appropriate application of different or even composite cell-loaded bioinks so that the cells or biofactors remain in a liquid state during the printing process and survive after the scaffold transition from liquid to solid, facilitating subsequent in vitro culture.
The application of bioprinting systems can be broadly divided into the following three levels: non-degradable implantation, degradable implantation and active fabrication.
In non-degradable implantation, the printed structure is well biocompatible due to the bioink applied and can be directly implanted into the body. However, the biomaterial is not degradable and the printed structure, as a spare part, should ensure permanent functionality without ageing or fatigue damage. These applications are mainly for bionic tissue engineering, including prosthetic ear grafts, mandibular grafts, meniscus or bone scaffolds, etc.
For degradable implantation, the printed structure with living cells can interact well with the existing tissues or organs due to the enhanced porous scaffolds, inducing tissue regeneration (cell growth) and degradation of bionic tissue engineering scaffolds at the same time. These applications include cell research, drug research and therapy, such as cellular immunity research, anti-HPV viral protein slow-release stents.
Building on this level, active manufacturing aims to achieve multiple biofunctionalities by creating tissues and organs with living cells, proteins and other extracellular matrix. The applications involve different dimensional scales: in the short term, the micro-scale organ or tissue-on-a-chip will help researchers overcome the problems posed by animal welfare legislation or ethical standards; in the long term, the bioprinting technique will solve the problem of tissue or organ shortage, in particular patient-specific tissue repair and organ transplantation.