Bioprinting: The 3D Printing of Living Tissues and Organs

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The science behind Bioprinting, which combines 3D printing and tissue engineering holds great promise for the field of healthcare and regenerative medicine. Bioprinting involves the use of specialised 3D printers that can create intricate structures using living cells and biomaterials. It uses a similar concept to regular 3D printing, where layer-by-layer composition of materials is used to build objects. The difference is that the “ink” bioprinting uses is a combination of living cells and bio-friendly materials known as bioinks. These bioinks serve as a kind of scaffolds to support the growth and organisation of cells.

The bioprinting process begins with the acquisition of cells, which can be derived from sources such as stem cells. These cells are then carefully prepared to ensure their viability and functionality. Bioinks are then prepared by mixing the cells with suitable biomaterials that provide structural support. The resulting bioink is then loaded into a bioprinter, which precisely releases it in a controlled way to manufacture the desired tissue or organ structure.

By creating custom-made tissues or organs, bioprinting could address donor shortages for organs needed for those critically ill requiring transplantation. Printed organs can also be specifically tailored to the genetic makeup of patients, which reduces the potential risk of rejection.  Bioprinting can also offer new ways to conduct laboratory testing such as the effect of new drugs on manufactured, yet realistic human tissue.

Whilst Bioprinting is still in its early stages, some examples of what can be currently printed include:

Tissue Constructs

The fabrication of complex tissue constructs, such as skin, blood vessels, bone, cartilage, and muscle can be done via Bioprinting. These tissues are then able to be used for regenerative medicine, drug testing, and disease modelling.

Organoids

Organoids are simple, miniature versions of organs that mimic their structure and function. Such examples include: liver organoids, kidney organoids, and brain organoids, which have the potential to be used for research.

Scaffold Structures

Bioprinting can create 3D scaffold structures that act as a supportive framework for tissue growth, which can then provide a physical structure for cells to attach to and organise themselves, resulting in the formation of functional tissues.

Blood Vessels

While the ability to recreate the network of blood vessels in order to pass oxygen and nutrients to printed tissues remains a challenge, progress is being made. This will open the door to more complex, longer-lasting tissue being able to be manufactured.

Cell-laden Constructs

This construct refers to a 3D structure that contains living cells embedded within a supportive matrix/ scaffold. This enables the precise placement of different types of cells within a construct, which then allows for the creation of heterogeneous tissues (these are tissues that are composed of different forms of cells and exhibit structural and functional diversity). This is essential to enable the engineering of complex tissues that consist of multiple cell types. Liver tissue and cardiac tissue are two prominent examples.

Implantable Structures

These structures have great potential to be used in regenerative medicine to repair or replace damaged tissues or organs. This involves the creation of things such as tissue engineered grafts that could be tailored to the specific needs of a patient.

Research continues on ways to improve the function and complexity of bioprinting, in the hope it will be able to assist with more complex tasks and even replace more complex organs or biological structures in the body in the future. As we know the body is an extremely complex beast that has many networks and biological systems. If bioprinting could advance to the stage it could easily help to regenerate and replicate things in the body, it could save so many lives and help advance anti-aging therapies.

Several challenges still need to be overcome by bioprinting though in its current form. One example is Vascularisation, which is the process of incorporating blood vessels into Bioprinted tissues to allow them to live for a longer period in a lab (or even a patient in the future). However, as advancements in bioprinting technology continue to arise, exciting breakthroughs await!