3D Bioprinting: A Solution To The Organ Shortage Crisis?

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But what if we could skip the whole process? What if we no longer had to harvest organs from people? What if we could make on-demand organs with a patient’s own cells?

  1. Pre-bioprinting: From computed tomography (CT) and magnetic resonance imaging (MRI) scans, a digital file can be created for the bioprinter to read. Researchers prepare cells and mix them with bioinks to ensure that a tissue model can be successfully printed.
  2. Bioprinting: Researchers then load the cell-laden bioink into a cartridge and choose one or multiple print heads depending on the desired construct. Developing different types of tissue requires researchers to use different types of cells, bioinks, and equipment.
  3. Post-bioprinting: To create stable structures for the biological material, printed parts usually undergo mechanical and chemical stimulation. Finally, the cell-laden constructs are placed inside an incubator or bioreactor for cultivation.
  • 3D imaging should provide a perfect fit of the desired tissue model, with exact dimensions and minimal or no necessary adjustments.
  • During 3D modeling, a blueprint is generated in high detail. Using CAD software, the blueprint may include layer-by-layer instructions for the bioprinter. Fine adjustments may be made at this stage to avoid the transfer of defects.
  • The process of bioink preparation combines living cells with a biomaterial, such as collagen, gelatin, hyaluronan, silk, alginate, or nanocellulose. Bioink provides the cells with the nutrients to survive and a scaffold on which they can grow. The complete substance is patient-based and function-specific.
  • 3D printing consists of depositing the bioink layer by layer, each having a thickness of 0.5 mm or less. The number of nozzles and the type of desired tissue determine the amount of deposit dispensed.
  • Finally, during solidification, the viscous liquid starts to hold its shape as more layers are continuously deposited. The process of blending and solidification is known as crosslinking and may be aided by UV light, specific chemicals, or heat.

What’s the matter with bioinks?

While significant strides have been made in the field of bioprinting in the last decade, the commercial availability and clinical application of bioprinting has been limited by the lack of appropriate bioinks.

What’s the status quo?

Step 1: Formulating bioinks

  • Collagen
  • Elastin
  • Matrigel
  • Fibrin
  • Alginate
  • Chitosan
  • Agarose
  • Hyaluronic acid

Step 2: Bioprinting the tissues

Step 3: Determining their properties

  1. The generation of tissue constructs with adequate mechanical strength and robustness, while retaining the mechanics that mimic tissue;
  2. Adjustable gelation and stabilization to aid the bioprinting of structures with high shape fidelity;
  3. Biocompatibility and biodegradability to avoid a toxic or immunological response and to mimic the natural microenvironment of the tissue;
  4. Suitability for chemical modifications to meet tissue-specific needs; and
  5. The ability for large-scale production with minimal batch-to-batch variation.

Step 4: Training a ML model

Next steps…

Acknowledgements

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Ammielle WB

Ammielle WB

computational biology & biological computing. ammiellewb.com