Bio-printing - From the organ to personalized medicine, results and promises

For more than 30 years, engineers have been developing so-called "additive manufacturing" processes that enable the production of objects based on a computerized – simultaneous or non-simultaneous – deposition of material and energy [André, 2017]. This market is worth several tens of billions of €/year, with growth of around 20%/year. New niches are being explored and, given the need expressed above (but not exclusively), new processes (bio-printing) are being developed, aimed at the additive manufacturing of computer-designed structured biological elements.

Bio-printing thus belongs to bio-engineering, which integrates physical, chemical and mathematical sciences, as well as engineering principles to study biology, medicine, behavior and health: it aims to manufacture living organs or tissues. Compared with conventional additive manufacturing techniques, the printing of biological elements adds a very significant additional level of complexity to the processes, because it is necessary to "intelligently" structure living or non-living materials mimicking the extracellular matrix, and to control the spatial distributions of different cell types or biomolecules which may play a role in cell differentiation, growth or apoptosis, etc. The aim is therefore to make it possible to create a "living" organ or tissue. The aim is therefore to provide biologists and physicians with processes for depositing cell suspensions, aqueous solutions or hydrogels, and biocompatible supports, while limiting the various stresses that cells can undergo through additive manufacturing processes to achieve the desired functionality. It also involves anticipating the effects of cellular self-organization processes resulting from cell deposition to achieve a medical objective (teleology and inverse problem).

In fact, two targets based on bioprinting are presented, the "historic" one aiming to create organs (regenerative medicine), and the more recent one concerning a more robust but recently emerging use of cell clusters mimicking organs, with a "diagnostic" vision of personalized medicine.