How will regenerative medicine evolve? One technology holds particular promise for its future: bioprinting.
Tissue engineering and molecular biology have made a new and effective tool available to doctors: regenerative medicine. Repairing damaged tissues or organs, literally rebuilding them or replacing them with others created for the occasion, seemed like a pipe dream just a few decades ago.
It is no longer science fiction. Cell therapies (introducing cells into a tissue to fight a disease) or organ cultures (usually obtained in animals exposed to human stem cells) are already a reality, although their journey has just begun and many of their advances are still experimental.
How will regenerative medicine evolve? One technology holds particular promise for its future: bioprinting. It consists of applying 3D printing techniques to living cells and biological and biochemical materials. That is, the addition of layers of these elements to produce three-dimensional structures. Bioinks, which despite being called that have nothing to do with printer ink, are a mixture of cells with polymers that create the scaffolding for them to settle and form three-dimensional structures.
The goal of bioprinting would be to print organs, such as a liver, to implant in patients. We are still far from seeing it (for the moment it has been possible to print human skin), but the truth is that experts are already calibrating the way in which bioprinting could revolutionize regenerative medicine.
What can be bioprinted
As summarized in the report Bioprinting in the Medicine of the Future, prepared by the Roche Institute Foundation and coordinated by José Luis Jorcano, professor in the Department of Bioengineering and Aerospace Engineering at the Carlos III University of Madrid, Current applications of bioprinting are limited, but real. These are the main ones:
- Drug testing. The production of standardized fabrics is postulated as a viable and economical alternative to animal testing, a practice that is falling into disuse. The fact that we can use cells from each patient also allows us to develop personalized treatments.
- 2d fabrics. They are the simplest structures that can be generated: skin and bone tissue.
- Hollow tubular structures. Vascular structures, such as blood vessels, would be on the next echelon in terms of complexity. It is the furthest this technology has gone so far.
What can be bioprinted
Although bioprinting is a very young and highly experimental technique, advances in the field presage further advances in the coming years. Here are some examples:
- Hollow organs. Conventional tissue engineering has already succeeded in producing bladders and vaginas, although they have been implanted with little success in some patients. Bioprinting this type of organ would be the next challenge.
- Solid organs. The next level will be printing livers, kidneys, lungs, and even hearts.
- Tumor models. In oncology, we are already thinking about generating tumour models with specific groups of cells for drug testing or to study, for example, whether there is a risk of expansion to other organs.
The possibilities opened up by bioprinting are manifold. For example, experts believe that in the future it will be possible to print skin in situ, that is, directly where the lesion is.
The Roche Institute Foundation report identifies several challenges that this technology will have to face before it succeeds. One of the main ones is that both bioprinters and bioinks should improve cell survival. There are also important stumbling blocks related to bioethics: which organs can or cannot be bioprinted? Under what
