THURSDAY, 6 JUNE 2024
How would you feel about using a plaster made from human skin? Uneasy? Nauseated? What if that plaster came from a printer rather than a human?This is one of the proposed applications of the Bioprint FirstAid Bioprinter, a device tested aboard the International Space Station. The bioprinter could create a wound healing patch from a culture of a patient’s own cells. The result? A personalised dressing that accelerates wound healing with the potential to revolutionise treatment. The Bioprint FirstAid Bioprinter is not yet ready to be trialled in the clinical setting, but given that 3D printing as a concept was once nothing but a pipe dream, the future certainly looks promising.
3D printing involves the generation of a physical, three-dimensional object from a digital model. To create biological material (or ‘bioprinting’), structures are created by layering mixtures of cells, matrix and other compounds to recreate an object imaged by, for example, medical technologies such as an MRI scanner. In an intense field such as medicine, with high demands and little scope for error, the ability of 3D bioprinting to recreate human tissues outside the body has several promising applications. Printing plasters made from lab-grown skin is just one of the ways this technology could transform medical practice.
TRAINING MEDICAL PROFESSIONALS | Before thinking about the diversity of organs we could generate through such printing, it is worth considering the utility of being able to create biologically accurate models of human tissue in medical schooling. Practical procedures are an integral part of medical work. Creating robust and beneficial training programmes can be difficult and experience may be hard to come by. This is currently particularly pertinent due to reduced clinical exposure post COVID-19; a survey by the British Orthopaedic Trainees Association in 2022 reported that only two thirds of trainees felt ready to safely transition to the next stage of their education.
There are efforts to bridge the gap between learning and clinical practice; for example, virtual reality in surgical training has shown promise, having been piloted in contexts such as simulated orthopaedic procedures. Why not introduce a new teaching aid in the real world? The opportunity to practice surgical skills on physical models could allow doctors and medical students to gain valuable experience. For example, researchers in South Korea have used 3D bioprinting to create a simulation model for surgery at the base of the skull. Surgeons trialling the model reported that it was anatomically realistic and helpful for their training. Similarly, researchers affiliated with Carnegie Mellon University in the USA have created an anatomical model of the human heart, proposing its utility in medical education. Furthermore, anatomical variation means that every patient is unique; 3D bioprinting could provide a way for surgeons to practise complex cases on a patient-specific model, should this be useful. After all, the more practice a surgeon can get before taking scalpel to flesh, the better.
PRINTING REPLACEMENT TISSUES | For patients with organ failure, a transplant may be the only treatment option. According to NHS Blood and Transplant, there are around 7,000 people in the UK on the waiting list for a transplant. Last year over 400 people died waiting for a transplant in the UK; in the USA the numbers are estimated to be as high as 20 patient deaths a day. Furthermore, not all donors are matches for all patients; immunological incompatability can lead to organ rejection, adding another layer of complexity. 3D organ printing could be the answer and, by seeding printed organs with the patient’s own cells, could circumvent the problem of organ rejection. Furthermore, there will likely be financial benefits - for example, according to the National Foundation for Transplants in the USA, a standard kidney transplant can cost over $300,000, tenfold more than a 3D bioprinter. Advances from institutions all over the world have demonstrated encouraging capabilities in 3D printing a wide range of different human tissues including proximal tubule cells in the kidney, the cornea and the skin. 3D bioprinting could also be used to generate replacements for structures within organs such as heart valves, where existing options are either mechanical (carrying a risk of clot formation) or porcine (taken from pigs, with immunological risks).
However, bioprinted organs are not likely to become a transplant mainstay until certain issues are addressed. For example, the bioengineering feat of integrating vasculature into a bioprinted organ has proven to be challenging and complex. Transplanted organs need a blood supply for the supply of nutrients and removal of waste products. Furthermore, some structures are much easier to 3D print accurately than others. When it comes to rigid materials such as bone, the accuracy is excellent, but there is still a gap between human soft tissues (such as ligaments) and the 3D-printed equivalent that needs to be bridged by post[1]processing. Ultimately, whilst bioprinted organ replicas may be reasonably accurate, will they be accurate enough?
3D-PRINTED DRUGS | Personalised treatment from a pharmaceutical perspective could be transformed by 3D printing, introducing the capacity to easily and efficiently produce a small batch of medication with specific tailored properties. For example, 3D printing enabled the preparation of the FDA-approved anti-epileptic drug Spritam by the company Aprecia, with the aim of helping patients who struggled with their experiences taking medication. The orodispersable tablet (dissolving on the tongue) achieves high doses that are typically not conventionally possible and disintegrates with seconds once in contact with saliva. This can be particularly helpful for patients who may have swallowing difficulties.
There is much work that remains to be done in the field of 3D bioprinting; we are far from printing organs instantly on demand. As well as the technical hurdles the field must surmount, we must also consider the patient reaction to this burgeoning field – would the thought of the heart beating away in your chest having been grown in a laboratory leave you with a sense of wonder at modern medical achievements, or just an unsettling knot in your stomach? Ultimately, 3D bioprinting represents just one of the many technological advances that will likely revolutionise healthcare and medical education in the future, and determining how it will be integrated with other practices will likely be an important future consideration in the field. However, applications of such technology may help healthcare services that are already overloaded, and in doing so, save patients’ lives. As with any attempt to recreate the human body, 3D bioprinting is not perfect. But it certainly holds promise.
Article by Sambhavi Kumar. Artwork by Rosanna Rann.
