Exploring the Future of Body Part Replacement: Mary Roach Delves into 3D Printing, Genetic Editing, and More

In a captivating exploration of human anatomy, award-winning science writer Mary Roach delves into the extraordinary functions of our bodies, with a particular fascination for the often overlooked “gooey bits and pieces” that perform miracles daily.

The resilience of the human heart is one such marvel. With luck, our hearts may continue beating for over 80 years – an impressive lifespan compared to most consumer electronics.

Known for her thought-provoking books on human physiology, Roach has delved deep into various topics, including human cadavers, the digestive system, and the science of sex. Her latest work, “Replaceable You: Adventures in Human Anatomy,” charts the history of body part replacement, from antique prosthetic noses dating back to the 1500s, to modern medical advancements.

This compelling narrative was inspired by a personal story – a friend living with spina bifida whose mobility was hindered by a twisted foot. Despite seeking a surgical amputation and subsequent replacement with a prosthetic limb, surgeons were hesitant to remove what they considered a healthy limb. Roach found this reluctance intriguing, noting the emotional aspect of removing a body part, even when it impedes function.

Roach’s book also explores potential future developments in gene editing and 3D printing technology that could further make our bodies “replaceable.” She profiles researchers at Carnegie Mellon University who used a 3D printer to create a miniature ventricle, which was implanted into a mouse heart. However, she cautions that funding cuts to medical research by the current administration could disrupt the pipeline of innovation and discovery in this field.

“The future of medical care and innovation is looking bleak due to these budgetary decisions,” Roach laments. “It’s disheartening to consider what we might be missing out on.”

One fascinating aspect of the book discusses the use of pigs as models for organ transplants. In the 1940s, ’50s, and ’60s, a collaboration between the Mayo Clinic, the Mayo Foundation, and Hormel Institute aimed to create a miniature pig with organs similar in size and function to humans. Extensive studies were conducted on pigs, including research into their susceptibility to coronary artery disease, which found that they are prone to many of the same health issues as humans.

When it comes to preventing organ rejection, a major challenge lies in the severe immune response caused by an organ from another species. Known as hyperacute rejection, this rapid attack can turn the organ black within minutes. To address this issue, scientists are editing genes such as alpha-gal protein, making the pig organ appear less foreign to the human body. This reduces the level of rejection to that of a human transplant, requiring similar immunosuppressive drugs.

There have been concerns regarding the use of pigs in transplants from certain religious communities. However, interviews with religious leaders suggest that receiving a pig organ is acceptable, as long as it is not consumed. The logic being that saving lives takes precedence over dietary restrictions.

Roach’s book also touches upon experiments involving 3D printing of muscle and tissue. At the Feinberg lab at Carnegie Mellon University, researchers are working on printing muscle cells with specific alignments to achieve the required function. For example, heart muscle needs a helical shape to enable its twisting motion during pumping, while shoulder muscles require a fan-like shape for versatile movement. The ultimate goal is not to print entire organs but rather to create functional tissue for repair and replacement.

The process of tissue recovery for organ donations involves tedious tasks such as labeling and packaging, which surpass the physical extraction of bones and ligaments in terms of unpleasantness. Lastly, Roach shares her personal experience of becoming overly aware of bodily functions after researching topics like digestion and chewing – a reminder that our bodies are complex machines that sometimes demand more attention than we’d care to give them.