A few months ago, I lost my cousin to liver cancer. She was several years older than me—a creative, warm, wise, and welcoming woman who had recently become a grandmother for the second time. In fact, her granddaughter was born the very day she began chemotherapy. I visited her in the hospital just days before she passed and she was knitting socks for her beloved grandchildren, bright colorful socks, which were never finished.
Rebecca needed a new liver but, generally, transplants are not used to treat cancer. The surgery is too traumatic for someone already so ill, complications are many, and chance of rejection great. No, transplant is not used for cancer patients, that is, except for liver cancer, if the cancer began in, and is confined solely to the liver. Even then, a liver transplant is only possible for very few people with primary liver cancer caught early. Hers was discovered far too late.
In November, a company, Organovo, announced that its 3D-printed biocompatible liver tissue was now commercially available, and that pharmaceutical laboratories could begin to use it for preclinical drug trials. That company and many others have plans for printing complete organs, but complete replacement 3D-printed livers are not yet available, and most likely won’t be for decades to come.
3D bioprinting is quite complex and organs are extremely complicated. Variables include choice of materials, cell types, growth and differentiation factors, and other technical challenges related to living cells and tissue construction. Government approvals will be yet another hurdle, once the technology is finally developed.
A research group at Harvard University says that it has invented novel 3D printing inks and nozzles that allow it to precisely print multiple materials, and is currently working toward printing functioning kidneys. They have printed human tissue that includes rudimentary blood vessels. University of Pennsylvania bioengineers have shown that 3D-printed templates can be used to create vasculature and improve the function of engineered living tissues. Russian scientists say that they are developing a transplant-ready thyroid to be tested in mice this year. And, cosmetics company L’Oreal has partnered with Organovo to 3D print human skin for product testing, but the technology could, ultimately, be used to help burn victims. These are just a few of the research groups hoping to expand the reach of 3D printing.
While some uses of 3D printing have been covered in Medical Design Briefs in recent months, such as creating outer ears and dissolvable airway splints for babies with collapsed tracheas, inexpensive prosthetic arms, as well as custom heart models for intricate cardiac surgery, rapid prototyping, and small batch manufacturing, this certainly is just the tip of the iceberg for the technology’s potential.
I hope and trust that 3D printing will continue to grow and evolve, so that organs, unlike unfinished socks, can be made whole in the near future, and used to save the lives of our loved ones.
Beth G. Sisk