3D printing, also known as rapid prototyping or additive manufacturing, used to be the manufacturing industry's best kept secret but now the technology is being used to transform many industries, including medicine.

Over the past year, hospitals around the world have begun talking about their burgeoning use of 3D printing in health care, from 3D printing an entire skull, to rehearsing incredibly complex surgeries and creating implants for reconstructive surgery.

"If I didn't have 3D printer technology, I wouldn't be able to do my work," Dr Muhanad Hatamleh, a senior clinical maxillofacial prosthetist at King's College Hospital, told IBTimes UK at the 3D Printshow 2015 in London.

"3D printing is revolutionising every aspect of the medical industry. It saves time, it saves more lives and it improves the efficiency of the surgery as well."

There are also great hopes for bioprinting, such as 3D printing human cells. The technology is still in its infancy but great strides have been achieved in the past few years.

Alan Faulkner-Jones, a research associate with the Biomedical Microengineering Group at Heriot-Watt University, has been researching bioprinting for the past five years and has created Biogenitor, a 3D printer that is able to produce pluripotent stem cells.

It is currently possible to grow stem cells in a laboratory, but since the cells are on a petri dish, they are 2D and do not behave the same way as cells in the body do, because they do not have surrounding cells to take instructions from.

"At the moment, drugs are tested by first testing them on small animals, then large animals, then human trials, but then the drugs don't work anymore, because you've tuned them to the response the animals had," Faulkner-Jones told IBTimes UK.

"By replacing all of that with microtissues, you can then straightaway tune the drugs to humans, and it also allows you to do personalised medicine, because you can use patient-specific cells, and you can work out how a person would respond to a particular medicine and then personalise the medicine for that person."

Retaining 3D structure

Instead, he has been developing a 3D printer that is capable of fabricating cells protected within hydrogel so that they retain their 3D structure.

Faulkner-Jones said: "Cells are never two-dimensional in the body and they lose a lot of functionality on a flat dish. But if you put cells within hydrogel and then you print structures the sam way you would using standard layer by layer additive manufacturing, then you can build up a three-dimensional structure and the cells are much happier."

Gartner analyst Pete Basiliere says the most exciting use of 3D printing is to make medical devices.

"By 2018, we expect that there will be 2.3 million 3D printer units sold," he told IBTimes UK. "Medical devices are the most exciting [use case]. But when you think about the personalisation that's available in prosthesis, implants, dental and restorative surgery, it's just phenomenal."