Bone is the second most commonly transplanted tissue in the world, behind blood transplants, and is used in many common procedures. The UK’s ageing population means demand is increasing due to conditions such as osteoporosis and hip fractures.
It is hoped that the technique will allow scientists to grow new pieces of bone from a patient’s own stem cells - without painful surgery to remove bone samples from other parts of the body, and without risk of rejection of the new tissue.
It’s a cleaner way of growing bones for grafting and avoids using bone forming chemicals or high doses of growth factors like BMP2. These growth chemicals are currently implanted into patients to grow bone or fuse bones together but risk complications and even tumors. This has led to some warnings from the US Food and Drug Administration over their clinical use.
Instead of chemicals or drugs, the team uses tiny high frequency vibration, called ‘nanokicking’, to trigger stem cells into becoming bone producing cells. These could then be implanted where needed to fuse with existing bone and heal bone damage or fractures.
The vibrations needed to kick the cells into action are remarkably small, shaking the cells by billionths of a metre- or
nanometres. To measure movements this small the team has used the same (scaled-down) laser technology as in the hunt for gravitational waves.
The team behind the tech is led by Professor Matt Dalby (UoG) and Professor Stuart Reid (UWS). Professor Matt Dalby, said:
“The bioreactor we have designed brings together fields of research from different ends of the spectrum: stem cell research on the building blocks of our bodies, to technology used to detect the ripples in space and time caused by the collisions of massive objects. It’s amazing that technology developed to look for gravitational waves has a down-to-earth application in revolutionising bone treatments for cleaner, safer and more effective therapy.”
The team are able to grow 3D bone from ‘multi-potent’ stem cells; these are cells which can grow into many types of tissue needed throughout the body such as fat, cartilage and bone. For bone graft treatments stem cells could be taken from a patient’s bone marrow or even from fat cells from liposuction. The stem cells already contain the genetic potential to grow into bone and nanokicking unlocks this, triggering the transformation that happens naturally as the bones in our body grow and heal throughout our lifetime.
UWS researcher, Professor Stuart Reid, adds: “The scale of movement that triggers the cells to transform is so small it would be the same as ‘sliding a single sheet of paper in and out from under a football on a table’.”
Scientists at the UoG realised that this kind of physical stimulation might trigger bone growth as bones are very responsive to pressure. When they don’t have stresses placed on them from movement, called ‘bone loading’, they can erode (for example astronauts’ can suffer bone loss in the weightlessness of space). Bone loading keeps bones repairing themselves - this gave the scientists a clue that loading the cells through vibration might help bone growth.
The team aim to test their lab-grown bone in people within 3 years and that therapy could be available in 10 years. Further down the line it may even be possible to ‘nanokick’ patients directly to heal fractures without surgery.
The researchers are commercialising the bioreactor they have designed to make it available to other scientists and bone researchers. The tech could have an important role in drug discovery and has also shown promise in other areas of research such as bone cancer. Early results suggest that nanokicking could be used to identify therapeutics which slow down fast growing bone cancers.