A bamboo-like wood could help repair damaged bones. The material, rattan, has a honeycomb-like core, much like real bone, making it an ideal material for use in orthopaedics, say researchers who are carrying out two clinical trials across Europe.
Bone defects — gaps in bone tissue — can be caused by surgery to remove bone infections and tumours, as well as operations to repair problem fractures.
Such defects are normally treated with grafts taken from the patient or a donor, or an animal-based substitute, but none is ideal.
Harvesting healthy bone from the patient for use as a graft is widely used to replace injured bone, and help heal fractures and bone around surgically implanted devices, such as joint replacements. More than two million bone grafts a year are performed worldwide.
A bamboo-like wood could help repair damaged bones. The material, rattan, has a honeycomb-like core, much like real bone, making it an ideal material for use in orthopaedics, say researchers who are carrying out two clinical trials across Europe
Bone grafts from another part of the patient’s body are still the ‘gold standard’ for the treatment of large bone defects that do not spontaneously heal.
However, although bone is good at repairing itself, its ability to bridge very large defects is limited. Plus, most bone grafts carry the risk of being rejected by the immune system, or cause infections. Grafts from animal tissue may cause allergic reactions.
Synthetic alternatives are available but are more rigid than real bone. As a result, they aren’t generally used to patch up large defects (bigger than 3cm), where a lack of flexibility could be problematic for the patient.
To find a new option, researchers at the Institute of Science and Technology for Ceramics in Italy screened large numbers of plants looking for one that had a similar structure to bone.
Rattan, which comes from palm trees, was found to have a similar elasticity, lightness and strength to real bone.
Importantly, like bone, its interior is peppered with tiny channels, and this porous structure can be colonised by the body’s own cells to help new bone and blood vessels grow. The body recognises the implant as real bone and, over time, it is filled with osteoblasts (the cells that form new bone).
Scans of sheep treated with the implant showed that after six months, it was completely replaced by new functioning bone without causing any side-effects.
The rattan is first processed to strip away extraneous starchy fibres, leaving behind a strong but porous carbon skeleton. This can then be moulded to the shape and size needed to fill defects. After successful trials in animals, two trials are now under way at Leeds General Infirmary and at centres across Europe on 40 patients with bone defects.
The manufacturer, Italian biotech firm Greenbone, says the implant could offer a viable alternative for millions of orthopaedic patients globally each year.
Load-bearing bones in the arms and legs, as well as bones in the pelvis and spine could all be mended with the bamboo-like material, it claims.
Sarkhell Radha, a consultant orthopaedic surgeon at Croydon University Hospital, says that by monitoring patients for a year after their grafts, the trials would reveal if the material does indeed ‘generate an environment for growth of blood vessels and other nutrient supplies to the bone’.
He adds that it could ‘provide a cost-effective alternative to the existing bone graft and bone substitutes’.
Stem cells, ‘master cells’ that can develop into different cell types, can treat bone defects.
Orthopaedic surgeons are making synthetic frameworks to fit individual bone defects and injecting them with stem cells taken from donor bone marrow.
The graft is then implanted into the defect, and the surrounding soft tissue and muscle are used to cover it and close the wound.
Forty patients who are taking part in the trial at Xijing Hospital in China will be monitored for up to two years to check that the stem cells have grown into bone.
Source: The Dailymail