Julian Jones, professor in the Department of Materials at Imperial College London and one of the developers of the bio-glass.
Julian Jones, professor in the Department of Materials at Imperial College London and one of the developers of the bio-glass.

A team of scientists from the UK and Italy have developed a synthetic material that can mimic cartilage and potentially encourage it to re-grow. Cartilage is a flexible connective tissue found in places such as joints and between vertebrae in the spine; compared with other types of connective tissue, it is not currently easy to repair.

The scientists from Imperial College London in the UK and the University of Milano-Bicocca in Italy have developed a bio-glass material that mimics the shock-absorbing and load bearing qualities of real cartilage. The bio-glass can be formulated to exhibit various different properties, and the scientists are now hoping to use it to develop implants for replacing damaged cartilage discs between vertebrae. They believe it also has the potential to encourage cartilage cells to grow in knees, which has not previously been possible using conventional methods.

The bio-glass is made up of silica and a polymer called polycaprolactone, and displays cartilage-like properties such as flexibility, strength, durability and resilience. It can be made in a biodegradable ink form, allowing the researchers to print it into structures that encourage cartilage cells to form and grow – a process they have demonstrated in test tubes. The bio-glass also displays self-healing properties when damaged, which could make it a more resilient and reliable implant, as well as easier to print when in the ink form.

One formulation of the bio-glass developed by the team could provide an alternative treatment for patients who have damaged their intervertebral discs. When cartilage degenerates in the spine, it leaves patients with debilitating pain; current treatment involves fusing the vertebrae together, which reduces a patient’s mobility.

The scientists believe they will be able to engineer synthetic bio-glass cartilage disc implants, which would have the same mechanical properties as real cartilage without the metal and plastic components that are currently used.

Another formulation could improve treatments for those with damaged cartilage in their knees, say the team. Surgeons can currently create scar-like tissue to repair damaged cartilage, but ultimately most patients require joint replacements, which again reduces their mobility. The team are aiming to ‘print’ tiny, biodegradable scaffolds using their bio-glass ink; these bio-degradable scaffolds would provide a template that replicates the structure of real cartilage in the knee.

When implanted, the stiffness and chemistry of the bio-glass scaffold would encourage cartilage cells to grow through microscopic pores in the glass. The idea is that over time the scaffold would degrade safely in the body, leaving new cartilage in its place with similar mechanical properties to the original cartilage.

“Bio-glass has been around since the 1960s, originally developed around the time of the Vietnam War to help heal bones of veterans, which were damaged in conflict,” explained Julian Jones, a professor in the Department of Materials at Imperial and one of the developers of the bio-glass. “Our research shows that a new flexible version of this material could be used as cartilage-like material.”

“Patients will readily attest to loss of mobility that is associated with degraded cartilage and the lengths they will go to try and alleviate often excruciating pain. We still have a long way to go before this technology reaches patients, but we’ve made some important steps in the right direction to move this technology towards the marketplace, which may ultimately provide relief to people around the world.”

The researchers have received funding from the UK Engineering and Physical Sciences Research Council (EPSRC) to take their technology to the next stage. They are aiming to conduct trials in the lab with the technology and to develop a surgical method for inserting the implants. They will also work with a range of industrial partners to further develop the 3D manufacturing techniques.

Justin Cobb, chair in orthopaedic surgery at Imperial’s Department of Medicine, will be co-leading on the next stage of the research. “This novel formulation and method of manufacture will allow Julian and his team to develop the next generation of biomaterials,” he said. “Today, the best performing artificial joints are more than a thousand times stiffer than normal cartilage. While they work very well, the promise of a novel class of bearing material that is close to nature and can be 3D printed is really exciting. Using Julian's technology platform, we may be able to restore flexibility and comfort to stiff joints and spines without using stiff metal and all its associated problems.”

Laura Cipolla in the Department of Biotechnology and Biosciences at the University of Milano-Bicocca, added: “Based on our background on the chemical modification of bio- and nanostructured materials, proteins and carbohydrates, we designed a new chemical approach in order to force the organic component polycaprolactone to stay together in a stable way with the inorganic component silica."

The team also includes PhD student Francesca Tallia from Imperial’s Department of Materials and senior researcher Laura Russo from the Department of Biotechnology and Biosciences at the University of Milano-Bicocca.

The technology still has a number of regulatory hurdles to overcome before it can be used for clinical applications, with the team predicting it will take 10 years to reach the market. They have patented the technology with Imperial Innovations – Imperial College’s technology commercialization partner.

This story is adapted from material from Imperial College London, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.