While they were being grown in culture, the toxicity parameters were observed to verify whether the cells were still very much alive in the matrix. Three observation periods were observed: 3, 21 and 28 days. Histological studies were carried out as well as dosages of catabolic mediators (MMP-3, an enzyme involved in osteoarthritis which destroys cartilage), inflammatory markers, (IL-6, IL-8, PG E₂) and anabolic mediators (hyaluronic acid and aggrecan).

The observation led to the conclusion that, in the presence of chitosan, there was a significant reduction in the inflammatory mediators IL-6, IL-8, PGE₂ and the catabolic mediators MMP-3. Conversely, an increase in the anabolic mediators, hyaluronic acid and aggrecan, components of the matrix. “It is essential, in the context of physiopathology that the fact of adding chitosan makes it possible to have more components in the matrix and to inhibit the main inflammatory mediators that are responsible for the degradation of cartilage”. Therefore IL-6 is as active with regard to the components as it is with regard to the synovial membrane resulting in degradation of the joint. The environment created in the beads is favourable to the cell and allows the cell to start glycosaminoglycan synthesis again.

The added value of chitosan in therefore unquestionable. In addition, apart from the use of this component, the method used is distinct from those that have generally been used to produce these kinds of beads. Placing diseased cells in contact with chitosan makes it possible to treat them. But that’s not all. “We have demonstrated that the beads could be formidable cell transporters. We could well imagine placing medicinal cells into the beads to later inject them into the joints and engage in cell therapy by this means. It would therefore be necessary to see how stem cells which have been genetically modified to become medicaments behave under the same conditions. If the tests were seen to be positive, biotherapy treatments would become available”.

For the moment, the first application will be by viscosupplementation. Professor Henrotin speaks of a “revolution “in this area. “Up to now we injected gels made of hyaluronic acid. But the problem is that this acid becomes absorbed and disappears very quickly in the joints. In a few days or even a few hours the individual is no longer able to perform. Once our gel is injected it will last longer because chitosan does not break down as quickly and will also protect the cartilage. So we will not only be able to reduce the pain but also improve the mechanical properties of the joint: less friction, less applied deleterious forces applied to the cartilage and less compression of the cartilage”.

The next step will be the clinical trials which should begin soon at the start of 2016. A contract has just been signed with Artialis(6). “We hope that our first product will be on the market in2017”.

(6) First spin-off created by Professor Henrotin in 2010. It is specialised in clinical trials for treatment of diseases affecting bones and muscles etc.