Medicine

Rate Regulating Hydrogels

Michel Vert, the Director of the Research Center on Artificial Biopolymers (1) is a major figure in technology transfer. Since 1984 he has created several start-ups and has filed 23 patents concerning polymers with therapeutic implications. He tells us about his innovations.

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© E. Perrin/CNRS Photothèque

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You have developed new methods using what are known as bioresorbable polymers. What therapeutic uses do they have?

MV: They are mainly used in surgery and pharmacology, which are areas of medicine that particularly require polymers with limited life spans. In surgery, for example, many temporary therapeutic materials exist to help the body repair itself when it has been damaged by illness or trauma. Once the body is healed, these materials, known as biostable materials, have to be removed with further surgery. So one part of our research goes into producing resorbable macromolecules that the human or animal body can eliminate naturally without needing further surgery. In pharmacology, a similar concept is used for injectable polymers that release bioactive compounds such as antibiotics, antitumoral agents, hormones, and enzymes in a controlled process. This gives us greater control over the quantities of drug released and the duration of action. In other words, these bioresorbable polymers aim to protect the patient from the drug and the drug from the patient!

So can you explain how these polymers are designed to break down in the body?

MV: In one of our inventions, the physical structure of certain polymers was modified to produce copolymer hydrogels made of three blocks: a hydrophilic block (attracted by water) sandwiched between two biodegradable hydrophobic blocks (with no affinity for water). It is the water that breaks down the hydrogels: The bonds between the molecules are hydrolyzed to release the drug held in the hydrophobic nodes or in the hydrogen network, in parallel to diffusion phenomena. The rate of biodegradation can also be adjusted depending on the desired duration for the diffusion and the action of the drug.

In 2005, you shared the European Grand Prix for Innovation, and you received the “Georges Winter” Prize from the European Biomaterial Society. You also helped create several start-ups. What is your motivation for transferring innovations to practical uses?

MV: My interest in bringing out the value of biomaterial research began when I filed a patent for a temporary orthopedic prosthesis in 1976. I realized then how important polymers were for medical uses, and in 1984 I helped create Phusis.² The aim of this company was to develop industrially resorbable polymeric biomaterial for orthopedic surgery using CNRS skills and lab scale processes. When researchers have worked for years to produce something new, it is vital to transfer it to industry to make the most of it. But even so, research remains my main activity. Advising others as a consultant or as an expert are extra motivations.

Interview by Alissar Cheaïb

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