Les biomatériaux Gaétan Laroche, PhD Département de génie des mines, de la métallurgie et des matériaux Laboratoire d’ingénierie de surface Centre de recherche du CHUQ
Lecture overview History Replaceable parts in the human body What are the materials used? What properties are expected? Few examples Where is the research going?
What’s a biomaterial? Any substance or combination of substances, other than drugs, of natural or synthetic origin, that can be used for any period of time, which augments or replace partially or totally any tissue, organ, or function of the body, in order to maintain or improve the quality of life; material suitable for use in prostheses that will be in contact with living tissue. (American Institute of Health)
History 2300-2000 BC: crutches, articulated artificial hands (Egyptians) ~ 1500 BC: articulated legs and arms made of wood. No implantation can be performed because of poor knowledge of human body anatomy
History 1536: Ligation of the arteries during amputations (Paré) 1543: First book of anatomy of the human body (Leonardo da Vinci) 1844: Anesthesia (Wells) 1865: Asepsis (Lister)
History 1938: Hip prosthesis 1952: Arterial prosthesis (Blackmore, Voorhes et Jaretski) 1960: Cardiac valve (Starr et Edwards) 1969: Artificial heart (Cooley, Kolff)
Replaceable parts in the human body
What are the materials used? Skeletal system Hip and knee: Titanium and titanium alloys, stainless steel, polyethylene Plate for fracture: Stainless steel, chromium- cobalt alloys Cement: Poly(methyl methacrylate) Bone repair: Hydroxyapatite Ligament, tendon: Polyester, Teflon, Nylon Tooth: Titanium, alumina, hydroxyapatite
What are the materials used? Dacron (PET) >6mm Téflon (ePTFE) <6mm Cardio-vascular system Arterial prostheses: Polyester, Teflon, polyurethane Cardiac valve: Fixed biological tissues, stainless steel, polyester, polyurethane Catheter: Silicone, Teflon, polyurethane
What are the materials used? Organs Artificial Hearth: Polyurethane Skin repair: silicone/collagen scaffold Artificiel kidney: Cellulose, polyacrylonitrile
What are the materials used? Senses Cochlear implant: Platinum Intra-ocular implant: Poly(methyl methacrylate, silicone, hydrogels) Contact lenses: Silicone-acrylate, hydrogels Eye patch: Collagen, hydrogels
Day-to-day use⇔ Biomedical application What are the materials used? Day-to-day use⇔ Biomedical application
Teflon, Polyester Day-to-day Biomedical
Polypropylene Day-to-day Biomedical
Stainless steel Day-to-day Biomedical
What properties are expected? Biomaterial device must provide the basic function of the organ or system they replace. Otherwise, it depends. Biocompatibility Biostability Biodurability
Biocompatibility Body response towards the material Inflammatory reaction Immune response Infection
Biocompatibility les matériaux constitutifs de la partie articulaire d’une prothèse totale de la hanche doivent permettre le mouvement de l’articulation sans frottement excessif, tout en produisant une quantité minimale de débris d’usure pendant la durée de vie de la prothèse ( ≥ 15 années); les débris d’usure produits ne doivent pas provoquer de réaction inflammatoire locale ou générale, ni déclencher de réaction immunitaire spécifique (allergie) ; la partie métallique de la prothèse en contact avec l’os ne doit pas relâcher de produits de corrosion toxiques pour les cellules osseuses, et favoriser la recolonisation par le tissu osseux en contact intime avec la prothèse.
Biocompatibility Une sonde urinaire ne doit pas faciliter la pénétration ou le développement de bactéries dans le tractus urinaire et dans la vessie. Un vaisseau sanguin artificiel ne doit pas favoriser la condensation de plaquettes et la formation d’un caillot sur la surface qu’il expose au flux sanguin.