Surface modification of Ti-6Al-4V alloy for biomineralization and specific biological response: Part II, Alkaline phosphatase grafting

Titanium and its alloys are the most widespread materials for the realization of orthopaedic and dental implants due to their good mechanical properties and biocompatibility. Surface functionalization of biomaterials aimed to improve and quicken implant integration and tissue regeneration is an active research field. The opportunity to confer biological activity (ability to directly stimulate cells with proper biological signals) to the Ti6Al4 V alloy, previously modified to be bioactive from the inorganic point of view (apatite precipitation), was explored in this research work. The alkaline phosphatase (ALP) enzyme was grafted to metal surface via tresyl chloride activation, maintaining its activity. A synergistic effect between biological functionalization and inorganic bioactivity was observed

Enzymes involved in lipid digestion

International audienceLipid digestion is a complex process that takes place at the lipid-water interface and involves various lipolytic enzymes present predominantly in the stomach and the small intestine [34]. These enzymes catalyse the hydrolysis of a variety of dietary lipids from animal and plant sources, such as triacylglycerols (TAGs), phospholipids, galactolipids, cholesterol and vitamin esters. They include gastric lipase, colipase-dependent pancreatic lipase, pancreatic lipase-related proteins 2 (PLRP2), carboxyl ester hydrolase or bile salt-stimulated lipase (CEH, BSSL), and pancreatic phospholipase A2. A debate still exist about the existence of a lingual lipase in human [30, 86, 140], an enzyme that has been demonstrated to be present and active in rat and mice tongue only and which is the product of a gene ortholog [53] to the gene of gastric lipase [24] in humans and many other species. Bakala N’Goma et al. [12] have reviewed the key findings that support the existence of lingual or gastric lipases in several species in term of gene expression, enzyme immunocytolocalization and lipase activity. So far, no supporter of the existence of a lingual lipase in humans has been able to provide similar data