Development of a bioresorbable self-hardening bone adhesive based on a composite consisting of polylactide methacrylates and beta-tricalcium phosphate.

In this work, a novel bioresorbable bone adhesive based on radically polymerizable polylactide with methacrylate endgroups known from polymethylmethacrylate (PMMA) cements and varying amounts of bioresorbable/biodegradable lactide moieties was developed. The swelling and degradation properties as well as the hardening time, viscosity, and adhesion properties (tension and shear resistance) were subsequently measured in vitro and optimized. For a broad use in surgery the handling properties, the shelf life and the storage temperature are important issues. The finally developed material consists of three substances that have to be mixed to start the reaction: a highly viscous mixture of oligomers and two beta-tricalcium phosphate (beta-TCP, Cerasorb) powders with the radical starter and the promoter. The material has a processing time of 2 min and is completely cured after another minute. The tension and shear resistance of the material is 3.1-13.9 MPa that will decrease by storing the substance in a humid atmosphere. Degradation experiments showed a mass loss of 20-35% during the first 5 weeks. Tests with MC3T3-E1 cells showed an increase of the alkaline phosphatase activity over a period of 14 days. The mechanical and handling properties and the in vitro data are showing a promising biomaterial for bone regeneration. (c) 2008 Wiley Periodicals, Inc.