ASSOCIATION OF HUMAN GROWTH-HORMONE AND CALCIUM-PHOSPHATE BY DYNAMIC COMPACTION - IN-VITRO BIOCOMPATIBILITY AND BIOACTIVITY

The association of therapeutic agents with biomaterials has been achie ved through various techniques, such as coating of the ceramic block s urface or drug incorporation into ceramics. The dynamic compaction met hod recently was developed to consolidate drug-loaded calcium phosphat e powder without a sintering step. Zn the present work, human recombin ant growth hormone was loaded on biphasic calcium phosphate powder and consolidated by a specific process of cold sintering (dynamic compact ion). Analyses of the biocompatibility of compacted pellets (mouse L92 9 fibroblastic cell culture) and the bioactivity of the drugs released by them (growth hormone bioassay) were performed. This report demonst rates the biocompatibility of the compacts prepared by dynamic compact ion. L929 cell proliferation was maintained and the capacity to secret e fibronectin was conserved in the presence of compacted materials. Co mparison of released growth hormone integrity, revealed by radioimmuno assay and eluted stain bioassay, has shown that the biological activit y of growth hormone was totally preserved after dynamic compaction. Ho wever, 35% of loaded growth hormone was not released in our experiment al conditions, probably because of the inaccessibility of growth hormo ne within the granulated compacts. Dynamic compaction shows good poten tial for the production of biomaterials capable of releasing therapeut ic agents in situ. (C) 1997 John Wiley & Sons, Inc.