Enhancement Of Periodontal Tissue Regeneration By Controlled Release Of Growth Factors From Synisized Biomaterial Microcarriers

Part 1Release of bioactive BMP from dextran-derived microspheres: Anovel delivery conceptA novel class of Dex-GMA microspheres were designed and synthesized by polymerization of Dex-GMA emulsified in an aqueous poly(ethylene glycol)(PEG) solution. Dex-GMA was prepared by substituting the hydroxyl groups in Dex by GMA. The drug loading and in vitro drug release was evaluated by routine procedure and the biological activity of BMP-loaded microspheres was studied by experimental cytology methods. Recombinant human bone morphogenetic protein-2(rhBMP-2) were entrapped in dextran-derived microspheres quantitatively and with full preservation of their biological activity. In vitro release kinetics indicated that dextran-derived microspheres could retain rhBMP-2 in a variable manner depending on the preparation and degradation of the microspheres. The release profiles of rhBMP-2 from microspheres as a function of time showed that rhBMP-2 releasing kinetics in vitro fitted to first-order and Higuchi equations. The release profile in vitro was in accord with two phases kinetics law and more than 60% drug were released during 12 days. Cytology studies showed rhBMP-2 microspheres have good biological effects on cultured periodontal ligament cells, and could achieve a longer action time than concentration of rhBMP-2 solution.These properties make those microspheres interesting osteo-conductive BMP carriers, allowing to decrease the amount of implanted factor required for tissue regeneration.Part 2Locally controlled delivery of BMP from dextran-co-gelatinmicrospheres...