Authors: H. Liu, T.J. Webster
Affilation: Brown University, United States
Pages: 519 - 522
Keywords: controlled drug delivery, nanocomposites, scaffolds, orthopedic applications, bone diseases
Pharmaceutical agents are often required to stimulate new bone formation for the treatment of bone injuries or diseases (such as osteoporosis and osteosarcoma). However, there are several problems associated with current drug delivery methods. First, conventional systemic administration of these agents can not effectively reach targeted sites and, thus, they can cause non-specific bone formation in areas not affected by injury or disease. Second, even if intentionally delivered or implanted locally to the damaged bone tissue, these agents tend to rapidly diffuse into adjacent tissues due to weak physical bonding to their drug carriers, which limits their potential to promote prolonged bone formation in targeted areas of bone. Therefore, this study explored methods for immobilizing bone morphogenetic proteins (BMPs) derived peptides to nanophase hydroxyapatite (nano-HA) to promote drug loading efficiency and to achieve controlled release at local disease sites. For this purpose, nano-HA was synthesized by wet chemistry precipitation method and a BMP derived model peptide was chemically bonded to nano-HA through amino-silane chemistry. Nano-HA/BMP conjugates were then dispersed in poly(lactide-co-glycolide) (PLGA) solutions to create an implantable scaffold by a solvent-casting technique. The results demonstrated that drug loading efficiency was improved and long term drug release was achieved on these scaffolds.