Bio-Inspired Materials: Peptide-Reinforced Nanocomposites and Self-Assembled Nanoparticle

Bio-Inspired Materials: Peptide-Reinforced Nanocomposites and Self-Assembled Nanoparticle

Featuring Esmaiel Jabbari, Ph.D.
Associate Professor, Departments of Chemical and Biomedical Engineering
University of South Carolina

Location:  McDonald Douglas Auditorium (MDEA)

Abstract:
Peptide-Reinforced Nanocomposites
Bone is a composite material consisting of a collagenous and a mineral phase. The collagenous phase gives bone its form and contributes to its ability to resist bending, while the mineral component resists compression. The collagenous phase plays a central role in regulation of cell differentiation and maturation, maintenance of matrix integrity, and the extent of mineral-collagen interactions. We demonstrate, for the first time, that the structural organization of a collagen scaffold supports concurrent differentiation of bone marrow stromal (BMS) cells to osteogenic and vasculogenic lineages, as evidence that the substrate has a profound effect on guiding the differentiation pathway of progenitor cells. In the process, we discovered that a glutamic acid-rich peptide, derived from osteonectin protein of the bone matrix, profoundly improves dispersion and increases the elastic modulus of a bone-mimetic nanocomposite. These findings can be utilized for developing advanced nanomaterials with broad biological applications (Euro Biophys J, 2007, p229).

Self-Assembled Nanoparticles
A novel strategy to circumvent the short half-life of antitumor drugs and improve their selectivity and patient compliance is to trap these drugs in colloidal particles (NPs). Jabbari's laboratory has discovered a novel poly (lactide-co-ethylene oxide fumarate) macromer that self-assembles in aqueous environment to form biodegradable NPs that can be conjugated with peptide-based ligands with high affinity for receptors on tumor cells and tumor endothelial cells. The degradable nature of the NPs potentially eliminates their accumulation in the tumor microenvironment (Pharm Res, 2008, online).

About the Speaker:
As a doctoral student at Purdue University (1999-1993), Jabbari demonstrated that the mechanism of chain interpenetration plays a dominant role in mucoadhesion. As a research fellow in the biotechnology group of Monsanto Corp. (1993-1994), he demonstrated that calcium ions alter the release mechanism of potent biological agents from polyurea microcapsules. In 1995, he joined the biomedical engineering faculty of Tehran Polytechnic Institute, where he established and directed a research program in biomaterials and drug delivery systems (1995-2000). As a visiting professor at Rice University (2001), Jabbari contributed to the development of hydrogels that served as a carrier for progenitor mesenchymal stem cells and sustained release of plasmid DNA used in the treatment of osteoarthritis. While he was in the department of orthopedic research at the Mayo Clinic from 2002-2004, his research focused on the development of biodegradable scaffolds to treat skeletal defects. Since Jabbari joined the department of Chemical Engineering at the University of South Carolina (USC) in 2004, he has established two laboratories to study functional biomaterials and develop medical devices for bone regeneration and tumor delivery.