Taymour Hammoudi

Current Status: M4

Graduate Department: Biomedical Engineering

Other Degrees: B.S. Biomedical Engineering, North Carolina State University;  

Advisor(s): Hang Lu, PhD; Johnna Temenoff, PhD;

Hometown: Marion, NC

Hobbies

Ultimate Frisbee, Hiking, Backpacking, Camping

Research

Engineering 3D hydrogel model systems to study intercellular crosstalk between bone marrow stem cells and other cells in their niche

Osteoporotic individuals experience a significant imbalance between bone deposition and bone resorption accompanied by excess marrow adipogenesis beyond that which occurs with normal development. Osteoblasts and adipocytes together represent the result of divergent, reciprocally regulated differentiation programs of a common multipotent precursor within the marrow stroma: mesenchymal stem cells (MSCs). Progress toward understanding this bone marrow microenvironment is currently hampered by the lack of in vitro model systems that enable the study of interactions between multiple cell types in physiologically relevant 3-dimensional (3D) architectures. Toward this goal, we have successfully developed an in vitro model system through photopatterning techniques that enables the study of paracrine interactions between multiple cell types in laminated, spatially defined modules at tissue-scale thicknesses that can be separated again for downstream genotypic and functional analyses. As an extension of this technology, we have recently patterned osteoblasts, adipocytes and MSCs in 3D hydrogel constructs. Preliminary gene expression data have shown that osteoblasts and adipocytes may affect lineage allocation of MSCs, and that these stem cells may be simultaneously affecting osteoblast and adipocyte function and crosstalk. Currently, we are further investigating mechanisms for these effects, including the types of signaling molecules involved, as this may provide key information to understand how the cellular composition of the marrow cavity affects overall bone deposition and quality in a variety of pathologies, including obesity and osteoporosis.

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