INTELLECTUAL MERIT: This project will investigate the use of a piezoelectric material that will act as a scaffold for stem cell induced tissue repair. The piezoelectric material acts as a highly sensitive mechanoelectrical transducer that will generate charges in response to minute mechanical deformations. By developing a piezoelectric, fibrous scaffold, the team can achieve a local electric field, which is a physical property similar to the natural extracelluar matrix observed during development and regeneration. This work focuses specifically on the design and characterization of these scaffolds for total joint replacement, i.e., for the reconstruction of cartilage and the underlying bone tissue, due to its vital clinical need, and therefore, will have significant impact on the fields of smart materials and tissue regeneration. Two specific aims will be addressed. Aim 1 will fabricate and fully characterize the piezoelectric properties of the scaffold. Piezoelectric polyvinylidine fluoride trifluoroethylene (PVDF-TrFE) fibrous scaffolds will be fabricated and characterized for electrical output in conditions that more closely mimic the biological setting. Piezoelectric scaffolds will be characterized for localized nanoscale electromechanical behavior using a novel microcopy technique as well as bulk properties in order to correlate biological response with electromechanical activity. Aim 2 will investigate the osteogenic and chondrogenic differentiation of human mesenchymal stem cells (MSCs) on the piezoelectric scaffold in vitro. The PI hypothesizes that the use of a fibrous scaffold having similar physical properties as the native extracellular matrix will stimulate the differentiation of MSCs.
BROADER IMPACTS: This study involves use of a novel smart material for use, in combination with stem cells, as a tissue engineering medium for regenerating severe cartilage defects. The studies propose a series of integrated investigations combining advances in materials science with engineering characterization techniques, nanomaterial characterization, microelectronics, stem cell bioengineering, and molecular biology/bioengineering techniques. The proposed studies will have significant impact in the fields of tissue engineering and regenerative medicine, smart materials, and biomaterials. The insights gained in the application of piezoelectric materials to stem cell bioengineering will also be of relevance to cell biologists and developmental biologists, since piezoelectric extracellular matrices are present during embryogenesis and wound healing. This project will have a significant impact on the recruitment and mentoring of underrepresented minorities and women in Biomedical Engineering. The PI is an active mentor in three programs that expose minorities and female students to engineering topics and projects as early as the elementary and junior high school levels. She will continue to be a mentor in the American Chemical Society Project SEED program, in which junior and senior level high school students from the Newark, NJ community conduct research projects in the PI's laboratory (two students per summer). Each summer, these students will participate in obtaining results for aims 1 and 2 by learning stem cell differentiation assays and the fabrication of the electrospun meshes. The PI will also continue to participate in the NJIT FEMME program, which impacts 150 elementary to junior high school female students each summer and provides students with tours and hands-on demonstrations of tissue engineering and biomaterials projects in the PI's laboratory. In addition, the PI will continue to mentor minority undergraduate students in the NJIT McNair Postbaccalaurate Achievement Program, through which the PI will work with one to two undergraduate students per year as a research mentor on the proposed project.
