AMADEus Seminar - Pr. Liisa T. Kuhn - Monday 26 june 2017 - 2:00 pm BioTiS Lab (grande salle de réunion)

Abstract: Bone regeneration involves a series of osteoinductive cellular events. Improved biomaterials for growth factor delivery are needed that can better mimic the natural sequential presentation of multiple biomolecules.  A layered polyelectrolyte multilayer /calcium phosphate coating has been developed to provide sequential delivery of multiple osteoinductive factors and tested to determine if it can increase the efficacy of synthetic bone grafting materials. It was hypothesized that the delivery of fibroblast growth factor-2 (FGF-2) prior to the delivery of bone morphogenetic protein-2 (BMP-2) would stimulate cell proliferation and improve bone regeneration. A poly-L-Lysine/poly-L-Glutamic acid polyelectrolyte multilayer (PEM) film was deposited above a biomimetic calcium phosphate (bCaP) layer to form the bilayer of bCaP-PEM that temporally separated the delivery of FGF-2 and BMP-2. Test and control scaffolds were implanted in mouse calvarial bone defects and harvested at 1 and 3 weeks.  In young mice, the sequential delivery of FGF-2 with BMP-2 produced more bone formation than BMP-2 alone. In FGF-2 knockout mice, co-delivery of FGF-2 and BMP-2 was required to significantly increase bone formation.  Areas of bone mineralization in the studies were positive for dual fluorochrome labeling of calcium and alkaline phosphatase producing osteoblasts, along with increased TRAP+ osteoclasts and Type I collagen reporter expression. This rigorous assessment of bone cell activity was necessary to demonstrate active bone formation distinct from the bone-like collagen/calcium phosphate scaffold used in these studies.

Bio: Dr. Liisa T. Kuhn is Associate Professor in the Reconstructive Sciences Department, Center for Regenerative Medicine and Skeletal Development, at the University of Connecticut Health Center (UConn Health). Her biomaterials research interests are diverse and include bone regeneration, stem cell culture and development of anti-cancer therapies; however calcium phosphates are the common theme. Currently the main goal of her research is to improve bone growth outcomes in elderly patients by developing coatings for bone graft substitutes that deliver multiple growth factors to enhance both proliferative and differentiation activities of stem cells during bone regeneration.

Dr. Kuhn completed her B.S in Mechanical Engineering from Duke University and received her PhD in Materials Engineering from the University of California-Santa Barbara. She completed postdoctoral training at Harvard Medical School/The Children's Hospital in Boston in Orthopedics with Dr. Melvin Glimcher. Dr. Kuhn co-founded and was the Director of Development for NaturApatites Co. in Boston, from 1988-2000. She was Director of Orthopedics Product Development for ETEX Corporation in Boston, MA from 2000-2002. Recent honors include the 2014 Award of Merit from the American Society of Testing and Materials (ASTM) and serving as President of the Society For Biomaterials (2016-2017).