Three dimensional, synthetic polymer scaffolds – by nature of their chemical and physical properties – can be used to guide cell behavior and ultimate tissue regeneration. To heal osteochondral tissues, an additional challenge is to design scaffolds to guide regeneration of bone tissue and cartilage in a spatially controlled way. The implantation of the scaffold into the site of an osteochondral or bone tissue defect must also be considered. To address these challenges, we have designed two distinct scaffold systems based on polymers containing polydimethylsiloxane (PDMS) segments. First, “inorganic-organic” hybrid hydrogel scaffolds were prepared based on combining UV-curable methacrylated star-PDMS and diacrylated poly(ethylene glycol) (PEG). We have shown that PDMS is bioactive and osteoinductive. Thus, we utilized solvent induced phase separation and fabrication of scaffolds as continuous gradients to control PDMS spatial distribution. In this way, scaffolds with the potential to recapitulate the osteochondral interface may be formed. Second, shape memory polymer (SMP) scaffolds were prepared based on UV-curable macromers containing PDMS and polycaprolactone (PCL) segments. Their shape memory behavior was explored for “self-fitting” into irregular bone defects. SMP scaffolds were coated with polydopamine and the bioactivity and associated osteoblast behavior explored.
Prof. Melissa Grunlan is currently an Associate Professor of Biomedical Engineering at Texas A&M University. She is also a faculty member of the Department of Materials Science & Engineering. Prof. Grunlan obtained her B.S. in Chemistry and M.S. in Polymers in Coatings from North Dakota State University (Fargo, ND). After spending four years at the H.B. Fuller Company (St. Paul, MN), she received her Ph.D. in Chemistry from the University of Southern California (Los Angeles, CA). Prof. Grunlan joined Texas A&M University as an Assistant Professor in August of 2005 and was promoted to Associate Professor with tenure in September 2011. She is the recipient of the Herbert H. Richardson Faculty Fellow Award (2010-2011), the Association of Former Students Distinguished Achievement Award (2009) and the BP Teaching Excellence Award (2013) from the College of Engineering at TAMU. Her research is supported by the NSF and the NIH.
Prof. Grunlan is the director of the “Silicon-Containing Polymeric Biomaterials Group” (http://biomed.tamu.edu/biomaterials). Her research is broadly focused on developing new materials to improve the performance of medical devices. Several specific research areas include: self-cleaning membranes for implanted biosensors, anti-fouling coatings for blood-contacting devices and marine applications and scaffolds for osteochondral and bone tissue healing.