Monday, October 17, 2016 at 12:10 p.m. in Todd 334
The Gene and Linda Voiland School of Chemical Engineering and Bioengineering is hosting a seminar presented by Juana Mendenhall, Associate Professor of Chemistry at Morehouse College.
Towards Enhancing Chondrogenesis using Injectable Therapeutic Laden Hydrogels
Injury and diseases that affect articular cartilage present a daunting challenge in orthopaedic medicine. During the onset of injury or disease, low oxygen environments decrease healthy cartilage cell growth reducing the efficacy of injectable hydrogels that maybe employed in a defective knee joint.1 Hence the use of injectable hydrogels with thermo-sensitive properties having therapeutic efficacy is needed for clinical enhancement to help improve cartilage tissue engineering strategies. Poly(N-vinylcaprolactam)[PVCL] is a smart biomaterial that changes its molecular orientation upon temperature change along with it’s mechanical properties. PVCL displays a lower critical solution temperature (LCST) ranging from 32ºC-40ºC, that always it to form reversible gels. We have developed a therapeutic injectable composite hydrogel system that contains PVCL, hyaluronic acid (HA), and bio-functional therapeutics (PVCL_HA-TH). In conjugation with hyaluronic acid, this thermo-sensitive hydrogel affords a robust hydrogel with tunable LCST parameters near physiological temperature. Hydrogels were prepared via various chemical strategies then used in vitro static cell culture studies and in vivo studies. 3D bioprinting of hydrogels were also fabricated to compare the effect material properties on cell proliferation and metabolism on extra cellular matrix (ECM) deposition. Fetal bovine chondrocytes were harvested and seeded [or 3D bioprinted] into various formulations of PVCL-HA-TH under normoxia (21%) and hypoxia (1%) low oxygen conditions. Chondroctye cell viability at 1% O2 levels remained higher than that of 20% O2 levels in PVCL-HA for each time point. PVCL-g-HA hydrogels reached a maximum of 89% on the third day of observance. Higher cell viability was also noted on meHA samples at 1% O2 levels than at 20% O2 levels, with the peak value at 74% on the first day of observance. Animal studies were performed for 30 days after injection of therapeutic hydrogels into the defective knee joint. Histology samples confirmed higher amounts of chondrocyte cloning with in murine joint after 30 days.
