Physiologic pulsatile flow bioreactor conditioning of poly(ethyleneglycol)-based tissue engineered vascular grafts
Hahn,MS; McHale,MK; Wang,E; Schmedlen,RH; West,JL
Abstract Mechanical conditioning represents a potential means to enhance thebiochemical and biomechanical properties of tissue engineered vascular grafts (TEVGs). A pulsatileflow bioreactor was developed to allow shear and pulsatile stimulation of TEVGs. Physiological 120mmHg/80 mmHg peak-to-trough pressure waveforms can be produced at both fetal and adult heart rates.Flow rates of 2 mL/sec, representative of flow through small diameter blood vessels, can begenerated, resulting in a mean wall shear stress of approximately 6 dynes/cm(2) within the 3 mm IDconstructs. When combined with non-thrombogenic poly(ethylene glycol) (PEG)-based hydrogels, whichhave tunable mechanical properties and tailorable biofunctionality, the bioreactor represents aflexible platform for exploring the impact of controlled biochemical and biomechanical stimuli onvascular graft cells. In the present study, the utility of this combined approach for improving TEVGoutcome was investigated by encapsulating 10T-1/2 mouse smooth muscle progenitor cells withinPEG-based hydrogels containing an adhesive ligand (RGDS) and a collagenase degradable sequence(LGPA). Constructs subjected to 7 weeks of biomechanical conditioning had significantly highercollagen levels and improved moduli relative to those grown under static conditions.
Keywords Bioreactors; Blood Vessel Prosthesis; Blood Vessels; Myocytes, Smooth Muscle
Annals of Biomedical Engineering
0090-6964, Volume 35, Issue 2, 2007, Pages 3-200
