Cellular engineering of conduits for coronary and lower limb bypass surgery: role of cell attachment peptides and pre-conditioning in optimising smooth muscle cells (SMC) adherence to compliant poly(carbonate-urea)urethane (MyoLink) scaffolds.
OBJECTIVE
We are developing a hybrid arterial bypass graft of compliant poly(carbonate-urea)urethane (MyoLink), endothelial and smooth muscle cells (SMCs). To enhance adhesion of SMCs we assessed various attachment factors and the effect of pre-conditioning on cell retention.


METHODS
MyoLink segments were coated with either RGD, superfibronectin, fibronectin, fibronectin-like engineered polymer protein (FEPP), FEPP plus or type 1 collagen overnight. (111)Indium-radiolabelled SMCs were placed onto MyoLink segments for 48 h before being aspirated, then lavaged off. All grafts, aspirates and lavages were counted in a gamma counter. SMC viability on the MyoLink segments was also assessed for viability using the Alamar blue redox assay. Separately, MyoLink grafts lined with radiolabelled SMCs were divided into a pre-conditioned group, exposed to subarterial pulsatile flow whilst another group were held in static culture. After 1-week, grafts were exposed to arterial pulsatile flow whilst radioactivity was assessed using a gamma camera.


RESULTS
Only FEPP plus significantly enhanced SMC attachment: mean of 32+/-6% cell attachment compared to 21+/-5% for uncoated control. Cell viability was enhanced by all attachment factors except fibronectin. Pre-conditioning was shown to significantly enhance the retention of SMCs onto the MyoLink once exposed to pulsatile arterial flow: the final attachment was 57+/-7% for the static and 76+/-7% for the pre-conditioned group.


CONCLUSIONS
FEPP plus enhances SMC attachment to MyoLink. We believe this is because of its repeating sequences of RGD and its positive charge. Pre-conditioning enhances the retention of SMCs to MyoLink once exposed to pulsatile arterial flow.
Rashid
S T
ST
Vascular Unit, University Department of Surgery, Royal Free Hospital, Hampstead NHS Trust, London, UK.
Salacinski
H J
HJ
Button
M J C
MJ
Fuller
B
B
Hamilton
G
G
Seifalian
A M
AM
D001807:Blood Vessel Prosthesis; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D011108:Polymers; D011140:Polyurethanes; D011474:Prosthesis Design; D011673:Pulsatile Flow; D023822:Tissue Engineering
D015815:Cell Adhesion Molecules; D011108:Polymers; D011140:Polyurethanes; C110029:poly(carbonate urea) urethane