| Properties |
Vascular Resorbable Scaffolds |
OrthopaedicResorbable Scaffolds |
| Constraints |
Constraints |
| Cell Response |
Encourage endothelial cell attachment, but not smooth muscle cell attachment, as it may have a negative effect on vessel patency [10,14] |
Encourage new bone formation through both osteoblast and osteoclast attachment and proliferation, but also avoid fibrous capsule formation [15] |
| Mechanical Integrity |
> 8 months
> 6-12 months [1,7,13,16] |
> 6 months (Based on longest
healing time for neck of femur) [16] |
| Yield Strength |
> 200MPa [17] |
> 230MPa [18] |
| Ultimate Tensile Strength |
> 300MPa [17] |
> 300MPa [17] |
Elongation to Failure
(%Strain) |
> 15-18%
Higher ductility is ideal for higher flexibility while expanded while in arteries, but still need enough radial force to open lesions [17,19] |
> 15-18% [17] |
| Elastic Modulus |
Low elastic modulus to be able to bend around the human circulatory system, but still stiff enough to retain necessary hoop and radial strengths for artery support [20-22] |
As close to cortical bone as possible to avoid stress-shielding
(10-20 GPa) [3] |
| Fatigue Strength at 10^7 cycles (Mpa) |
> 256
Strength must be sufficient to prevent acute recoil and negative remodeling [2,4,17,29] |
> 256 [17,19] |
| Elastic Recoil on Expansion |
< 4% [17] |
N/A |
| Hydrogen Evolution |
< 10 uL/cm^2/day
(Though blood flow may increase this maximum tolerance) [17,25] |
< 10 uL/cm^2/day [25,26] |
