Biodegradable stents have shown great potential in reducing complications in patients. Biodegradable stent must have five main requirements:
- The manufacturing process should be precise
- Degradation should have minimal toxicity
- The rate of degradation should match the recovery rate of vascular tissue
- They should induce rapid endothelialization to restore the functions of vascular tissue but should at the same time reduce the risk of restenosis
- Their mechanical behavior should comply with medical requirements, particularly the flexibility required to facilitate placement but also sufficient radial rigidity to support the vessel
The stents were then seeded with cells and left for three days, and then tests were performed to assess the morphological features, cell proliferation, cell adhesion, degradation rate and radial behavior.
The researchers state:
“The results prove the materials’ biological compatibility and encourage us to believe that PCL/PLA composite stents would comply with the fourth requirement, i.e., rapid endothelization without risk of restenosis. PCL’s better cell proliferation may be useful to increase the proliferation of endothelial vessel cells in the external wall of the stents, while an internal PLA wall may help to reduce the proliferation of cells that produce restenosis. However, further studies with other kinds of cells or substances need to be performed to confirm this. The results here show low cell proliferation because of the small amount of material that the stents have. Additional studies that use longer culture times may be beneficial to obtain better proliferation results.”
PCL and PLA showed themselves to be biocompatible, and the composite stents showed the most promise, with medium levels of degradation rates and mechanical modulus.
Authors of the paper include Antonio J. Guerra, Paula Cano, Marc Rabionet, Teresa Puig and Joaquim Ciurana.