Validation of a new vascular graft: inflammation and hyperplasia
D Durán-Rey, C Sánchez-Rumbo, R Brito-Pereira, V Crisóstomo, S Lanceros-Méndez, F M Sánchez-MargalloAbstract
Introduction
Narrowing or stenosis of blood vessels induces reduced blood flow and tissue damage due to insufficient nutrient supply. Currently, tissue-engineered vascular grafts (TEVGs) are capable of replacing or repairing the biological functions of blood vessels. Considering that the electroactive effect has shown great promise for the development of grafts with biomedical applicability, poly(vinylidene fluoride) (PVDF) is a synthetic and biocompatible material that induces a specific cellular response capable of favouring tissue regeneration, thanks to its piezoelectric properties.
Methods
PVDF electrospun TEVGs were designed and implanted into the right common carotid artery (RCCA) of 6 sheep (test group). As a control group, commercial expanded polytetrafluoroethylene (ePTFE) grafts were implanted into the RCCA of 6 sheep. After 4 weeks of follow-up, a histological study was performed to analyse the inflammation and hyperplasia of the vascular grafts.
Results
Statistically significant differences were observed in inflammation, which was higher in PVDF TEVGs than in ePTFE grafts. Although no statistically significant differences were observed in hyperplasia, histology showed that PVDF TEVGs exhibited less smooth muscle cell proliferation than ePTFE grafts.
Conclusion
Inflammation is a necessary process for tissue regeneration and was more pronounced in PVDF TEVGs. In contrast, hyperplasia causes a mismatch in elasticity, influencing the lack of vascular permeability. This issue was observed more severely in commercial ePTFE grafts. Thanks to the piezoelectric properties of PVDF, this material is able to mimic the dynamic electroactive microenvironment of cells and tissues, inducing specific cellular responses. However, further preclinical studies are required to understand the specific behaviour and interaction between the piezoelectricity of PVDF and cells.