The expression of cross-linked elastin by rabbit blood vessel smooth muscle cells cultured in polyhydroxyalkanoate scaffolds

In order to evaluate the possibility for making artificial blood vessels, a series of microbial copolyesters poly(3-hydroxybutyrate-co-4-hydroxybutyrate)s (P3HB4HB)s containing 0–40 mol% 4-hydroxybutyrate (4HB) were studied for growth and formation of elastin of rabbit blood vessel smooth muscle cells (RaSMCs) incubated on the solvent-casting polyester films. Porous scaffolds of all P3HB4HBs except P(HB-40 mol% 4HB) were used to compare their potentials as materials for tissue engineering blood vessel (TEBV). The polyesters were studied using static contact angles, differential scanning calorimetry (DSC), cell count kit-8 (CCK-8) and Fastin elastin assays. Simultaneously, SEM, H&E and DAPI staining were employed to study cell morphology and cell growth in the polyester scaffolds. Viability of rabbit blood vessel smooth muscle cells (RaSMCs) grown on P(HB-7 mol% 4HB) films was the strongest among all other tested polyester films during the whole growth process. H&E and DAPI staining clearly suggested good cells' growth and even confluent growth in the P3HB4HB scaffolds. Fastin elastin assay demonstrated that 4HB component in the P3HB4HB copolymer benefited the elastin formation and accumulation. P(HB-20 mol% 4HB) showed a 160% more elastin production compared with that on the well-studied poly(3-hydroxybutyrate-co-12 mol% 3-hydroxyhexanoate) (PHBHHx) incubated under the same conditions. Since the P3HB4HB has adjustable elasticity and strength, combined with its ability to induce elastin formation, it can be regarded as a useful material for developing into a material for artificial blood vessels.