In order to find an appropriate scaffold for the tissue engineered heart valve, the poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHH_x), a biodegradable material with a good stress-strain mechanical property, was utilized as a porous scaffold material. But its biocompatibility is not good enough. To improve its biocompatibility, the silk fibroin (SF) was applied to modify the PHBHH_x scaffold, and the human smooth muscle cells were seeded on the scaffold in vitro for the demonstration. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay was used to test the cell growths and to evaluate the biocompatibility of the scaffold. SEM was used to observe the cell morphologies. The results reveal that the human smooth muscle cells grow better on the silk fibroin modified hybrid scaffold. It proves that the silk fibroin modification can improve the biocompatibility of the PHBHH_x scaffold. The silk fibroin modified hybrid PHBHH_x scaffold can be potentially used for the heart valve tissue engineering for further research.

Key words: heart valve tissue engineering, porous scaffold, silk fibroin, polyhydroxyalkanoate, human smooth muscle cell