Silk fibroin(SF) was used to enhance the biocompatibility of poly(3-hydroxybutyrate-co-3-hydroxylhexnoate)(PHBHHx) porous scaffold through surface-coating.The decrease in the water contact angle from 90° to 51° and the increase in the surface free energy from 37.9 mJ /m2to 57.4 mJ /m2on the basis of comparison of SF modified PHBHHx films with SF un-modified ones

respectively

demonstrated that SF was successfully anchored on the surface of PHBHHx

enhancing the PHBHHx hydrophilicity.In order to verify the influence of the modification on the cells growth

the human umbilical vein endothelial cells(HUVECs) were seeded on the SF /PHBHHx scaffolds with un-modified PHBHHx scaffolds as control.MTT assay quantitatively demonstrated that HUVECs adhered faster and proliferated better on the SF /PHBHHx porous scaffolds than on the un-modified PHBHHx scaffolds at day 3

5 and 7.The cell morphologies observed by SEM at day 5 indicated that HUVECs formed continuous cell monolayer on the SF /PHBHHx scaffolds

while they did not on the un-modified PHBHHx scaffolds.Also

the higher collagen content on the modified scaffolds demonstrated that more extracellular matrices(ECM) were secreted by HUVECs similar to the environment of the cell growing in vivo.Therefore

the SF-modified PHBHHx is potential to be applied into the cardiovascular tissue engineering.