BIO-HYBRID 3D TUBULAR SCAFFOLDS FOR VASCULAR TISSUE ENGINEERING—A MATERIALS PERSPECTIVE - Biomaterial Applications: Macro to Nanoscales - page 36

silk fibers with PEO nonextracted and extracted to visualize the silk scaf-
fold morphology [79].
Liu et al. have used the biocompatible properties of silk to improve
hemocompatibility and endothelialization of vascular graft made of PLGA
[80]. One of the biggest difficulties is to achieve a consistent endothelial
cell layer in the lumen. Loosely attached ECs will easily separate from the
lumen wall and washed away in vivo condition. Therefore, the sulfated
silk fibroins were prepared to improve antithrombogenicity and enhance
cytocompatibility of the scaffold made from silk fibroin. Liu et al. have
also electrospun sulfated silk nanofibers for vascular tissue engineering
application [81]. Sulfated silk fibers were created by standard electros-
pinning method using chlorosulfonic acid and pyridine. ECs and SMCs
seeded onto the scaffold in vitro condition indicated that the sulfated silk
fibroin has a better affinity for cell than pure silk fibroin [81].
FIGURE 2.7 SEM micrographs of electrospun silk fibroin scaffolds: (A) PEO
nonextracted scaffold; (B) PEO extracted scaffold. Scale bars are 2 µm. Reprinted from
Biomaterials Volume 29, Issue, Xiaohui Zhang, Cassandra B. Baughman, David L.
Kaplan, In vitro evaluation of electrospun silk fibroin scaffolds for vascular cell growth,
2217-2227, 2008, with permission from Elsevier.
In the human body ECM has a general defined arrangement of the pro-
tein fibers depending on the tissue type. Bowlin's group has fabricated
highly aligned and random electrospun PDO/silk and PCL/Silk fibroin
scaffold for vascular regeneration [82]. In order to achieve aligned and
random fibers of PDO/Silk and PCL/silk, the RPM of the mandrel were
ranged from 500 to 8000. Wang et al. have fabricated another electrospun