[Fabrication of tissue engineered vein containing valve scaffolds].

OBJECTIVE: To fabricate porous biodegradable tissue engineered vein containing valve scaffolds. METHODS: Based on the self-made cast, the tissue engineered vein containing valve scaffolds was fabricated by injection molding plus thermally induced phase separation. Poly (lactic-co-glycolic acid) (PLGA, LA/GA mole ratio 75:25) was used as matrices. Morphological structures and biocompatibility of scaffolds were tested. Cell seeding on scaffold was performed and the mechanic characteristics of cellular constructs evaluated. RESULTS: The scaffold had an inner diameter of 9 mm with a wall thickness of 0.9 mm and the thickness of valves was (0.32 ± 0.04) mm. Scanning electron microscopic (SEM) micrographs showed regular ladder-like porous structures and the average pore size and porosity of scaffolds were 10 - 20 µm and 90%. The PLGA scaffolds were biocompatible. The cellular constructs were tested in vitro, and the valve leaflets were functionally capable of opening and closing when stimulated. CONCLUSION: Based on the self-made cast, the tissue engineered vein containing valve scaffolds can be fabricated by injection molding plus thermally induced phase separation. Further researches are warranted.

Intensive statin therapy: a favorable adjunct to the improvement of small-diameter vascular grafts.

To assess the effect of intensive statins therapy on the outcome of small-diameter vascular prosthesis, we investigated whether atorvastatin treatment (30 mg/d) could accelerate the re-endothelialization process and improve the patency rate in a canine infrarenal abdominal aorta-expanded polytetrafluoroethylene (ePTFE) bypass model. Furthermore, we also evaluated the effect of atorvastatin on the migratory and adherent capacity of circulating endothelial progenitor cells (EPCs) in vitro. Improved patency was confirmed by Doppler sonography and arteriography. Histological and scanning electron microscopy illustrated enhanced re-endothelialization process. Treatment with atorvastatin enhanced the circulating pool of EPCs with fortified migratory and adherent capacity. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that atorvastatin treatment increased endothelial nitric oxide synthase (eNOS) and kinase insert domain receptor (KDR) messenger RNA (mRNA) expression in cultured EPCs and neointima. In conclusion, intensive statin therapy could be considered a favorable option to improve small-diameter vascular graft patency.