[Investigation of the surface layer of 3D-matrices for tissue engineering]. / Issledovanie poverkhnostnogo sloia 3D-matriksov dlia tkanevoi inzhenerii.

Electrospinning is a convenient and promising manufacturing method a variety of materials for tissue engineering. 3D matrices fabricated by electrospinning from solutions of polycaprolactone with human serum albumin or gelatin in 1,1,1,3,3,3-hexafluoroisopropanol were studied. The microstructure of the 3D matrices and surface of the fibers were investigated using scanning electron microscopy. Protein distribution in the surface layer was studied by modification of protein amino groups with N-(2-hydroxyethyl)phenazine and X-ray photoelectron spectroscopy. It was shown, that concentration of the proteins in the surface layer of fibers exceeded their concentration in the initial electrospun solution up to 12 times and the surface layer was enriched in the protein inversely to the concentration of the protein in solution. The minor part of the proteins was released from fibers during first 30-60 min after swelling in water. Treatment of matrices with proteinase K hydrolyzed about 1/3 of the surface exposed human serum albumin. Thus, both methods can be used to study the surface content of the materials produced by electrospinning from blends of synthetic and natural polymers, however X-ray photoelectron spectroscopy appears to be more convenient and informative.

[Study of patency of vascular grafts manufactured by means of electrospinning].

UNLABELLED: In vivo experiments were carried out to study functioning of vascular grafts manufactured by means of electrospinning from solutions of polycaprolactone (PCL) and hexafluoroisopropanol (HFIP), PCL with 10% gelatine and a low-permeability inner layer (LPIL) 10 µm thick and PCL with 10% gelatine and LPIL (10 µm) wherein as polymeric base instead of PCL copolymer of lactic and hydroxyacetic acids (polylactide-co-glycolide, PLGA) was used. The grafts were implanted into the infrarenal portion of the aorta to 45 rats, 15 rats for each type of the graft. Patency of artificial vessels was assessed by means of magnetic resonance tomography and diagnostic ultrasound Dopplerography at 2, 4 and 20 weeks (5 animals for each time point). The state of the graft and surrounding tissues was analysed by means of intraoperative assessment, survey microscopy and survey fluorescent microscopy. CONCLUSION: The obtained findings demonstrated that vascular grafts made by electrospinning technique with a low-permeability inner layer are less prone to formation of the neointima and stenosing as compared with grafts having no such layer.