Tissue-Engineered Vascular Graft of Small Diameter Based on Electrospun Polylactide Microfibers

Guriy Popov ¹, Valeriy Vavilov ¹, Pavel Popryadukhin ², Irina Dobrovolskaya ², Elena Ivan’kova ³, Vladimir Yudin ³, Galina Yukina ¹

¹ First Pavlov State Medical University of Saint-Petersburg, Saint-Petersburg, Russia; ² Institute of Macromolecular Compounds, Russian Academy of Sciences, Saint-Petersburg, Russia; ³ Peter the Great Saint-Petersburg State Polytechnical University, Saint-Petersburg, Russia;

Date, time and location: 2018.05.26 13:30, Exhibition area, 1st Floor. Zone – B

Abstract

Tubular vascular grafts 1.1 mm in diameter based on poly(L-lactide) microfibers were obtained by electrospinning. X-ray diffraction and scanning electron microscopy data demonstrated that the samples treated at T = 70 ∘ C for 1 h in the fixed state on a cylindrical mandrel possessed dense fibrous structure; their degree of crystallinity was approximately 44%. Strength and deformation stability of these samples were higher than those of the native blood vessels; thus, it was possible to use them in tissue engineering as bioresorbable vascular grafts.

The experiments on including implantation into rat abdominal aorta demonstrated that the obtained vascular grafts did not cause pathological reactions in the rats; in four weeks, inner side of the grafts became completely covered with endothelial cells, and fibroblasts grew throughout the wall. After exposure for 12 weeks, resorption of PLLA fibers started, and this process was completed in 64 weeks. Resorbed synthetic fibers were replaced by collagen and fibroblasts. At that time, the blood vessel was formed; its neointima and neoadventitia were close to those of the native vessel in structure and composition.

One can conclude from the obtained results that PLLA grafts produced by electrospinning are promising for clinical uses, although some methods for strengthening walls of the newly formed blood vessels should be developed.

The authors are grateful to the Russian Science Foundation for financial support (Grant no. 14-33-00003).