ORIGINAL ARTICLE  VASCULAR SECTION 

The Journal of Cardiovascular Surgery 2020 April;61(2):208-13

DOI: 10.23736/S0021-9509.19.10594-0

Copyright © 2019 EDIZIONI MINERVA MEDICA

lingua: Inglese

Shape memory of in-body tissue-engineered Biotube® vascular grafts and the preliminary evaluation in animal implantation experiments

Yasuhide NAKAYAMA ¹ ✉, Maya FURUKOSHI ², Eisuke TATSUMI ³

¹ Biotube Co., Ltd., Tokyo, Japan; ² Division of Cell Engineering, Graduate School of Chemical Science and Engineering, Hokkaido University, Sapporo, Hokkaido, Japan; ³ Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan

BACKGROUND: Tissues formed by in-body tissue architecture (iBTA) are soft and flexible. However, strongly bending iBTA-induced vascular grafts, called biotubes, may cause lumen collapse by kinking, subsequently leading to occlusion after implantation. In this study, we developed a method for biotube shape memory and verified its performance in preliminary animal implantation experiments.
METHODS: Straight biotubes were prepared by subcutaneous embedding of straight molds into beagle dogs for two months. Upon overnight immersion of the obtained straight biotubes in a 70% ethanol solution under U-shape framing, the biotubes maintained their U shape even after washing with saline solution. Additionally, spiral-shaped biotubes formed from goats using spiral molds could be stretched straight via the same alcohol treatment.
RESULTS: Within limited acute-phase animal implantation experiments, U-shaped biotubes functioned as AV shunt grafts in the femoral region of the beagle without deformation of vascular shape (N.=11). In addition, the long straight biotubes derived from spiral molds could be interposed between goat carotid arteries while maintaining their straight shape (N.=2). All implants maintained perfect patency at the 1-month follow-up period without any evidence of vascular deformation.
CONCLUSIONS: By retaining iBTA-induced tissues in an alcohol solution in the target shape, the shape of the tissues was imprinted and maintained even after implantation within a limited acute period. Therefore, in order to obtain tissues of various shapes, it is unnecessary to use a mold design to maintain the individual shape.

KEY WORDS: Vascular grafting; Smart materials; Tissue engineering