Development of tissue‐engineered self‐expandable aortic stent grafts (Bio stent grafts) using in‐body tissue architecture technology in beagles

Abstract

In this study, we aimed to describe the development of tissue-engineered self-expandable aortic stent grafts (Bio stent graft) using in-body tissue architecture technology in beagles and to determine its mechanical and histological properties. The preparation mold was assembled by insertion of an acryl rod (outer diameter, 8.6 mm; length, 40 mm) into a self-expanding nitinol stent (internal diameter, 9.0 mm; length, 35 mm). The molds (n = 6) were embedded into the subcutaneous pouches of three beagles for 4 weeks. After harvesting and removing each rod, the excessive fragile tissue connected around the molds was trimmed, and thus tubular autologous connective tissues with the stent were obtained for use as Bio stent grafts (outer diameter, approximately 9.3 mm in all molds). The stent strut was completely surrounded by the dense collagenous membrane (thickness, ∼150 µm). The Bio stent graft luminal surface was extremely flat and smooth. The graft wall of the Bio stent graft possessed an elastic modulus that was almost two times higher than that of the native beagle abdominal aorta. This Bio stent graft is expected to exhibit excellent biocompatibility after being implanted in the aorta, which may reduce the risk of type 1 endoleaks or migration.

Implantation study of a tissue-engineered self-expanding aortic stent graft (bio stent graft) in a beagle model

“…As we reported previously, the elastic modulus of the walls of the BSG was approximately twice as high as that of the beagle abdominal aorta [10]. Regarding the durability of in vivo tissue-engineered cardiovascular materials, Watanabe et al [17] described the thickness and tensile strength of an in-body tissue-engineered graft (biotube) b Fig.…”

“…BSGs were prepared as described previously [10]. Briefly, the molds for the preparation of BSGs were assembled with cylindrical acryl rods (outer diameter 8.6 mm, length 40 mm), produced using a three-dimensional printer (ProJet HD 3000; 3D Systems; Rock Hill, SC, USA), and self-expanding nitinol metal stents (Luminexx: diameter 6.0 mm, length 36 mm; BARD: Karlsruhe, Germany; adjusted to an internal diameter of 9.0 mm by Piolax Medical Devices; Yokohama, Japan).…”

“…Recently, we developed a self-expanding stent graft covered with autologous connective membranous tissues (bio stent graft; BSG) using in-body tissue architecture technology [10]. The connection between the stent and the tissue was extremely robust.…”

Endovascular Management of Abdominal Aortic Aneurysms: the Year in Review

“…These may address some of the challenges associated with current stent-grafts, and likely will not cause any significant inflammatory response. [68]. The combination of this technology with 3-D printing may represent an important future therapy for AAA.…”

Limiting factors of current thoracic aortic endovascular technologies

“…Sustained-release antibioticimpregnated device technologies are being developed but have as yet unproven efficacy. Alternatively, tissueengineered technologies that incorporate human cells and subsequent matrix deposition within a biodegradable scaffold may ultimately be feasible and offer a better biocompatibility and infection resistance than non-biodegradable materials like polyester or polytetrafluoroethylene (9).…”