Original articleAdult cardiacNovel Bioresorbable Vascular Graft With Sponge-Type Scaffold as a Small-Diameter Arterial Graft
Section snippets
Preparation for Bioresorbable Vascular Grafts
The grafts were constructed by pouring a solution of 50:50 PLCL into a glass tube, then freeze-drying under a vacuum as previously described [11]. The pore size was adjusted to obtain two different scaffold groups: small (12.8 ± 1.85 μm) and large (28.5 ± 5.25 μm; Fig 1). Next, these scaffolds were reinforced by electrospinning PLA nanofiber (40-μm thickness) to the outer side of the PLCL scaffold. Inner luminal diameters of each graft were approximately 600 μm.
Animal Model and Surgical Implantation
All animals received humane care
Animal Survival
Fifteen grafts for each group were implanted as infrarenal interposition aortic conduits. All mice in the small-pore group survived the 8-week implantation period with patent grafts. There were no complications, such as bleeding, acute thrombosis, aneurysmal change, or graft rupture (8 weeks), in the small-pore group. However, in the large-pore group, 2 mice were euthanized due to lower limb paralysis from acute thrombosis, and 1 mouse died of undetermined causes (the graft that was explanted
Comment
On the basis of current advances of our clinical trial using a bioresorbable vascular graft in a high-flow, low-pressure venous circulation, we demonstrated that a porous sponge-type scaffold has potential to be applied as a small-diameter vascular graft used in a high-flow and high-pressure arterial system. In this study, we applied an electrospinning technique to the outer layer of the graft to endure arterial pressures and prevent blood leakage from the scaffold [15]. This bilayered approach
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Peritoneal pre-conditioning impacts long-term vascular graft patency and remodeling
2023, Biomaterials AdvancesA bioactive compliant vascular graft modulates macrophage polarization and maintains patency with robust vascular remodeling
2023, Bioactive MaterialsCitation Excerpt :The synthetic graft scaffold appears intact, with no visible signs of erosion, as expected from our DPY-PU materials, which demonstrate slow in vitro degradation, similar to the degradation profile of unmodified PCL [18]. Cellular infiltration was observed within the pores of the graft walls, with the deposition of intramural tissues resembling that of similarly slowly degrading synthetic vascular grafts [46–48]. In places, the cellular infiltration appeared inconsistent, with regions of little to no cellular ingrowth visible after 4 months, perhaps indicating excessive tortuosity or small windows connecting the larger pores, which is not uncommon in salt-leached porous scaffolds [5].
Engineered tissue vascular grafts: Are we there yet?
2022, Applications in Engineering ScienceCitation Excerpt :These investigations focus on several features of their method on diverse measurable aspects of the in vivo response to vascular grafting (Fukunishi et al., 2020). Examples of such are the choice of different scaffold materials, e.g., small diameter sponge-type scaffolds suitable for arterial bypasses made of PLA-PCL reinforced with PLLA (Kurobe et al., 2015; Sugiura et al., 2016) or scaffolds with a compliant inner core of poly(glycerol sebacate) with a stiffer sheath of PCL (Wu et al., 2021), or the effects of different braiding patterns (Zbinden et al., 2020), pore sizes (Matsuzaki et al., 2020), degradation rates/profiles (Fukunishi et al., 2020), or even bulk dimensions of the ETVGs themselves (Best et al., 2018). Two typical problems persist and remain to be solved – acute occlusion due to thrombosis when diameters are small and the grafts are deployed as an arterial bypass, or mid-to-late term stenosis when serving as cavopulmonary graft possibly due to insufficient mechanical support of the degrading scaffold and/or chronic fibrotic encapsulation triggered by the inflammatory FBR.
Tissue-engineered vascular grafts and regeneration mechanisms
2022, Journal of Molecular and Cellular CardiologyCitation Excerpt :Then, the grafts were reinforced by electrospinning a layer of PLA onto the exterior. The grafts were patent and had a layer of endothelial cells followed by smooth muscle cells without aneurysmal dilatation when implanted at the infrarenal aorta of female mice for 8 weeks [55]. Yokota T et al. combined a collagen microsponge with a biodegradable double-layer tube made of polyglycolic acid (core) and poly-L-lactic acid (sheath) fibers by freeze-drying.
Biocompatible Synthetic Polymers for Tissue Engineering Purposes
2022, BiomacromoleculesCCL2 loaded microparticles promote acute patency in silk-based vascular grafts implanted in rat aortae
2021, Acta BiomaterialiaCitation Excerpt :In response to the pressing need for a more suitable arterial graft, our laboratory and others have explored various tissue-engineered vascular graft (TEVG) solutions [8–13]. The success of TEVGs is reliant on a suitable scaffold [14–17] combined with an appropriate cell type or other payload [11,13,18–20]. The biocompatibility of silk, the tunability of its properties, and the nontoxic nature of its degradation byproducts make it a promising scaffold option in vascular tissue engineering [16,20–24].
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Drs Sugiura and Tara contributed equally to this work.