April 20, 2020 by admin 0 Comments

ECM-based microchannel for culturing in vitro vascular tissues with simultaneous perfusion and stretch

Authors
Azusa Shimizu a, Wei Huang Goh b, Shun Itai a, Michinao Hashimoto b,c, Shigenori Miura d, and Hiroaki Onoe *,a,e
Abstract
We present an extracellular matrix (ECM)-based stretchable microfluidic system for culturing in vitro three-dimensional (3D) vascular tissues, which mimics in vivo blood vessels. Human umbilical vein endothelial cells (HUVECs) can be cultured under perfusion and stretch simultaneously with real-time imaging by our proposed system. Our ECM (transglutaminase (TG) cross-linked gelatin)-based microchannel was fabricated by dissolving water-soluble sacrificial polyvinyl alcohol (PVA) molds printed with a 3D printer. Flows in the microchannel were analyzed under perfusion and stretch. We demonstrated simultaneous perfusion and stretch of TG gelatin-based microchannels culturing HUVECs. We suggest that our TG gelatin-based stretchable microfluidic system proves to be a useful tool for understanding the mechanisms of vascular tissue formation and mechanotransduction.

April 10, 2020 by admin 0 Comments

Structurally Reinforced Biodegradable Antithrombotic Small-Caliber Vascular Grafts Immobilized with VEGF to Accelerate Endothelialization: When 3D Printing Meets Electrospun Fiber

Authors
Gladys A. Emechebe, Francis O. Obiweluozor, In Seok Jeong, Park June Kyu, Chan Hee Park, Cheol Sang Kim
Abstract
The major challenge of commercially available vascular substitutes come from their limitations in terms of good mechanical strength and host remodeling. To date, tissue-engineered and synthetic grafts have not translated well to clinical trials when looking at small diameters. We conceptualized a cell-free structurally reinforced biodegradable vascular graft recapitulating the anisotropic feature of native blood vessel by using nanofibrous scaffold that will gradually degrade systematically to yield a neo-vessel, facilitated by an immobilized bioactive molecule-vascular endothelial growth factor (VEGF). The nanotopographic cue of the device is capable to directs host cell infiltration. We evaluated the burst pressure, Histology, hemocompatibility, compression test and mechanical analysis of the new graft. Hence, we proposed that future long-term studies of this technology on porcine models due to their similar vasculature regeneration to humans is needed prior to clinical translation. This acellular off-the-shelf approach will mark a paradigm shift from the current dominant focus on cell incorporation in vascular tissue engineering thus strongly influencing regenerative medicine as we move forward in this new decade.