Collagen Microfibers Induce Blood Capillary Orientation and Open Vascular Lumen

• Published in: Advanced biosystems 2020-05, Vol.4 (5), p.e2000038-n/a
• Main Authors: Liu, Hao, Kitano, Shiro, Irie, Shinji, Levato, Riccardo, Matsusaki, Michiya
• Format: Article
• Language: English
• Subjects: blood capillary; capillary orientation; collagen microfibers; vascular lumen
• ISSN: 2366-7478; 2366-7478
• DOI: 10.1002/adbi.202000038

Achieving vascularization of engineered tissues or structures is a major challenge in the field of tissue engineering. Hitherto, studies on vascularization have demonstrated limited control of vascular network geometry, such as vasculature direction and network density. An open vascular lumen is crucial to ensure that cells survive and that metabolic activity is fully functional in large‐sized tissues. Herein, a method based on high water‐dispersible collagen microfibers (CMF) to fabricate capillary orientation‐controllable 3D tissue with an open vascular lumen using a dispensing machine is reported. A twenty micrometers‐long CMF (CMF‐20) with high dispersion property are shown to be more effective for dispensing a homogenous tissue and inducing formation of an interconnected capillary network than two hundred micrometers‐long CMF (CMF‐200). One of the advantages is the prevention of shrinkage on the z‐axis of hydrogel‐based tissue which acts as a microscaffold. The gaps between the fibers can support endothelial cell migration and maturation, thus forming a larger vascular lumen compared to CMF‐free controls. Besides, shear forces produced by the dispensing process cause the collagen microfibers to align, and these microfibers guide cell alignment by integrin‐induced adhesion. The findings based on CMF to allow blood capillary alignment and vascular lumen stabilization will be an important technology in tissue engineering. A method based on high water‐dispersible collagen microfibers (CMF‐20) is demonstrated to fabricate 3D blood capillary tissues, which provides a homogenous tissue structure. The CMF‐20 acts as a microscaffold to support endothelial cell migration and maturation, thus forming a vascular lumen. The aligned CMF‐20 is produced by the shear force, guiding the formation of an oriented capillary network.