Pre-vascularization of in vitro three-dimensional tissues created by cell sheet engineering

Area of Science:

• Tissue Engineering
• Biomaterials Science
• Cell Biology

Background:

• Vascular network reconstruction is crucial for 3-D tissue engineering.
• Co-culturing endothelial cells (ECs) with stratified tissues promotes vascularization.
• Understanding EC behavior within 3-D constructs is essential for effective tissue fabrication.

Purpose of the Study:

• To investigate how tissue fabrication processes influence pre-vascular network formation.
• To compare the behavior of human endothelial cells (HUVECs) in different positions within stratified tissues.
• To determine the critical factors for successful vascular network development in engineered tissues.

Main Methods:

• Human umbilical vein endothelial cells (HUVECs) and normal human dermal fibroblasts (NHDFs) were cultured as cell sheets.
• Cell sheets were harvested from temperature-responsive dishes at low temperatures.
• Triple-layered constructs were assembled by stacking HUVEC and NHDF cell sheets in various orders using a cell sheet collecting device.

Main Results:

• Pre-vascular networks composed of HUVECs were successfully formed in all triple-layer constructs.
• Confocal microscopy revealed that these networks formed tube-like structures resembling native microvasculature.
• The positioning of endothelial cells within the 3-D tissue appeared to be a critical factor in vascular network formation.

Conclusions:

• The spatial arrangement of endothelial cells during tissue fabrication is vital for constructing functional vascular networks.
• This research provides insights into optimizing cell sheet layering techniques for enhanced vascularization in tissue engineering.
• Further studies can leverage these findings to improve the vascularization of engineered tissues for transplantation.