Regression and persistence: remodelling in a tissue engineered axial vascular assembly

Area of Science:

• Biomedical Engineering
• Vascular Biology
• Tissue Engineering

Background:

• Vascular networks undergo significant remodeling during later stages of vasculoangiogenesis.
• This remodeling optimizes perfusion and energy efficiency.
• Understanding neovascular maturation is crucial for tissue engineering and regenerative medicine.

Purpose of the Study:

• To quantitatively assess remodeling phenomena in a bioartificial neovascular network.
• To propose variance of caliber as a novel parameter for neovascular maturation.
• To investigate the temporal changes in vascular network characteristics.

Main Methods:

• Utilized an AV loop operation in Lewis rats combined with a biogenic matrix and isolation chamber.
• Animals were grouped for explantation at 2, 4, and 8 weeks.
• Evaluated vascular density, fractional area, and variance of caliber within a region of interest (ROI) using quantitative analysis and scanning electron microscopy.

Main Results:

• Vessel number decreased significantly after week 4 (P < 0.03), while fractional area increased (P < 0.02).
• Variance in caliber significantly increased in the 8-week group (P < 0.05).
• Identified lymphatic growth, pericyte migration, and intussusceptive angiogenesis immunohistologically post-week 4.

Conclusions:

• Remodeling phenomena in neovascular networks can be quantitatively evaluated.
• Variance of caliber is a potential parameter for assessing net vascular maturation.
• The study provides insights into the dynamic changes and maturation processes of engineered vascular networks.