The evolution of collagen fiber orientation in engineered cardiovascular tissues visualized by diffusion tensor...

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Cardiovascular Research

Background:

• Collagen architecture is crucial for cardiovascular tissue function and mechanical properties.
• Understanding collagen orientation is essential for engineering load-bearing cardiovascular tissues.
• Existing imaging methods for collagen in tissue-engineered constructs have limitations in depth or complexity.

Purpose of the Study:

• To explore Diffusion Tensor Imaging (DTI) as a reliable method for visualizing collagen orientation in tissue-engineered (TE) constructs.
• To investigate the evolution of collagen orientation over time in TE constructs.
• To compare collagen orientation in high and low aspect ratio TE constructs.

Main Methods:

• Tissue-engineered (TE) strips were cultured under uniaxial constraint for up to 6 weeks.
• Diffusion Tensor Imaging (DTI) was used to visualize collagen arrangement.
• Confocal Laser Scanning Microscopy (CLSM) served as a validation technique.

Main Results:

• DTI and CLSM showed similar collagen fiber orientation patterns.
• High aspect ratio TE constructs exhibited collagen fibers aligned with the constraint direction.
• Low aspect ratio TE constructs displayed collagen fibers oriented obliquely, shifting towards oblique with extended culture time.

Conclusions:

• Diffusion Tensor Imaging (DTI) is a fast, non-destructive, and reliable tool for studying collagen orientation in TE constructs.
• DTI can effectively capture changes in collagen orientation influenced by construct geometry and culture duration.
• This imaging approach aids in understanding and optimizing the development of functional cardiovascular tissues.