The Effect of Mechanical Loading on Sprouting Angiogenesis from Engineered Macro-vessel Model

Area of Science:

• Biomechanics
• Tissue Engineering
• Angiogenesis

Background:

• Mechanical signals are crucial for sprouting angiogenesis.
• Understanding these signals is vital for tissue engineering and biomechanics applications.
• Existing models lack precise mechanical loading control for studying angiogenesis.

Purpose of the Study:

• To develop and utilize a novel experimental setup to investigate the impact of mechanical loading on angiogenic sprouting in an engineered macro-vessel model.
• To characterize strain distribution within the model under different loading conditions.
• To correlate mechanical stimuli with angiogenic responses.

Main Methods:

• An engineered macro-vessel embedded in a polydimethylsiloxane (PDMS) stretchable device within a collagen matrix was subjected to longitudinal and lateral mechanical loading.
• Finite element analysis (FEA) was employed to map strain distribution.
• Angiogenic sprouting and capillary orientation were quantified experimentally.

Main Results:

• Longitudinal loading induced high, uniform strain around the vessel, resulting in sprouting inhibition.
• Lateral loading produced low horizontal and high vertical strain, leading to increased sprouting and capillary alignment with the stretch direction.
• Matrix fiber organization followed the direction of applied strain.

Conclusions:

• Mechanical loading directionality critically regulates angiogenic sprouting in engineered vascular networks.
• The developed model provides a platform for predicting and controlling vascular architecture through physical means.
• This approach is adaptable for studying cell behavior in various physiological tubular models under mechanical stress.