Modeling and Optimization of Nonlinear Viscoelastic Behavior for Tissue-Engineered Blood Vessels

Area of Science:

• Biomaterials Science
• Mechanical Engineering
• Tissue Engineering

Background:

• Vascular tissue engineering relies on tubular viscoelastic materials to transmit mechanical stimuli for vascular graft development.
• Existing elastic models fail to capture the time-dependent nature of viscoelastic materials, limiting their application in tissue engineering.
• Challenges in tissue engineering include long fabrication cycles, high costs, and complex parameter measurements, necessitating improved modeling approaches.

Purpose of the Study:

• To develop a viscoelastic mechanical model that combines physical interpretability, computational efficiency, and predictive accuracy for vascular grafts.
• To address the predictive deviations of conventional models in nonlinear viscoelastic scenarios using an error-corrected approach.
• To establish a unified and scalable framework for predicting and optimizing the mechanical performance of tissue-engineered vessels.

Main Methods:

• Proposed an error-corrected linear solid (ECLS) model with an embedded correction term for improved predictive performance.
• Conducted stress relaxation and creep tests on silicone rubber, polyurethane, and polytetrafluoroethylene to gather time-resolved response data.
• Quantitatively evaluated fitting performance using Euclidean norm and Akaike information criterion for systematic comparison with Kelvin-Voigt, Maxwell, and standard linear solid (SLS) models.

Main Results:

• The ECLS model demonstrated higher predictive accuracy across a wide time range, achieving an average goodness of fit (R²) of 0.99.
• ECLS model showed approximately 6% improvement in fit compared to the SLS model.
• Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) for the ECLS model were at least one order of magnitude lower than traditional models, significantly improving nonlinear viscoelastic behavior description.

Conclusions:

• The ECLS model significantly enhances the accuracy of modeling viscoelastic behavior in materials relevant to vascular tissue engineering.
• The developed model provides a unified and scalable framework for predicting and optimizing the mechanical performance of tissue-engineered vessels.
• The ECLS model expands the application potential of mechanical modeling in bioreactor design and biomaterials development for improved vascular graft outcomes.