Constitutive models for a poly(e-caprolactone) scaffold.

Area of Science:

• Biomaterials Science
• Polymer Engineering
• Computational Mechanics

Background:

• Porous polymeric scaffolds are essential for bone tissue engineering and regeneration.
• Poly(e-caprolactone) (PCL) and poly(ethylene oxide) (PEO) are commonly used biodegradable polymers for scaffold fabrication.
• Accurate material models are needed to predict scaffold mechanical behavior for design and analysis.

Purpose of the Study:

• To develop and evaluate material models for porous PCL/PEO bone scaffolds.
• To establish relationships between scaffold microstructure and bulk mechanical properties.
• To provide tools for designers for quasi-static analysis and quality control of scaffolds.

Main Methods:

• Fabrication of porous scaffolds via co-extrusion of PCL and PEO, followed by PEO removal.
• Compressive testing to obtain stress-strain data.
• Fitting experimental data with a hyperbolic phenomenological model.
• Development of a microstructural finite element model using micrographs.
• Calculation of elastic constants using Hooke's law.

Main Results:

• A hyperbolic material model was developed for quasi-static analysis of PCL/PEO scaffolds.
• The secant modulus at 10% strain provided a reliable measure for quality control.
• The microstructural finite element model accurately predicted the small strain Young's modulus within one standard deviation.
• Scaffold bulk properties can be predicted from constituent material properties and microstructure.

Conclusions:

• The developed material models are valuable for predicting the mechanical performance of porous bone scaffolds.
• Microstructure-based modeling offers a powerful approach to understand and design scaffolds with desired properties.
• These findings facilitate the use of PCL/PEO scaffolds in bone regeneration applications.