In situ measurement of native extracellular matrix strain

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Developmental Biology

Background:

• Cells interact with the extracellular matrix (ECM), but its mechanical properties at the cellular scale are not well understood.
• Understanding ECM mechanics is crucial for designing biomaterials that support cell function.

Purpose of the Study:

• To develop and validate a method for quantifying 3D in situ extracellular matrix (ECM) network strain.
• To investigate how ECM mechanical properties vary across different tissue types in developing murine embryos.

Main Methods:

• Utilized embryonic day 14.5 murine forelimbs, employing a novel decellularization technique within a hydrogel to preserve ECM architecture.
• Visualized ECM networks using fibrillin-2 and proteoglycan staining, followed by confocal microscopy.
• Applied a MATLAB-based digital volume correlation algorithm to quantify strain fields before and after static loading.

Main Results:

• Successfully quantified in situ ECM network strain in a 3D native environment.
• Observed significant differences in Green-Lagrange strain experienced by ECM components between cartilage and adjacent connective tissues.
• Demonstrated the feasibility of combining experimental and computational approaches to analyze ECM mechanics.

Conclusions:

• The developed method allows for the characterization of ECM mechanical behavior at the microscale.
• Findings provide essential data for developing constitutive equations describing ECM material properties.
• This research offers mechanical guidelines for engineering physiologically relevant scaffolds to enhance cell-ECM interactions.