Steering cell orientation through light-based spatiotemporal modulation of the mechanical environment

Area of Science:

• Biomaterials Science
• Mechanobiology
• Tissue Engineering

Background:

• Anisotropic organization of cells and extracellular matrix (ECM) is vital for tissue function, especially in the myocardium.
• This organization is altered during diseases like myocardial infarction, with mechanical stimuli playing a key role in its regulation.
• Current understanding of the underlying mechanobiological mechanisms controlling tissue organization is limited.

Purpose of the Study:

• To develop advanced in vitro model systems for spatiotemporally controlling multiscale mechanical environments.
• To investigate the mechanobiological mechanisms governing cell and ECM orientation using these novel systems.
• To study the effects of stiffness anisotropies on cardiac fibroblast (cFBs) and ECM alignment.

Main Methods:

• Fabrication of 2D and 3D in vitro models using light-sensitive materials and illumination techniques.
• Creation of spatiotemporally resolved stiffness anisotropies at both cellular (micron) and tissue (millimeter) scales.
• Introduction of stiffness anisotropies at defined timepoints post-cell seeding to assess temporal effects.

Main Results:

• 2D stiffness micropatterns induced anisotropic alignment of cardiac fibroblasts (cFBs), dependent on micropattern spacing but not stimulus timing.
• 3D stiffness macropatterns also promoted organized cFB alignment, influenced by stimulus timing.
• In 3D models, cFB alignment was temporally followed by slower extracellular matrix (ECM) co-alignment.

Conclusions:

• The developed model systems enable a deeper understanding of mechanobiological factors influencing cell and ECM orientation.
• Stiffness guidance and boundary constraints are identified as key factors steering tissue organization.
• These models provide a platform for studying tissue remodeling and mechanobiology in health and disease.