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Published on: November 28, 2015
Substrate pre-stretch reprograms macrophage behavior through surface topographical remodeling
Gang Yang1, Yi Han2, Tao Tang3
1Department of General Surgery, Affiliated Hospital of North Sichuan Medical College, National Clinical Key Specialty (General Surgery), Sichuan Branch of National Clinical Research Center for Digestive Diseases, Sichuan Clinical Research Center for Digestive Diseases, No. 63 Wenhua Road, Nanchong, 637000, PR China.
Mechanically preconditioned surfaces instruct macrophage behavior, altering cell shape, migration, and promoting a pro-inflammatory response. This reveals substrate mechanics as a key regulator in macrophage mechanoimmunology.
Area of Science:
- Biomaterials Science
- Immunology
- Cell Biology
Background:
- Mechanical forces significantly influence cell behavior, but the long-term biological effects of preconditioned surfaces are not fully understood.
- Macrophages are critical immune cells whose functions are sensitive to their microenvironment.
Purpose of the Study:
- To investigate if mechanically preconditioned polydimethylsiloxane (PDMS) surfaces can continuously direct macrophage behavior after mechanical loading ceases.
- To explore the impact of substrate mechanical properties on macrophage morphology, adhesion, migration, and inflammatory polarization.
Main Methods:
- Developed a uniaxial pre-stretch device to create PDMS membranes with defined tensile histories.
- Utilized atomic force microscopy to characterize surface topography changes.
- Cultured RAW264.7 macrophages on pre-stretched and control PDMS membranes.
- Assessed macrophage behavior including morphology, F-actin intensity, adhesion, migration, phagocytosis, reactive oxygen species generation, proliferation, and inflammatory marker expression (TNFα, IL-1β, Arg1, IL-10).
Main Results:
- Pre-stretching altered PDMS surface topography (reduced step height and roughness) without significantly changing elastic modulus or water contact angle.
- Macrophages on pre-stretched surfaces showed increased cell and nuclear spreading, enhanced adhesion, and improved migratory activity.
- Pre-stretched surfaces promoted phagocytosis and reactive oxygen species generation, and induced a pro-inflammatory phenotype (elevated TNFα and IL-1β expression and secretion).
Conclusions:
- Mechanically preconditioned PDMS surfaces act as instructive interfaces that modulate macrophage behavior, including morphology, motility, and inflammatory polarization.
- Substrate mechanics represent an underappreciated regulator of macrophage function and inflammatory responses.
- This study provides a valuable platform for biomaterials research, disease modeling, and drug screening in the context of macrophage mechanoimmunology.
