How aging impacts skin biomechanics: a multiscale study in mice

Area of Science:

• Biomedical Engineering
• Dermatology
• Materials Science

Background:

• Skin aging is characterized by significant alterations in mechanical properties.
• Understanding the relationship between dermal microstructure and mechanical behavior is crucial for anti-aging research.

Purpose of the Study:

• To investigate the link between age-related changes in dermal mechanical behavior and microstructure.
• To analyze the reorganization of dermal collagen during mechanical stress in aging skin.

Main Methods:

• Utilized multiphoton microscopy for real-time monitoring of dermal collagen.
• Performed mechanical traction assays on ex vivo skin from young and old mice.
• Analyzed mechanical and microstructural parameters using a multiscale mechanical framework.

Main Results:

• Old murine skin exhibited increased tangent modulus and a lengthened heel region.
• These changes are attributed to increased collagen cross-linking and water loss from proteoglycan deterioration.
• Microstructure reorganization during stretching showed no age-related differences, suggesting counteracting effects of collagen content and cross-linking.

Conclusions:

• Age-related changes in skin mechanical behavior are primarily driven by collagen fiber alterations and water content.
• Increased collagen cross-linking and proteoglycan-mediated water loss are key factors in reduced skin elasticity.
• While mechanical properties change with age, the fundamental microstructural reorganization patterns during stretching remain consistent.