A Novel In Vitro Wound Healing Assay Using Free-Standing, Ultra-Thin PDMS Membranes

Area of Science:

• Polymer Science
• Biomedical Engineering
• Cell Biology

Background:

• Polymer science advancements enable new life science applications.
• Polydimethylsiloxane (PDMS) membranes offer unique properties for biological studies.
• In vitro models are crucial for understanding complex biological processes like wound healing.

Purpose of the Study:

• To evaluate ultra-thin PDMS membranes (CellDrums) as substrates for an in vitro wound model.
• To investigate the effects of mechanical strain and donor age on dermal fibroblast wound closure.
• To establish a practical tool for wound healing research using a cell monolayer on stretchable substrates.

Main Methods:

• Cultured dermal fibroblasts from donors of different ages (28 and 88 years) on CellDrums.
• Created circular cell-free areas (wounds) using stainless steel balls.
• Applied sinusoidal mechanical strain (1 Hz, 5% strain) to membranes in controlled sessions.
• Monitored gap circumference and closure rate over 4 days for both stretched and unstretched samples.

Main Results:

• Younger donor samples showed decreased gap circumference and increased closure rate with strain.
• Older donor control samples exhibited decreased gap circumference and increased closure rate.
• Older donor strained samples showed decreased closure rate and increased wound circumference.
• Donor age and mechanical strain significantly influenced wound closure dynamics.

Conclusions:

• CellDrums provide a practical platform for in vitro wound healing research.
• Mechanical strain affects wound closure differently in younger versus older donors.
• This model, combined with molecular analyses, holds promise for advancing wound healing research.