A durable and biocompatible ascorbic acid-based covalent coating method of polydimethylsiloxane for dynamic cell...

Area of Science:

• Biomaterials Science
• Cell Biology
• Microfluidics

Background:

• Polydimethylsiloxane (PDMS) is crucial for microfluidic devices but its hydrophobicity hinders cell attachment.
• Existing covalent coating methods using glutaraldehyde (GA) are cytotoxic, limiting biological applications.
• Improved PDMS surface modification is needed for effective cell culture in dynamic microfluidic systems.

Purpose of the Study:

• To introduce a novel, non-cytotoxic covalent collagen type I coating method for PDMS using ascorbic acid (AA) as a cross-linker.
• To compare the efficacy of AA-based covalent coating against physisorption and GA-based covalent coating.
• To evaluate the biocompatibility and durability of the AA-coated PDMS for human adipose stem cell (hASC) culture under static and dynamic conditions.

Main Methods:

• Covalent binding of collagen type I to PDMS using ascorbic acid (AA) as a cross-linker.
• Characterization of PDMS coatings using immunostaining, contact angle measurements, atomic force microscopy, and infrared spectroscopy.
• Assessment of human adipose stem cell (hASC) attachment, proliferation, and viability on coated PDMS under static and dynamic (stretching) conditions for up to 13 days.

Main Results:

• Ascorbic acid (AA) effectively replaces glutaraldehyde (GA) as a cross-linker for covalent collagen I coating on PDMS.
• The AA-based covalent coating demonstrates durability, withstanding sonication and 6 days of mechanical stretching.
• Human adipose stem cells (hASCs) exhibit significantly improved attachment and proliferation on AA-cross-linked PDMS compared to physisorbed or GA-based coatings.

Conclusions:

• Ascorbic acid provides a safe and effective alternative to glutaraldehyde for covalently immobilizing collagen I on PDMS.
• The developed AA-based coating method enhances cellular adhesion and proliferation, making PDMS suitable for dynamic cell culture.
• This novel coating technique is a significant advancement for PDMS-based microfluidic devices in cell engineering and tissue engineering applications.