Plasma processing of PDMS based spinal implants for covalent protein immobilization, cell attachment and spreading

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Biocompatibility Engineering

Background:

• Poly dimethyl siloxane (PDMS) is a common material for prosthetic devices.
• Conventional ion implantation methods create brittle surfaces on PDMS, leading to delamination and poor biocompatibility.
• Existing treatments fail to adequately enhance PDMS for medical applications.

Purpose of the Study:

• To develop novel plasma-based surface modification techniques for PDMS.
• To improve the biocompatibility and cellular interaction of PDMS surfaces.
• To establish a method for creating stable, functional PDMS surfaces for biodevices.

Main Methods:

• Developed plasma processes to balance carbon etching and implantation into PDMS.
• Utilized carbon from plasma phase and carbon-based polymer coatings as carbon sources.
• Investigated surface chemistry changes using radical formation and surface energy.
• Assessed protein binding capacity and cell attachment/spreading of MG63 osteosarcoma cells.
• Applied the method to a 3D PDMS balloon prosthesis for spinal implants.

Main Results:

• Plasma-treated PDMS surfaces showed improved structural integrity, intermixed with the bulk material, and resisted delamination.
• Enriched surface carbon enabled the formation of carbon-based radicals, leading to covalent protein binding.
• Enhanced PDMS surfaces demonstrated improved MG63 osteoblast cell attachment and spreading compared to untreated surfaces.
• Balancing carbon etching and deposition, using different carbon sources, yielded similar beneficial surface properties.
• Combined protein linkage and bioactivity by tethering tropoelastin further enhanced cell response.

Conclusions:

• Novel plasma processes effectively enhance PDMS biocompatibility by creating stable, carbon-rich surfaces.
• The developed method facilitates covalent protein binding and improves cellular interactions, crucial for biodevice applications.
• This approach offers a pathway for fabricating advanced PDMS-based prosthetic devices with tailored cellular responses.