Development and characterization of a high-throughput system for assessing cell-surface receptor-ligand engagement

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Assay Development

Background:

• Developing nonfouling surfaces is crucial for sensitive biomolecular interaction assays.
• Existing platforms often suffer from non-specific protein adsorption, hindering accurate screening.
• Polystyrene surfaces require modification to prevent unwanted surface interactions.

Purpose of the Study:

• To create a novel nonfouling interfacial interpenetrating polymer network (IPN) platform for high-throughput screening of specific biomolecular interactions.
• To characterize the IPN surface properties and its ability to prevent non-specific adsorption.
• To investigate the controlled grafting of biological ligands and subsequent receptor-ligand engagement studies.

Main Methods:

• Grafting of poly(acrylamide-co-ethylene glycol/acrylic acid) [p(AAm-co-EG/AAc)] IPN onto polystyrene surfaces.
• Surface characterization using X-ray photoelectron spectroscopy (XPS), contact angle goniometry, and protein adsorption analysis.
• Quantification of ligand density and assessment of cell adhesion using cell culture and centrifugal adhesion assays.

Main Results:

• The IPN surfaces significantly reduced fibrinogen adsorption (>96%) and prevented mammalian cell adhesion.
• Biological ligands were successfully grafted onto the nonfouling IPN surface via a polyethylene glycol (PEG) spacer.
• Ligand density was precisely controlled (1-20 pmol/cm(2)), directly correlating with cell adhesion, demonstrating effective receptor-ligand engagement.

Conclusions:

• The developed IPN-modified polystyrene platform offers a robust, nonfouling surface for high-throughput screening.
• This technology enables precise control over ligand density for studying cell-surface receptor-ligand interactions.
• The system provides a powerful tool for simultaneously probing numerous receptor-ligand interactions in a high-throughput manner.