Microfluidic assessment of adhesion by surface display (MAPS-D): a novel method for evaluating peptide adhesion to polystyrene and poly(methyl methacrylate).

Many common polymers have low surface energies and limited chemical functionalities, making it difficult to promote adhesion to them without chemical or physical pre-treatment. This reduces the ability to conduct repairs of these materials at the point of need and limits their application. Biology already solves difficult adhesive problems and there may be novel biologically-derived adhesive mechanisms that can be used against these challenging substrates. However, biological materials such as peptides exist in a vast compositional space, can be expensive to synthesize, and techniques to evaluate their adhesive characteristics such as SFA, QCM, and SPR are often low-throughput. The Microfluidic Assessment of Adhesion by Surface Display (MAPS-D) technique is a semi-quantitative, on-cell, fluidics-based method to compare the ability of peptides to promote adhesion to substrates, demonstrated using polystyrene (PS) and poly(methyl methacrylate) (PMMA). Performance of the on-cell peptide was also compared to free-peptide and found to correlate well provided that more than 60% of evaluated cells successfully displayed the peptide of interest. It was also found that the number of cells that remained on the surface was dependent on flow rate, suggesting a "releasing force" could be calculated. This MAPS-D technique does not require expensive equipment, removes the need to synthesize and purify peptides, and has the potential to be made higher-throughput.