Spreading of bio-adhesive vesicles on DNA carpets

Cell-adhesion events involve often the formation of a contact region between phospholipid membranes decorated with a variety of bio-macromolecular species. We mimic here such hairy bio-adhesive contact zones by spreading phospholipid vesicles onto surfaces carpeted with end-grafted lambda-phage DNA. Our study reveals that the spreading front acts as a scraper that strongly stretches the DNA molecules, and that the multiple bonds created during vesicle spreading effectively staple the stretched chains in the gap between the membrane and the substrate. The scraping and stapling mechanisms revealed here for the long DNA molecules are expected to also play a role in actual bio-adhesion events of cell walls and tissues.