Plasma-micropatterning of albumin nanoparticles: Substrates for enhanced cell-interactive display of ligands

The authors demonstrate a novel, efficient, and widely applicable approach to direct the patterning of ligand-functionalized organic nanoparticles derived from albumin on nonconductive, biodegradable polymeric substrates. In contrast to traditional deposition methods for inorganic nanoparticles, the approach involves oxygen plasma treatment of spatially restricted regions on a nonbiopermissive polymer. Albumin nanoparticles conjugated with a truncated fragment of fibronectin containing the Arg-Gly-Asp domain were successfully patterned and used as templates to elicit adhesion and spreading of human mesenchymal stem cells and fibroblasts. Attachment and spreading of both cell types into the plasma-exposed polymer areas was considerably more pronounced than with the ligand alone. The authors hypothesize that the underlying mechanism is oxygen plasma treatment-induced selective enhancement of ligand exposure from the deposited functionalized nanoparticles, which facilitates ligand receptor clustering at the cell membrane. The results highlight a promising nanoscale approach to modulate ligand presentation and spatially direct cell attachment and phenotypic behaviors.