Cellular transduction gradients via vapor-deposited polymer coatings.

Spatiotemporal control of gene delivery, particularly signaling gradients, via biomaterials poses significant challenges because of the lack of efficient delivery systems for therapeutic proteins and genes. This challenge was addressed by using chemical vapor deposition (CVD) polymerization in a counterflow set-up to deposit copolymers bearing two reactive chemical gradients. FTIR spectroscopy verified the formation of compositional gradients. Adenovirus expressing a reporter gene was biotinylated and immobilized using the VBABM method (virus-biotin-avidin-biotin-materials). Sandwich ELISA confirmed selective attachment of biotinylated adenovirus onto copolymer gradients. When cultured on the adenovirus gradients, human gingival fibroblasts exhibited asymmetric transduction with full confluency. Importantly, gradient transduction occurred in both lateral directions, thus enabling more advanced delivery studies that involve gradients of multiple therapeutic genes.