Microfluidic assembly of cationic-β-cyclodextrin: hyaluronic acid-adamantane host: guest pDNA nanoparticles

Transfection complexes are typically formed by bulk mixing, producing particles with high polydispersity and limited control over vector size. Herein, we demonstrate the use of a commercial microreactor to assemble pDNA: cationic cyclodextrin: pendant polymer nanoparticles using a layer-by-layer approach. Our studies reveal that the particles formulated via microfluidic assembly have much smaller sizes, lower polydispersity, lower zeta-potentials, and comparable cell viability and transfection profiles in HeLa cells than bulk mixed particles. The complexes also show a flow rate-dependent stability, with particles formed at slower flow rates giving rise to more stable complexes as determined by heparin challenge experiments. Our findings suggest that microfluidic reactors offer an attractive method for assembling reproducible, size-controlled complexes from multi-component transfection complex assemblies.