TY - JOUR

T1 - Network Formation of DNA/Polyelectrolyte Fibrous Aggregates Adsorbed at the Water–Air Interface

AU - Chirkov, N.S.

AU - Akentiev, A. V.

AU - Campbell, R.A.

AU - Lin, S.-Y.

AU - Timoshen, K. A.

AU - Vlasov, P. S.

AU - Noskov, B. A.

PY - 2019

Y1 - 2019

N2 - It is discovered that complexes of DNA and hydrophobically modified polyelectrolytes form a rigid network of threadlike or fibrous aggregates at the liquid-gas interface whose morphology can dramatically affect the mechanical properties. While mixed solutions of DNA and poly(N,N-diallyl-N,N-dimethylammonium chloride) (PDADMAC) exhibit no notable surface activity, the complexes formed from DNA with poly(N,N-diallyl-N-butyl-N-methylammonium chloride) are surface-active, in contrast to either of the separate components. Further, complexes of DNA and poly(N,N-diallyl-N-hexyl-N-methylammonium chloride) (PDAHMAC) with its longer hydrophobic side chains exhibit pronounced surface activity with values of surface pressures up to 16 mN/m and dynamic surface elasticity up to 58 mN/m. If the PDAHMAC nitrogen to DNA phosphate molar ratio, N/P, is between 0.6 and 3, abrupt compression of the adsorption layer leads unexpectedly to a noticeable decrease of the surface elasticity. The application of imaging techniques reveals that this effect is a consequence of the destruction of a rigid network of threadlike DNA/polyelectrolyte aggregates at the interface. The toroidal aggregates, which are typical for the bulk phase of DNA/PDADMAC solutions in this range of N/P ratios, are not observed in the surface layer. The observed link between the mechanical properties and interfacial morphology of surface-active complexes formed from DNA with hydrophobically modified polyelectrolytes indicates that tuning polyelectrolyte hydrophobicity in these systems may be a means to develop their use in applications ranging from nonviral gene-delivery vehicles to conductive nanowires.

AB - It is discovered that complexes of DNA and hydrophobically modified polyelectrolytes form a rigid network of threadlike or fibrous aggregates at the liquid-gas interface whose morphology can dramatically affect the mechanical properties. While mixed solutions of DNA and poly(N,N-diallyl-N,N-dimethylammonium chloride) (PDADMAC) exhibit no notable surface activity, the complexes formed from DNA with poly(N,N-diallyl-N-butyl-N-methylammonium chloride) are surface-active, in contrast to either of the separate components. Further, complexes of DNA and poly(N,N-diallyl-N-hexyl-N-methylammonium chloride) (PDAHMAC) with its longer hydrophobic side chains exhibit pronounced surface activity with values of surface pressures up to 16 mN/m and dynamic surface elasticity up to 58 mN/m. If the PDAHMAC nitrogen to DNA phosphate molar ratio, N/P, is between 0.6 and 3, abrupt compression of the adsorption layer leads unexpectedly to a noticeable decrease of the surface elasticity. The application of imaging techniques reveals that this effect is a consequence of the destruction of a rigid network of threadlike DNA/polyelectrolyte aggregates at the interface. The toroidal aggregates, which are typical for the bulk phase of DNA/PDADMAC solutions in this range of N/P ratios, are not observed in the surface layer. The observed link between the mechanical properties and interfacial morphology of surface-active complexes formed from DNA with hydrophobically modified polyelectrolytes indicates that tuning polyelectrolyte hydrophobicity in these systems may be a means to develop their use in applications ranging from nonviral gene-delivery vehicles to conductive nanowires.

KW - ADSORPTION

KW - AIR/WATER INTERFACE

KW - CATIONIC SURFACTANT

KW - COMPLEXATION

KW - DNA

KW - IONIC-STRENGTH

KW - LANGMUIR MONOLAYERS

KW - MIXTURES

KW - MORPHOLOGY

KW - PHASE-TRANSITIONS

UR - http://www.scopus.com/inward/record.url?scp=85073822863&partnerID=8YFLogxK

U2 - 10.1021/acs.langmuir.9b02487

DO - 10.1021/acs.langmuir.9b02487

M3 - Article

VL - 35

SP - 13967

EP - 13976

JO - Langmuir

JF - Langmuir

SN - 0743-7463

IS - 43

ER -