Effects of Topology and Ionic Strength on Double-Stranded DNA Confined in Nanoslits

We investigate experimentally the effects of electrostatic interactions and topological constraints on DNA dynamics in nanoslit confinement by studying the equilibrium shape and dynamics of single linear and circular λ-DNA confined in a silicon/glass nanoslit. Having examined the dependence of chain radius of gyration <i>R</i>_∥, shape asphericity <i>A</i>, and relaxation time τ on chain topology, slit height <i>h</i> (20–782 nm), and solvent ionic strength <i>I</i> (8.2–268.8 mM), it is found that the chain shape becomes more aspherical as <i>h</i> and <i>I</i> decrease. Moreover, in strong sub-Kuhn length confinement, the DNA relaxation time increases with decreasing <i>h</i> in a smooth and broad transition. Our results provide experimental evidence to confirm that the scaling exponents of radius of gyration and of relaxation time are the same for linear and circular DNA and help resolve conflicting observations of the qualitative dependencies of chain radius of gyration and relaxation time in sub-Kuhn length slits

Customizable Optical and Biofunctional Properties of a Medical Lens Based on Chemical Vapor Deposition Encapsulation of Liquids

An innovative intraocular lens (IOL) device was fabricated based on a chemical vapor deposition encapsulation process using functionalized poly-<i>p</i>-xylylenes. The advanced IOL device provides noncompromised design parameters for both its optical and biological properties. As an excellent optical device, it provides a high refractive index and a tunable effective focal length that is realized by manipulating the wetting properties of the encapsulated liquids; the device also offers protection from UV radiation. As a key medical device, it exhibits excellent biocompatibility and reduced postoperative calcification through the intrinsic properties of poly-<i>p</i>-xylylenes. In addition, these synergic functions are provided with precise surface chemistry for location to a guided attachment or repellent properties for eye epithelial cells, which is important in preventing device-associated complications