Generation of 2D DNA Microstructures via Topographic Control and Shearing

Abstract

2D DNA microstructures are fabricated by applying the shear force to the DNA solution on the microchannels. The “U”‐like textures of DNA are clearly observed when the mechanical shearing is applied on the aqueous DNA sample under the topographic confinement, in which the shearing direction is perpendicular to the grooves. The optical textures of U‐like microstructures are directly observed by polarized optical microscopy (POM) and laser scanning fluorescent confocal polarizing microscopy (FCPM). The DNA microstructures can be modified by varying the width, showing the multiple U‐patterns along with channel direction due to the synergistic interaction between the elastic behavior of DNA chains and topographic boundary condition. The resultant microstructures can be used to align rod‐like liquid crystals (LCs) to generate alternatively oriented nematic phase and tilted focal conic domains (FCDs) in the smectic A phase. It is believed that this approach can suggest a hint to use to DNA materials for organizing multiscale hierarchical structures of soft‐ and biomaterials.

Cyclometalated Pt(II)‐Terpyridine Metallomesogen: What Is Visible or Invisible That Is a Matter of Molecular Packing and Orientation

“…[ 40,41 ] The molecular orientation of uniaxially aligned PtM was determined by the color measurement due to the phase retardation shift. [ 42,43 ] As shown in Figure 2d,e, the aligned PtM shows different colors when the slow axis ( n max ) of the retarder is perpendicular or parallel to SD. When SD is perpendicular to n max , the color of the POM image turns blue due to the additional retardation effect (Figure 2d).…”

Directing Polymorphism in the Helical Nanofilament Phase

“…[4] For example, in pharmacology,s timuli-responsive supramolecular assembly is one of the possible strategies to control the crystal structure to enhancet he specific activity. [5][6][7][8] Among the various kinds of supramolecules, low molecular weight liquid-crystalline (LC) materials are the most promising candidates to form different types of crystal structures for studies on polymorphism due to their strongr esponset oe xternale nvironments. [9,10] Af ew studieso nt he polymorphism of supramolecular LC materialsh ave been reported.…”

“…This field has received much interest in chemistry, materials science, and biology, since the specific crystal structure is essential for practical applications such as pharmaceuticals and agriculture [4] . For example, in pharmacology, stimuli‐responsive supramolecular assembly is one of the possible strategies to control the crystal structure to enhance the specific activity [5–8] . Among the various kinds of supramolecules, low molecular weight liquid‐crystalline (LC) materials are the most promising candidates to form different types of crystal structures for studies on polymorphism due to their strong response to external environments [9, 10] .…”

Hierarchically Fabricated Amyloid Fibers via Evaporation-Induced Self-Assembly

“…Interestingly, the assembled fibrils in the LC phase are oriented parallel with the contact line of the solution to minimize the elastic energy during the receding/dewetting process. − This is quite different from the diluted colloidal dispersions of DNA and virus, showing the molecular orientation perpendicular to the contact line. The ordering and orientation are much improved when the LC phase of fibrillar structures is specifically confined by geometric constraints like topographic templates. − …”