Fluorophobic Effect Induces the Self-Assembly of Semifluorinated Tapered Monodendrons Containing Crown Ethers into Supramolecular Columnar Dendrimers Which Exhibit a Homeotropic Hexagonal Columnar Liquid Crystalline Phase

The rational design, synthesis, and characterization of the building blocks obtained by the esterification of the first generation of tapered monodendrons 3,4,5-tris(p-dodecan-1-yloxy)benzoic acid (12-AG) and 3,4,5-tris[p-(n-dodecan-1-yloxy)benzyloxy]benzoic acid (12-ABG) containing semifluorinated dodecyl groups [i.e., 12Fn-AG-15C5 (n = 0, 4, 6, 8), 12Fn-AG-B15C5, 12Fn-ABG-15C5, and 12Fn-ABG-B15C5 (n = 0 and 8) where n following the letter F represents the number of outer perfluorinated methylenic units of the dodecyl group] with 4‘-hydroxymethyl(benzo-15-crown-5) (B15C5) and 1-hydroxymethyl(15-crown-5) (15C5) are described. All building blocks self-assemble into supramolecular cylindrical or rod-like dendrimers via ion-mediated complexation processes. These rod-like supermolecules form a thermotropic hexagonal columnar (Φh) liquid crystalline (LC) phase. The fluorination of the dodecyl groups of these tapered building blocks enhances dramatically their self-assembly ability. The building blocks based on n = 6 and 8 self-assemble into supramolecular columns solely via the fluorophobic effect. Direct structural characterization of the supramolecular columns obtained via these two molecular recognition processes by a combination of techniques consisting of differential scanning calorimetry, X-ray diffraction, and thermal optical polarized microscopy, and of the columns obtained solely via the fluorophobic effect allowed the construction of molecular models for the supramolecular columns obtained via these two organizing forces. An increase in the column diameter with increasing n and with the complexation of metal salts (i.e., alkali metal trifluoromethanesulfonates) accounts for a structural model in which the uncomplexed and complexed crown ethers are placed side-by-side in the center of the column with the melted tapered side groups radiating toward its periphery. The perfluorinated segments of the building blocks are microsegregated from the perhydrogenated and aromatic segments of the column. The supramolecular columns obtained from building blocks with n = 8 align homeotropically in the Φh LC phase on untreated glass slides, i.e., form single crystal liquid crystals in which the long axes of their columns are perpendicular to the glass surface. Both the self-assembly of supramolecular columns induced solely by the fluorophobic effect and the homeotropic alignment of these columns in their Φh LC phase open extremely interesting new synthetic and technologic opportunities in the area of self-assembly of well-defined supramolecular architectures obtained from monodendrons and other building blocks

Additional file 1: Table S1. of WT1-AS promotes cell apoptosis in hepatocellular carcinoma through down-regulating of WT1

Sequence information for primer and siRNA. (DOCX 13 kb

Selection of a region of interest.

A cube of trabecular bone (700μm×700μm×700 μm) mesial to the middle third of the distobuccal root of the maxillary left first molar was selected for analysis. (A) Sagittal view. (B) Horizontal view.</p

Measurement of tooth movement distance.

<p>(A) The first and second maxillary molars were extracted from the alveolar bone. (B) An optimization plane (plane 1) was created on the distal surface of the first molar. (C) The parallel fitting plane (plane 2) was moved distally. (D) The plane contacted the mesial surface of the second molar.</p

Rat model appliance.

Nickel-titanium springs were ligated between the incisors and maxillary left first molars in rats.</p

<i>In vivo</i> micro-CT scanning.

<p>(A) A fixed plane in the middle of the specific mask. (B) The sample platform. (C) The maxillary molars of rats were placed on the fixed plane indicated by the black arrow. (D)The fixed plane (the black line indicated by the black arrow) paralleled to the ground. (E) The rats were transferred to the sample platform and placed in a stable position, and the mask was simultaneously affixed to each rat. (F) Each anesthetized rat was placed on the object stage of the micro-CT apparatus.</p

Using Micro-Computed Tomography to Evaluate the Dynamics of Orthodontically Induced Root Resorption Repair in a <i>Rat</i> Model

<div><p>Objective</p><p>To observe dynamic changes in root resorption repair, tooth movement relapse and alveolar bone microstructure following the application of orthodontic force.</p><p>Materials and Methods</p><p>Forces of 20 g, 50 g or 100 g were delivered to the left maxillary first molars of fifteen 10-week-old rats for 14 days. Each rat was subjected to micro-computed tomography scanning at 0, 3, 7, 10, 14, 28 and 42 days after force removal. The root resorption crater volume, tooth movement relapse and alveolar bone microarchitecture were measured at each time point.</p><p>Results</p><p>From day 3 to day 14, the root resorption volume decreased significantly in each group. In the 20-g force group, the root resorption volume gradually stabilized after 14 days, whereas in the 50-g and 100-g force groups, it stabilized after 28 days. In all groups, tooth movement relapsed significantly from day 0 to day 14 and then remained stable. From day 3 to day 10, the 20-g group exhibited faster relapse than the 50-g and 100-g groups. In all groups, the structure model index and trabecular separation decreased slowly from day 0 to day 10 and eventually stabilized. Trabecular number increased slowly from day 0 to day 7 and then stabilized.</p><p>Conclusions</p><p>The initial stage of root resorption repair did not change significantly and was followed by a dramatic repair period before stabilizing. The most serious tooth movement relapse occurred immediately after the appliance was removed, and then the tooth completely returned to the original position.</p></div

MOESM3 of Extracellular matrix derived from human urine-derived stem cells enhances the expansion, adhesion, spreading, and differentiation of human periodontal ligament stem cells

Additional file 3 : Figure S1. The file is for review purpose only

Repair of root resorption craters.

(A) Repair volume percentage following the application of different magnitudes of force. (B) Root resorption volume following the application of different magnitudes of force. (C) Reconstructed 3D images of root lacunae on the surface of a mesial root on days 0, 3, 7, 10, 14, 28, and 42.</p