Synthesis, liquid crystalline mesophases and morphologies of diblock copolymers composed of a poly(dimethylsiloxane) block and a nematic liquid crystalline block

<p>In this study, a series of liquid crystalline diblock copolymers, composed of a soft poly(dimethylsiloxane) (PDMS) block with a defined length and a side-on liquid crystalline poly(3ʹʹ-acryloyloxypropyl 2,5-di(4ʹ-butyloxybenzoyloxy) benzoate) (P3ADBB) block with different lengths, are synthesised by the atom transfer radical polymerisation. The macromolecular structures, liquid crystalline properties and the microphase-separated morphologies of the diblock copolymer are investigated by ¹H NMR, FT-IR, GPC, POM, DSC and TEM. The results show that the well-defined diblock copolymers (PDMS_n-<i>b</i>-P3ADBB_m) possess four different soft/rigid ratios (<i>n</i> = 58, <i>m</i> = 10, 25, 42, 66) and relatively narrow molecular distributions (PDI ≤ 1.30). P3ADBB blocks of the copolymers show nematic sub-phases, which are identical to the mesomorphic behaviour of the homopolymer P3ADBB. After being annealed at 90°C in a vacuum oven for 48 h, the copolymers form a lamellar morphology when <i>m</i> = 10 and morphologies of PDMS spheres embedded in P3ADBB matrix when <i>m</i> = 25, 42 and 66.</p

Elevated Levels of Serum Tumor Markers CEA and CA15-3 Are Prognostic Parameters for Different Molecular Subtypes of Breast Cancer

<div><p>Background & Aims</p><p>The utility of measuring carcinoembryonic antigen(CEA) and cancer antigen 15-3 (CA15-3) levels in patients with breast cancer remains controversial. The present study aims to investigate the prognostic value of preoperative serum CEA and CA15-3 levels in breast cancer patients.</p><p>Methods</p><p>Serum preoperative CEA and CA 15-3 concentration levels were measured in a total of 432 breast cancer patients. The association of tumor markers levels with clinicopathological parameters and outcomes were analyzed.</p><p>Results</p><p>Elevated serum levels of CEA and CA15-3 were identified in 47 (10.9%) and 60(13.9%) patients, respectively. Larger tumor size, advanced axillary lymph nodal and TNM stage exhibited higher proportion of elevated CEA and CA15-3 levels. The elevation of CEA levels was significantly greater in patients with HER2 positive tumors, and the elevation of CA15-3 levels was significantly greater in ER negative breast patients. Univariate and multivariate Cox’s regression analysis revealed that elevated preoperative CEA and CA 15-3 levels were independent prognostic factors for DFS and OS. When considering the combination of both markers levels, patients with both elevated markers presented the worst survival. Independent prognostic significance of elevated preoperative serum CEA and CA15-3 levels were reconfirmed in Luminal B breast cancer.</p><p>Conclusions</p><p>Preoperative serum levels of CEA and CA15-3 are independent prognostic parameters for breast cancer.</p></div

Kaplan-Meier survival curves of Luminal B breast patients with normal or elevated CEA and CA15-3 levels.

<p>DFS according to CEA(A) and CA15-3(B), OS according to CEA(C) and CA15-3(D).</p

Multivariate Cox’s regression analysis according to tumor size,nodal status, stage, HER2 status, and serum tumor markers.

<p>TNM tumor-node-metastasis, HER2 human epidermal growth factor receptor 2, CA 15–3 cancer antigen 15–3, CEA carcinoembryonic angigen, DFS disease-free survival; OS overall survival, HR, Hazard ratio, CI, Confidence interval.</p><p>*P < 0.05 indicates a significant difference.</p><p>Multivariate Cox’s regression analysis according to tumor size,nodal status, stage, HER2 status, and serum tumor markers.</p

Azo Coupling Reaction Induced Macromolecular Self-Assembly in Aqueous Solution

This communication reported azo coupling reaction induced macromolecular self-assembly in aqueous solution. Diblock copolymer (PEG-<i>b</i>-PSNHBoc) consisting of a hydrophilic PEG block, and a hydrophobic N-Boc protected poly­(<i>p</i>-vinylaniline) block was synthesized by RAFT polymerization. Then double hydrophilic diblock copolymer (PEG-<i>b</i>-PSN₂⁺) composed of PEG and PS based macromolecular diazonium salts was prepared by the diazotization of PEG-<i>b</i>-PSNH₂, which was obtained by deprotection of PEG-<i>b</i>-PSNHBoc. As <i>N</i>,<i>N</i>-dimethylaniline was gradually added into the freshly prepared PEG-<i>b</i>-PSN₂⁺ aqueous solution, the azo coupling reaction between <i>N</i>,<i>N</i>-dimethylaniline and diazonium salts took place, which would lead to the generation of azobenzene pendants. Due to the poor solubility of azobenzene pendants in water, the formed hydrophobic polymeric chains aggregated to form the self-assembly colloidal particles. By incorporating a fluorescent group into the aniline, the aggregates formed through azo coupling reaction induced macromolecular self-assembly showed enzyme-triggered fluorescent behaviors

Fast Photoinduced Large Deformation of Colloidal Spheres from a Novel 4‑arm Azobenzene Compound

A novel 4-arm shaped amphiphilic azobenzene compound was synthesized. The tetraphenylethylene (TPE) core precursor was prepared and further modified by azo coupling reaction at the four peripheral groups. Colloidal spheres could be directly prepared by self-assembly of the prepared amphiphilic azobenzene compound in selective solvents (THF/H₂O), which were characterized by using transmission electron microscopy. The colloid diameters could be controlled by adjusting the initial compound concentration and water-adding rate in the preparation processes. By irradiation with visible linearly polarized LED light (450 nm), fast photoinduced deformation of the colloidal spheres along the polarization direction was observed. A very large deformation degree (<i>l</i>/<i>d</i> > 4) could be easily obtained

Univariate analysis of prognostic factors for survival time of breast cancer patients.

<p>TNM tumor-node-metastasis, ER estrogen receptor, PR progesterone receptor, HER2 human epidermal growth factor receptor 2, CA 15–3 cancer antigen 15–3, CEA carcinoembryonic angigen, TNBC triple-negative breast cancer, DFS disease-free survival, OS overall survival.</p><p>*P < 0.05 indicates a significant difference.</p><p>Univariate analysis of prognostic factors for survival time of breast cancer patients.</p

Clinicopathological characteristic of subjects and correlation between serum CA 15–3 and CEA level and clinicopathological factors.

<p>TNM tumor-node-metastasis, ER estrogen receptor, PR progesterone receptor, HER2 human epidermal growth factor receptor 2, CA 15–3 cancer antigen 15–3, CEA carcinoembryonic angigen, TNBC triple-negative breast cancer.</p><p>*P < 0.05 indicates a significant difference.</p><p>Clinicopathological characteristic of subjects and correlation between serum CA 15–3 and CEA level and clinicopathological factors.</p

Kaplan-Meier survival curves of patients with normal or elevated CEA and CA15-3 levels.

<p>Disease-free survival (DFS) according to carcinoembryonic antigen (CEA) (A) and cancer antigen 15–3 (CA15-3) (B). Overall survival (OS) according to CEA(D) and CA15-3(E). DFS according to the combination of both marker levels(C) and OS according to the combination of both marker levels (F).</p

Synthesis and Characterization of Photoprocessable Lignin-Based Azo Polymer

Lignin-based azo polymer-bearing pseudo-stilbene-type azo chromophores have been synthesized by a post-azo coupling reaction between the modified alkali lignin and diazonium salts of 4-aminobenzoic acid in DMF with high yield. The polymer synthesized was characterized by using spectroscopic methods. Significant dichroism and surface relief patterns could be photoinscribed on the prepared azo polymer films by using appropriate laser beams. Self-assembly of the lignin-based polymer in selective solvents (THF/H₂O) can give uniform colloidal spheres, which can be elongated along the polarization direction of the irradiation light. This novel synthesized lignin-based azo polymer could potentially be used for applications such as reversible optical data storage, photoswitching, sensors, and other photo-driven devices, which provide a simple strategy for value-added utilization of lignin biomass resources