Fibres from blends of epoxidized natural rubber and polylactic acid by the electrospinning process: compatibilization and surface texture

Fibres were electrospun from blends of an epoxidized natural rubber (ENR) with a minor amount of a crystalline grade of polylactic acid (PLA), using a graft copolymer compatibilizer (ENR-g-JM) produced by reaction processing of a mixture of PLA and monoamine terminated polypropylene glycol (Jeffamine M600). The incorporation of PLA into the elastomer spinning solution in the form of a blend was necessary to obtain the required solution properties and to establish the appropriate operational conditions for the successful electrospinning of fibres. The addition of a small quantity of compatibilizer to the ENR/PLA blend reduced the severity of surface roughness of the fibres. Moreover, the use of monoamine terminated polypropylene glycol alone, as a plasticizer, was also found to exert a control on the development of surface texture during electrospinning. The rate of solvent induced crystallization in the swollen fibres jet was identified as the factor determining the surface topography

Metal-Free Oxidative Spirocyclization of Alkynes with Sulfonylhydrazides Leading to 3‑Sulfonated Azaspiro[4,5]trienones

A novel and direct oxidative spirocyclization of arylpropiolamides with sulfonylhydrazides leading to 3-sulfonated azaspiro­[4,5]­trienones has been developed under metal-free conditions. The reaction is performed in a tandem manner constituted by the sequential sulfonylation of alkynes, <i>ipso</i>-carbocyclization, dearomatization, hydration, and oxidation processes, providing a convenient and efficient approach to various sulfonated azaspiro­[4,5] trienones of biological importance

Effects on apoptosis and necrosis of NSCs.

<p>(A) Images of flow cytometry analysis of Annexin-V and PI staining of NSCs exposed to the harvesting media or the PCM for 12 h. (B) Images of TUNEL staining of NSCs exposed to the harvesting media or the PCM for 16 h. (C–D) Quantitative analysis of the percentage of apoptotic (C) and necrotic cells (D) in NSCs exposed to the harvesting media or the PCM for 12 h. Data are presented as mean ±SEM. ***, p<0.001 versus PCM. n = 5 per group. (E) Quantitative analysis of TUNEL-positive NSCs exposed to the harvesting media or the PCM for 16 h. Data are presented as mean ±SEM. ns, nonsignificant; ***, p<0.001 versus PCM. n = 10 per group. (F) TEM images of NSCs exposed to the harvesting media or the PCM for 12 h. For Saline, arrow denotes a loss of cytoplasm and evident karyopyknosis and nuclear fragmentation; for PBS, arrow denotes a loss of cytoplasm and evident karyopyknosis; for ACSF, arrow denotes apoptotic bodies and a loss of cytoplasm; for PCM, arrow denotes an intact nuclear envelope and uniformly dispersed chromatin. Scale bar: (C)  = 100 µm; (F)  = 1 µm. Abbreviation: NSC, neural stem cell; PCM, proliferation culture medium; PI, propidium iodide; SEM, standard error of the mean; TEM, transmission electron microscopy; TUNEL, terminal deoxynucleotidyl transferase (TdT) dilutions of cell-delivered dUTP nick 3′-end DNA labeling.</p

Effects on cell viability and proliferation.

<p>(A) Phase contrast image of neurospheres at passage 3 from the cerebral cortex of E14.5 C57BL/6 mice. (B) Immunofluorescence images of neurospheres stained for nestin and DAPI. (C) Quantitative analysis of the viability of NSCs exposed to the harvesting media or the PCM for 0, 1, 2, 4, 6, 8, 12, 16 or 24 h. (D) Quantitative analysis of S-phase entry (percentage of BrdU-positive cells) in dissociated NSCs exposed to the harvesting media or the PCM for 0, 1, 2, 4, 6, 8, 12, 16 or 24 h. (E) Images of cell cycle analysis by flow cytometry of NSCs exposed to the harvesting media or the PCM for 6 h. (F) Quantitative analysis of S-phase entry (percentage of BrdU-positive cells) in dissociated NSCs exposed to the harvesting media for 6 h and successively cultured in the PCM for another 24 h. (G) Quantitative analysis of S-phase entry (percentage of BrdU-positive cells) in dissociated NSCs exposed to the harvesting media for 8 h and successively cultured in the PCM for another 24 h. (H) Quantitative analysis of S-phase entry (percentage of BrdU-positive cells) in dissociated NSCs exposed to the harvesting media for 16 h and successively cultured in the PCM for another 24 h. For (C) and (D), data are presented as mean ±SEM; n = 5 per group per time point. For (F), (H) and (G), data are presented as mean ±SEM; ns, nonsignificant; ***, p<0.001; n = 5 per group. Scale bar: (A)  = 100 µm; (B)  = 50 µm. Abbreviation: BrdU, 5-bromo-2-deoxyuridine; DAPI, 4′,6′-diamidino-2-phenylindole; E14.5, embryonic day 14.5; NSC, neural stem cell; PCM, proliferation culture medium; SEM, standard error of the mean.</p

Mechanism of harvesting media exposure-induced proliferation inhibition.

<p>(A) Western blots of p53 and cyclin E1 from NSCs exposed to the harvesting media or the PCM for 6 h. β-actin was used as a loading control. (B) Images of BrdU incorporation assays of NSC-neurospheres exposed to the harvesting media or the PCM for 1 week. (C–D) Quantitative analysis of the relative levels of p53 (C) and cyclin E1 (D) to β-actin in NSCs exposed to the harvesting media or the PCM for 6 h. Data are presented as mean ±SD. n = 5 per group. bdi, below detectable limit; *, p<0.05; **, p<0.01; ***, p<0.001 versus PCM. (E) Quantitative analysis of S-phase entry (percentage of BrdU-positive cells) of NSCs in neurospheres exposed to the harvesting media or the PCM for 1 week. The box plots have Min to Max whiskers, a line for the median, and edges for the minimum and maximum. ns, nonsignificant; n = 5 per group. Scale bar: (B)  = 100 µm. Abbreviation: bdi, below detectable limit;BrdU, 5-bromo-2-deoxyuridine; NSC, neural stem cell; PCM, proliferation culture media; SD, standard deviation; SEM, standard error of the mean.</p

Effects on the synaptogenesis by graft-derived cells.

<p>(A) Immunofluorescence images of TBI murine cerebral cortex receiving the harvesting media or PCM-exposed NSC grafting for 21 days and stained for GFP and synaptophysin. (B) Quantitative analysis of percentage of synaptophysin-positive cells in GFP-positive graft-derived cells.. Data are presented as mean ±SEM; *, p<0.05; ***, p<0.001. (C) Quantitative analysis of fluorescence intensity of graft-derived synaptophysin. Data are presented as mean ±SD; ***, p<0.001. Scale bar: (A)  = 25 µm. Abbreviation: GFP, green fluorescence protein; NSC, neural stem cell; PCM, proliferation culture medium; SD, standard deviation; SEM, standard error of deviation; TBI, traumatic brain injury.</p

Western blot analysis of apoptosis-related molecules in harvesting media-exposed NSCs.

<p>(A) Western blots of Fas-L, cleaved caspase 8 and 3 from NSCs exposed to the harvesting media or the PCM for 12 h. β-actin was used as a loading control. (B) Western blots of cleaved caspase 9 from NSCs exposed to the harvesting media, the PCM or 5 µM staurosporine (positive control) for 12 h. β-actin was used as a loading control. (C–D) Quantitative analysis of the levels of Fas-L (C), cleaved caspase 3 (D) and cleaved caspase 8 (E) relative to β-actin in NSCs exposed to the harvesting media or the PCM for 12 h. Data are presented as mean ±SD. n = 5 per group. bdi, below detectable limit; *, p<0.05; **, p<0.01; ***, p<0.001 versus PCM. Abbreviation: ACSF, artificial cerebrospinal fluid; bdi, below detectable limit; NSC, neural stem cell; PCM, proliferation culture medium; SD, standard deviation; STS, staurosporine.</p

Effects on motor function recovery.

<p>(A) Quantitative analysis of the maximal speeds of mice in the rotarod test. (B) Quantitative analysis of foot faults per 50 steps of mice when walking across the beam. For (A) and (B), data are presented as mean ±SD; #, p<0.001 versus PCM-exposed NSC. n = 6 per group per time point. Transplantation was conducted 7 days post-TBI. Abbreviation: SD, standard deviation; TBI, traumatic brain injury.</p

MMP analysis of harvesting media-exposed NSCs.

<p>(A) Confocal images of dissociated NSCs exposed to the harvesting media, the PCM or 5 µM staurosporine (positive control) for 12 h and stained for MMP. (B) Quantitative analysis of average fluorescence intensity of MMP of NSCs exposed to the harvesting media, the PCM or 5 µM staurosporine (positive control) for 12 h. Data are presented as mean ±SD; #, p<0.001 versus STS; ns, nonsignificant versus STS; n = 5 per group. No significant difference was detected between the harvesting media-exposed NSCs and PCM-exposed NSCs. Scale bar: (A)  = 100 µm. Abbreviation: ACSF, artificial cerebrospinal fluid; MMP, mitochondrial membrane potential; NSC, neural stem cell; PCM, proliferation culture medium; SD, standard deviation; STS, staurosporine.</p