Sterically Induced Shape and Crystalline Phase Control of GaP Nanocrystals

We demonstrate a novel synthetic scheme that can be used to control the crystalline phase and shape of GaP semiconductor nanocrystals. Our study shows that steric effects of surfactant ligands can modulate the crystalline phases and control the shapes of nanocrystals. The shape of the nanocrystals obtained varies from zero-dimensional spheres to one-dimensional rods via controlling the ratio between primary and tertiary alkylamines. III-V semiconductors (in our case:  GaP) under 10 nm in width are first reported, and unique optical properties due to shape anisotropy are also observed

The experimental protocols followed for all <i>in vitro</i> experiments are represented as follows.

<p>Normoxia = normoxia group, Control = no remifentanil treatment group, RPT = remifentanil post treatment group, 3-MA = both 3-MA and remifentanil treatment group, NLX = both naloxone and remifentanil treatment group.</p

The effect of remifentanil on cell viability in human keratinocytes assessed by MTT assay.

<p>(A) Effect of remifentanil on HaCaT cells under H/R conditions assessed by MTT assay. *P < 0.05 as compared with the control group.(B) Cell viability comparison between RPT and 3MA groups.*P < 0.05 as compared with the RPT group.</p

AO staining of autophagosomes after remifentanil treatment in human keratinocytes.

<p>Fluorescence microscopic (×400) analysis of autophagosome in the H/R injured HaCaT cells. Stained with acridine orange the green shows where the dye has stained the nucleus and the red is where the cell is starting to’digest' parts of itself in small capsules called autophagasomes. H/R caused accumulation of autophagosomes containing partially digested cytoplasmic contents compared to the control group. The remifentanil during H/R dramatically increased formation of autophagosomes and the autophagy pathway inhibitor 3-MA blocked formation of autophagosomes by remifentanil. But naloxone did not block that.</p

MDC staining of cytoplasmic vacuoles after remifentanil treatment in human keratinocytes.

<p>Fluorescence microscopic (×400) analysis of autophagosome in the H/R injured HaCaT cells. H/R caused accumulation of autophagosomes containing partially digested cytoplasmic contents compared to the control group. The remifentanilduring H/R dramatically increased formation of autophagosomes and the autophagy pathway inhibitor 3-MA blocked formation of autophagosomes by remifentanil. But naloxone did not block that.</p

Effects of remifentanil on the expression of caspase-3, caspase-9, Bcl-xl, and Bax in human keratinocytes.

<p>Western blot analysis and densitometry. In RPT and NLX groups, cellular expression of cleaved caspase-3, 9, and BAX were down-regulated while that of Bcl-xl was elevated. *P < 0.05 as compared with the control group.</p

Detection of apoptosis and necrosis with Annexin-V-FITC and propidium iodide staining.

<p>All the groups of cells with Annexin-V and propidium iodide staining were measured by flow cytometry. Normoxia = normoxia group, Control = no remifentanil treatment group, RPT = remifentanil post treatment group, 3-MA = both 3-MA and remifentanil treatment group.</p

Hoechst staining: Morphological changes in H/R-induced HaCaT cells treated with remifentanil (1ng/ml), 3-MA and naloxone.

<p>H/R-induced HaCaT cells treated with remifentanil, 3-MA and naloxone as observed by fluorescence microscopy. Apoptotic bodies were seen in control and 3-MA group cells. In contrast they were markedly reduced in RPT and NLX group cells. Normoxia = normoxia group, Control = no remifentanil treatment group, RPT = remifentanil post treatment group, 3-MA = both 3-MA and remifentanil treatment group, NLX = both naloxone and remifentanil treatment group.</p

Effects of remifentanil on autophagy markers in human keratinocytes.

<p>Western blot analysis and densitometry. ATG5, Becline-1, LC-3 II, and P62 were elevated in RPT and naloxone group cells. *P < 0.05 as compared with the control group.</p

<i>In vitro</i> wound healing.

<p>Remifentanil restored cell proliferation and migration, which had been decreased by hypoxia. Investigation of cell migration capability after H/R was performed.Confluent monolayers of HaCaT cells were wounded by scratching the surface as uniformly as possible with a 1 mL pipette tip. *P < 0.05 as compared with the normoxia group.</p