For each PAH species three samples were prepared and each sample was measured three times. Results Microscopy and DLS of Vesicle Solutions Phase-contrast and fluorescence microscopy of vesicle preparations with a 1:200 ratio of pyrene/decanoic acid are shown in Fig. 1. PAHs are fluorescent under UV light and incorporation https://www.selleckchem.com/products/hydroxychloroquine-sulfate.html can therefore be determined by fluorescence microscopy. The vesicles were heterogeneous, ranging from 100 nm to 5 μm with a mean of 200 nm. Vesicles were largely spherical at first, but tubular vesicles dominated a few minutes later after attaching to the surface of the glass slide
or coverslip (Apel et al., 2002). Incorporation of PAHs did not influence mean vesicle sizes or the size distribution. Vesicles of pure decanoic acid disappeared at pH 7.6, but incorporation of 1-hydroxypyrene had a modest stabilizing effect, with vesicles still apparent at pH 8.1. Fig. 1 Phase-contrast a and fluorescence b microscopy of 0.3 mM pyrene + 59.7 mM DA (200:1) + FA mix. Tubular structures are formed by vesicles adhering to the coverslip or glass slide. Pyrene fluorescence is clearly localized to the membrane PAH Incorporation UV Fluorescence microscopy showed that PAH derivatives could be incorporated into the membrane in different concentrations. Pyrene could be incorporated in a 1:200 Palbociclib cell line mole ratio with decanoic acid while 1-hydroxypyrene (Fig. 2-a) and
9-anthracene carboxylic acid (Fig. 2-b) were incorporated up to 1:10 ratios. Only 1:50 ratios of 9-fluorenone and 1-pyrene carboxaldehyde Cediranib (AZD2171) could be incorporated before macroscopic aggregates formed or PAHs precipitated. In some cases (1-pyrene carboxaldehyde, 9-fluorenone), 10 freeze-thaw cycles using liquid nitrogen to homogenize the bilayers prevented the formation of macroscopic aggregates. Fig. 2 Fluorescence microscopy of a
5.5 mM 1-hydroxypyrene + 54.5 mM DA (1:10) + FA mix and b 5.5 mM 9-anthracene carboxylic acid + 54.5 mM DA (1:10) + FA mix samples. Fluorescence is clearly localized to the membrane boundary CVC Measurements Conductimetric titration was performed on vesicle preparations to determine CVC values. Figure 3 shows CVC measurements for a 1:10 1-hydroxypyrene / decanoic acid sample, the measured CVC values (Fig. 4) are in the range of previously published values (Monnard and Deamer 2003; Cape et al. 2011). Of the PAH derivatives that were tested, only 1-hydroxypyrene showed a significant reduction in CVC, forming fluffy macroscopic aggregates around the measured CVC value. All other samples became completely clear when diluted below the measured CVC values. Fig. 3 Conductimetric titration of a 5.5 mM 1-hydroxypyrene + 54.5 mM DA (1:10) + FA mix sample. The measured CVC is 21.6 mM and this coincides with the formation of macroscopic fluffy aggregates Fig. 4 CVC values determined by conductimetric titration. CVC’s are: 24.00 ± 0.7 mM for 60 mM DA + FA mix samples, 24.3 ± 2.