Additional file 1: Figure S1a1-e2. of Influence of dendritic polyglycerol sulfates on knee osteoarthritis: an experimental study in the rat osteoarthritis model

Characterization of cultured rat primary knee joint chondrocytes. Primary chondrocytes immediately after isolation (passage 0, upper row, a1-e1) and in the first passage (lower row, a2-e2) are depicted light microscopically (a1-2) and were characterized for the expression of type II collagen (green, b1-2), type I collagen (green, c1-2), sox9 (green, d1-2) and vinculin (red)/F-actin (green) (e1-2). Cell nuclei are counterstained using DAPI (blue). a1-2: scale bar 100 μm, b1-e2: scale bar 50 μm. (TIF 7376 kb

An Amphiphilic Perylene Imido Diester for Selective Cellular Imaging

A new amphiphilic membrane marker based on a water-soluble dendritic polyglycerol perylene imido dialkylester has been designed, synthesized, and its optical properties characterized. In water it forms fluorescently quenched micellar self-aggregates, but when incorporated into a lipophilic environment, it monomerizes, and the highly fluorescent properties of the perylene core are recovered. These properties make it an ideal candidate for the imaging of artificial and cellular membranes as demonstrated by biophysical studies

Tandem Coordination, Ring-Opening, Hyperbranched Polymerization for the Synthesis of Water-Soluble Core–Shell Unimolecular Transporters

A water-soluble molecular transporter with a dendritic core–shell nanostructure has been prepared by a tandem coordination, ring-opening, hyperbranched polymerization process. Consisting of hydrophilic hyperbranched polyglycerol shell grafted from hydrophobic dendritic polyethylene core, the transporter has a molecular weight of 951 kg/mol and a hydrodynamic diameter of 17.5 ± 0.9 nm, as determined by static and dynamic light scattering, respectively. Based on evidence from fluorescence spectroscopy, light scattering, and electron microscopy, the core–shell copolymer transports the hydrophobic guests pyrene and Nile red by a unimolecular transport mechanism. Furthermore, it was shown that the core–shell copolymer effectively transports the hydrophobic dye Nile red into living cells under extremely high and biologically relevant dilution conditions, which is in sharp contrast to a small molecule amphiphile. These results suggest potential applicability of such core–shell molecular transporters in the administration of poorly water-soluble drugs

Quantification of in vivo imaging results of dPGS-NIRF and pure dye.

<p>Box plots of ratios of average fluorescence intensity over the lung area compared with the mean value of each control group respectively are reported for asthmatic and healthy mice. Mice treated with free dye 4 hrs post injection showed a slight increase in fluorescence signal in asthmatic mice (n = 5) when compared to healthy mice (n = 5; increase in average ∼11%, p-value = 0.047, panel A). Mice treated with dPGS-NIRF probe 4 hrs post injection (healthy n = 6, asthmatic n = 6) showed an increased fluorescence signal in the thorax in asthmatic mice (increase in average ∼44% with p-value = 0.004, panel B left side). At 24 hrs post injection fluorescence signals over the lung areas of healthy (n = 5) and asthmatic mice (n = 10) shown no difference (difference ∼8%, p-value = 0.162, panel B right side). Both control dye and dPGS-NIRF probe were injected 72 hrs after last aerosol challenge. Note, intensity ratios were used to compare probes with different brightness, therefore the box plots are depicted in the same scale.</p

Ex vivo imaging results of dPGS-NIRF and pure dye.

<p>Box plots of ratios of average fluorescence intensity over the explanted lungs compared with the mean value of each control group respectively are reported for asthmatic and healthy mice treated with free dye 4 hrs post injection (panel A), and treated with dPGS-NIRF probe 4 hrs (panel B left side) and 24 hrs (panel B right side) post injection. The corresponding fluorescence intensity images of representative lungs are given at the bottom of each box plot. A significant difference between the fluorescence intensity within the lungs of asthmatic (n = 5) and healthy mice (n = 5) was observed 4 hrs post injection of the dPGS-NIRF conjugate (difference of ∼65%, p-value = 0.009), but not of the control dye (healthy n = 5, asthmatic n = 5; difference of ∼18%, p-value = 0.127). Both control dye and dPGS-NIRF probe were injected 72 hrs after last aerosol challenge. Note, intensity ratios were used to compare probes with different brightness, therefore the box plots are depicted in the same scale.</p

Chemical structure of dPGS-NIRF.

<p>The chemical structure indicates the linker structure and connection to the dye (approx. 3 dyes per polymer). Please note that the polymer is not depicted in original molecular weight, but is shown only as principle sketch.</p

In vivo distribution of free dye (indocyanine green) 4 hours post probe injection and 76 hours post last OVA challenge.

<p>Panel A: whole body fluorescence intensity distribution of a representative healthy and asthmatic mouse displayed in normalized counts [NC]. Panel B: Fluorescence microscopy images of F4/80 stained macrophages and DAPI stained cell nuclei of lungs isolated from asthmatic and healthy mice injected with the NIRF labeled control dye and sacrificed 4 hrs post injection demonstrate no fluorescent control dye. F4/80 expression on macrophages are depicted in green, cell nucleus in blue, control dye was not detected (bar = 50 µm). In the healthy model few macrophages have been detected with respect to the asthmatic mouse, where cluster of cells are visible (see white arrows indicating macrophages). In both samples no unconjugated NIRF dye 6S-ICG has been visualized.</p

Experimental design of optical imaging biodistribution study.

<p>Experimental design of optical imaging biodistribution study.</p

Allergic inflammation and mucus hypersecretion in the lungs of asthmatic, but not control mice.

<p>Lungs were harvested 76 hrs after the final ovalbumin (OVA) challenge meaning 4 hrs post i.v. probe injection. Representative H&E (A and B) and PAS (D and E) stained photomicrographs of lungs from healthy (A and D) or asthmatic mice (B and E) are shown (magnification 40×, inset 400×). (B) Arrows indicate inflammation, and in (E) arrows indicate mucus hypersecretion. Allergic inflammation (C) and mucus hypersecretion (F) scores in H&E and PAS stained lung sections, respectively, of healthy (open symbols) or asthmatic mice (filled symbols). Each symbol represents individual mice (n = 5–6 for healthy groups and n = 5–7 for asthmatic groups), and line represents group mean. One-way ANOVA followed by Tukey's multiple comparison test (*P<0.05) was used to compare differences between groups.</p

Calculated average fluorescence intensity ratios between healthy and asthmatic mice after injection of control dye, dPGS-NIRF, or two commercially available probes: ProSense and MMPSense.

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057150#s2" target="_blank">Results</a> are shown as mean calculated average fluorescence intensity ratios ± standard deviation, while statistical significance between each pair of control and asthmatic mice is given by p-value for the Welch-T-Test in brackets. Legend: n.d. – not done.</p