DOI: 10.5061/dryad.dz08kps05
title: Atropine-functionalised gold nanoparticles binding to muscarinic receptors after passage across the intestinal epithelium

description: Gold nanoparticles have a high potential to be a treatment of diseases by
 their specific drug delivery properties and multivalent receptor
 stimulation. For the present project, spherical gold nanoparticles were
 synthesised and functionalised with the muscarinic receptor antagonist
 atropine (Au-MUDA-AT NPs). The diameter of the gold core could precisely
 be controlled by using different synthetic methods and reducing agents
 resulting in functionalised gold nanoparticles with diameters ranging from
 8 to 16 nm. The ability to interact with intestinal muscarinic receptors
 is size-dependent. When using intestinal chloride secretion induced by the
 stable acetylcholine derivative, carbachol, as read-out, the strongest
 inhibition, i.e. the most efficient blockade of muscarinic receptors, was
 observed with 13 nm sized Au-MUDA-AT NPs. Functional experiments indicate
 that Au-MUDA-AT NPs with a diameter of 14 nm are able to pass the
 intestinal mucosa in a time-dependent manner after administration to the
 intestinal lumen. For example, luminally administered Au-MUDA-AT NPs
 inhibited contractions of the small intestinal longitudinal muscle layer
 induced by electrical stimulation of myenteric neurons. A similar
 inhibition of basolateral epithelial receptors was observed after luminal
 administration of Au-MUDA-AT NPs when using carbachol-induced chloride
 secretion across the intestinal epithelium as a test system. Thus,
 Au-MUDA-AT NPs might be a therapeutic tool for the modulation of
 intestinal secretion and motility after oral application in the future.
description: METHODOLOGICAL INFORMATION about the original data sets
 (unprocessed csv files):<br>The CCh-induced change of isometric
 tension (in gram) after administration of Au-MUDA-AT NPs (5 pmol/l at the
 serosal side of rat jejunum, 14 nm diameter) was recorded in organ bath
 experiments. In the corresponding control experiments, equivalent volumes
 of buffer were applied instead of Au-MUDA-AT NPs. <br>The organ bath
 chamber (volume 10 ml) was filled with carbogen-gassed buffer solution and
 warmed up to 37 °C. At the beginning of each experiment, the pre-tension
 was set to 2 g. After the manual reduction of the pre-tension to 1 g, NPs
 or buffer were applied and incubated for at least 20 minutes, before
 carbachol (500 nmol/l) was administered to the serosal side of rat
 jejunum. At the end of each, the chamber solution was washed with buffer
 solution three times and potassium chloride (15 mmol/l at the serosal
 side) served as viability control. DATA-SPECIFIC
 INFORMATION FOR: Data_not_shown_Au-MUDA-AT_NPs.csv<br>1. Number of
 records (columns): 8<br>2. Important information:<br>The first
 column named "Marker" gives information about specific events
 (e.g. drug administration) during the experiment.<br>Markers in the
 file:<br>    0: No event<br>    1: Manual reduction of
 pre-tension to 1 g<br>    2: Serosal application of equivalent
 volumes of buffer instead of Au-MUDA-Atropine NPs<br>    3: Serosal
 application of Au-MUDA-Atropine NPs (5 pmol/l, 14 nm diameter)<br>  
  4: Serosal application of carbachol (500 nmol/l)<br>    5.
 Replacement of the whole chamber volume by buffer solution
 (washing)<br>    6: Serosal application of KCl (15 mmol/l) serving
 as viability control<br>The second column "Time" shows the
 time scale in 1 second steps. Time jumps occur due to synchronisation of
 the marker for all experiments.<br>Each following column is a single
 record of one incubated jejunal segment. The name of each record consists
 of the abbreviation of the name of the experimenter, the date on which the
 experiment was perfomed and in which organ bath chamber the tissue was
 incubated. <br>    For example: RMai19_03: R = Rebecca Classen
 performed this experiment, Mai19 = Experiment was performed on 19th March
 2020, _03 = This jejunal segment was incubated in organ bath chamber
 number 3. <br><br>DATA-SPECIFIC INFORMATION FOR:
 Data_not_shown_No_Drug.csv<br>1. Number of records (columns):
 8<br>2. Important information:<br>The first column named
 "Marker" gives information about specific events (e.g. drug
 administration) during the experiment.<br>Markers in the
 file:<br>    0: No event<br>    1: Manual reduction of
 pre-tension to 1 g<br>    2: Serosal application of equivalent
 volumes of buffer instead of Au-MUDA-Atropine NPs<br>    3: Serosal
 application of Au-MUDA-Atropine NPs (5 pmol/l, 14 nm diameter)<br>  
  4: Serosal application of carbachol (500 nmol/l)<br>    5.
 Replacement of the whole chamber volume by buffer solution
 (washing)<br>    6: Serosal application of KCl (15 mmol/l) serving
 as viability control<br>The second column "Time" shows the
 time scale in 1 second steps. Time jumps occur due to synchronisation of
 the marker for all experiments.<br>Each following column is a single
 record of one incubated jejunal segment. The name of each record consists
 of the abbreviation of the name of the experimenter, the date on which the
 experiment was perfomed and in which organ bath chamber the tissue was
 incubated. <br>    For example: RMai19_04: R = Rebecca Classen
 performed this experiment, Mai19 = Experiment was performed on 19th March
 2020, _04 = This jejunal segment was incubated in organ bath chamber
 number 4.   DATA-SPECIFIC
 INFORMATION FOR:
 Supporting_Information_Synthesis_and_analysis_of_the_nanoparticles.docx<br>1. Number of figures: 10<br>TEM images: Suppl. Figure 1 (Au-Citrate NPs), Suppl. Figure 4 (Au-MUDA NPs), Suppl. Figure 7 (Au-MUDA-AT NPs)<br>TEM images were taken on a Zeiss LEO 912. (300 kV, LaB6 cathode) equipped with a GATAN digital camera.<br><br>UV/Vis spectra: Suppl. Figure 2 (Au-Citrate NPs), Suppl. Figure 5 (Au-MUDA NPs), Suppl. Figure 8 (Au-MUDA-AT NPs)<br>UV/Vis spectra were recorded with an UV-1600PC spectrophotometer from VWR. Elemental analyses for C, H, N and S were acquired by Mr. Dirk Pullem on a Eurolab EA Elemental Analyzer at the University of Cologne.<br><br>NMR spectra: Suppl. Figure 3 (Au-Citrate NPs), Suppl. Figure 6 (Au-MUDA NPs), Suppl. Figure 9 (Au-MUDA-AT NPs)<br>1H-NMR and 13C-NMR spectra were recorded on Bruker Avance 400 MHz (AV 400), Bruker Avance II 300 MHz (AV 300) and Bruker Avance II+ 600 MHz (AV II 600) spectrometers at the Institute of Organic Chemistry, University of Cologne. 1H-NMR data are reported as follows: chemical shifts (multiplicity [ppm], classification). Multiplicity is recorded as s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet. All spectra were displayed with the software MestReNova.<br><br>IR spectra: Suppl. Figure 10 (MUDA-AT, Au-MUDA-AT NPs)<br>IR measurements were performed on a Perkin Elmer FTIR-ATR (UATR TWO) at rt with a maximum resolution of 1 cm-1. Absorption bands are given in cm-1.<br><br>