Ⅲ-5

Life, Earth andPlanetary SciencesⅢ -5. Life, Earth and Planetary Sciences

BL4U

Quantitative Penetration Profiles of Free and Nanocarrier-Bound
Bound
Dexamethasone in Human Skin Studied by Soft X-Ray Spectromicroscopy
K. Yamamoto1, T. Ohigashi2, Y. F. Wang2, S. Hedtrich3, F. Rancan4, R. Flesch1, A. Klossek1,
E. Fleige1, S. Ahlberg4, A. Vogt4, U. Blume-Peytavi4, P. Schrade5, S. Bachmann5, R. Haag1,
M. Schäfer-Korting3, N. Kosugi2 and E. Rühl1
1

Institute for Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany
2
UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
3
Institut für Pharmazie, Freie Universität Berlin, 14195 Berlin, Germany
4
Charité Universitätsmedizin, 10117 Berlin, Germany
5
Abteilung für Elektronenmikroskopie at CVK, 13353 Berlin, Germany

The penetration of topically applied drugs in skin is
known to be enhanced by drug nanocarriers [1].
However, quantitative drug uptake studies with highspatial resolution in which the exposure time anddrug formulation are systematically varied are lacking
to date. We have investigated the uptake of theanti-inflammatory drug dexamethasone by humanskin using soft X-ray spectromicroscopy.
Chemical selectivity of this approach is gained byexcitation of the O 1s→π*-transition of
dexamethasone at 530.65 eV, which is suitable tosuppress the background absorption of fixed humanskin as well as drug nanocarriers (core-multi-shell
nanocarriers (CMS)), which were loaded by 5%
dexamethasone. In addition, we used two different
exposure times (4 h and 16 h) and varied the drug
formulation, where either ethanolic solution or HEC
gel (drug concentration: 0.5%) were used,
respectively. Any cross sensitivities from absorptionof untreated skin were subtracted, so that exclusively
the drug concentration was monitored.
The experiments were performed at the BL4U
beamline at UVSOR III using a scanning X-ray
microscope (STXM), similar to previous work, inwhich the feasibility of this approach was explored[2,3].
Figure 1 shows a comparison of depth profiles ofdexamethasone in different skin samples along with
an optical micrograph, in which the skin regions arelabeled (stratum corneum (SC), viable epidermis(VE), and dermis (D)). Figure 2 shows the integrated
drug concentration for the samples under study,
which facilitates to derive quantitative information
regarding the drug distribution, if the exposure timeand drug formulation are varied. Specifically, Fig.
1(a) indicates that after 4 h most of the drug is foundin the SC, whereas a lower fraction is found in the VE(cf. Fig. 2). No drug is observed in the dermis (D).
This situation changes, when 16 h of drug exposure in
HEC gel are used (cf. Fig. 1(b) and Fig. 2). The
intense maximum in the SC is weaker and the drugconcentration in the VE is enhanced. If drug
nanocarriers in HEC gel are used instead of the neatdrug (cf. Fig. 1(c)), no drug signal was observed after
16 h in the SC rather than in the VE. This underscores
the expected drug transport into deeper skin layers bynanocarriers. A drop in local drug concentration isobserved for all samples in the dermis (D). This
indicates that in this region rapid clearance is possible,
so that no enhanced drug concentration is observed.

Fig. 1. Distribution of dexamethasone in the top skinlayers (right hand side: typical optical micrograph,
see text for details): (a) dexamethasone in ethanol:
exposure time: 4 h; (b) dexamethasone in HEC gel:
exposure time: 16 h; (c) CMS nanocarriers in HEC
gel, exposure time: 16 h.

Ⅲ- 5

Fig. 2. Relative abundance of dexamethasone in thestratum corneum and viable epidermis (green: drugloaded CMS nanocarriers in HEC gel, exposure time:
16 h; blue: dexamethasone in HEC gel: exposure
time: 16 h; red: dexamethasone in ethanol: exposure
time: 4 h) compared to the dose applied to skin.
[1] N. Alnasif, C. Zoschke, E. Fleige, R. Brodwolf, A.
Boreham, E. Rühl, K.-M. Eckl, H.-F. Merk, H.-C.
Hennies, U. Alexiev, R. Haag, S. Küchler and M.
Schäfer-Korting, J. Control. Rel. 185 (2014) 45.
[2] R. Flesch et al., UVSOR Activity Report 2013 41(2014) 156.
[3] K. Yamamoto, et al., Anal. Chem., accepted (2015)
DOI : 10.1021/acs.analchem.5b00800

147

Ⅲ -5. Life, Earth and Planetary Sciences

BL4U

Evaluation of Sample Damage of XANES and Application to the Analysis of
Carbonaceous Materials in Hayabusa-Returned Samples
M. Uesugi and A. Nakato

Institute of Space and Astronautical Science, Japan aerospace exploration agency, Sagamihara 252-5210, JapanⅢ- 5

Hayabusa spacecraft has successfully retrieved
regolith particles from the surface of asteroid Itokawa.
Silicate materials found in the sample catcher of the
Hayabusa spacecraft were typically 50µm in diameter,
and their origin was confirmed by mineralogical,
chemical and isotopic analyses in the preliminary
examination of the Hayabusa- returned particles [e.g.
1-6].
Carbonaceous particles, those have been found in
the sample catcher together with silicate particles,
were still under the investigations, including precise
determination of their origin. Results of isotopic
analysis of H, C and N of the carbonaceous materials
by NanoSIMS did not show any signatures of their
extraterrestrial origin, i.e. isotopic anomalies against
the terrestrial composition [7]. Some of the results ofanalyses by Transmission Electron Microscopy (TEM,[8]) and X-ray absorption near edge structure(XANES, [9]) indicated relation to the terrestrial
material. Thus, those particles might indicate thecontamination of terrestrial material into the sample
catcher before, during and/or after the operation of
Hayabusa spacecraft.
XANES analysis of C, N and O is useful for thecharacterization of molecular structure of theunknown carbonaceous material, which would relate
to their origin. We expected to obtain the information
for the source of contamination of Hayabusa
spacecraft by comparing possible contaminants andHayabusa-returned samples using XANES/STXM
installed in UVSOR.
It is well known that high voltage electron beam of
TEM could modify the C-XANES spectrum largely[9]. Thus TEM observation has generally been
applied after XANES analysis. However, in this study,
we focused on the sample damage induced C-XANES.
To evaluate the damage, TEM observations weredone before and after C-XANES analysis. As theresults, TEM observations (Fig. 1) clearly show that
if the sample contains NaCl or KCl inclusions, theywould be damaged heavily by the XANES analysis.
The phenomenon was also observed in the samples
analyzed by other XANES/STXM instrument, though
the detail of the process is uncertain.
This result should be important not only for the
analyses of Hayabusa-returned samples, but also for
the future analyses of Hayabusa2 returned samples.
Because the amount of sample obtained directly by
spacecraft is very small, sequential analysis will be
inevitable for the characterization of those samples.
In this case, we should construct the analytical flow

148

based on the sample damage effective to thedownstream analyses. Results of XANES analyses ofa Hayabusa-returned sample, RA-QD02-0180-03,
showed clear relation to the particles collected bywitness plates those exposed to the cleanroom of
Hayabusa2 spacecraft, though the data should be
re-examined carefully (in progress).
In future work, we will apply the XANES/STXM
analysis to further possible contaminants such as
rubbers and particles of biological materials, for the
precise determination of the origin of carbonaceous
particles in Hayabusa-returned samples.

1µm

Fig. 1. STEM/DF image of the Ultra-thin section ofcarbonaceous material of a Hayabusa-returned sample,
RA-QD02-0180-03 before (upper) and after (lower)
the C-XANES analysis. White objects are the NaCland KCl inclusions. We can observe the disrupted
inclusions entire section after the C-XANES analysis.
[1] T. Nakamura et al., Science 333 (2011) 1113.
[2] H. Yurimoto et al., Science 333 (2011) 1116.
[3] M. Ebihara et al., Science 333 (2011) 1119.
[4] A. Tsuchiyama et al., Science 333 (2011) 1121.
[5] T. Noguchi et al., Science 333 (2011) 1125.
[6] K. Nagao et al., Science 333 (2011) 1128.
[7] M. Ito et al., Earth planet. Space 66 (2014) 102.
[8] M. Uesugi et al., Earth planet. Space 66 (2014)102.
[9] H. Yabuta et al., Earth planet. Space 66 (2014)156.

Ⅲ -5. Life, Earth and Planetary Sciences

BL4U

Absorption Spectra of Bio-Cell Organelles in Cultural Fluid
T. Ejima1, M. Kado2, M. Aoyama3, K. Yasuda3 and T. Tamotsu3
1

IMRAM, Tohoku University, Sendai 980-8577, Japan
Japan Atomic Energy Agency, Kizugawa 619-0215, Japan
3
Dept. of Biological Sciences, Fac. of Science, Nara Women’s University, Nara 630-8263, Japan
2

Organelles in bio-cells are composed of proteins,
and the proteins consist of specific 20 kinds of aminoacids. Spectra of these amino acids are known at C-K
and N-K absorption edges [1], therefore absorption
spectrum of a small organelle will be interpreted by aspectral combination of these amino acids in zero-thorder approximation. If both position of organelles ina bio-cell and C-K and/or N-K absorption spectra at
the organelles are measured simultaneously, positions
and compositions of the organelles will be obtained in
the bio-cell. Water-window wavelength region(λ=2.3-4.5nm) is suitable for this simultaneous
measurements, because water is transparent andcarbides and nitrides are absorbable, which are theprincipal components of proteins. On the other hand,
the measurements have hardly been made especiallyfor bio-cells of eukaryotes, because thickness of the
eukaryotes cells is thick for absorption spectroscopy
even in Water-window wavelength region. In addition,
usual analytical method takes much time to separate
the positions and spectra from measured SX images.
In this study, a Leydig cell in a mouse testis wasused and thickness of the bio-cell was controlled with
culture fluid under 5 μm thick by a sample holder.
The thickness of the Leydig cell contained in thesample holder was measured by an interference

method, therefore the thickness of the bio-cells wereconfirmed as 5 μm or less. The SX images of the
Leydig cells were taken under the spatial resolutionof 200nm at around N-K absorption edge. Spectra andpositions of the organelles in the Leydig cell wereseparated from the measured SX images by the use ofimage analysis methods [2], and absorption
coefficients of the separated structures are also
obtained. Obtained spectra are composed mainly of
σ* and π* bonds, and shapes of small structures in the
bio-cell depend on the density of the organelles.
[1] for example, Y. Zubavichus, A. Shaporenko, V.
Korolkov, M. Grunze and M. Zharnikov, J. Phys.
Chem. B 112 (2008) 13711.
[2] M. Lerotic, C. Jacobsen, J. B. Gillow, A. J.
Francis, S. Wirick, S. Vogt and J. Maser, J. Elec.
Spectro. Rel. Phenom. 144-147 (2005) 1137.
Acknowledgements

This work was supported by JSPS KAKENHI Grant
Numbers 23241038 and by Nanotechnology Platform
Program (S-13-MS-1002) of MEXT, Japan.

Fig. 1. From the measured sx images, cluster structures were separated according to the similar spectrum ofeach dot in the images. It are presented in the figure that an average sx image of the measured sx images (upper
left), details of sx image at 395 eV (lower left), clusters separated and its thicknesses measured by aninterference method (upper right), and absorption spectra of the clusters obtained from sx images (lower right).

149

Ⅲ- 5

Ⅲ -5. Life, Earth and Planetary Sciences

BL4U

Evaluation of FIB Beam Damage in XANES Spectra of Organics inMeteorites: Preliminary Measurements for Implementation Planning of a
Synchrotron Cosmochemistry Research Base at UVSOR BL4U
1

H. Yabuta1, A. Takahashi1, Y. Inagaki2 and T. Ohigashi2

Department of Earth and Space Science, Osaka University, Osaka 560-0043, Japan
2
UVSOR Facility, Institute for Molecular Science, Okazaki, 444-8585, Japan

Ⅲ- 5

(a)

This study aimed to evaluation of FIB beam
damage in XANES spectra of organics in meteorites.
However, unfortunately, it was impossible to carryout the analysis during the beam time in June, 2014,
due to a mistake by a manufacturer (a maker) of
placing a diffraction grating upside down, after theircleaning the carbon contamination. For this reason,
the schedule had to be changed, and the analogue oforganic materials in meteorite was analyzed by
STXM during the beam time in December 2014.
Carbon contamination on the surface of the mirror
was still remained and it was difficult to acquire an
ideal
Carbon-XANES
spectrum,andthemeasurements were limited to Nitrogen-XANES.
Paraformaldehyde (120 mg), glycolaldehyde (120mg), NH3(aq) (54 µl), Ca(OH)2 (30 mg) in 2 ml ofwater in a glass tube was heated at 90°C for 3-100
days [1-2]. After heating, the precipitation was rinsed
with HCl and dried. The purified organic solids weresuspended in ethanol and the suspension was drippedto the Cu-TEM grid (200 mesh) with SiO film using a
micropipette. N-XANES spectra of the samples wereacquired using a scanning transmission x-ray
microscope (STXM) at the BL 4U, UVSOR.
Our previous study revealed that the organic solids
include a number of micro spherules of 3-20 µm in
diameter. Their size and shape distributions changed
with a heating period of time. In contrast, N-XANES
spectra of the organic solids were similar throughout
a heating period of time (Fig. 1), exhibiting
absorption peaks of imine (C=N) at 398.8 eV,
protonated imine (C=NH+) at 400.8 eV, and amide(NHx(C=O)C) around at 401.6 eV, respectively.
Combining the results by infrared analysis, thesefeatures imply that the organic microspherule is aself-organized polymer of a amphiphilic molecule
including alkyl group and pi-bonding.

400.92 eV
C=NH+?
401.8 eV
Amide NHx(C=O)C

398.81 eV
Imine
C=N

2 um

(b)

(c)
400.8 eV
C=NH+
398.8 eV
C=N

401.6 eV
Amide

2 um

Fig. 1. N-XANES spectra of analogues of organic
materials in meteorite, which were synthesized fromformaldehyde and ammonia for different heating
periods of times (a) 10 days, (b) 20 days, and (c) 60
days.
[1] G. D. Cody, E. Heying, C. M. O.’D. Alexander, L.
R. Nittler, A. L. D. Kilcoyne, S. A. Sandford and R.
M. Stroud, PNAS 108 (2011) 19171.
[2] Y. Kebukawa, A. L. D. Kilcoyne and G. D. Cody,
Astrophys. J. 771 (2013) 19.

150

Ⅲ -5. Life, Earth and Planetary Sciences

BL4U

Chemical Mapping of DNA and Protein in Isolated Cell Nuclei during
Apoptotic Process Using STXM
A. Ito1,2, T. Ohigashi2,3, K. Shinohara1, S. Tone4, M. Kado5, Y. Inagaki2 and N. Kosugi2
1

School of Engineering, Tokai University, Hiratsuka 259-1292, JapanUVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
3
The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
4
Department of Biochemistry, Kawasaki Medical School, Kurashiki 701-0192, Japan
5
Japan Atomic Energy Agency, Kizugawa 619-0215, Japan
2

Apoptosis is characterized as a programmed cell
death controlled by the expression of the relating
genes. One of the remarkable morphological featuresof cells which undergo apoptosis is the deformationof nuclei during the apoptotic process. Tone et al.
observed the distribution change of DNA in isolated
cell nuclei with the progression of apoptosis bylabelling DNA with fluorescent dye [1]. They
classified the apoptotic process into threecharacteristic stages, stage 1, 2 and 3. DNA in thenormal nuclei (stage 0) proceeds to ring-shapestructure (stage 1) accumulated in the peripheral
region, followed by necklace-shape structure where
the ring structure is broken intermittently (stage 2).
Finally the nuclei are collapsed toward the center(stage 3). In the present study, we observed
distributions of DNA as well as nuclear protein
including histone, using chemical mapping of STXM
with higher spatial resolution than optical microscope.
Our previous study for the DNA mapping in
mammalian cell nuclei was successfully achieved
with the aid of the different XANES profiles between
DNA and protein at the N-K absorption edge [2].
Chemical mapping was extended to apoptotic nuclei
in this study.
XANES profiles of DNA and histone were
measured by the STXM around the N-K absorption
edge from 390 to 410 eV as reference spectra.
Solution of these biomolecules was dropped on
collodion membrane supported by an EM grid, andthen dried in the air. S/M extract of chicken DU249
cells was used to induce apoptosis on isolated nucleiof human HeLa S3 cells. The nuclei were fixed withglutaraldehyde at the timing of four different stages
described above, and dropped on Formvar membrane
supported by EM grid, and then dried in the air.
The 61 X-ray transmission images (an energy
stack) for each stage were acquired from 397 to 403
eV. The dwell time and scanning pitch were 10 ms
and 0.1 μm, respectively. DNA and histone (protein)
distributions were obtained fitting the reference
spectra of DNA and histone to the energy stack byusing aXis2000 software (fitting method).
Alternatively the maps were obtained by thesubtraction of images taken between at the top andthe bottom of the resonance peak of DNA or histone(subtraction method).
Figure 1 shows distributions of DNA and protein in

151

four stages of apoptosis. In the case of normal nuclei
at the stage 0 shown by the panel a, b and c, DNA andprotein were distributed in the nearly whole nucleus
with similar pattern, since nucleus mainly consists ofchromatin, a complex structure of DNA and proteins.
At the stage 1, DNA and protein were accumulated in
the ring shape on the rim of nucleus (panel e and f).
The width of the ring was less than 0.5 μm. Note thatin the central part of the nucleus DNA seems to be
distributed more preferentially than protein. In
addition, an image of “constant” (panel g), whichmeans the existence of molecules with no spectralfeature at the N-K absorption edge, shows significant
distribution in the inner region. The identification of
the molecules is an issue for the future research.
These distributions of DNA and protein were also
confirmed by the subtraction method. For the stages 2
and 3, remarkable difference was not observed
between DNA and protein maps. Necklace structurein the stage 2 as shown by arrows in panel h wasevident in both DNA and protein maps. To improve
the quality of the images, reproducibility of reference
spectra and the acquisition time to assure enoughphoton counts per pixel should be considered.
Stage
0

(a)

(b)

(c)

(d)

(e)

(f)

(h)

(i)

(j)

(k)

(l)

(m)

(g)

Stage
1
Stage
2
Stage
3

Fig. 1 Distributions of DNA and protein in fourstages of apoptotic nuclei.
X-ray image at 397 eV: (a), (d), (h), (k); DNA map:(b), (e), (i), (l); protein map: (c), (f), (j), (m); constant
map: (g)bar: 1 μm (stage 0, 1, 3), 2 μm (stage 2)[1] Toné et al., Exp. Cell Res. 313 (2007) 3635.
[2] T. Ohigashi et al., UVSOR Activity Report 201341 (2014) 158.

Ⅲ- 5

Ⅲ -5. Life, Earth and Planetary Sciences

BL4U

Observation of Prokaryotic Organelles of Musty-Odor Producing
Filamentous Cyanobacterium Using STXM
1

K. Takemoto1,2, M. Yoshimura2, T. Ohigashi2,3 and H. Kihara2,4

Department of Physics, Kansai Medical University, Hirakata 573-1010, Japan2
SR center, Ritsumeikan University, Kusatsu 525-8577, Japan
3
UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
Himeji Hinomoto College, Himeji 679-2151, JapanⅢ- 5

In a source of potable water, musty-odor producedby blue-green algae suddenly appear all over theworld. Since 1969, a problem of musty-odor in
potable water has occurred due to sudden propagationof Phormidium tenue (Pseudanabaena sp.) green
strain (PTG) in Lake Biwa. Because there are few
studies on PTG, an exhaustive study of PTG is
required of water resource managers.
PTG is a small filamentous cyanobacterium, andthe trichome consists of cells 1.0–1.6 μm in width,and 2.5–10 μm in length. Due to a diffraction limit,
light microscope (LM) is impossible to provide
intracellular observation with a sufficient spacial
resolution. Therefore, we applied a soft X-ray
microscope (XM) to PTG observation. The XM iscapable of imaging thick and untreated specimens,
allowing viewers to investigate whole cells up to 10
μm thick with much higher resolution than LM. In
our full field transmission soft XM observation,
several intracellular granules were observed. [1].
Based on the transmission electron microscopy(TEM) observation and the energy dispersive X-ray(EDX) analysis on low temperature/low vacuum
scanning electron microscope (LT/LV SEM), we
inferred that the granules were polyphosphate and/or
carboxysome. Carboxysome is one of the bacterial
microcompartment that contains enzymes, RuBisCO,
involved in carbon dioxide fixation. Polyphosphate
granule is one of the bacterial microcompartment thatis characterized by their high content of phosphorus.
Polyphosphate has the general formula M(n+2)PnO(3n+1),
where M is H+ or monovalent metal cation [2].
However, there is no objective evidence to identify
them. In this study, it is aimed to obtain the objective
evidence to identify them using oxygen K-edge X-ray
absorption near edge structure (XANES).
Oxygen K-edge XANES spectra were collected on
the scanning transmission X-ray microscope (STXM)
at UVSOR BL4U [3]. PTG was isolated from Lake
Biwa and culture was carried out under the fixed
condition for four weeks [1].
Figure 1 shows a STXM image of the distributionof oxygen in PTG. Four oxygen accumulated granules
were confirmed. Characterization of intracellular
granules was performed by oxygen K-edge XANES(Fig. 2). The spectrum from cytoplasm shows anintense pre-peak. On the other hand, the spectrum
from granule shows a small pre-peak at the same152

energy region. Although the pre-peak energies arealmost similar, the main edge energy of the granule
shifts towards lower than that of cytoplasm. To
identify the granules, we intend to promote a moredetailed analysis.

Fig. 1. Distribution of oxygen in PTG. Scale bar is 1μm.

Fig. 2. Oxygen-XANES spectra of cytoplasm (blackline) and granule (gray line).
[1] K. Takemoto et al., Jpn. J. Water Treat. Biol. 48(2012) 157. [in Japanese.][2] I.S. Kulaev et al., The Biochemistry of Inorganic
Polyphosphates, 2nd Ed., John Wiley & Sons, Inc.,New York (2004) 3.
[3]T. Ohigashi et al., J. Phys. Conf. Ser. 463 (2013)
012006.

Ⅲ -5. Life, Earth and Planetary Sciences

BL4U

Skin Penetration Study of Drug Carriers
Using Soft X-Ray Spectromicroscopy
1

P. Pan-In1, T. Ohigashi2,3, N. Kosugi2,3 and S. Wanichwecharungruang1

Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
2
UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan3
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585,
Japan
Skin is a natural barrier to protect human body andcontrol molecular transports from and into the body.
Nanoparticles can be developed to deliver drugs both
into the skin and through the skin into the circulation.
Although it has been stated that drug/bioactive
molecules can penetrate through skin barrier via
intracellular, intercellular and follicular pathways [1,2], recent researches have proven that the follicularpathway is important for the nanoparticulate drugdelivery systems [3]. Researchers have shown that
nanoparticles with appropriated sizes could penetratewell into skin via hair follicle because the rigid hairshafts acted as the geared pump that upon movement
or massage the particles could be pushed down. The
loaded drugs could then be stored more than 10 daysin hair follicles [3].
Thus, the aim of this research is to study the skinpenetration level of oxidized carbon nanoparticles
with the size between 150-800 nm [4]. BODIPY® FL(4,4-Difluoro-5,7-Dimethyl-4-Bora-3a,4a-Diazas-Indacene-3-Propionic Acid) was grafted on theparticles. Porcine skin penetration of the particles wasinvestigated ex vivo. The BODIPY-grafted particles
were massaged on fresh porcine skin samples at thecoverage of 100 µg/cm2 and the applied skin was left
for 30 minutes before being subjected to the treatment
with 4% glutaraldehyde and then cryo-sectioning.
The thickness of the skin sections was 400 nm. Then,the skin samples were mounted on Cu grids(300-mech) and subjected to the soft X-ray
microscopic investigation. The experiment was
carried out at the B 1s-edge (170-200 eV) for tracking
the BODIPY-grafted particles.
The soft X-ray experiment was performed at the
BL4U beamline at UVSOR using a scanning X-ray
microscope (STXM) [5]. The experimental design
was that the presence of the boron element in the
BODIPY® FL (Fig. 1) could make a significant
difference in X-ray signal when compared to signals
from tissue with no BODIPY® FL. Chemical
selectivity was obtained from excitation at the B
1s-edge (170-200 eV). The presence of the 182 eV
peak observed in the B 1s-absoption of only the
BODIPY-grafted particles, not the skin tissue (Fig. 2),
provided a chemical selectivity for tracking thecarrier uptake into porcine skin.
Unfortunately, the (BODIPY-grafted particle)-treated porcine skin samples did not show any
obvious 182 eV peak in their B 1s spectra, even at thevery uppermost location where the carriers wereapplied. We speculate a too low concentration of the
BODIPY moieties in the particles. To investigate forthe skin penetration ability of this carrier in the future,a more intense BODIPY labeling will be required. In
addition, skin application at a high dose will beneeded.

Fig. 1. Structure of BODIPY® FL.

Ⅲ- 5
Fig. 2. B 1s excitation of BODIPY-grafted particles(a) and porcine skin (b).
[1] M. A. Bolzinger et al., Curr. Opin. Colloid
Interface Sci. 17 (2012) 156.
[2] K. Moser et al., Eur. J. Pharm. Biopharm. 52(2001) 103.
[3] J. Lademann et al., Skin Pharmacol. Physiol. 19(2006) 232.
[4] S. Arayachukiat et al., Nano Lett. Accepted(2015).
[5] T. Ohigashi et al., J. Phys.: Conf. Ser. 463 (2013)
012006.

153

Farewell Parties