Photo and redox-responsive vesicles assembled from Bola-type superamphiphiles

Article abstract of DOI:10.1039/c6ra05808f

Superamphiphiles are considered as a promising approach for fabricating stimuli-responsive materials. Sensitivity to more than one stimulus can improve the system's versatile performance. In this study, we proposed a facile dual-responsive vesicle constru

Full text of DOI:10.1039/c6ra05808f

View Article Online
View Journal
RSC Advances
This article can be cited before page numbers have been issued, to do this please use: T. Sun, L. Shu, J.
Shen, C. Ruan, Z. Zhao and C. Jiang, RSC Adv., 2016, DOI: 10.1039/C6RA05808F.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. This Accepted Manuscript will be replaced by the edited,
formatted and paginated article as soon as this is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the Ethical guidelines still
apply. In no event shall the Royal Society of Chemistry be held
responsible for any errors or omissions in this Accepted Manuscript
or any consequences arising from the use of any information it
contains.
www.rsc.org/advances

Page 1 of 12
Please Rd So Cn oA t da vd aj un sc te ms argins
View Article Online
DOI: 10.1039/C6RA05808F
Journal Name
ARTICLE
Photo and Redox-Responsive Vesicles Assembled From Bola-type
Superamphiphiles
a
a
b
a
a
a
Tao Sun, Lan Shu, Jian Shen, Chunhui Ruan, Zhifeng Zhao and Chen Jiang*
Received 00th January 20xx,
Accepted 00th January 20xx
Superamphiphiles are considered as a promising approach for fabricating stimuli-responsive materials. Sensitivity to more
than one stimulus can improve the system’s versatile performance. In this study, we proposed a facile dual-responsive
vesicle constructed from Bola-type superamphiphiles. An azobenzene dimer linked by disulfide bond was synthesized. As
the gust molecule, the azobenzene dimer can be included into the β-cyclodextrin’s cavity from both ends to form a novel
Bola-type superamphiphile, which can further assemble into vesicular structure in aqueous solution. The vesicles were
characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The formation mechanism of
the vesicular structure was suggested based on the NMR, Fourier transform infrared spectroscopy (FT-IR) and X-ray
diffraction (XRD) results. The photo and redox responsiveness of the vesicles was studied. The vesicles were found capable
to carry mitomycin C (MMC) and the drug-release can be greatly promoted upon UV irradiation or reductant.
DOI: 10.1039/x0xx00000x
www.rsc.org/
Superamphiphiles,1~3 with hydrophilic and hydrophobic
moieties linked via non-covalent bonds, are regarded as convenient
Introduction
and promising “building blocks” in preparing versatile stimuli-
responsive materials. To our knowledge, however, no reports on
photo and redox responsive superamphiphlies were found. The dual-
responsive approach employing exogenous (light) and endogenous
Narrowing the gap between the general concepts of molecular-
recognition/self-assembly and their applications still remains a great
challenge in current supramolecular chemistry. In this regard,
sophisticated stimuli-responsive materials have been well studied
with the hope of usage in controllable release and molecular
machine. Multiple means employing H-bonding, π-π stacking or
metal-ligand coordination as the linkage, ambient condition factors
2
1
(
redox) triggers both in a noninvasive way should be of pronounced
advantage in the pharmaceutical and biomedical sciences.
Sugar-based materials have been extensively explored as a
means to increase bio-oriented systems' biocompatibility and
like pH, redox, temperature and light as the “Turn-On” switches have
been developed.2
~11
Among most stimuli-responsive materials, the
21
biodegradation. Cyclodextrins (CDs), a class of biocompatible
truncated-cone polysaccharides mainly composed of 6~8 D-
glucosemonomers (correspondingly named as α, β and γ-CD
respectively) with hydrophilic exterior and hydrophobic interior, are
known able to encapsulate many model substrates to form host-
triggers are always realized by adding heterogenous reagents to the
1
2
initial systems, which, however, could cause non-ignorable
convective motion and mechanically injurious to fragile samples or
1
3
living tissues. In situ tailoring the aggregates in solution or
1
4
intracellular in a noninvasive manner (for instance, heat,
2
2
ultrasound intensity,1 electric pulses, magnetism, light and
5
16
17
18
guest complexes. Vesicles enclose membranes consisting of a
bilayer or multilayer of amphiphiles and a volume of water in the
core, can carry hydrophilic and hydrophobic molecules
simultaneously and attract increasing attention with the hope of
1
9
endogenous glutathione (GSH) in tumor cells ) provides an
attractive alternation without introducing new exogenous species.
The combination of different noninvasive triggers into single
responsive nanoarchitecture will provide multiple means to increase
the responsive sensibility and realize the functions at aimed positions
in a more controllable way. For example, light as the trigger can
realize a clean and precise spatio-temporal control, but meanwhile
the low efficiency and poor penetrating ability prevents its further
applications. Employing redox as the co-activator of the system can
enhance the responding efficacy and combine the advantages of
both triggers.
2
3
24
promising applications in drug/gene delivery, nanoreactors and
artificial cell membranes.
2
5
2
0
Herein, we report
a
photo- and redox-responsive
superamphiphile constructed from an inclusion complexation of β-
CD and disulfide-linked azobenzene dimer 1. The azobenzene dimer
1
was designed, synthesized and fully characterized. The
superamphiphiles can self-assemble into vesicles in aqueous solution.
TEM and DLS were employed to characterize the vesicles’ size and
micromorphology. The formation mechanism was revealed based on
1
the results of H NMR, NMR-NOESY, FT-IR, XPRD and UV-vis
a.
spectrometer. The vesicles tend to be disrupted upon the
introduction of dithiothreitol (DTT) and irradiation of UV light. The
vesicles were found able to carry the model drug and the drug
release can be promoted by UV light and reductant in vitro. This
novel photo and redox responsive vesicles based on
superamphiphiles are promising materials in meeting the
Key Laboratory of Smart Drug Delivery (Ministry of Education), State Key
Laboratory of Medical Neurobiology, Department of Pharmaceutics, School of
Pharmacy, Fudan University, Shanghai 201203, PR China.
b.
School of Chemistry and Chemical Engineering, Weifang University, Weifang
2
61061, PR China.
†
jiangchen@shmu.edu.cn.
Electronic Supplementary Information (ESI) available: detailed synthesis and
mechanism study. See DOI: 10.1039/x0xx00000x
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please Rd So Cn oA t da vd aj un sc te ms argins
Page 2 of 12
ARTICLE
requirements for functional, regular, well-defined, and stimuli- a 1 mL/min flow rate was used. The R
Journal Name
of the analyte (MMC) and the
t
View Article Online
responsive nanoarchitectures, which could be further used in the internal standard (riboflavin) are 7.8 and 6.7DmOiIn: ,10re.1s0p3e9c/Cti6veRAly0.5808F
fields of drug delivery, molecular machine, and nanoreactor.
Synthesis of the compounds
Experimental section
Compound 2: Compounds 2 and 3 were synthesized in a similar way
2
6
as reported. Commercial available p-hydroxyazobenzene (1.98 g,
0 mmol, 1 eq), 1,4-dibromobutane (7.1 mL, 60 mmol, 6 eq) and KOH
1.12 g, 20 mmol, 2 eq) in pure EtOH (150 mL) was refluxed under an
atmosphere of N for 12 h. After cooling down to r.t., EtOH was
Materials
1
(
β-CD was a gift from Zhiyuan Biotechnology Co. Ltd. (Binzhou, China),
recrystallized twice in water, and dried under vacuum at 50 °C for 12
h before using. p-Hydroxyazobenzene, 1,4-dibromobutane thiourea,
DTT and GSH were purchased from Aladdin (Shanghai, China). 2, 2'-
Dithiobispyridine was from TCI Europe (Eschborn, Germany). Agents
2
removed under reduced pressure. Dichloromethane (DCM, 100 mL)
was added to the resulting residue and the solid was filtered off. DCM
was removed in vacuo and the crude product was purified by a flash
column chromatography (SiO , ethyl acetate/petroleum ether (PE),
2
from 1/10 to 1/5 v/v). 2 (1.50 g, 45%) was obtained as a dark brown
3 3
including DMSO-δ6, CD OD and CDCl for nuclear magnetic
resonance (NMR) spectroscopy were from J&K Scientific Ltd. (Beijing,
China). HCl, KOH and all the solvents mentioned here were from
Sinopharm Chemical Reagent (Shanghai, China). Silica gel for flash
column chromatography (SilicaFlash F60, 230~400 mesh) was from
Haiyang Chemical Co., Ltd. (Qingdao, China). N and Ar were from
2
Chenggong Gas (Shanghai, China). MMC was from Knowshine
Pharmachemicals Inc. (Shanghai, China). PBS (pH = 7.40) buffer was
powder.
1
R
f
= 0.9 (ethyl acetate/PE, 1/8 v/v); H NMR (400 MHz, CDCl
3
, δ, ppm):
7
7
=
.92 (d, J = 8.8 Hz, 2H), 7.88 (d, J = 7.6 Hz, 2H), 7.51 (t, J = 7.6 Hz, 2H),
.45 (dd, J = 6.0 Hz, J = 7.6 Hz, 1H), 7.01 (d, J = 8.8 Hz, 2H), 4.09 (t, J
6.4 Hz, 2H), 3.51 (t, J = 6.4 Hz, 2H), 2.09 (m, 2H), 2.00 (m, 2H);
, δ, ppm): 160.8, 152.1, 146.3, 129.8 (2C), 128.4
2C), 124.2 (2C), 121.9 (2C), 66.6, 32.7, 28.8, 27.2;MS-ESI Calc. for
1
2
13
C
NMR (600 MHz, CDCl
(
C
3
prepared by adding NaCl (8 g), Na
2 4 2
HPO ·12H O (2.9 g), KCl (0.2 g),
and KH PO (0.2 g) into 1000 mL distilled water, and then the mixture
2
4
+
16 2
H18BrN O [M+H] 333.1 (100%) and 335.1 (97%), Found, 333.0
was sonicated for 20 min at 300 K. All chemicals were used as
received unless indicated otherwise.
(
v
100%) and 335.0 (97%); IR (vcm-1): 2880.0 (m, vCH2-O-Ar), 1605.2 (vs,
N=N), 1258.2 (s, wCH2-S), 776.4 (m, vCH), 689.7 (s, vC-Br).
Analytical Measurements and Methods.
Compound 3: A solution of 2 (0.19 g, 0.57 mmol, 1 eq) and thiourea
(0.22 g, 2.89 mmol) in EtOH (10 mL) was heated under reflux for 12
h. After cooling down to r.t., a solution of KOH (0.19 g, 3.47 mmol) in
1
Proton-1 NMR ( H NMR) spectra were recorded on a Varian Oxford
NMR spectrometer (Palo Alto, California, USA) operating at 400
1
3
H
2
O (10 mL) was then added into the above solution, refluxed for
another 3 h and cooled down to r.t.. The mixture was acidified by HCl
1N) to pH = 1 and extracted by Et O (30 mL×3). Organics were
combined and washed with brine, dried over Na SO . The solvent
was removed in vacuo and the crude product was purified by a flash
column chromatography (SiO , ethyl acetate/PE, 1/5 v/v). 3 (0.12 g,
5%) was obtained as a brown oil.
MHz/25 °C, while carbon-13 NMR ( C NMR) and NMR ROESY spectra
were recorded on a Bruker NMR Ascend 600 spectrometer (Billerica,
Massachusetts, USA) operating at 600 MHz/25 °C. Fourier transform
infrared spectroscopy (FTIR) spectra were obtained using ATR
geometry on a Spectrum 65 infrared spectrophotometer (Perkin-
Elmer, Waltham, Massachusetts, USA) at 25 °C. Mass spectrometry
(
2
2
4
2
7
R
(
MS-ESI) data were obtained from Agilent LCMSD (Santa Clara,
California, USA). All TEM observations were carried on a JEM-100CX
1
f
3
= 0.8 (ethyl acetate/PE, 1/5 v/v); H NMR (400 MHz, CDCl , δ, ppm):
electron microscope from JEOL Ltd. (Tokyo, Japan). Cryo-TEM was
recorded with a JEOL JEM-1400 TEM (120 kV) at −174 C cooled by
liquid nitrogen. DLS measurements were carried out with a Wyatt
QELS Technology DAWN HELEOS instrument (Santa Barbara, USA)
poised at constant room temperature (25 °C) by using a 12-angle
replaced detector in a scintillation vial and a 50 mW solid-state laser
◦
7.92 (d, J = 8.8 Hz, 2H), 7.88 (d, J = 7.6 Hz, 2H), 7.51 (t, J = 7.6 Hz, 2H),
7
.45 (dd, J
6.4 Hz, 2H), 2.64 (dd, J
1
= 6.0 Hz, J
2
= 7.6 Hz, 1H), 7.00 (d, J = 8.8 Hz, 2H), 4.07 (t, J
= 6.8 Hz, J = 7.2 Hz, 2H), 1.95 (m, 2H), 1.85
, δ, ppm): 161.0,
51.8, 146.1, 129.8, 128.4 (2C), 124.4 (2C), 121.9 (2C), 114.1 (2C),
=
1
13
2
(
m, 2H), 1.58 (m, 1H); C NMR (600 MHz, CDCl
3
1
6
+
19 2
7.1, 29.9, 27.3, 23.8; MS-ESI Calc. for C16H N OS [M+H] 287.1,
(
λ = 658.0 nm). All solutions for DLS were filtered through a 0.45 μm
Found, 287.0; IR (vcm-1): 2934.3 (vs, vCH2 linking SH), 2872.3 (m, vCH2-O-Ar),
filter before measurement. MM2 energy minimize and molecular
size calculation was undertaken on ChemBio 3D Ultra (14.0 version,
Cambridge Software, Massachusetts, USA). Drug-release was
monitored by analytical HPLC, with a Dionex system equipped with
gradient flow control pump (Merck HITACHI pump L-7100, Dartford,
UK), autosampler (Merck HITACHI L-7200, Dartford, UK), Merck
HITACHI Interface L-7000 (Dartford, UK), solvent degasser (Merck L-
1600.5 (vs, vN=N), 1253.5 (vs, wCH2-S), 767.1 (m, vCH), 686.6 (m, vC-SH).
Compound 4: To a stirred solution of 2, 2'-dithiobispyridine (440 mg,
mmol, 4 eq) in AcOH/EtOH (1/20 v/v, 10 mL, degassed by N for 3
min), 3 (143 mg, 0.5 mmol, 1 eq) in AcOH/EtOH (1/20 v/v, 5 mL,
degassed with N for 3 min) was injected dropwise over 20 min under
an atmosphere of N . The mixture was allowed to react at r.t. for 12
2
2
2
2
7
612, Dartford, UK), autosampler, diode array detector (DAD, Merck
h. The solvents were then evaporated to dryness in vacuo. The
resulting residue was subjected to a flash column chromatography
HITACHI L-7455, Dartford, UK), fluorescence detector (Merck
HITACHI FL L-7485, Dartford, UK) and column oven (Merck L-7360,
Dartford, UK). All the parameters of HPLC were controlled by LC
solutions software Ezchrom Elite (SIM GmbH, Oberhausen, Germany).
(
SiO
2
, ethyl acetate/PE, from 1/9 to 1/4 v/v) to afford 4 (73 mg, 37%)
as an orange powder.
®
A LiChroCART 250-4 column (100 RP-18 (5 μm), Merck KGaA,
1
f 3
R = 0.3 (ethyl acetate/PE, 1/8 v/v); H NMR (400 MHz, CDCl , δ, ppm):
Darmstadt, Germany) was employed for the HPLC analysis of MMC.
A UV detector with wavelength from 200 to 600 nm was used and
the absorbance was recorded at 365 nm. An isocratic mobile phase
of 15% acetonitrile in 10 mM phosphate buffer (pH 6.5) in 18 min at
8
7
7
=
.48 (d, J = 4.4 Hz,1H), 7.90 (d, J = 8.8 Hz, 2H), 7.88 (d, J = 9.2 Hz, 2H),
.74 (d, J = 8.0 Hz, 1H), 7.66 (t, J = 8.0 Hz, 1H), 7.50 (t, J = 7.6 Hz, 2H),
.45 (dd, J = 7.2 Hz, J = 7.6 Hz, 1H), 7.10 (t, J = 6.0 Hz, 1H), 6.97 (d, J
1 2
8.4 Hz, 2H), 4.04 (t, J = 6.4 Hz, 2H), 2.90 (t, J = 6.4 Hz, 2H), 1.94 (m,
2
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 12
Please Rd So Cn oA t da vd aj un sc te ms argins
Journal Name
ARTICLE
4
1
1
H); 13C NMR (600 MHz, CDCl
46.4, 136.8, 129.7, 128.4 (2C), 124.1 (2C), 121.9 (2C), 120.1, 119.4, simply mixing compound 1 and β-CD togethDeOr Iw: 1it0h.10th3e9/sCa6mRAe0m58o0l8aFr
3
, δ, ppm): 160.8, 159.6, 152.1, 148.6, aqueous solution samples. The physical mixture waVsieowbAtraticinleeOdnlibnye
14.1 (2C), 67.0, 37.9, 27.3, 24.9; MS-ESI Calc. for C21
H
N
22 3
OS
2
ratio as the inclusion. The mixture should be freshly prepared to
+
[
(
M+H] 396.1, Found, 396.0; IR (vcm-1): 3042.7 (m, vCH of pyridine), 2867.6 avoid the possible complexion activity between the host and guest
m, vCH2-O-Ar), 1600.5 (vs, vN=N), 1248.9 (vs, wCH2-S), 1041.3 (m, wpyridine molecules during the placed period. It should be noted that for FTIR
ring), 826.0 (s, γCH of pyridine), 771.8 (m, vCH), 722.2 (m, vC-S).
spectra, the physical mixture sample β-CD and compound 1 should
be grinded with dry KBr separately, then mixed together quickly and
Compound 1: To a stirred solution of 4 (80 mg, 0.2 mmol, 1 eq) in tableted into a single cake, in order to weaken the possible inclusion
AcOH/EtOH (1/20 v/v, 10 mL, degassed by N
.5 mmol, 2.5 eq) in AcOH/EtOH (1/20 v/v, 5 mL, degassed with N
for 3 min) was injected dropwise over 20 min under an atmosphere Preparation of samples for Job’s plots and complex constant.
of N . The mixture was allowed to react at r.t. for 12 h. The solvents
were then removed in vacuo. The resulting residue was subjected to The complex stoichiometry of β-CD with compound 1 in water was
a flash column chromatography (SiO
, ethyl acetate/PE, 1/8 v/v) to determined by Job’s continuous variation method using a UV-vis
2
for 3 min), 3 (143 mg, phenomenon between them during the grinding procedure.28
0
2
2
2
afford 1 (38 mg, 33%) as an orange powder.
spectrometer. A set of working solutions were obtained by mixing Vg
-
4
mL of the stock 1 solution (10 mol/L) with (V
t
-V
g
) mL of the stock β-
is a
t
). To obtain the complex
1
-4
R
f
= 0.7 (ethyl acetate/PE, 1/8 v/v); H NMR (400 MHz, CDCl
3
, δ, ppm): CD solution (10 mol/L), where V
t
is a fixed total volume and V
≤ V
g
7
7
=
.91 (d, J = 8.8 Hz, 4H), 7.87 (d, J = 7.2 Hz, 4H), 7.50 (t, J = 7.2 Hz, 4H), variable value (from 0 to 10 mL, 0 ≤ V
.44 (dd, J = 6.8 Hz, J = 7.2 Hz, 2H), 7.00 (d, J = 8.8 Hz, 4H), 4.07 (t, J constant, the concentration of 1 (2 × 10 mol/L) was kept constant
6.4 Hz, 4H), 2.80 (t, J = 6.4 Hz, 4H), 1.93 (m, 4H), 1.94 (m, 8H);
, δ, ppm): 160.9 (2C), 152.1 (2C), 146.3 (2C), 10 mol/L.
g
-5
1
2
13
-4
C
with the concentration of β-CD ranging from 4 × 10 mol/L to 3.6 ×
-
3
NMR (600 MHz, CDCl
3
1
3
29.7 (2C), 128.4 (4C), 124.2 (4C), 121.9 (4C), 114.1 (4C), 67.1 (2C),
8.0 (2C), 29.1 (2C), 27.3 (2C), 25.1 (2C); MS-ESI Calc. for Photo-responsive property
+
C
C
32
H
H
35
N
N
4
O
2
S
S
2
[M+H] 571.2, Found, 571.2; HR-MS-TOF Calc. for
[M+H] 571.2201, Found, 571.2214; IR (vcm-1): 2861.0
-2
+
UV irradiation (365 nm, 60 mW·cm ) and irradiation by visible light
32
35
4
O
2
2
-
2
(
λ = 434 nm, 20 mW·cm ) were carried out with a ZF-20D UV analyzer
(
m, vCH2-O-Ar), 1600.8 (vs, vN=N), 1258.2 (s, wCH2-S), 1136.1 (m, vCH2-O-Ar),
39 (m, γCH), 763.6 (m, vCH), 482.4 (w, vS-S).
(
Chengxian Instrument Co., Ltd. (Shanghai, China). It should be noted
8
that the samples for DLS, TEM, NMR or UV-vis measurement should
be well sealed in order to avoid possible solvent evaporation. The
treated samples should be vortexed again for 3 min before measured.
Preparation of the vesicles.
The β-CD/1 vesicles’ preparation procedure was followed as
27
Redox-responsive property
previously reported. Typically, the vesicles were prepared by slowly
adding drips of 1’s ethanol solution into the β-CD aqueous solution
over 5 min at 10 °C. Bluish opalescence appeared immediately,
indicating the formation of assembled particles. The mixture was
treated by vortex and then sonicated for 30 min, and ethanol was
removed under vacuum or dialysis at room temperature.
Before DLS and TEM detection, excess DTT was added to the
vesicular sample and vortexed vigorously for 15 min at 300 K. Notably,
no filtrate screening procedure by 0.45 μm filter was carried out
before DLS measurement unless indicated.
Drug loading and release
Preparation of the TEM and cryo-TEM samples
MMC solution (218 μL) dissolved in methanol with a concentration
All TEM samples were freshly prepared via the phosphotungstic acid
staining technique: the copper mesh was dripped into the sample
solution and air-dried, then a drop of phosphotungstic acid aqueous
solution (0.5%) was dripped onto the mesh and baked under the
infrared lamp for 20 min. Cryo-TEM samples were prepared in a
controlled environment vitrification system (CEVS) at 25 ◦C. A
micropipette was employed to load 5 μL solution onto a TEM copper
grid, which was then blotted with filter paper, resulting in the
formation of thin films suspended on the mesh holes. After 5 s, the
samples were quickly plunged into a reservoir of liquid ethane
-
4
of 55 mg/mL was dispersed in 6 mL vesicular solution (5 × 10 mol/L)
at room temperature under vigorous vortex. Methanol was removed
employing a rotary evaporator at 300 K. After vortex and sonication
for 5 min respectively, the dispersion was treated on table
concentrator at 4 °C for 5 min. The solid was removed by
centrifugation (2 000 g), while the supernatant was distributed
equally into 3 dialysis bags (3 × 1 mL, CE MWCO 500) for the drug-
release test. The vesicular solution loading with MMC was dialyzed
against pure water (25 mL). At the indicated incubation times, 20 µL
solution was transferred into a closed tube containing riboflavin
solution (80 µL, 100 µg/mL). The tube was vortexed with continuous
mixing over 30 s, and 20 µL solution was submitted for HPLC analysis.
The integral of the peaks of MMC and riboflavin was recorded. The
pyrene-loading attempt was undertaken using a similar protocol.
◦
(
cooled and kept by liquid nitrogen) at −165 C. The vitrified samples
were then stored in liquid nitrogen until they were completely
transferred to a cryogenic sample holder (Gatan 626) and examined
with a JEOL JEM-1400 TEM (120 kV) at −174 C cooled by liquid
◦
nitrogen. The phase contrast was enhanced by under-focus. The
images were recorded on a Gatan multiscan CCD and processed with
Digital Micrograph.
To determine the drug loading rate and entrapment efficiency, 40 µL
of the MMC-loading vesicular solution before dialysis treatment was
transferred into a closed tube containing riboflavin aqueous solution
Preparation of the β-CD/1 inclusion complex and the physical
mixture.
(
60 µL, 100 µg/mL). The tube was vortexed with continuous mixing
over 30 s, and 20 µL solution was submitted for HPLC analysis.
The sample of β-CD/1 inclusion complex for FT-IR and XRD
characterizations were isolated by freeze-drying the vesicular β-CD/1
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please Rd So Cn oA t da vd aj un sc te ms argins
Page 4 of 12
ARTICLE
Journal Name
The drug-release promoted by UV was realized by irradiation of the overall layer thicknesses of these vesicles was meVaieswurAertdicletOonlbinee
-
2
sample under UV light (365 nm, 60 mW·cm ) for 30 min. The drug- around 20 nm from TEM images. The layer thDicOkIn: 1e0s.s10v3a9lu/Ce6sRaAr0e5c8l0o8seF
release promoted by reductant was realized by direct addition of to the long-axis dimensions of 2β-CD@1 supramolecular system
excess DTT solid into the dialysis bags.
(Figure S20), suggesting a single-layered molecular packing model.
The spherical morphology suggests a favourable rigid property to
withstand the electron impact from TEM observation. The diameters
of the obtained spheres are ranged from 100 to 800 nm. No vesicles
were detected in the suspension of sole β-CD (irregular particles,
Figure S21) or 1 (crystalline particles, Figure S22), demonstrating the
importance of the combination with the supramolecular host and
guest in forming the vesicular aggregates. To be more exact, DLS
measurement was employed to further measure the particle size
distributions (Figure 1 (C)), which gave an average diameter as 282.2
nm in pure water and 312.5 nm in PBS, which is slightly larger than
the diameters obtained by TEM. It is understandable that TEM
measures the solid spheres, whereas DLS measures the
Results and discussion
Design, synthesis and characterization of 1
35
hydrodynamic diameters.
The polydispersion of the size
distribution in DLS results is also in agreement with the TEM
morphology. There are few differences in the size and morphology
change observed by DLS and TEM one week after the preparation of
the vesicular solution. .
With the aim of designing photo and redox-responsive vesicles, a
modularly approach were employed to construct the building block.
The photo-responsiveness of azobenzene/β-CD complex and redox-
responsiveness of disulfide bond were used in the molecular design.
Driving force of the vesicular formation
The knowledge on the know-how mechanism of the microstructure’s
11
Then, a retrosynthesis was carried on and a classic method was
adopted to form the key disulfide bond via an intermediate of 2-
mercaptopyridine derivate 4. All compounds were characterized in
formation is regarded crucial in guiding the initial structure design
36
and tailoring the corresponding properties. Multiple means,
1
including XRD, FTIR, H NMR, NMR-NOESY and UV-vis, were
1
13
detail (Figure S1 to S17, including H NMR, C NMR, MS, HR-MS-TOF
and FT-IR spectra).
employed to investigate the mechanism of the vesicles’ formation.
XRD analysis
Morphologies and sizes of the vesicles
β-CD aqueous solution exhibited a typical true solution, whereas 1
aqueous dispersion can generate obvious cloudy suspension and
some precipitation will appear if left to stand still for 2 h. The
vesicular solution exhibited a slightly milky opalescence and totally
differed from the samples with single compositions (Figure S18),
2
7, 29
indicating the formation of assembled particles.
Typical Tyndall
phenomenon of the β-CD/1 vesicular solution was observed when a
laser pointer was used to light the sample (Figure S18).
Figure 1. TEM micromorphology images (A: in water, B: in PBS) and
DLS result (C) of β-CD/1 vesicular sample. Phosphotungstic acid was
used as the negative staining agent.
2
9,
To demonstrate the microstructures of the self-aggregation, TEM
and DLS
3
0
16, 18, 31
was used to study the morphologies of β-CD/1
sample in pure water and PBS.
Figure 2. The XRD spectra of β-CD, 1, their physical mixture, and
inclusion complex at 300 K.
The TEM results in Figure 1 (A) and (B) show clear empty shells with
obvious contrast between the center and the verge, which is the
typical characteristic of vesicular aggregates based on the classical
XRD37 was applied in analyzing the species in the supramolecular
complex (Figure 2). Freeze-dried β-CD/1 complex, which can
maintain the in situ dimensional molecular position, was prepared.
2
, 4, 32,33
34
literatures.
and our experience. To further verify the onion-
3
8
like structure, cryo-TEM was undertaken as shown in Figure S19. The
4
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 12
Please Rd So Cn oA t da vd aj un sc te ms argins
Journal Name
ARTICLE
In the β-CD/1 physical mixture spectra, the peaks at 9.6◦, 12.7◦, 13.3◦ aDHO peak (δ = 4.790) is as the interior label.
and 18.2◦ were found, evidencing β-CD molecules with a cage-type
View Article Online
DOI: 10.1039/C6RA05808F
crystalline structure,39 and in herringbone-type and brick-type.40 The
b
Δδ = δ(β-CD) - δ(β-CD/1).
physical mixture is obviously an overlying of β-CD and 1, whereas the
β-CD/1 complex is more like in an amorphous state, suggesting the
formation of a new specie.
1
H NMR, as one of the most powerful and versatile methods in
4
3
studying the supramolecular interactions in aqueous solutions, was
employed to investigate the mechanism. The comparison of H NMR
1
FTIR analysis
results of β-CD and β-CD/1 samples was shown in Table 1 and Figure
S23. It is known that H2 and H4 protons are located outside of the
cyclodextrin cavity, while H3 and H5 protons are located inside the
43
cavity . From the table, it is easy to find out that both H3 and H5
protons exhibit slightly larger chemical shifts than H1, H2 and H4
proton, which means that 1 molecule is included into the
cyclodextrin cavity. Meanwhile, H6 proton existing on the primary
face also shows obvious chemical shift, indicating the guest molecule
6
00
00
1
3
-CD
4
3
enter the cavity from the primary side . During the supramolecular
inclusion procedure, there is no change of covalent bonds and the
chemical shifts are more ascribed to the micro environmental
physical mixture
2
differences, mainly including: (1) the substitution of H O molecules
0
4
inclusion complex
in high energy state in the cavity by the azo moiety of compound 1;
(2) the hydrodynamic radius change after the complexation; (3) the
destruction and formation of hydrogen bonds. The chemical shifts
are thus not as pronounced as the ones resulted from the covalent
bonds.
1
136
947
839
1
258
000 3500 3000 2500 2000 1500 1000
500
-1
Wavelength/cm
NMR NOESY
Figure 3. FT-IR spectra comparison of β-CD, 1, their physical mixture,
and inclusion complex in KBr capsules at 300 K.
FT-IR is widely employed in investigating the interactions among
41
molecular in supramolecular science. The solid supramolecular
inclusion complex was obtained from the vesicular solution by
freeze-drying, which is supposed able to maintain the in-situ
interactions. The FT-IR spectral comparison of 1, β-CD, their physical
mixture, and the inclusion complex was undertaken as shown in
Figure 3. Both the characteristic peaks of 1 (the blue dotted lines,
-1
-1
1
136 cm : vCH2-O-Ar) and β-CD (947 cm : vC-O) can be found in the
spectra of the physical mixture and inclusion complex, suggesting the
composition of 1 and β-CD in them. The spectrum of the inclusion
complex shows obvious differences from the physical mixture’s: (1)
based on the red-circled area, it is obvious to recognize that the
physical mixture spectrum is the simple overlap of 1 and β-CD ones.
Both 1 and β-CD are thus supposed to exist in an independent status;
-
1
(
(
2) in the inclusion complex, the peaks of wCH2-S (1268 cm ) and γCH Figure 4. 2D NMR ROESY (600 MHz) spectrum of β-CD/1 in DMSO-δ6
-
1
839 cm ) in 1’s spectrum shifted or disappeared, evidencing the at T = 300 K.
formation of a new specie; (3) the stretching vibration peaks of the
hydroxyl group appearing near the wavelength of 3350 cm are 2D NMR nuclear overhauser enhancement spectroscopy (2D NMR
-1
obviously different both in shape and in intensity, indicating the ROESY) is a reliable and versatile tool in detecting the interactions
4
2
newly formed hydrogen bonds in the inclusion complex.
between pairs of nuclei that are closer than 5 Å, even if not covalently
bound. The solubility of β-CD/1 in D O is too low to show the NMR
2
44
1H NMR characterizations
peaks, DMSO-δ6 was used instead. Clear cross correlation between
the signals of the inner CD protons (3.3 and 3.6 ppm) and the phenyl-
protons of 1 (from 7 to 8 ppm) were found (Figure 4), demonstrating
the entrance of 1 into β-CD cavity. Meanwhile, no interactions were
found between 1 and H1 (locating outside the CD cavity), further
evidencing the supposed inclusion model.
1
Table 1. H NMR: comparison of the chemical shifts of single β-CD
Entry
H1
H2
H3
H4
H5
H6
δ(β-CD)
δ(β-CD/1)
Δδb
5.028 3.606 3.926 3.543 3.837 3.814
5.020 3.598 3.914 3.537 3.825 3.798
0.008 0.008 0.012 0.006 0.012 0.016
UV-vis spectra
and β-CD/1a
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Please Rd So Cn oA t da vd aj un sc te ms argins
Page 6 of 12
ARTICLE
Journal Name
β-CD, with a hydrophobic inner dimensional cavity anVidewhAyrdticrloe pOhnliilnice
rims, have the capability to encapsulateDOoIr: 10tr.1a0p39h/Cy6dRrAo0p5h8o0b8iFc
substrate to form a supramolecular inclusion complex in aqueous
0
0
0
0
0
0
.5
.4
.3
.2
.1
.0
49
solution. The host-guest binding is normally based on the non-
covalent interactions, and thus reversible. Based on the analysis of
the molecular structures (Figure S20) and the above experimental
results, compound 1 as the guest molecule could be recognized and
caged by the host molecule via hydrogen bonds, hydrophobic and
5
0
van der Waals interactions. The both-ended benzene rings of 1
molecule enter the β-CD cavity through the primary face, while the –
N=N– moiety remains outside the cavity, participating with the
hydroxyl groups in the rims via hydrogen bonds. In this way, the
constructed “Bola” superamphiphiles can be homogeneously
dispersed in water and self-assemble into bilayer vesicles. The
0.0
0.2
0.4
0.6
0.8
1.0
[
G]/[G] + [H]
Figure 5. Job’s plots by UV–vis for the binding of β-CD with
compound 1 in water at room temperature.
“
sandwich”-like bilayer membrane is illustrated in Scheme 1: the
The complex stoichiometry of β-CD with 1 in water was measured by
the continuous variation method (Job’s method) using a UV-vis
hydrophilic β-CD heads interact with surrounding water and
hydrophobic linkers minimize their exposure to water by aggregating
together. The vesicles’ formation mechanism can be concluded into
two levels of supramolecular assembly: construction of
superamphiphiles based on host-guest recognition and organization
of the superamphiphiles into vesicular structure. Different topology
structures will lead different properties and corresponding functions.
Since there are very few reports on “Bola-type” superamphiphile,
enriching the topology structure of superamphiphile is regarded
valuable.
45
spectrophotometer. The Job’s plots for the binding of β-CD with 1
in water showed a maximum value at a molar fraction of 0.4 (Figure
S24, Figure 5), suggesting that 1/β-CD complex stays in a 1:2
4
6
stoichiometry mode. The result is also in accordance with previous
47
study. The stoichiometry and the inclusion constants were further
calculated by UV double-reciprocal method based on the Benesi-
4
8
Hildebrand equation:
/ΔA = 1/α+ 1/αKap[β-CD]n
1
Photo-reversible
Where ΔA is the change of UV absorbance of 1 in presence of β-CD,
α is a constant, [β-CD] is the initial concentration of β-CD. Kap is the
constant for the formation of n:1 (H:G) inclusion complex, which
n
could be calculated from a plot of 1/ΔA versus 1/[β-CD] (Figure S25).
6
The inclusion constants of 2:1 (H:G) were calculated as 3.69 × 10
L /mol .
2
2
Figure 6. TEM micromorphology images of β-CD/1 samples (A) UV-
irradiated in water; (B) UV-irradiated in PBS; (C) visible light-
irradiated in water; (D) visible light-irradiated in PBS, where the
irregular particles could be ascribed to the dried inorganic salts in PBS.
Phosphotungstic acid was employed as the negative staining agent.
Scheme 1. Illustration of the formation mechanism for the vesicle
and “Bola-type” superamphiphiles
6
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 7 of 12
Please Rd So Cn oA t da vd aj un sc te ms argins
Journal Name
ARTICLE
Figure 7. DLS size distributions of β-CD/1 vesicles, UV-irradiated corresponding spectrum was in good coherence with the 0 min one,
View Article Online
5
2
sample (30 min) and visible-light-irradiated sample (5 h) in water (A) which indicates the favorable reverse isomerDizOaIt:i1o0n.1.039/C6RA05808F
and PBS 7.40 buffer (B).
Table 2. DLS results of the vesicles in the aqueous solution at 300 K
upon UV (0.5 h) and visible light (5 h) irradiation.
Media
Initial
Upon
UV Upon visible light
irradiation (0.5 irradiation (5 h)
h)
pure
water
PBS 7.40
282.2
312.5
30.8
297.6
a
a
48.7
343.4
a
Theunit is nm.
Light, as a non-invasive regulating approach, has its special
advantages over chemical triggers. For instance, it takes several
minutes for chemical triggers to reach the target, while it takes less
13
than one second for light . Furthermore, light as the trigger can be
12
completely removed quickly on-demand. Other than the rapidness
and cleanness, light can even realize a precise regulation at a
nanometer size. The reversibility of our vesicles’ formation governed
by light was studied using DLS and TEM. As shown in Figure 6/7 and
Table 2, upon UV irradiation for 30 min, the particles’ diameter sizes
decrease significantly and particles with irregular shapes were
observed. Then, upon visible light irradiation again, the size
distribution and vesicular structures can be recovered. The
recovered vesicles shown in Figure 6 (C) and (D) show more rigid and
shrunk structure compared with the original ones in Figure 1 (A) and
(
B). This could be ascribed to the water escape from the core during
the vesicle-reconstruction procedure. The results show fine
reproducibility of the size distribution and morphology investigated
by DLS and TEM. It is interesting that in PBS media, some cross-linked
vesicles were found upon recovery by visible light (Figure S26).
1
Figure 9. Enlarged H NMR spectra (400 MHz in mixed CD
3 3
OD/CDCl
(
2/1 v/v) at 298 K) from the same tube of 1 before (A), after (B) UV
-
2
irradiation (365 nm, 60 mW·cm , 30 min) and (C) visible light
irradiation (λ = 434 nm, 20 mW·cm , 5 h).
-
2
1
Based on the H NMR spectra (Figure 9), approximately 64% of the
trans isomers switched to cis isomers after 365 nm UV irradiation for
-
2
3
0 min (60 mW·cm ). The new peaks’ chemical shifts are in
5
3
accordance with the previous report. The whole version can be
found in Figure S26. It was reported that the cis 1 could change back
to trans isomers by heating or visible light irradiation. The
photoresponse indicated in Figure 9 would have to be a sequential
two photon process in order to isomerize the two azobenzene
moieties. Then after visible light irradiation for 5 h, nearly all the cis
Figure 8. (A) UV/vis spectra of β-CD/1 in water for increasing
durations of UV irradiation (λ = 365 nm) of 0, 5, 10, 20, 30, 40, 50, 60,
1
isomers switched back to the trans isomers according to the H NMR
8
0, 100, 120 min (shown from down to top) and the spectrum of the
recovered sample upon visible light irradiation (λ = 434 nm) for 5 h;
B) Absorbance changes at 265 nm of β-CD/1 in water with
spectra, proving the favorable reversibility of 1. Quantitive research
have been reported that β-CD can include the trans azobenzene into
(
5
4
its cavity but not the cis one. Thus, we have reason to deduce that
after UV irradiation, the cis 1 could be liberated from the cavity of β-
CD, and caged back to the cavity after the visible light irradiation,
alternating UV and visible light irradiation.
We studied the UV-induced isomerization of 1 by UV/vis absorption
spectroscopy (Figure 8) and H NMR (Figure 9, Figure S27). UV/vis
spectra of β-CD/1 after UV irradiation (λ = 365 nm) for different
durations at room temperature was undertaken as shown in Figure
leading
the
reversible
assembly-disassembly
of
this
1
superamphiphiles. During the reversible photo-responsive
procedure, the steric effects should predominate in the formation of
5
5
complex with respect to hydrogen bonds. The reversible light-
responsive procedure can be repeated at least 5 times.
8
. A caused substantial change in the UV/vis spectra was observed.
As the irradiation went on, the absorption peak at 265 nm increased
gradually and moved slightly to 267 nm. Meanwhile, the wave trough
at 214 nm shifted remarkably to 226 nm. These phenomenon can be
ascribed to the isomerization of the azo groups from trans (π-π*) to
5
1
cis (n-π*) form. The UV-irradiated sample was subjected to visible
light irradiation at 434 nm at room temperature for 5 h, and the
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 7
Please do not adjust margins

Please Rd So Cn oA t da vd aj un sc te ms argins
Page 8 of 12
ARTICLE
Journal Name
View Article Online
DOI: 10.1039/C6RA05808F
Figure 10. The illustration of the photo-responsive mechanism
The vesicles can undergo disassembly and assembly reversibly by
light irradiation because of the photo isomerization of the azo group
(
Figure 10, Figure S20). The light-switchable property can be applied
in designing photo-tailored microstructures.
Redox-responsive
The major drawback of light-triggered drug delivery is the low
penetration depth (~10 mm) that results from the strong scattering
properties of soft tissues. It should be of great advantage if we can
combine other endogenous co-activators (for example, highly
expressed GSH in tumor cells) into the same system for dual
regulation. It is known that DTT is a widely-used reductant to cleave
56
the disulfide bonds. Excess DTT was added to the vesicular solution
and it was found that the vesicles disappeared by DLS (Scheme 2 (A))
and TEM (Figure S28). The DTT-treated dispersion (100 mL) was
Scheme 2. (A) DLS results of the β-CD/1 vesicles upon DTT treatment
in the aqueous solution at 300 K (black: in pure water; red: in PBS
2
extracted by Et O (3 × 100 mL), and compound 3 can be isolated by
7.40); (B) the illustration of possible mechanism and molecular sizes
a flash column chromatography. The structure was confirmed by TLC
and MS-ESI results. Hence, we deduce that after the cleavage of the
disulfide bond by DTT, compound 3 will be liberated from the dimer.
It could be deduced that compound 3 owns too limit hydrophobic
volume to play as the hydrophobic tail of the superamphiphiles,
which prevents the formation of vesicles. It was reported that the
included guest’s single alkyl chain should possess at least 6 carbon to
after energy minimization.
Drug loading and triggered drug-release
57
play the role of hydrophobic tail of superamphiphile. As shown in
Scheme 2 (A), upon DTT treatment, two independent peaks were
found in the DLS results both in pure water and PBS 7.40. Based on
the molecular-size calculation after energy minimized (Figure S20),
the peak around 1 nm could be ascribed directly from β-CD, while the
peak around 3 nm from the dissociative β-CD/3 complex. The peak
distribution was further confirmed by comparing with the DLS results
of β-CD/3 in water and β-CD in PBS 7.40 (Figure S29). It is interesting
that in pure water, β-CD/3 complex is still somehow stable, and in
PBS 7.40 buffer, the complex tends to be dissociated, which could be
due to the stronger electrostatic repulsion in saline media. The
second peaks with larger sizes should be resulted from the
precipitated compound 3. GSH, highly expressed in tumor cells, was
also tested as the reducing agent and found to have similar effect as
DTT.
Figure 11. A: TEM micromorphology images (A) and DLS result (B) of
MMC-loaded vesicles in water. Phosphotungstic acid was employed
as the negative staining agent.
About 40% of drugs are poorly soluble in aqueous solutions and this
number is believed to be still increasing as the development of
5
8
modern high-throughput screening drug-discovery technologies.
Increasing the solubility and dissolution rate are key steps in the drug
12
formulation and delivery process. MMC, which finds use as a
59
chemotherapeutic agent by virtue of its antitumour activity, can
1
1
serve as a model drug with low aqueous solubility. Obvious
-
1
characteristic vc=c peaks (1729, 3267, 3314, 3450 cm ) of MMC in the
FTIR spectrum of MMC-loaded vesicle sample demonstrate
successful carrying of MMC to the vesicular system (Figure S30). The
61
solubility of MMC was increased from 0.9 mg/mL to 4.24 mg/mL by
the vesicles. Based on the HPLC qualification (Figure S31, S32), the
drug loading coefficient and encapsulating rate were calculated as
8
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 9 of 12
Please Rd So Cn oA t da vd aj un sc te ms argins
Journal Name
ARTICLE
2
8.2 wt% and 27.8%, respectively. Upon the drug loading, the β-CD/1 azobenzene dimer linked by disulfide bond was syntheVsieiwzeAdrtiaclnedOnclianne
vesicles’ diameters increase slightly observed from TEM and DLS be included by β-CD from both ends toDcOoI:n1s0t.r1u0c3t9/aC6BRoAl0a5-8ty0p8eF
observations (295 nm, Figure 11). This may be due to the insertion of superamphiphile in aqueous solution. The superamphiphiles can
6
0
hydrophobic molecules into the bilayers. The spheres with core– further self-assemble into dynamic vesicular structure, which is
shell structures have significant contrast between the centre and the characterized by TEM, cryo-TEM and DLS. The formation mechanism
periphery are regarded with a vesicular structure under TEM of the vesicular structure was suggested based on the results of XRD,
1
observation. We also attempted to load pyrene into the vesicles, but FTIR, H NMR, NMR-NOESY and UV-vis results. The vesicles will be
only weak peaks of pyrene can be detected from the FTIR spectrum disrupted upon treatment by UV irradiation and can be recovered by
of dried pyrene-loaded vesicle (Figure S34), suggesting a lower visible light irradiation. Reducing agents like DTT and GSH can cause
loading rate. This could be ascribed to the poor hydrogen bonds dispersion of the vesicle clusters via breaking the disulfide bond. We
formed between pyrene and the building blocks.
attempted to employ the vesicles to load antitumor drug MMC. Upon
stimuli, the drug release can be significantly promoted. We believe
the study can enrich the topology structure of superamphiphiles and
cast a new light on the facile design of noninvasive stimuli-responsive
materials.
80
60
40
20
0
DTT-treated
UV-treated
Control
Acknowledgements
This work was supported by the Scientific Research
Foundation of Fudan University for Talent Introduction
Addition of excess DTT
UV-irradiated (0.5 h)
(
JJF301103), National Science Fund for Distinguished Young
Scholars (81425023), National Natural Science Foundation of
China (81172993) and Fudan's Undergraduate Research
Opportunities Program (FDUROP, SSH6285006/004/021). The
authors declare no competing financial interest. The authors
appreciate a lot for Mr. Pengyao Xing from Shandong
University for the assistance on the careful TEM
characterization. Supporting information is available online
from the author.
0
2
4
6
Time/h
Figure 12. In vitro release profiles of MMC-loaded vesicles at 300 K.
Blue: no trigger; black: UV irradiated; red: excess DTT added. Values
are represented as means ± SD (n = 3).
The drug release upon UV and redox triggers was studied using the
classic method of semipermeable membrane. UV light (0.5 h) can
trigger 11% more MMC release from the vesicles than control, while Notes and references
the value of DTT trigger can reach 37%. We deduce that after the
1
X. Zhang and C. Wang, Supramolecular amphiphiles, Chem.
dissociation of β-CD and 1 triggered by UV, the recovered β-CD cavity
can reload MMC.6 The disulfide bonds are cleaved by DTT, however,
the resulting compound 3 can be still caged in β-CD’s cavity,
excluding partial MMC from the vesicular system. There is
competition for the β-CD’s complexation among the rest MMC and
compound 3.
Soc. Rev., 2011, 40, 94−101.
2
2
Y. Cao, X. Hu, Y. Li, X. Zou, S. Xiong, C. Lin, Y. Shen and L. Wang,
Multistimuli-responsive supramolecular vesicles based on
water-soluble pillar[6]arene and SAINT complexation for
controllable drug release, J. Am. Chem. Soc., 2014, 136,
10762−10769.
P. Xing, T. Sun and A. Hao, Vesicles from supramolecular
amphiphiles, RSC Adv., 2013, 3, 24776−24793.
Y. Liu, C. Yu, H. Jin, B. Jiang, X. Zhu, Y. Zhou, Z. Lu and D. Yan,
A Supramolecular Janus hyperbranched polymer and its
photoresponsive self-assembly of vesicles with narrow size
distribution, J. Am. Chem. Soc., 2013, 135, 4765−4770.
I. Tomatsu, A. Hashidzume and A. Harada, Photoresponsive
hydrogel system using molecular recognition of α-
cyclodextrin, Macromolecules, 2005, 38, 5223−5227.
R. Dong, Y. Zhou, X. Huang, X. Zhu, Y. Lu and J. Shen,
Functional supramolecular polymers for biomedical
applications, Adv. Mater., 2015, 27, 498–526.
3
4
Other than the disulfide approach, the design of redox-responsive
vesicles can be achieved by employing the functional moieties of
6
3
64
65
ferrocene , quinone , tetrathiafulvalene or poly (propylene
6
6
sulphide) . However, there are few reports on redox and light
63
responsive drug carriers. It was known that the disulfide bonds can
also be cleaved by highly expressed intracellular GSH in tumor cells.
5
6
7
6
7
Considering the limit penetrating ability of UV light for the
responsiveness, the vesicular systems could be explored in delivering
6
8
drugs to the surficial targets like mammary and melanoma tumors.
Vesicles that can be responsive to near infrared (NIR) light6 is under
development for more applications. It can be concluded that the
vesicles are photo-reversible and can be thoroughly destructible by
reductants. This could be used in the morphology control during the
blood circulation by light to adjust the drug loading rate and a total
burst release at the aimed tissue to reach a high drug level.
9
Y. Liu, K. Wang, D. Guo and B. Jiang, Supramolecular assembly
of perylene bisimide with β-cyclodextrin grafts as a solid-state
fluorescence sensor for vapor detection, Adv. Funct. Mater.,
2
009, 19, 2230−2235.
8
R. Eelkema, K. Maeda, B. Odell and H. L. Anderson, Radical
cation stabilization in a cucurbituril oligoaniline rotaxane, J.
Am. Chem. Soc., 2007, 129, 12384−12385.
9
T. Aida, E. W. Meijer and S. I. Stupp, Functional
supramolecular polymers, Science, 2012, 335, 813–817.
0 A. Tsuda, Y. Nagamine, R. Watanabe, Y. Nagatani, N. Ishii and
T. Aida, Spectroscopic visualization of sound-induced liquid
Conclusions
1
In this work, we demonstrate a new type of “Bola-type”
superamphiphiles with photo and redox-responsive properties. An
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 9
Please do not adjust margins

Please Rd So Cn oA t da vd aj un sc te ms argins
Page 10 of 12
ARTICLE
Journal Name
vibrations using a supramolecular nanofiber, Nat. Chem., 30 Q. Zhang, Y. Liao, L. He and W. Bu, Spherical polVyimeweArrtbicrleuOsnhlienes
2
010, 2, 977−983.
in solvents of variable quality: an experimental insight by TEM
DOI: 10.1039/C6RA05808F
imaging, Langmuir, 2013, 29 (13), 4181−4186.
1
1
1
1 T. Sun, A. Morger, B. Castagner and J.-C. Leroux, An oral redox-
sensitive self-immolating prodrug strategy, Chem. Commun., 31 J. R. S. Martin, I. Bihannic, C. Santos, J. P. S. Farinha, B. Demé,
2015, 51, 5721−5724.
F. A. M. Leermakers, J. P. Pinheiro, E. Rotureau and J. F. L.
Duval, Structure of multiresponsive brush-decorated
nanoparticles: a combined electrokinetic, DLS, and SANS
study, Langmuir, 2015, 31 (16), 4779−4790.
2 S. Mura, J. Nicolas and P. Couvreur, Stimuli-responsive
nanocarriers for drug delivery, Nat. Mater., 2013, 12 (11),
991−1003.
3 R. Labruère, A. Alouane, T. Le Saux, I. Aujard, P. Pelupessy, A. 32 Y. Kim and M. Lee, Supramolecular capsules from bilayer
Gautier, S. Dubruille, F. Schmidt and L. Jullien, "Self-
immolative" spacer for uncaging with fluorescence reporting,
Angew. Chem. Int. Ed. Engl., 2012, 51 (37), 9344−9347.
4 K. Chen, H. Liang, H. Chen, Y. Wang, P. Cheng, H. Liu, Y. Xia and
H. Sung, A thermoresponsive bubble-generating liposomal
system for triggering localized extracellular drug delivery, ACS
Nano, 2013, 7 (1), 438−446.
membrane scission driven by corannulene, Chem. Eur. J., 2015,
21, 5736−5740.
33 R. Tamate, T. Ueki, M. Shibayama and R. Yoshida, Self-
oscillating vesicles: spontaneous cyclic structural changes of
synthetic diblock copolymers, Angew. Chem. Int. Ed., 2014, 53,
11248−11252.
34 T. Sun, Q. Guo, C. Zhang, J. Hao, P. Xing, J. Su, S. Li, A. Hao and
Liu, G. Self-assembled vesicles prepared from amphiphilic
cyclodextrins as drug carriers, Langmuir, 2012, 28, 8625−8636.
1
1
5 N. Y. Rapoport, A. M. Kennedy, J. E. Shea, C. L. Scaife and K. H.
Nam, Controlled and targeted tumor chemotherapy by
ultrasound-activated nanoemulsions/microbubbles, J. Control. 35 R. Maurice, M. L. Eftink, K. Bystrom, H. D. Perlmutter and D. S.
Release, 2009, 138, 268−276.
Kristol, Cyclodextrin inclusion complexes: studies of the
variation in the size of alicyclic guests, J. Am. Chem. Soc., 1989,
111, 6765−6772.
1
6 J. Ge, E. Neofytou, T. J. Cahill, R. E. Beygui and R. N. Zare, Drug
release from electric-field-responsive nanoparticles, ACS
Nano, 2011, 6 (1), 227−233.
36 Q. Zhao, Y. Wang, Y. Yan and J. Huang, Smart nanocarrier: self-
assembly of bacteria-like vesicles with photoswitchable cilia,
ACS Nano, 2014, 8 (11), 11341−11349.
1
7 M. B. Bannwarth, S. W. Kazer, S. Ulrich, G. Glasser, D. Crespy
and K. Landfester, Well-defined nanofibers with tunable
morphology from spherical colloidal building blocks, Angew. 37 K. Zhu, C. A. O'Keefe, V. N. Vukotic, R. W. Schurko and S. J.
Chem. Int. Ed. Engl., 2013, 52, 10107−10111.
8 P. K. Kundu, D. Samanta, R. Leizrowice, B. Margulis, H. Zhao,
Loeb, A molecular shuttle that operates inside a metal–
organic framework, Nat. Chem., 2015, 7, 514−519.
1
M. Börner, T. Udayabhaskararao, D. Manna and R. Klajn, Light- 38 W. Yin and M. Z. Yates, Effect of interfacial free energy on the
controlled
self-assembly
of
non-photoresponsive
formation of polymer microcapsules by emulsification/freeze-
drying, Langmuir, 2008, 24 (3), 701−708.
nanoparticles, Nat. Chem., 2015, 7 (8), 646−652.
1
9 J. H. Ryu, R. T. Chacko, S. Jiwpanich, S. Bickerton, R. P. Babu 39 P. L. Nostro, I. Santoni, M. Bonini and P. Baglioni, Inclusion
and S. Thayumanavan, Self-cross-linked polymer nanogels: a
compound from a semifluorinated alkane and β-cyclodextrin,
Langmuir, 2003, 19, 2313−2317.
versatile nanoscopic drug delivery platform, J. Am. Chem. Soc.,
2010, 132, 17227−17235.
40 W. Weng, Z. Li, A. M. Jamieson and S. J. Rowan, Control of gel
2
2
2
0 J. H. Schenkel, A. Samanta and B. J. Ravoo, Self-assembly of
soft hybrid materials directed by light and a magnetic field,
Adv. Mater., 2014, 26, 1076−1080.
morphology and properties of a class of metallo-
supramolecular polymers by good/poor solvent environments,
Macromolecules, 2009, 42, 236−246.
1 Y. Zhang, J. W. Chanb, A. Morettia and K. E. Uhrich, Designing 41 G. Li and L. B. McGown, Molecular nanotube aggregates of β-
polymers with sugar-based advantages for bioactive delivery
and γ-cyclodextrins linked by diphenylhexatrienes, Science,
1994, 264, 249−251.
applications, J. Control. Release, 2015, 219, 355−368.
2 A. Alsbaiee, B. J. Smith, L. Xiao, Y. Ling, D. E. Helbling and W. 42 J. H. Jung, G. John, M. Masuda, K. Yoshida, S. Shinkai and T.
R. Dichtel, Rapid removal of organic micropollutants from
Shimizu, Self-assembly of a sugar-based gelator in water: Its
remarkable diversity in gelation ability and aggregate
structure, Langmuir, 2001, 17, 7229−7232.
water by a porous β-cyclodextrin polymer, Nature, 2016, 529,
190−194.
23 T. M. Allen and P. R. Cullis, Drug delivery systems: entering the 43 H. J. Schneider, F. Hacket, V. Rüdiger and H. Ikeda, NMR
mainstream, Science, 2004, 303, 1818−1822.
studies of cyclodextrins and cyclodextrin complexes, Chem.
Rev., 1998, 98, 1755−1785
24 S. M. Christensen and D. Stamou, Surface-based lipid vesicle
reactor systems: fabrication and applications, Soft Matter, 44 S. Hu, J. Li, J. Xiang, J. Pan, S. Luo and J. Cheng, Asymmetric
2
007, 3, 828−836.
5 D. E. Discher and A. Eisenberg, Polymer vesicles, Science, 2002,
97, 967−973.
supramolecular primary amine catalysis in aqueous buffer:
connections of selective recognition and asymmetric catalysis,
J. Am. Chem. Soc., 2010, 132 (20), 7216−7228.
2
2
2
6 N. O. Mahmoodi, A. Ghavidast, S. Mirkhaef and M. A. 45 D. Bardelang, A. Rockenbauer, H. Karoui, J. P. Finet and P.
Zanjanchi, Photochromism of azobenzene-thiol-1, 3-
diazabicyclo-[3.1.0]hex-3-ene on silver nanoparticles, Dyes
Pigments, 2015, 118, 110−117.
7 J. Zou, F. Tao and M. Jiang, Optical switching of self-assembly
and disassembly of noncovalently connected amphiphiles,
Langmuir, 2007, 23, 12791−12794.
8 K. Uekama, F. Hirayama and T. Irie, Cyclodextrin drug carrier
systems, Chem. Rev., 1998, 98, 2045−2076.
Tordo, Inclusion complexes of PBN-type nitrone spin traps and
their superoxide spin adducts with cyclodextrin derivatives:
parallel determination of the association constants by NMR
titrations and 2D-EPR simulations, J. Phys. Chem. B, 2005, 109,
10521−10530.
2
46 P. MacCarthy, Simplified experimental route for obtaining
Job’s curves, Anal. Chem., 1978, 50, 2165.
2
47 W. An, H. Zhang, L. Sun, A. Hao, J. Hao and F. Xin, Reversible
vesicles based on one and two head supramolecular
cyclodextrin amphiphile induced by methanol, Carbohyd. Res.,
2010, 345, 914−921.
2
9 P. S. K. Gehlot, S. Rao, P. Bharmoria, K. Damarla, H. Gupta, M.
Drechsler and A. Kumar, Spontaneous formation of
multiarchitecture vesicles of [C8mim]Br + [Na]DBS in aqueous
medium: synergic interplay of electrostatic, hydrophobic, and 48 G. M. Escandar, Spectrofluorimetric determination of
π–π stacking interactions, J. Phys. Chem. B, 2015, 119 (49),
5300−15309.
piroxicam in the presence and absence of β-cyclodextrin,
Analyst, 1999, 124, 587−591.
1
1
0 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 11 of 12
Please Rd So Cn oA t da vd aj un sc te ms argins
Journal Name
ARTICLE
4
5
5
9 G. Crini, Review: a history of cyclodextrins, Chem. Rev., 2014,
reporting drug release in vitro and in vivo. CheVmiew. CAortimclemOunlnin.e,
114, 10940−10975.
2015, 51, 6948−6951.
DOI: 10.1039/C6RA05808F
0 M. V. Rekharsky and Y. Inoue, Complexation thermodynamics 68 S. Monti and I. Manet, Supramolecular photochemistry of
of cyclodextrins, Chem. Rev., 1998, 98, 1875−1917.
drugs in biomolecular environments, Chem. Soc. Rev., 2014,
43, 4051−4067.
1 A. Prestel and H. M. Möller, Spatio-temporal control of
cellular uptake achieved by photoswitchable cell-penetrating 69 B. Yan, J.-C. Boyer, N. R. Branda and Y. Zhao Near-infrared
peptides, Chem. Commun., 2016, 52, 701−704.
light-triggered dissociation of block copolymer micelles using
upconverting nanoparticles, J. Am. Chem. Soc., 2011, 133,
19714−19717.
5
5
5
5
2 T. Liu, C. Bao, H. Wang, Y. Lin, H. Jia and L. Zhu, Light-
controlled ion channels formed by amphiphilic small
molecules regulate ion conduction via cis-trans
photoisomerization, Chem. Commun., 2013, 49, 10311−10313.
3 D. Wang, M. Wagner, H.-J. Butt and S. Wu, Supramolecular
hydrogels constructed by red-light-responsive host–guest
interactions for photo-controlled protein release in deep
tissue, Soft Matter, 2015, 11, 7656−7662.
4 Y. P. Wang, N. Ma, Z. Q. Wang and X. Zhang, Photo-controlled
reversible supramolecular assembly of an azobenzene-
containing surfactant with α-cyclodextrin, Angew. Chem. Int.
Ed., 2007, 49, 2823−2826.
5 A. Nakamura and Y. Inoue, Electrostatic manipulation of
enantiodifferentiating
photocyclodimerization
of
2-
anthracenecarboxylate within γ-cyclodextrin cavity through
chemical modification. Inverted product distribution
andenhanced enantioselectivity, J. Am. Chem. Soc., 2005, 127,
5
338−5339.
5
6 W. W. Cleland, Dithiothreitol, a new protective reagent for SH
groups, Biochemistry, 1964, 3, 480−482.
5
7 T. Sun, H. Zhang, H. Yan, J. Li, G. Cheng, A. Hao, H. Qiao and F.
Xin, Sensitive fluorescent vesicles based on the
supramolecular inclusion of β-cyclodextrins with N-
alkylamino-1-anthraquinone, Supramol. Chem., 2011, 23 (5),
351−364.
5
5
6
8 J. Rautio, H. Kumpulainen, T. Heimbach, R. Oliyai, D. Oh, T.
Jarvinen and J. Savolainen, Prodrugs: design and clinical
applications, Nat. Rev. Drug Discov., 2008, 7, 255−270.
9 J. Renault, M. Baron and P. Mailliet, Heterocyclic quinones 2.
Quinoxaline-5,6-(and 5-8)-diones - Potential antitumoral
agents, Eur. J. Med. Chem., 1981, 16 (6), 545−550.
0 J. X. Zhang, X. D. Li, M. Q. Yan, L. Y. Qiu, Y. Jin and K. J. Zhu,
Hydrogen bonding-induced transformation of network
aggregates into vesicles-A potential method for the
preparation of composite vesicles, Macromol. Rapid
Commun., 2007, 28 (6), 710−717.
6
1 T. Kakutani, R. Atsumi, E. Sumimoto and M. Hashida,
Deconvolution analysis of the regeneration process of
mitomycin C from prodrug in a muscle perfusion system based
on statistical moment theory, Chem.Pharm. Bull. (Tokyo),
1987, 35, 4907−4914.
6
2 O. Bekers, J. H. Beijnen, E. H. Groot Bramel, M. Otagiri, A. Bult
and W. J. M. Underberg, Stabilization of mitomycins on
complexation with cyclodextrins in aqueous acidic media,
Inter. J. Pharmaceut., 1989, 52 (3), 239−248.
6
6
6
3 A. Samanta and B. J. Ravoo, Metal Ion, light, and redox
responsive interaction of vesicles by a supramolecular switch,
Chem. Eur. J., 2014, 20, 4966−4973.
4 W. Ong, Y. Yang, A. C. Cruciano, and R. L. McCarley, Redox-
triggered contents release from liposomes, J. Am. Chem. Soc.,
2008, 130, 14739−14744.
5 K. D. Zhang, T. Y. Zhou, X. Zhao, X. K. Jiang, and Z. T. Li,
Redox-responsive reverse vesicles self-assembled by
pseudo[2]rotaxanes for tunable dye release, Langmuir, 2012,
28, 14839−14844.
66 A. Napoli, M. Valentini, N. Tirelli, M. Müller and J. A. Hubbell,
Oxidation-responsive polymeric vesicles, Nat. Mater., 2004, 3,
183−189.
67 Y. Zhang, Q. Yin, J. Yen, J. Li, H. Ying, H. Wang and Y. Hua,
Chaney, E. J.; Boppart, S. A.; Cheng, J. Non-invasive, real-time
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 11
Please do not adjust margins

RSC Advances
Page 12 of 12
View Article Online
DOI: 10.1039/C6RA05808F
Photo and redox-responsive vesicles assembled from “Bola-type” superamphiphiles were
developed.