Supplementary Information
Sugar-Grafted Cyclodextrin Nanocarrier as a
“Trojan Horse” for Potentiating Antibiotic Activity
Min Li · Koon Gee Neoh* · Liqun Xu · Liang Yuan · David Tai Leong · En-Tang Kang
Department of Chemical and Biomolecular Engineering, National University of Singapore,
Kent Ridge, Singapore 117585
Kim Lee Chua
Department of Biochemistry, National University of Singapore, Kent Ridge, Singapore
117543
Li Yang Hsu
Department of Medicine, National University of Singapore, Kent Ridge, Singapore 119228
*To whom correspondence should be addressed.
Koon Gee Neoh
Tel.: +65 65162176. Fax: +65 67791936. E-mail: chenkg@nus.edu.sg.
Table S1. Hydrodynamic diameter (Dh) and zeta potential of CD-MAN, CD-GLU and their
antibiotic complexes
Sample
CD-MAN
CD-MAN-ERY
CD-MAN-RIF
CD-MAN-CIP
CD-GLU
CD-GLU-ERY
CD-GLU-CIP
Dh (nm)
3.9±1.7
24.4±2.6
12.6±4.5
10.1±1.6
3.8±1.5
21.0±3.5
9.8±2.2
Zeta potential (mV)
-3.85±0.45
-3.77±3.35
-8.05±5.22
-3.60±1.45
-3.51±0.19
-3.4±0.77
-2.52±1.25
Table S2. S. aureus ATCC 25923 count after antibiotic resistance assay
(a) After 8 days
TSB
TSB + 0.25×MICa) CD-MAN-ERY
TSB + 0.25×MICa) CD-ERY
TSB
only
2.4×109
1.9×109
2.5×109
TSB + 0.25×MICa) free ERY
3.0×109
Culture medium
S.
aureus
(b) After 16 days
Culture medium
TSB
only
4.1×109
3.7×109
3.3×109
3.3×109
Average bacterial counts (CFU/mL)
TSB+2×MICa) CD-MANTSB+2×MICa) CDTSB+2×MICa)
ERY
ERY
free ERY
0
0
0
0
NA
NA
NA
0
NA
NA
NA
0
Average bacterial counts (CFU/mL)
TSB+2×MICa) CD-MANTSB+2×MICa) CDTSB+2×MICa)
ERY
ERY
free ERY
0
0
0
0
NA
NA
NA
0
1.2×105
NA
NA
1.3×105
Resistant bacteria
0
0
0
0
Resistant bacteria
TSB
0
S.
TSB + 0.25×MICa) CD-MAN-ERY
0
aureus TSB + 0.25×MICa) CD-ERY
1 in 26700
TSB + 0.25×MICa) free ERY
1 in 25300
NA: not applicable.
a)Refer to Table 1 for MIC value of free ERY and ERY in CD-MAN-ERY and CD-ERY. ERY in CD-MAN-ERY and CD-ERY constitutes 15 wt% and 23 wt%,
respectively.
Table S3. E. coli DH5α count after antibiotic resistance assay.
(a) After 8 days
Culture medium
E. coli
NB
NB + 0.25×MICa) CD-MAN-RIF
NB + 0.25×MICa) CD-RIF
NB + 0.25×MICa) free RIF
NB only
4.9×109
4.6×109
3.9×109
4.6×109
(b) After 16 days
Culture medium
NB only
Average bacterial counts (CFU/mL)
NB+2×MICa) CD-MANNB+2×MICa) CDNB+2×MICa)
RIF
RIF
free RIF
0
0
0
0
NA
NA
NA
0
NA
NA
NA
0
Average bacterial counts (CFU/mL)
NB+2×MICa) CD-MANNB+2×MICa) CDNB+2×MICa)
RIF
RIF
free RIF
0
0
0
0
NA
NA
NA
6.6×105
NA
NA
NA
5.6×105
Resistant bacteria
0
0
0
0
Resistant bacteria
NB
3.7×109
0
NB + 0.25×MICa) CD-MAN-RIF
2.3×109
0
E. coli
NB + 0.25×MICa) CD-RIF
4.1×109
1 in 6210
NB + 0.25×MICa) free RIF
3.5×109
1 in 6250
NA: not applicable.
a)Refer to Table 1 for MIC value of free RIF and RIF in CD-MAN-RIF and CD-RIF. RIF in CD-MAN-RIF and CD-RIF constitutes 15 wt% and 20 wt%, respectively.
Figure S1. Schematic illustration of the procedures of antibiotic resistance assay.
S5
Figure S2. Accumulation assay of CD-MAN-PBI, CD-PBI and free PBI in (a) E. coli DH5α, (b)
P. aeruginosa PAO1 and (c) S. aureus ATCC25923. ∗ and # denote significant difference (P <
0.05) compared to that of control (bacterial cells incubated in growth medium only) over the same
incubation period and between the designated agents, respectively.
S6
Figure S3. UV-vis spectra of PBS solution of CD-MAN.
S7
Figure S4. Effect of CD-MAN on the viability of 3T3 fibroblasts after 24 and 72 h. Viability is
expressed as a percentage relative to the result obtained with the control (3T3 fibroblast cells
incubated in growth medium only).
S8
Figure S5. Effect of (a) free ERY and (b) CD-MAN-ERY on the viability of NCM460 colonic
epithelial and HEK 293T embryonic kidney cells, respectively, after 24 h. Viability is expressed as
a percentage relative to the result obtained with the control (NCM460 colonic epithelial and HEK
293T embryonic kidney cells, respectively, incubated in growth medium without any antibiotic).
S9