Supporting Information
Self-assembly micelles from novel tri-armed star
C3-(PS-b-PNIPAM) block copolymers for anticancer drug release
Feng Xu*, Bi-Xia Zhang, Yan-Ling Luo*
(Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry
and Chemical Engineering, Shaanxi Normal University, Xi’an 710062, P. R. China)
*Corresponding authors, Tel.: +86-29-81530776; Fax: +86-29-81530727;
E-mail addresses: luoyanl@snnu.edu.cn (Y.L. Luo) and fengxu@snnu.edu.cn (F. Xu).
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1. FT-IR analysis of the tri-armed star block copolymers
Figures
S1(A)
and
1(B)
depict
FT-IR
spectra
of
trimethyl
benzene-1,3,5-tricarboxylate, 1,3,5-benzene tricarboxylic acid tris-N-(2-aminoethyl)
amide and C3; C3-PS and C3-(PS-b-PNIPAM). The appearance of characteristic
Figure S1 FT-IR spectra of (A) (a) trimethyl benzene-1,3,5-tricarboxylate, (b)
1,3,5-benzene tricarboxylic acid tris-N-(2-aminoethyl) amide and (c) C3; (B) (d)
C3-PS and (e) C3-(PS-b-PNIPAM).
absorption peaks at 1740, 2921-3100, 2846-2921, 1447, 1495-1600, 1252, 740 and 878
cm-1 preliminarily discloses the synthesis of TMBT (Figure S1(A)-a). Compared to
TMBT, BTATAA produces new vibration bands at 3284-3352, 1659, 1545 and 1283
cm-1, which belongs to primary/secondary amine (–NH2/–NH-) stretch, amindocarbonyl
stretch, –NH2/–NH- bending and –C-N stretch modes, respectively (Figure S1(A)-b). In
the case of the star initiator (Figure S1(A)-c), it can be seen that only the secondary
amine (-NH-) stretch vibration at 3285 cm-1 appears.
Figure S1(B)-(d) and –(e) display FT-IR spectra of C3-PS and C3-(PS-b-PNIPAM)
starlike block copolymers The C3-PS polymer (Figure S1(B)-d) gives characteristic
amidocarbonyl stretch at about 1656 cm−1, –NH- stretch at 3325-3387 cm−1, and Ar-H
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and-C-H stretch vibration bands at 2860-3012 cm−1, especially C-H out-of-plane
bending of single (main) substituted benzene rings at 660-725 cm−1. The
C3-(PS-b-PNIPAM) copolymer has almost the same FTIR characteristics as the C3-PS
copolymer due to similar chemical groups, but difference in relative intensities (Figure
S1(B)-e).
2. 1H NMR analysis of the tri-armed star block copolymers
Figures
S2(A)
and
2(B)
present
1
H
NMR
spectra
of
trimethyl
benzene-1,3,5-tricarboxylate, 1,3,5-benzene tricarboxylic acid tris-N-(2-aminoethyl)
amide and C3; C3-PS and C3-(PS-b-PNIPAM). The shift signals at 3.93 and 8.60 ppm
are ascribed to hydrogen protons of methyl (-COOCH3) and benzene rings (Ar-H)
(Figure S2(A)-a). Since BTATAA could not be dissolved in DMSO-d6 very well, D2O
was selected as solvent. It is clear that three characteristic hydrogen chemical shift
signals emerge at 8.00, 3.34 and 2.75 ppm, which are ascribed to the hydrogen proton
of benzene rings (Ar-H), methylene protons next to acylamino groups (-CONHCH2-)
Figure S2 1H NMR spectra of (A) (a) trimethyl benzene-1,3,5-tricarboxylate,
solvent: DMSO-d6, (b) 1,3,5-benzene tricarboxylic acid tris-N-(2-aminoethyl)
amide, solvent: D2O and (c) C3, solvent: DMSO-d6; (B) (d) C3-PS, solvent: CDCl3
and (e) C3-(PS-b-PNIPAM), solvent: CDCl3.
S3
and methylene protons next to amido groups (-CH2CH2NH2),
respectively (Figure
S2(A)-b), confirming the synthesis of BTATAA. In the case of the star initiator, 1H
NMR spectra (Figure S2(A)-c) show distinct resonance signals at 4.09 ppm assigned to
methylene protons in -NHCOCH2Cl (signal f) and at 8.55 ppm ascribed to imino
protons in -CONHCH2CH2NHCO- (signals d and e').
Figure S2(B) shows 1H NMR spectra of C3-PS and C3-(PS-b-PNIPAM) starlike block
copolymers. The C3-PS polymer gives birth to new chemical shift signals at 1.43-1.53,
1.86 and 6.58-7.09 ppm, representing the proton signals of methylene (-CH2CHC6H5-),
methyne (-CH2CHC6H5-) and primary Ar-H in PS repeating units in Figure S2(B)-d, in
comparison with the initiator C3. The
1
H NMR spectra of C3-(PS-b-PNIPAM)
copolymer provide characteristic distinguishable shift signals attributed to PNIPAM
blocks, at 6.58 ppm partially ascribed to -CONHCH(CH3)2, at 1.86 ppm assigned to
-CH2CHC6H5- and –CH(CONHCH(CH3)2)CH2-, and at 1.42 ppm belonging to
-CH2CHC6H5- and –CH(CONHCH(CH3)2)CH2-. In particular, the methyne protons
(-NHCH(CH3)2) at 3.86-4.00 ppm and methyl protons (-NHCH(CH3)2) at 1.14 ppm
consumingly support the incorporation of PNIPAM blocks (Figure S2B (e)).
3. GPC measurements
The number-average molecular weight (Mn), weight-average molecular weight (Mw)
and polydispersity index (PDI) were also measured by gel permeation chromatography
(GPC, Waters, USA). Chromatographic-grade THF was employed as an eluent at a flow
rate of 1.0 ml min-1 at 35 oC. The samples solutions dissolved in THF were filtered
through a 0.45 μm (pore size) needle-type filter (organic, diameter: Φ13 mm) and
afterwards injected into sample bottles for measurements. The experimental results are
shown in Table S1.
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Table S1 GPC data of the intermediates and resulting copolymers.
Samples
Mass ratios a
Mn
Mw
PDI
C3-PS-(Cl)
1:200
19000
25080
1.32
C3-(PS-b-PNIPAM)1
1:200:300
22600
28020
1.24
C3-(PS-b-PNIPAM)2
1:200:600
24830
29300
1.18
a
Stands for molar ratios of C3-PS-(Cl) to NIPAM.
All these corroborate the synthesis of starlike C3-(PS-b-PNIPAM) block copolymers.
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