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Supporting Information

Polymeric arsenicals as scaffolds for functional and responsive hydrogels

Joji Tanaka,a Ji-Inn Song,a Andrew M. Lunn, a Rachel A. Hand,a Satu Häkkinen,a Tara L. Schiller,b Sébastien Perrier, a,c,d Thomas P. Davis, c Paul Wilson.*a,c

aDepartment of Chemistry, University of Warwick, Coventry, CV4 7AL, UK

bWMG, University of Warwick, CV4 7AL, Coventry, UK

cARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 399 Royal

Parade, Parkville, Victoria 3152, Australia

dWarwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK

Electronic Supplementary Material (ESI) for Journal of Materials Chemistry B.This journal is © The Royal Society of Chemistry 2019

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Reverse Phase High performance liquid chromatography (RP-HPLC)

The gradient of the mobile phase varied in each analysis and purification. The standard analysis method is as followed:

Time (min) A (%) B (%)

0.00 90.0 10.0

15.00 50.0 50.0

25.00 0.0 100.0

27.00 90.0 10.0

35.00 90.0 10.0

Calculation of AsAm content with respect to DMA by 1H-NMR

Method 1

∫[2[𝑀]𝐴𝑠𝐴𝑚 + 2[𝑀]𝐷𝑀𝐴]1.0 ‒ 1.8 𝑝𝑝𝑚 ‒∫4[[𝑀]𝐴𝑠𝐴𝑚]7.2 ‒ 7.8 𝑝𝑝𝑚

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= [𝑀]𝐷𝑀𝐴

Method 2

∫[[𝑀]𝐴𝑠𝐴𝑚 + 7[𝑀]𝐷𝑀𝐴]2.1 ‒ 3.0 𝑝𝑝𝑚 ‒∫4[[𝑀]𝐴𝑠𝐴𝑚]7.2 ‒ 7.8 𝑝𝑝𝑚

47

= [𝑀]𝐷𝑀𝐴

The value from each method was averaged.

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1 2 3 4 5 6 7 8 9

Đ

Đ

Đ

: 5.5

: 4.1

: 4.1

: 4.8

Mw : 310000

Mw : 450000

Mw : 330000

Mw : 460000

Mn : 56000

Mn : 110000

Mn : 81000

dwdl

ogM

P4

P3

P2

P1 Mn : 95000

Đ

logM

Figure S1. Molecular weight data for polymeric arsenical scaffolds P1 – P4 obtained from aqueous SEC

Table S1. Composition and molecular weight data for the polymeric arsenical scaffolds P1 – P4

Composition* Mn** Mw

** Đ**

P1 P(DMAm0.98-AsAm0.02) 95000 460000 4.8

P2 P(DMAm0.96-AsAm0.04) 81000 330000 4.1

P3 P(DMAm0.94-AsAm0.06) 110000 450000 4.1

P4 P(DMAm0.92-AsAm0.08) 56000 310000 5.5

* from 1H NMR (vide supra) ** from aqueous SEC

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Figure S2: Image of 2.5 wt % arsenohydrogels P1 – P4 in which P1 and P2 formed stable gels while P3 and P4 undergo syneresis, expelling up to 40% of the aqueous solution after 2 hours.

0 200 400 600 800 10001E-61E-51E-4

0.0010.01

0.11

10100

100010000

P1_2.5 wt%

Time / s

G'' /

Pa

1E-61E-51E-40.0010.010.1110100100010000

G' /

Pa

Figure S3: Rheology of the arsenohydrogel formation of P1 (2.5 wt %, strain = 1.0 %, frequency = 10 rad.s-1, temperature = 60 °C) in the presence of H3PO2 and KI

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0 200 400 600 800 10001E-61E-51E-4

0.0010.01

0.11

10100

100010000

P2_2.5 wt%

Time / s

G'' /

Pa

1E-61E-51E-40.0010.010.1110100100010000

G' /

Pa

Figure S4: Rheology of the arsenohydrogel formation of P2 (2.5 wt %, strain = 1.0 %, frequency = 10 rad.s-1, temperature = 60 °C) in the presence of H3PO2 and KI

0 200 400 600 800 10001E-61E-51E-4

0.0010.01

0.11

10100

100010000

P3_2.5 wt%

Time / s

G'' /

Pa

1E-61E-51E-40.0010.010.1110100100010000

G' /

Pa

Figure S5: Rheology of the arsenohydrogel formation of P3 (2.5 wt %, strain = 1.0 %, frequency = 10 rad.s-1, temperature = 60 °C) in the presence of H3PO2 and KI

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1 10 100 10000.1

1

10

100

1000

G' Storage ModulusG'' Loss Modulus

G',G

'' (P

a)

Strain %1 10 100 1000

0.1

1

10

100

1000

G' Storage ModulusG'' Loss Modulus

G',G

'' (P

a)

Strain %

Figure S6: Amplitude sweep of arsenohydrogel of P1 at 30 °C and frequency of 1 rad s-1 1st cycle (left) and 2nd (right)

0.0 0.2 0.4 0.6 0.8 1.0

0.0

0.4

0.8

1.2

1.6

2.0 P1_2.5%

Stre

ss x

103 /

MP

a

Strain

Figure S7: Representative stress/strain curve for arsenohydrogel of P1 (2.5 wt%).

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0.0 0.2 0.4 0.6 0.8 1.0

0.0

1.0

2.0

3.0

4.0

5.0

Stre

ss x

103 /

MP

a

Strain

P2_2.5%

Figure S8: Representative stress/strain curve for arsenohydrogel of P2 (2.5 wt%).

0.0 0.2 0.4 0.6 0.8 1.0

0.0

2.0

4.0

6.0

8.0

10.0

Stre

ss x

103 /

MP

a

Strain

P3_2.5%

Figure S9: Representative stress/strain curve for arsenohydrogel of P3 (2.5 wt%).

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0.0 0.2 0.4 0.6 0.8 1.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

Stre

ss x

103 /

MP

a

Strain

P4_2.5%

Figure S10: Representative stress/strain curve for arsenohydrogel of P4 (2.5 wt%).

Figure S11: Image of the arsenohydrogel P1 showing catastrophic failure after the first cycle of compression testing.

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0.0 0.2 0.4 0.6 0.8 1.00.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

Stre

ss x

103 /

MP

a

Strain

P3_1st cycle P3_2nd cycle P3_3rd cycle

Figure S12: Overlay of the stress/strain curves of arsenohydrogel P3 through 3 cycles of compression tests (load 5 N, hold 30 secs).

0.0 0.2 0.4 0.6 0.8 1.00.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

Stre

ss x

103 /

MP

a

Strain

P4_1st cycle P4_2nd cycle P4_3rd cycle

Figure S13: Overlay of the stress/strain curves of arsenohydrogel P4 through 3 cycles of compression tests (load 5 N, hold 30 secs).

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Figure S14: Scanning electron microscopy of dry 10 wt % arsenohydrogels after dialysis and lyophilisation. P1 = 2 mol% AsAm; P2 = 4 mol% AsAm (Scale bar = 2 µm).

Table S2: Elemental analysis summary from EDX of the arsenohydrogels.

Wt %a

C N O AsP1 41.41 9.46 46.52 2.61P2 35.67 9.89 51.24 3.20P3 37.24 9.73 48.15 4.89P4 39.45 11.09 43.06 6.41

aOther elements such as potassium, iodide and phosphorous is not taken into account.

Table S3: Degree of swelling (Ws-W0/W0) x 100 for P1-P4 in PBS (pH 7.4)

Time / hrs24 48 72 96 120

P1 175 385 900 1610 2040P2 50 195 400 615 880P3 25 80 140 250 360P4 5 25 60 115 160

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20 40 60 80 100 1200

500

1000

Sw

ellin

g R

atio

time (hr)

P1 P2 P3 P4

Figure S15: Swelling ratio of the arsenohydrogels derived from P1-P4 calculated as (Ws-W0)/W0 x 100 where W0 is the weight of the hydrogel after drying in the oven and Ws is the weight of the swollen hydrogel at a definite time interval (Table S4). Swelling was performed in GSH (5 mM).

Table S4: Degree of swelling (Ws-W0/W0) x 100 for P1-P4 in GSH (5 mM)

Time / hrs24 48 72 96 120

P1 200 305 495 720 950P2 90 220 355 525 580P3 45 50 80 110 140P4 25 35 50 65 80

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20 40 60 80 100 1200

5000

10000

15000

20000

25000

30000

Sw

ellin

g R

atio

time (hr)

P1 P2 P3 P4

Figure S16: Swelling ratio of the arsenohydrogels derived from P1-P4 calculated as (Ws-W0)/W0 x 100 where W0 is the weight of the hydrogel after drying in the oven and Ws is the weight of the swollen hydrogel at a definite time interval (Table S5). Swelling was performed in H2O2 (5 mM).

Table S5: Degree of swelling (Ws-W0/W0) x 100 for P1-P4 in H2O2 (5 mM)

Time / hrs24 48 72 96 120

P1 885 1750 7230 16350 27850P2 460 2050 6620 15000 24400P3 215 990 5000 14900 22300P4 170 1525 6240 11500 18500

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Figure S17: z-Stack tomography of NIH/3T3 cells encapsulated within arsenohydrogel matrices (10 wt%) derived from (A) P1; (B) P2; (C) P3; (D) P4, imaged with Hoechst dye.

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Figure S18: z-Stack tomography of PC3 cells encapsulated within arsenohydrogel matrices (10 wt%) derived from (A) P1; (B) P2; (C) P3; (D) P4, imaged with Hoechst dye.

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Figure S19: Inverse test qualitatively demonstrating gelation of P1-P4 at 2.5 wt% in the presence of p-arsanilic acid (3.8 wt%).

P1

P1 P2 P3 P4

P2 P3 P4