Supporting Information Voltage/pH Driven Mechanized Silica Nanoparticles for the Multimodal Controlled Release of Drugs

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1 Supporting Information Voltage/pH Driven Mechanized Silica Nanoparticles for the Multimodal Controlled Release of Drugs Ting Wang, GuangPing Sun, MingDong Wang, BaoJing Zhou and JiaJun Fu*, *Corresponding Author, School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing , P. R. China Institute of Computation in Molecular and Materials Science and Department of Chemistry, Nanjing University of Science and Technology, Nanjing , P. R. China S-1

2 1. Materials Hexadecyltrimethylammonium bromide (CTAB, 98.0%), tetraethylorthosilicate (TEOS, 99.0%), β-cyclodextrin (β-cd, 97%), lithium hydride (powder, 95%), propargyl bromide (80% in toluene), lithium iodide (anhydrous, 99.9%), ferrocenemethanol (97%), sodium azide ( 99%), triethyl phosphite (99.8%), sodium methoxide ( 97%), propargyl alcohol (99%), 3-(triethoxysilyl)propyl isocyanate (ICPTES, 95%), p-toluenesulfonyl chloride ( 98%), 2-bromoethanol (95%), 2,2-dimethoxypropane (98%), p-toluenesulfonic acid monohydrate ( 98.5%), tetrabutylammonium bromide (TBAB, 98.0%), bis(cyclopentadienyl)cobalt(iii) hexafluorophosphate (Cob +, 98%), gemcitabine hydrochloride (GEM), and doxorubicin hydrochloride (DOX, 98.0%) were purchased from Sigma-Aldrich. Copper iodide ( 99.5%), triphenylphosphine ( 99.5) and MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, 98%) were obtained from Aladdin Industrial Inc. (Shanghai, China). S-2

3 2. Preparation and Synthesis 2.1 Synthetic Procedure of PTPC 2.2 Synthetic Procedure of ABP Scheme S1 Synthesis of PTPC. Scheme S2 Synthesis of ABP. 2.3 Synthetic Procedure of NH 2 -Fc-β-CD Scheme S3 Synthesis of NH 2 -Fc-β-CD. S-3

4 2.4 Preparation of MSNPs 1 Scheme S4 Synthetic procedure for preparing MSNPs 1. S-4

5 3. Analytical Data 3.1 Characterization of MSNs Figure S1. (A) SA-XRD pattern and (B) N 2 adsorption-desorption isotherm and pore size distribution of MSNs. Table S1. Physicochemical properties of the MSNs. Materials Specific surface area (m 2 g -1 ) Average pore size (nm) Pore volume (cm 3 g -1 ) MSNs As seen in Figure S1A, the three well-defined diffraction peaks at 2.39, 4.05 and 4.65, which corresponded to (100), (110) and (200) reflections, respectively, suggested the hexagonal mesostructure of the prepared MSNs. N 2 adsorption-desorption isotherm of MSNs (Figure S1B) showed the characteristic type- Ⅳ isotherm, and the specific surface area, average pore diameter, as well as total pore volume are summarized in Table S1. S-5

6 3.2 N 2 Adsorption-Desorption Isotherms and SA-XRD Analysis Figure S2. (A) N 2 adsorption-desorption isotherms and (B) pore size distributions of MSNs, MSNs-PTPC, MSNs-ABP, and MSNPs 1. Table S2. Physicochemical properties of the MSNs, MSNs-PTPC, MSNs-ABP, and MSNPs 1. Materials Specific surface area (m 2 g -1 ) Average pore size (nm) Pore volume (cm 3 g -1 ) MSNs MSNs-PTPC MSNs-ABP MSNPs Figure S3. SA-XRD patterns of MSNs, MSNs-PTPC, MSNs-ABP, and MSNPs 1. S-6

7 3.3 TG Analysis Figure S4. TGA analysis of (a) MSNs, (b) MSNs-PTPC, (c) MSNs-ABP, and (d) MSNPs D ROESY NMR Spectra Figure S5. Partial 2D ROESY spectra (300 MHz, 25, D 2 O) of Fc + -β-cd (0.1 mm) reduced by -1.5 V voltage. S-7

8 3.5 1 H NMR Spectra Figure S6. Partial 1 H NMR spectra (300 MHz, 25, D 2 O) (A) Fc-β-CD (0.1 mm); (B) adding 1.0 equiv. (NH 4 ) 4 Ce(SO 4 ) 4 4H 2 O; (C) adding 1.0 equiv. Vitamin C. Figure S6 demonstrates the cyclic conversion from Fc-β-CD to Fc + -β-cd by chemical redox agents. (NH 4 ) 4 Ce(SO 4 ) 4 4H 2 O and vitamin C were used as the oxidizing and reducing reagents, respectively. In comparison, upon addition of 1.0 equiv. (NH 4 ) 4 Ce(SO 4 ) 4 4H 2 O, the peaks assigned to cyclopentadiene groups disappeared due to the paramagnetic nature of ferrocenium (Fc + ). After reduction by adding Vitamin C, the peaks for ferrocene (Fc) emerged again, indicating the potential of Fc-β-CD for reversible supramolecular nanovalves. 3.6 UV-Vis Analysis Figure S7. The UV-Vis spectra of (a) Fc-β-CD (0.1 mm) in aqueous solution; (b) adding 1.0 equiv. (NH 4 ) 4 Ce(SO 4 ) 4 4H 2 O; (c) adding 1.0 equiv. Vitamin C. S-8

9 The reversible transformations were also monitored by UV-Vis. Upon addition of 1.0 equiv. of (NH 4 ) 4 Ce(SO 4 ) 4 4H 2 O, the peak around 630 nm was observed, concomitant with the obvious change in color, resulting from oxidation of Fc to Fc +. With the addition of Vitamin C, the peak vanished and the color of solution returned to the original Fc state. 3.7 Calculation Method for Binding Affinity The molecular dynamics/quantum mechanics/continuum solvent model (MD/QM/ CSM) method was used to calculate binding affinities in aqueous solution between β-cd and the drugs, including GEM, p-coumalic acid and DOX. Briefly, we first carried out MD simulations using Amber12 software to sample the large number of conformations of the β-cd inclusion complex. Then, we categorized similar conformations along the MD trajectory based on coordinates of the O atoms at 2, 3, 4, 6 positions of β-cd as well as the heavy atoms of the guest molecules. The threshold of the RMS difference for cluster analysis was set to ca.1.0 Å to generate 6~9 clusters. Next, the conformations at local minima on the potential energy surface of the two largest clusters were collected, which were subjected to further energy minimization. Finally, the global minimum was identified and deemed as the representative conformation of the β-cd complex, which served as the starting structure for further binding free energy calculations. The calculated free energy includes both the interaction between β-cd and the guest molecules and that between the inclusion complex and the aqueous solution. Based on thermodynamic cycle, the total binding free energy in aqueous solution is partitioned as following, where G = G + G (1) aqu vacu solv bind bind bind vacu G bind and solv G bind are the binding free energy in vacuum and the change of solvation free energy when the system is transferred from vacuum to aqueous solution, respectively. The latter is calculated as the difference between the solvation energy of the β-cd complex and those of the separated CD and guest, solv solv solv solv G = G ( G + G ) (2) bind comp host guest The binding free energy in vacuum in Eq. (1), include the enthalpy and entropy changes, G = H T S (3) vacu vacu vacu bind bind bind We first optimized the representative conformations of the β-cd complex, β-cd, S-9

10 and guest in the gas phase. Then these thermodynamic quantities are computed from the PM3 frequency calculation. Figure S8. Representative conformations of the β-cd inclusion complexes with (A) GEM, (B) p-coumalic acid and (C) DOX, DOX cannot form the stable complexation with β-cd due to the limitation of molecular size. Table S3. Calculated binding affinities in aqueous solutions for the β-cd complexes. System H -T S G vacu G el G np G solv G aqu GEM/β-CD p-coumalic acid/β-cd According to the following equation, The higher aqu G = RT ln K (4) aqu G, the lower K (binding affinity). Therefore, Compared with p-coumalic acid, the relatively lower binding affinity between GEM and β-cd was theoretically obtained, indicating that GEM was more prone to pass through β-cd s cavity by diffusion under the concentration gradient. S-10

11 4. Control Experiments Ⅰ 4.1 Preparation of MSNPs 2 Scheme S5. Synthetic procedure for preparing MSNPs Synthetic procedure of heptakis(6-deoxy-6-amino)-β-cyclodextrin (NH 2 -β-cd) Scheme S6. Synthesis of NH 2 -β-cd. The synthesis process of NH 2 -β-cd was according to the previously literature. 1 The NMR and MS measurements were used to characterize NH 2 -β-cd. 1 H NMR (NH 2 -β-cd, 300 MHz, D 2 O) δ 4.20 (t, J=7.0Hz, 7H, H-1), 3.83 (m, 7H, H-6 ), 3.57 (m, 14H, H-3, 5), 3.44 (dd, 14H, H-2, 4), 3.26 (dd, 7H, H-6). 13 C NMR (NH 2 -β-cd, 75 MHz, D 2 O) δ (C-1), (C-4), (C-2, C-3, C-5), 42.9 (C-6). MS (NH 2 -β-cd, ESI): m/z calcd forc 42 H 77 N 7 O 28 : ; found: [M+H] Preparation of MSNPs 2 The synthetic procedure of MSNPs 2 was as the same as that for MSNPs 1, except for employing NH 2 -β-cd (equal mol.% to NH 2 -Fc-β-CD) to replacing NH 2 -Fc-β-CD. S-11

12 The FTIR (Figure S9) and 13 C SS-NMR (Figure S10) spectra proved the successful construction of MSNPs 2. Figure S9. FTIR spectra of (a) MSNs; (b) MSNs-PTPC; (c) MSNs-ABP; and (d) MSNPs 2 (without GEM and DOX). Figure S C SS-NMR spectra of (A) MSNs-PTPC, (B) MSNs-ABP, and (C) MSNPs 2 (without GEM and DOX). S-12

13 5. Control Experiments Ⅱ 5.1 Preparation of MSNPs 3 Scheme S7. Synthetic procedure for preparing MSNPs Synthetic procedure of mono-2-o-[[1-(ferrocenylmethyl)-1h-1,2,3-triazole -4-yl]methyl]-mono-(6-deoxy-6-amino)-β-cyclodextrin (mono-nh 2 -Fc-β-CD) Scheme S8. Synthesis of mono-nh 2 -Fc-β-CD. Compound 7: To a solution of Fc-β-CD (2.49 g, mmol) in water (20 ml) was added sodium hydroxide solution (2 ml, 8.21 M), and then the reaction was stirred for 1 h in ice bath. Next, p-toluenesulfonyl chloride (0.727 g, 3.52 mmol) in acetonitrile (3 ml) was added dropwise within 15 min and reacted for 4 h. After removing the precipitate, the ph of filtrate was adjusted by HCl (aq. 10 wt%) to 7, the reaction mixture was cooled to 4 and kept overnight. The precipitate was filtered, recrystallized from distilled water and dried in vacuo to afford mono-2-o- S-13

14 [[1-(ferrocenylmethyl)-1H-1,2,3-triazol-4-yl]methyl]-mono-(6-O-(p-tolylsulfonyl))-βcyclodextrin (Intermediate Compound 1). To a solution of Intermediate Compound 1 (0.334 g, mmol) in DMF (3.3 ml) was added sodium azide (118 mg, 1.82 mmol). After reaction for 6 h at 80, the mixture was poured into acetone (45 ml) and the crude product was filtered, washed with ethanol (20 ml 2), purified by recrystallized from distilled water, and dried in vacuo to give Compound 7 (0.262 g, yield 12.8%). 1 H NMR (300 MHz, DMSO-d 6 ) δ 8.05(s, 1H, H5-C 2 HN 3 ), 5.71 (m, 12H, OH), 5.26 (d, J =9.3 Hz, 2H, CHN), (m, 9H, H-1, CHO), 4.52 (m, 6H, OH), 4.35 (brs, 2H, H Cp ), 4.23 (s, 5H, H Cp ), 4.20 (s, 2H, H Cp ), (m, 69H, H-2~6, HDO). 13 C NMR (75 MHz, DMSO-d 6 ) δ (C4-C 2 HN 3 ), (C5-C 2 HN 3 ), (C-1), (C-1 A ), (C-4), (C-2, C-3, C-5), (C Cp ), 67.61(C Cp ), (C-6), 52.5 (C-6 A ), (CH 2 N). mono-nh 2 -Fc-β-CD: To a solution of Compound 7 (220 mg, mmol) in anhydrous DMF (4 ml) was added triphenylphosphine (636 mg, 2.42 mmol). The reaction was stirred for 1 h at room temperature under nitrogen atmosphere. Next, the concentrated aqueous ammonia (2.25 ml, 28 wt%) was added within 5 min. After being stirred at room temperature for 18 h, the reaction mixture was concentrated in vacuo, and the residue was poured into ethanol. The precipitate was filtered and evaporated in vacuo to give mono-nh 2 -Fc-β-CD (153 mg, yield 71%). For NMR measurement, the mono-nh 2 -Fc-β-CD was converted to amine salt by addition of a dilute solution of DCL (down to ph 6). 1 H NMR (300 MHz, D 2 O) δ 7.72 (s, 1H, H5-C 2 HN 3 ), 5.71 (m, 12H, OH), 5.25 (d, J = 9.3 Hz, 2H, CHN), 5.12 (m, 9H, H1, CHO), 4.52 (m, 6H, OH), 4.42 (brs, 9H, H Cp, H Cp ), 4.04 (t, J=9.4Hz, 7H, H-1), 3.81 (m, 7H, H-6 ), 3.52 (m, 14H, H-3, 5), 3.43 (dd, 14H, H-2, 4), 3.26 (dd, 7H, H-6). 13 C NMR (75 MHz, D 2 O) δ (C-1), (C-4), (C-2 A ), (C-2, C-3, C-5), (C-3 A ), (C-6), (C-6 A ) Preparation of MSNPs 3 The synthetic procedure of MSNPs 3 was as the same as that for MSNPs 1, except for employing mono-nh 2 -Fc-β-CD (equal mol.% to NH 2 -Fc-β-CD) to replacing NH 2 -Fc-β-CD. The FTIR and 13 C SS-NMR spectra of MSNPs 3 were similar to MSNPs 1 and not provided here. S-14

15 REFERENCES (1) Ashton, P. R.; Koniger, R.; Stoddart, J. F.; Alker D.; Harding, V. D. Amino Acid Derivatives of β-cyclodextrin. J. Org. Chem. 1996, 61, S-15