Electronic Supplementary Material Electrically pulsatile responsive drug delivery platform for treatment of Alzheimer s disease Li Wu 1,2, Jiasi Wang 1,2, Nan Gao 1, Jinsong Ren 1, Andong Zhao 1,2, and Xiaogang Qu 1 ( ) 1 Laboratory of Chemical Biology and State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China 2 University of Chinese Academy of Sciences, Beijing 100039, China Supporting information to DOI 10.1007/s12274-015-0750-x Figure S1 Typical SEM (a) and TEM (b) images of GSNs. The large surface-to-volume area and the well-definedinternal structure of MSNsmake them ideal for adsorption and release of a varietyof chemical substances [S1]. In addition, the hydrophilic properties ofmsns readily encourage attachment and spreading of cells. For example, mesoporous silica nanoparticles (MSNs)-based nerve growth factor (NGF)delivery system has been successfully embedded within an electroactive polypyrrol (PPy) [S2]. Although significant improvement of the drug delivery performance has been achieved, the incorporation of an insulated inorganic phase into conducting polymer may slow the electrical response. Recently, the use of drug-loaded hydrogel composed of reduced graphene oxide (rgo) and poly(vinyl alcohol) has been demonstrated for on-demand control of drug release rate with the application of an external electric field [S3]. As a one-atom-thick planar sheet of sp 2 -bonded carbon atoms, graphene owns unusual electronic properties, such as ballistic electron transport along with highly electrical conductivity [S4]. It has been widely used in electrochemical studies [S5, S6]. The introduction of rgo significantly reduced the electrode impedance, which is desired for neuralrecording and stimulation.however, this system required the use of large voltages that could be damaging to biological tissues, and drug passively diffused from the bulk of the polymer in the absence of stimulation because of the porous morphology of the hydrogel. Multifunctional hybrid materials, by Address correspondence to Xiaogang Qu,xqu@ciac.ac.cn
taking advantages of both the superior of graphene and functional material, have opened new avenues of opportunityin the field of electro-stimulated drug delivery. Figure S2 (a) BET nitrogenadsorption desorption isotherm and (b) BJH pore size distribution curve. The BJH pore size distributionof as-synthesized nanomaterials were characterized by N 2 adsorption-desorption isotherm, which hadaverage pore diameter of about 2.5 nm and a narrow pore distribution. Figure S3 (a) Representative AFM image of GSNs; (b)the corresponding height profile along the line in (a). The typical AFM image and height analysis of GSNsalso revealed consistent results as obtained from SEM and TEM. The sample separated well in single layer with the average height of 24.4 nm. www.editorialmanager.com/nare/default.asp
X-ray photoelectron spectroscopy (XPS) is a useful technique to analyze chemical state information of elements, which providesquantitative information about the type and extent of surface functionalization on thegsns nanocomposites. XPS spectra of GSNs (Fig. S4(a)) clearly indicated the presence of silicon and carbon. More importantly, reduction of oxygen functional groups in GSNs could also be confirmed by XPS (Figs. S4(b) and 4(c)). It is well-known that graphene oxide is an electrically insulating material, which arises from the presence of a wide range of oxygen functional groups on their basal planes, such as epoxide, hydroxyl, carboxyl and carbonyl groups. In comparison to the C1s spectrum of the graphene oxide, peaks assigned to oxygen-containing functional groups in GSNs were significantly decreased after reduction. Figure S4 XPS profiles of (a) GSNs, (b) carbon 1s of GSNs and (c) carbon 1s of graphene oxide. Figure S5 (a) The FT-IR spectra of GSNs, NH 2 -GSNs and COOH-GSNs; (b) The zeta potential of NH 2 -GSNs and COOH-GSNs. www.thenanoresearch.com www.springer.com/journal/12274 Nano Research
Figure S6 Electrochemical impedance spectroscopy of different electrodes in the solutioncontaining 10 mm [Fe(CN) 6 ] 3 /4 and 0.1 M KCl. Figure S7 Typical TEM image of MSNs. Figure S8 Release profiles of CQ from PPy/GSNs films at different stimulus: 50% duty square wave potential stimulation, 0.5 V for 5 s followed by 0.5 V for 5 s, 2 V for 5 s followed by 0 V for 5 s and immersion, repeadly for 12 h. www.editorialmanager.com/nare/default.asp
Nano Res. Figure S9 Inhibition of Cu2+ induced Aβ aggregation by electrical stimulus. TEM images of samples of Cu2+ induced Aβ aggregates (24 h, 37 C, no agitation) followed by 24 h incubation: (a) without any chelators; (b) with CQ; (c)with CQ released from PPy/GSNs film by immersion; (d)with CQ released from PPy/GSNs film by electrical stimulation with 0.5 V for 5 s followed by 0.5 V for 5 s; (e) with CQ released from PPy/GSNs film by electrical stimulation with 2 V for 5 s followed by 0 V for 5 s. [Aβ]=10 µm, [Cu2+]=10 µm, [CQ]=20 µm. Buffer: 10 mm HEPES, 150 mmnacl, ph 6.6.(Scale bars: 20 nm.) Figure S10 Determination of the inhibition effects of compounds on the Cu2+-induced formation of Aβ fibrils by native-page: (1) Aβ-Cu2+complex; (2) control (Aβ); (3) Aβ-Cu2+complex with CQ; (4) Aβ-Cu2+complexwith CQ released from PPy/GSNs film by immersion; (5) Aβ-Cu2+complexwith CQ released from PPy/GSNs film by electrical stimulation with 2 V for 5 s followed by 0 V for 5 s; (6) Aβ-Cu2+complexwith CQ released from PPy/GSNs film by electrical stimulation with 0.5 V for 5 s followed by 0.5 V for 5 s. [Aβ]=10 µm, [Cu2+]=10 µm, [CQ]=20 µm. Buffer: 10 mm HEPES, 150 mmnacl, ph 6.6. Lane 1 in Fig. S10 showed that Aβ treated with Cu alone almost had no monomer band. In contrast, Aβ oligomer formation was markedly inhibited by co-incubating with CQ, as shown by the stronger monomer www.thenanoresearch.com www.springer.com/journal/12274 Nano Research
band and a weaker aggregate band in the native gel (Fig. S10, lane 3). In the presence of the sample obtained from electrically actuated drug loaded PPy/GSNs film, the monomer band became stronger due to the release of CQ (Fig. S10, lane 5, 6). While for the control experiment carried with immersion (Fig. S10, lane 4), no inhibition was observed. Figure S11 Fluorescence images of PC-12 cells cultivated on PPy and PPy/GSNs films at 6h, 12 h, 24 h, 48 h and 72 h. Then stain the live cells with AO dye molecules. Figure S12 The average length of neurite for PC-12 cells on PPy/GSNs film: (1) control (Aβ+Cu 2+ -untreated cells), (2) incubated with Aβ, (3) incubated with Aβ-Cu 2+ complex in the presence of CQ, (4) incubated with electrical stimulus, (5) incubated with Aβ-Cu 2+ complex in the presence of CQ and electrical stimulus. Column height represents the mean while error barsreflect the standard error of the mean for 10 neurites per condition (n = 10). References [S1] Chen, Y.; Chen, H.; Shi, J. In Vivo Bio-Safety Evaluations and Diagnostic/Therapeutic Applications of Chemically Designed Mesoporous Silica Nanoparticles. Adv. Mater. 2013, 25, 3144 3176. [S2] Cho, Y.; Shi, R.; Ivanisevic, A.; Ben Borgens, R. A mesoporous silica nanosphere-based drug delivery system using an electrically conducting polymer. Nanotechnology 2009, 20, 275102. [S3] Liu, H.-W.; Hu, S.-H.; Chen, Y.-W.; Chen, S.-Y. Characterization and drug release behavior of highly responsive chip-like electrically modulated reduced graphene oxide-poly(vinyl alcohol) membranes. J. Mater. Chem. 2012, 22, 17311 17320. [S4] Feng, L.; Wu, L.; Qu, X. New Horizons for Diagnostics and Therapeutic Applications of Graphene and Graphene Oxide. Adv. Mater. 2013, 25, 168 186. [S5] Chen, D.; Feng, H.; Li, J. Graphene Oxide: Preparation, Functionalization, and Electrochemical Applications. Chem. Rev. 2012, 112, 6027 6053. [S6] Pumera, M. Graphene-based Nanomaterials and Their Electrochemistry. Chem. Soc. Rev. 2010, 39, 4146 4157. www.editorialmanager.com/nare/default.asp