Department of Chemistry, Capital Normal University, Beijing , People s

Transcription

1 Supporting Information Polydopamine-encapsulated Fe 3 O 4 with an adsorbed HSP70 inhibitor for improved photothermal inactivation of bacteria Dongdong Liu, Liyi Ma, Lidong Liu, Lu Wang, Yuxin Liu, Qi Jia, Quanwei Guo, Ge Zhang, Jing Zhou * Department of Chemistry, Capital Normal University, Beijing , People s Republic of China College of Resource Environment and Tourism, Capital Normal University, Beijing , People s Republic of China jingzhou@cnu.edu.cn S-1

2 EXPERIMENTAL SECTION 1.1. Chemicals and Materials Ethylene glycol and dopamine were purchased from Shanghai Energy Chemical Co. Ltd. Ethanol, trisodium citrate dihydrate, and sodium acetate trihydrate (NaAc) were purchased from Sinopharm Chemical Reagent Co. China. FeCl 3 6H 2 O was obtained from Alfa Aesar. All other chemical reagents were of analytical grade, and were used directly without further purification. Deionized water was used throughout Characterization The sizes and morphologies of Fe 3 O 4 and PDA@Fe 3 O 4 were determined using a JEOL JEM-1011 transmission electron microscope (TEM) under 100 kv accelerating. X-ray photoelectron spectroscopy (XPS) was conducted by using an ESCALAB 250 spectrometer equipped with an Al Kα 150 W source. Ultraviolet-visible-near-infrared (UV-vis-NIR) absorption spectra were obtained on a Shimadzu UV-3600 ultraviolet-visible-near-infrared spectrophotometer. Fourier transform infrared (FTIR) spectra were measured using a Fourier Transform Infrared Spectrophotometer IRPRESTIGE-21 (Shimadzu) from samples in KBr pellets. Dynamic light scattering (DLS) and Zeta potential experiments were carried out on an ALV/CGS-3 spectrometer-goniometer equipped with a cylindrical He-Ne laser (623 nm) with an output power of 22 mw. The size distribution was measured with a detection angle of S-2

3 90. Magnetic property characterization was performed with a vibrating sample magnetometer (VSM) on a model 6000 physical property measurement system (Quantum) at 300 K Photothermal properties studies Photothermal imaging system was designed as described in previously. 1 The photothermal images of PDA@Fe 3 O 4 solution were obtained using FLIR E40 equipment running on FLIR tools systems, in conjunction with a 785 nm laser. Dilutions of PDA@Fe 3 O 4 solution were placed in a specimen bottles irradiated by 785 nm laser (0.57 W cm 2 ). The temperature signals recorded at different time intervals were analyzed with FLIR tools systems. The photothermal conversion efficiency (η) can be determined as follows 2 : ha T max QS η= Aλ I(1 10 ) (1) where η is the photothermal conversion efficiency from the absorbed light energy to thermal energy, h is the heat transfer coefficient, A is the surface area of the container, T max is the temperature change at the maximum steady-state temperature, Q s is the heat associated with the light absorbance of the solvent, which is measured using pure water, I is the laser power, and A λ is the absorbance of PDA@Fe 3 O 4 solutions at the wavelength of 785 nm. S-3

4 In the equation (3), only ha is unknown for calculation. In order to get the value of ha, θ is introduced, which is defined as the ratio of T to T max : T θ = T max (2) where T is the temperature change, which is defined as T-T surr (T and T surr are the solution temperature and ambient temperature of the surroundings, respectively). Thus, ha can be determined as following: ha= mc p τ (3) where τ is the slope of the linear time data from the cooling period vs lnθ. m and C p are the mass and heat capacity of water, respectively Bacteria and cell culture Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria strains were purchased from the Institute of Microbiology, Chinese Academy of Sciences. Bacteria were grown overnight at 30 C on a shaker bed under 130 rpm rotation in liquid nutrient medium prior to the assay. The human colon cancer cell line (HCT116) cell lines were provided by the Institute of Basic Medical Sciences Chinese Academy of Medical Sciences. HCT116 cells were grown in high-glucose Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS). Cultures were maintained at 37 C under a humidified atmosphere S-4

5 containing 5% CO cells well 1 were seeded in 10 mm glass coverslips and allowed to attach for 24 h prior to the assay Toxicity studies in vitro In vitro cytotoxicity was measured by performing methyl thiazolyl tetrazolium (MTT) assays on HCT116 cells. Cells were seeded into a 96-well cell culture plate at well 1, under 100% humidity, and were cultured at 37 C and 5% CO 2 for 24 h. Different concentrations of PDA@Fe 3 O 4 (0, 2, 4, 6, 8, and 10 mg ml 1 ) were then added to the wells. The cells were subsequently incubated for 12 or 24 h at 37 C under 5% CO 2, respectively. Thereafter, MTT (10 µl, 5 mg ml 1 ) was added to each well and the plate was incubated for an additional 4 h at 37 C under 5% CO 2. After the addition of 10% sodium dodecyl sulfate (100 µl well 1 ), the assay plate was allowed to stand at room temperature for 12 h. The optical density OD570 value (Abs.) of each well, with background subtraction at 690 nm was measured by means of a Tecan Infinite M200 monochromator-based multifunction microplate reader. The following formula was used to calculate the inhibition of cell growth: Cell viability mean of Abs. value of treatment group (%) = 100% mean Abs. value of Control (4) S-5

6 Figure S1. XPS spectrum (a) and TGA analysis (b) of 3 O 4. S-6

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8 Figure S3. Magnetic hysteresis curves of Fe 3 O 4 and PDA@Fe 3 O 4 at 300 K. S-8

9 Figure S4. The UV-vis-NIR spectra of 3 O 4 +PES in deionized water, PBS buffer (ph = 7.4), 5% glucose solution, 0.9% NaCl solution, serum solution. S-9

10 Figure S5. (a) UV-vis-NIR absorption spectra of amidogen with different concentrations. (b) The standard curve of the amidogen tested by the UV-vis- NIR spectra and the amidoge concentrations of the PES released from 3 O 4 at 37 C, 40 C, 50 C, and 60 C, respectively. S-10

11 Figure S6. Bacteria viability of the colonies of E. coli (a) and S. aureus (b) incubated on the solid nutrient medium with different treatments. S-11

12 Figure S7. UV-vis-NIR absorption spectra of free PES solution (a) and 3 O 4 +PES solution (b). S-12

13 Figure S8. (a) UV-vis-NIR absorption spectra of different concentrations of 3 O 4 +PES solution. (b) The standard curve of the PDA@Fe 3 O 4 +PES solution tested by the UV-vis-NIR spectra. 1. Gao, H. C.; Sun, Y. M.; Zhou, J. J.; Xu, R.; Duan, H. W. Mussel-Inspired Synthesis of Polydopamine-Functionalized Graphene Hydrogel as Reusable Adsorbents for Water Purification. ACS Appl. Mater. Interfaces 2013, 5, Liu, Y. L.; Ai, K. L.; Liu, J. H.; Deng, M.; He, Y. Y.; Lu, L. H. Dopamine-Melanin Colloidal Nanospheres: An Efficient Near-Infrared Photothermal Therapeutic Agent for in Vivo Cancer Therapy. S-13

14 Adv. Mater. 2013, 25, S-14