Supporting Information Photo-Regulated Cross-Linking of Superparamagnetic Iron Oxide Nanoparticle (SPION)-Loaded Hybrid Nanovectors with Synergistic Drug Release and Magnetic Resonance (MR) Imaging Enhancement Kangning Zhu, Zhengyu Deng, Guhuan Liu,* Jinming Hu,* and Shiyong Liu* CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, ichem (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China. * To whom correspondence should be addressed. E-mail: ghliu@ustc.edu.cn (G.L.); jmhu@ustc.edu.cn (J.H.); sliu@ustc.edu.cn (S.L.). S1
Figure S1. TEM images recorded for (a) oleic acid (OA)-stabilized and (b) CTAB-stabilized superparamagnetic iron oxide nanoparticles (SPIONs). The average diameters of SPIONs are 7 nm. S2
Figure S2. Typical 1 H NMR spectrum recorded in CDCl 3 for PEO 45 -b-pnboc 37 (BP1). Note. The DP of PNBOC block was calculated from the following equation,,, 90 where, and, are the integral areas of peak e and g, respectively S3
Figure S3. TEM images recorded for SPION-loaded hybrid BP3 nanoparticles through ultrasonication in a pulse-pause manner of 10 s and 30 s for total pulse durations of (a) 90 s and (b) 300 s, and continuous ultrasonication for (c) 90 s and (d) 300 s, respectively. The residual CHCl3 solvent was removed via rotary evaporation after ultrasonication treatments. S4
Weight retention / % 100 80 60 40 20 0 a) OA-stabilized SPIONs b) Hybrid BP3 NPs w/o UV c) Hybrid BP3 NPs w/ UV 100 300 400 500 600 700 800 Temperature / o C a) 89.6% c) 29.3% b) 15.8% Figure S4. Thermogravimetric analysis (TGA) curves of (a) oleic acid-stabilized SPIONs, (b) untreated and (c) UV-irradiated SPION-loaded hybrid BP3 nanovectors. TGA measurements were performed in air at a heating rate of 10 o C/min. S5
Zeta potential / mv 3 0-3 -6-9 0 5 10 15 20 25 30 Irradiation Time / min Figure S5. Irradiation time dependence of zeta potentials recorded for aqueous dispersions ( g/l) of SPION-loaded hybrid BP3 nanovectors under UV 365 nm light irradiation (~1.0 mw/cm 2 ). S6
Normalized Intensity 1.2 1.0 0.8 0.6 I/I 0 1.0 0.5 0 10 20 30 Time / min 600 620 640 660 680 700 720 Wavelength / nm Figure S6. Incubation duration-dependent evolution of fluorescence emission spectra (λ ex = 550 nm) of Nile red-loaded hybrid BP3 nanovectors without UV irradiation. The inset shows normalized emission intensity changes at 628 nm (λ ex = 550 nm) without UV irradiation. S7
w/o UV irradiation > = 12 nm w/ UV irradiation > = 220 nm 10 100 1000 D h / nm Figure S7. D h distributions of SPION-loaded hybrid nanovectors without and with UV irradiation for 20 min in THF. S8
a) b) 1 Increasing concentration of HEA FL Intensity 800 400 c) d) 1 1000 0 400 450 500 550 600 650 700 Wavelength / nm FL (@485 nm) 800 400 y = 16120x + 122 R 2 > 0.99 FL Intensity 800 600 400 0 1 2 3 4 5 6 [HEA] / mm 0 400 450 500 550 600 650 700 Wavelength / nm Figure S8. (a) Schematics of the fluorogenic reaction of fluorescamine (FA) with primary amine functionalities for the quantitative assay of primary amines. (b) Fluorescence emission spectra (λ ex = 390 nm) recorded for aqueous solutions of 2-hydroxyethylamine (HEA, PBS buffer, ph 7.4) at varying concentrations (4.81-57.9 µm). Prior to fluorescence analysis, 500 µl borate buffer (ph 9.2, 50 mm) was added to 400 µl HEA solution, 100 µl FA (2 mm in acetone) was then added and the mixture was allowed to react for at least 1 min. (c) Fluorescence emission intensity at 480 nm plotted as a function of HEA concentrations. Data are presented as mean ± SD (n = 3). (d) Fluorescence spectrum (λ ex = 390 nm) recorded for the filtrate obtained by ultrafiltration (MWCO: 10 kda) of UV-irradiated SPION-loaded hybrid BP3 nanovectors (0.3 g/l). 400 µl irradiated BP3 nanovectors was sample out, 500 µl borate buffer (ph 9.2, 50 mm) was then added; next, 100 µl FA solution in acetone (2 mm) was introduced and the mixture was allowed to react for at least 1 min before fluorescence measurements. S9
Figure S9. Representative CLSM images recorded for HepG2 cells after incubation with SPION/DOX-loaded hybrid BP3 nanovectors for 2 h, followed by rinsing with PBS buffer and incubation for additional 2 h, 6 h, 10 h, and 22 h, respectively. Late endosomes/lysosomes and cell nuclei were stained with LysoTracker green (green channel) and DAPI (blue channel), respectively. The blue channel was excited at 405 nm and collected between 420 nm and 480 nm; the green channel was excited at 488 nm and collected between 500 nm and 550 nm; the red channel was excited at 543 nm and collected between 570 nm and 650 nm. S10
Figure S10. Apoptosis of HepG2 cells induced by SPION/DOX-loaded hybrid BP3 nanovectors was detected by Live/Dead assay (carboxyfluorescein diacetate and propidium iodide). Representative CLSM images of HepG2 cells (a,b) in the absence of SPION/DOX-loaded hybrid nanovectors (a) without UV light irradiation and (b) with UV 365 nm light irradiation for 10 min; HepG2 cells (c,d) in the presence of DOX-loaded hybrid BP3 nanovectors (c) without and (d) with UV 365 nm light irradiation for 10 min. Cells were incubated with hybrid nanovectors for 2 h, followed by rinsing with PBS buffer three times, irradiation under UV light for 10 min, and incubation for additional 24 h. S11
a) > / nm 220 210 190 w/o UV irradiation 10 mm PBS 0.3 0.1 µ 2 /Γ 2 > / nm 220 210 190 w/ UV irradiation 10 mm PBS 0.3 0.1 µ 2 /Γ 2 b) > / nm c) > / nm 180 400 300 100 400 300 0 4 8 12 16 20 24 Incubation Time / h w/o UV irraidation 45 g/l BSA 0 4 8 12 16 20 24 Incubation Time / h w/o UV irradiation 90 v/v% FBS 0.8 0.6 0.8 0.6 µ 2 /Γ 2 µ 2 /Γ 2 > / nm > / nm 180 240 220 180 160 240 220 180 0 4 8 12 16 20 24 Incubation Time / h w/ UV irradiation 45 g/l BSA 0 4 8 12 16 20 24 Incubation Time / h w/ UV irradiation 90 v/v% FBS 0.5 0.3 0.1 0.3 0.1 µ 2 /Γ 2 µ 2 /Γ 2 100 0 4 8 12 16 20 24 Incubation Time / h 160 0 4 8 12 16 20 24 Incubation Time / h Figure S11. Hydrodynamic diameters ( >) and polydispersities (µ 2 /Г 2 ) of (left panel) untreated or (right panel) UV-irradiated SPION/DOX co-loaded hybrid BP3 nanovectors at 37 o C and ph 7.4 in the presence of (a) 10 mm PBS, (b) 45 g/l BSA, and (c) 90 v/v% FBS. S12