Supporting Information Nanodiamond-Gadolinium(III) Aggregates for Tracking Cancer Growth In Vivo at High Field Nikhil Rammohan 1,2, Keith W. MacRenaris 1, Laura K. Moore 2, Giacomo Parigi 3, Daniel J. Mastarone 1, Lisa M. Manus 1, Laura M. Lilley 1, Adam T. Preslar 1, Emily A. Waters 1, Abigail Filicko 1, Claudio Luchinat 3, Dean Ho 4, and Thomas J. Meade* 1,2 Affiliations: 1 Department of Chemistry, Molecular Biosciences, Neurobiology, Radiology, and Center for Advanced Molecular Imaging, Northwestern University, Evanston, Illinois 60208, United States 2 Feinberg School of Medicine, Northwestern University, Chicago, Illinois, 60611, United States 3 Center for Magnetic Resonance Research, University of Florence, Sesto Fiorentino, Italy 4 School of Dentistry, University of California - Los Angeles, Los Angeles, California, 90095, United States *Correspondence to: tmeade@northwestern.edu; dean.ho@ucla.edu Contents Figure S1: Synthesis of Gd-C5-COOH... 2 Figure S2: TEM and EDX spectroscopy of NDG and NDA...3 Figure S3: FTIR spectra of NDG, NDA, and Gd-C5-COOH..4 Figure S4: Modified Kaiser Test..5 Figure S5-7: DLS and zeta potentials of NDG 6 Figure S8: NMRD profiles of NDG, Gd-C5-COOH, NDG + Gd-C5-COOH... 7 Table S1: NMRD parameter estimates... 8 Figure S9: T1-weighted MRI of cell pellets labeled with increasing NDG 9 Figure S10: m-cherry fluorescence of NDG tumor and unlabeled tumor.10 Figure S11: ROI selection and T 1 -fitting in tumors and muscle 11 Figure S12: Gd(III) content in clearance organs... 12 Figure S13: Figure 7d enlarged... 13 Figure S14: Laser Ablation ICP-MS... 14 1
Figure S1: Synthesis of ethyl protected DO3A macrocycle (1,4,7-TRIS(ETHYL ACETATE)- 1,4,7,10-TETRAAZACYCLODODECANE HBr, followed by addition of six-carbon ethyl ester, followed by deprotection and metalation with Gd(III). 2
Fig. S2. Transmission Electron Microscopy with EDX spectroscopy of NDA and NDG. (a) NDA images at low magnification, and (b) high magnification show a granular appearance with dense aggregates of particles, where individual particles are approximately 5 nm. (c-d) Low- and highmagnification images of NDG retain a similar appearance but also includes the presence of enhancing bridging structures. (e) EDX spectroscopy of NDG and NDA the Lα 1 and Lα 2 peaks of gadolinium are clearly observed in the NDG spectrum and not in the NDA spectrum. Present in both spectra are Cu, Al, and Si (from sample preparation). 3
Figure S3: FTIR spectra of NDA (blue), NDG (red), and Gd-C5-COOH (black), where an amide C=O stretch is visualized at ~1500 cm -1 in NDG but not in NDA or Gd-C5-COOH. 4
Figure S4: Primary amines are quantified based on absorbance at 570 nm. Spectra are shown for different concentrations of benzylamine, along with the spectra for 1 mg/ml solutions of NDA and NDG. 5
Figure S5: Hydrodynamic size and zeta potential for increasing Gd:ND coupling ratios. Hydrodynamic size increases for increasing coupling ratios, while zeta potentials are not significantly different (p > 0.3 for one-way ANOVA). Figure S6: Histograms of DLS intensity spectra of three batches of NDG aggregates bearing 1.4 μmol Gd/mg of ND Figure S7: Histograms of zeta potential spectra of three batches of NDG aggregates bearing 1.4 μmol Gd/mg of ND 6
Proton Relaxivity (s -1 mm -1 ) 25 20 NDGd2 25 C (0.345 mm) NDGd2 37 C (0.345 mm) NDGd1 25 C (0.405 mm) NDGd1 37 C (0.405 mm) Gd-free 25 C (0.369 mm) Gd-free 37 C (0.369 mm) NDMix 25 C (0.279 mm) NDMix 37 C (0.279 mm) 15 10 5 0 0.01 0.1 1 10 100 Proton Larmor frequency (MHz) Figure S8: NMRD profiles at 25 C and 37 C of two different batches of NDG ( NDGd 1 and NDGd 2 ), Gd-C5-COOH ( Gd-free ) and an uncoupled mix of NDA and Gd-C5-COOH ( NDMix ). Measurements in red were acquired separately, as detailed in Materials & Methods, sections (c) and (d) of manuscript. 7
NDG @ 25 C NDG @ 37 C Gd-C5-COOH @ 25 C Gd-C5-COOH @ 37 C R (ps) 77 62 78 56 q 1st sphere (#) 2 1 1.6 2 r 1st sphere (Å) 1 3.05 3.05 2 m (1st sphere) (ns) 1 36 25 36 25 q 2nd sphere (#) 13.4 - r 2nd sphere/outer (Å) 1 3.6 3.6 3 m (2st sphere) (ps) 38 26 - - Table S1: Parameter estimates for NMRD fits of NDG and Gd-C5-COOH at 25 C and 37 C. 1 Values kept fixed in the best fit minimization 2 q 1st sphere = 2 with r 1st sphere = 3.16 Å 3 Outer-sphere relaxation calculated with a distance of closest approach fixed to 3.6 Å and diffusion coefficients fixed to 2.3 10-9 and 3.3 10-9 m 2 /s at 25 and 37 C, respectively. 8
Figure S9: MR imaging at 7 T of MDA-MB-231 m-cherry cells labeled with NDG. (a) Axial MRI section of cell pellets having 0 (i), 0.6 (ii), 6.4 (iii) and 117.6 (iv) fmol/cell of Gd(III) after labeling with increasing concentrations of NDG for 24 hours. (ii) yields significantly greater contrast than (i). As cellular concentration of Gd(III) increases, positive contrast diminishes to yield negative contrast. At these higher concentrations, T 2 -relaxation times are even shorter than the short echo time TE of a T 1 -weighted sequence, resulting in a predominant T 2 effect over T 1. 9
Figure S10: Top Row - NDG tumor (right flank) and unlabeled tumor (left flank) of representative mouse imaged at 2-, 14- and 26-days post-inoculation imaged by an IVIS Lumina optical system detecting m-cherry fluorescence. Bottom Row m-cherry fluorophore-mediated radiant efficiency of each tumor at each timepoint. Images are from same mouse whose MR images are shown in Figure 6 of manuscript. 10
Figure S11: ROI selection and fitting of T 1 -relaxation times of representative mouse at Day 26. 11
Figure S12: Gd(III) content in clearance organs, namely liver, spleen, stomach and intestines (GI), and kidneys (n = 5). 12
Figure S13: Figure 7d enlarged to show greater detail. H&E section of NDG tumor (60x magnification) showing a similar morphology to the unlabeled tumor but containing visible NDG aggregates within neoplastic cells and in the interstitial space (black arrows). 13
NDG CTRL Figure S14: Laser Ablation ICP-MS for spatial distribution of Gd(III) content in tumor sections. Both 66 Zn and 157 Gd values are reported for each of the NDG and unlabeled tumor sections. 66 Zn is uniformly distributed in the tumor sections corresponding closely with the tumor section boundaries. Only the NDG tumor has Gd(III) distributed throughout the tissue with highest concentrations in the center. 14