Achieving Biocompatible SABRE: An in vitro Cytotoxicity Study

Abstract Production of a biocompatible hyperpolarized bolus for signal amplification by reversible exchange (SABRE) could open the door to simple clinical diagnosis via magnetic resonance imaging. Essential to successful progression to preclinical/clinical applications is the determination of the toxicology profile of the SABRE reaction mixture. Herein, we exemplify the cytotoxicity of the SABRE approach using in vitro cell assays. We conclude that the main cause of the observed toxicity is due to the SABRE catalyst. We therefore illustrate two catalyst removal methods: one involving deactivation and ion‐exchange chromatography, and the second using biphasic catalysis. These routes produce a bolus suitable for future in vivo study.


Table of contents
ment with 10 µl of (0:100) prepared in medium. The data **P<0.005 and ns ANOVA. An increase in cell viability is denoted by a '^'.

. Effect of deuterated solvent
Supporting figure for Figure 1.
10 µl of ethanol in heavy water (deuterium oxide The data represents **P<0.005 and ns -Not significant vs. the untreated control ANOVA. An increase in cell viability is denoted by a '^'.
Supporting Information viability cells treated with (0:100) prepared in . The data are presented as mean + *P<0.05, **P<0.005 and ns way ANOVA. An increase in cell viability is denoted by a '^'.

Supporting Information
treated with 10 µl of prepared in water (H . The data are presented as mean + *P<0.05, **P<0.005 and ns way ANOVA. An increase in cell viability is denoted by a '^'.     prepared under SABRE reaction conditions . In the absence of a substrate or ligand (as shown in Figure S4 emulsion was taken in the same solvent (30% ethanol was estimated by MTT assay independent experiments (n=3). *P<0.05, **P untreated control group; one-

the catalyst [IrCl(COD)(IMes)] Cell viability data showing (A) A549 and (B) MCF7
under SABRE reaction conditions a substrate or ligand Figure S4). Prior to treatment d was taken as bolus in the same solvent (30% ethanol-d 6 in D MTT assay. The data independent experiments (n=3). *P<0.05, **P -way ANOVA.

Figure S
Cytotoxicity 5, 7.5 and 10%) of the bolus from that contained the substrate further assay after 1, 6 and 24 h independent experiments (n=3). Figure S9. Evaluating the cytotoxicity of Cytotoxicity data showing 5, 7.5 and 10%) of the bolus from that contained the substrate further to 10 µl in the same fraction ( assay after 1, 6 and 24 h independent experiments (n=3).

Evaluating the cytotoxicity of
data showing (A) A549 and (B) MC 5, 7.5 and 10%) of the bolus from that contained the substrate in the same fraction ( assay after 1, 6 and 24 h of treatment. independent experiments (n=3).
Evaluating the cytotoxicity of (A) A549 and (B) MC 5, 7.5 and 10%) of the bolus from the aqueous that contained the substrate d 2 -MN alone.
in the same fraction (0.9% NaCl treatment. The data are e independent experiments (n=3).

Supporting Information
Evaluating the cytotoxicity of substrate from aqueous phase of biphasic (A) A549 and (B) MCF7 cells treated with various volumes (0, 2.5, the aqueous fraction alone. Prior to treatment each sample was diluted 0.9% NaCl in D The data are e Supporting Information substrate from aqueous phase of biphasic F7 cells treated with various volumes (0, 2.5, fraction of a biphasic Prior to treatment each sample was diluted in D 2 O). Cell viability The data are expressed as mean + SD and are from 3 Supporting Informationsubstrate from aqueous phase of biphasic F7 cells treated with various volumes (0, 2.5, biphasic mixture (see Figure S8) Prior to treatment each sample was diluted . Cell viability was measured b xpressed as mean + SD and are from 3 -Manoharan substrate from aqueous phase of biphasic reaction F7 cells treated with various volumes (0, 2.5, mixture (see Figure S8) Prior to treatment each sample was diluted was measured b xpressed as mean + SD and are from 3 reaction F7 cells treated with various volumes (0, 2.5, mixture (see Figure S8) Prior to treatment each sample was diluted was measured by MTT xpressed as mean + SD and are from 3