Fig. 2: Synthesis and 31P MRI of gradient copolymer micelles PPnGRAD. | Nature Communications

Fig. 2: Synthesis and 31P MRI of gradient copolymer micelles PPnGRAD.

From: Biodegradable polyphosphoester micelles act as both background-free 31P magnetic resonance imaging agents and drug nanocarriers

Fig. 2

A Synthesis of gradient copolymer by anionic ring-opening copolymerization. B Copolymerization kinetics: Monomer concentration in solution as a function of the total conversion of monomers Et-Pn and Ph-Pn. C Monte-Carlo simulated microstructure for 10 representative polymer chains, calculated from the determined reactivity ratios. D Average composition of monomer fraction F plotted against total conversion. E Schematic of PPnGRAD micelles with NMR spectrum (158 MHz, D2O). F 31P MRI of PPnGRAD micelles (top row). The signals of both Ph- and Et-units were added to a sum image, resulting in the highest SNR. The images of block copolymer micelles PPnCORE and PPnSHELL are shown at the same intensity scale for comparison. Polymer content 4 wt% (31P 0.1 M in PPnCORE, 2x0.1 M in each block of PPnGRAD; and 0.05 M 31P In PPnSHELL; similar polymer concentration was chosen. FOV 20 × 20 mm2, matrix 64 × 64, 9.4 T. G PPnGRAD micelles could be imaged and localized with 31P MRI after injection in physalis berry. 1H MRI (matrix 512 × 512), 31P MRI and an overlay image (31P MRI in hot iron, matrix 64 × 64) are shown. Arrow indicates the injection site, mCSSI, TAcq 17 min, FOV 30 × 30 mm2, 9.4 T. Color scale in arbitrary units (a.u.).

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