Perfluorocarbon-PLGA particle ultrastructure affects pH sensitivity in 19F NMR and MRI

Motivation: We aim to advance biocompatible 19F-MR contrast agent to enhance imaging diagnostic in cancer. Goal(s): Nanoparticles (NPs) internal structure impacting Gd-enhanced effect on 19F-MR signal strength, relaxation times and pH-sensitivity. Approach: Systematic investigation using 1H/19F-MR to understand how NPs structure affects the interaction between co-encapsulated Gd and 19F and focusing on multi-core NPs and their acidic pH-sensitivity on 19F-MR relaxation times. Results: Our study revealed that 19F-MR signal strength is pH-dependant. After cellular uptake, multi-core NPs co-encapsulating Gd and PFCE exhibited higher T2 values and stronger signal, influenced by lysosomal acidity, highlighting pH role in MR signal modulation. Impact: The pH-sensitive 19F-MR probe enhance NPs tracking after cell internalization and by that it holds great promise for tissue pathology imaging, as cancer diagnostics.