Physicochemical characterization of nanoparticles in highly diluted preparations and exploratory plasma proteomic correlates in an N-of-1 study.

The physicochemical properties of highly diluted homeopathic preparations remain insufficiently characterized. This study investigated particulate features of Kali carbonicum (K2CO3) at 50-millesimal potencies (LM4-LM7, ∼1:50,000 dilutions per step) and explored plasma proteomic changes in a placebo-controlled N-of-1 trial. Scanning electron microscopy showed larger particle size in Kali carbonicum (67.3 nm) than in the lactose control (47.5 nm) at LM4 in a descriptive comparison. Dynamic light scattering showed no significant differences in size, polydispersity, or zeta potential among Kali carbonicum, lactose control, and solvent blank, accounting for vial-level clustering. Atomic force microscopy showed more compact dendritic assemblies in Kali than in lactose controls, suggesting trituration influences self-organization. Raman spectroscopy of LM7 detected carbonate-associated bands absent in controls. Plasma proteomics identified six FDR-significant proteins during Kali exposure, including increased S100A9, with exploratory enrichment for inflammation, cytoskeletal, and motility terms. These findings are exploratory and do not imply causality.