Characterization of Particulate Impurities in Complex Injectable Drugs to Predict Their Effects on Vascular Endothelial Cells

Abstract To address misjudgment of endothelial toxicity caused by chemical heterogeneity of impurities in traditional Chinese medicine injections, this paper established a systematic research framework for chemical and biological effects. A three-dimensional fingerprint was constructed by combining microscopy, Raman spectroscopy, and dynamic light scattering; an energy dispersive spectroscopy (EDS)-based source apportionment model using energy dispersive spectroscopy and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) accurately distinguishes medicinal material residues, excipient leaching, and packaging-introduced particles. A particle–cell interaction kinetics simulation algorithm was designed to quantify the bloodstream deposition behavior of particles with varying zeta potentials. Transcriptome and phosphoprotein micro-array data were integrated to identify core mitochondrial stress pathways. Finally, a chemical–biological scoring system was constructed for interpretable toxicity prediction. Experimental results showed polysaccharide/protein aggregates are the key particle type inducing damage to human umbilical vein endothelial cells, increasing reactive oxygen species (ROS) production, disrupting the transendothelial electrical resistance (TEER) barrier, promoting inflammatory factor release, and inducing late apoptosis. Model validation demonstrated a Kappa coefficient of 0.78 with high predictive accuracy (73.3%). This study reveals how the chemical nature of microparticles dominates endothelial toxicity and establishes an integrated “multidimensional characterization-biological response-risk prediction” paradigm. The proposed “characterization-mechanism” strategy can be extended to safety evaluation of microparticles in other complex injections, providing a universal technical path for improving quality control of high-risk injections.