Ultrahigh-Power Sonicator Lysis Enables Deep Proteomic Profiling of Hair Shafts for Fetal Growth Restriction Biomarker Discovery

The hair shaft provides a noninvasive, easily accessible specimen with exceptional molecular stability, retaining metabolic signatures from fetal development. However, its dense keratinization impedes efficient protein extraction, thereby restricting the proteomic depth and clinical applicability. To surmount this barrier, we designed an ultrahigh-power sonicator (UHPS) that disrupts keratin networks, boosting the protein yield by more than 1.8-fold. We coupled UHPS with the Deep Efficient Peptide Sequencing and Quantification (DEEP SEQ) mass spectrometry platform for the in-depth proteomic profiling of hair shafts. This integrated workflow quantified 3,925 proteins from just 1 mg of hair shaft sample. In fetal growth restriction (FGR) cases versus healthy controls (HCs), we identified 239 differentially expressed proteins (DEPs). Candidate biomarkers from this panel were validated using parallel reaction monitoring (PRM) and an enzyme-linked immunosorbent assay (ELISA) in independent cohorts. Their expression levels showed strong correlations with FGR clinical indicators. The UHPS-DEEP SEQ pipeline marks a significant advancement in hair shaft proteomics, enabling noninvasive biomarker identification and offering significant potential for perinatal diagnostics.