{
  "abstract": "Raman spectroscopy provides a label-free vibrational profile of extracellularvesicle (EV)-enriched biofluid fractions. Participant-level Raman profiles were obtained from 97 participants with ischemic stroke and 50 controls. After quality control and region-specific normalization, spectra acquired at individual spatial sampling locations were aggregated into a single median spectrum per participant in the fingerprint (734–1788 cm −1 ) and C–H stretching (2451–3197 cm −1 ) regions, so that inference was carried out at the participant rather than the measurement level. The objectives were to characterize participant-level spectral variation, assess exploratory case-control separation, and examine associations with clinical outcomes within the stroke cohort. Participant-level spectra showed 21 reproducible Raman bands and shoulder features associated with lipids, proteins, nucleic acids, and carotenoids. Lipid-associated regions accounted for most of the normalized spectral variance (fingerprint PC1, 75.8%; C–H PC1, 67.1%), a pattern that persisted when PCA was repeated using only spectra from participants with ischemic stroke. All 21 features differed between stroke and control participants after false-discovery-rate correction, with increases and decreases distributed across multiple correlated Raman domains. The primary whole-spectrum partial least-squares discriminant analysis (PLSDA) model gave modest discrimination (balanced accuracy 0.655, 95% CI 0.538–0.771; ROC–AUC 0.711, 95% CI 0.550–0.823; sex-stratified permutation p = 0.005). Within the stroke cohort, no whole-spectrum association survived correction for multiplicity, and Montreal Cognitive Assessment (MoCA) scores gave negative cross-validated R 2 , so the spectra did not support the prediction of cognitive outcome. Participant-level Raman spectroscopy, therefore, identifies reproducible biochemical differences within compositionally complex EV-enriched fractions and identifies lipid-, protein-, nucleic acid-, and carotenoid-associated regions for molecular follow-up in larger, balanced cohorts.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Physics and Mathematics",
    "University of Eastern Finland (UEF)",
    "School of Pharmacy",
    "University of Eastern Finland",
    "A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland",
    "Experimental Research Center in Normal and Pathological Aging (ARES), University of Medicine and Pharmacy of Craiova, Strada Petru Rares, Nr. 2, Craiova, Romania, 200349",
    "Chair of Vascular Neurology, Dementia and Ageing Research, Department of Neurology, Essen University Medical School, University of Duisburg-Essen, Hufelandstraße 55, Essen, Germany, 45147",
    "Faculty of Pharmacy, University of Helsinki, Viikinkaari 5 E, Helsinki, Finland, 00790",
    "Pharmaceutical Sciences Laboratory, Åbo Akademi University, Artillerigatan 6A, Turku, Finland, 20520",
    "Department of Chemistry, University of Turku, Henrikinkatu 2, Turku, Finland, FI-20500"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 14,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Emanuele Nardone",
      "orcid": "0009-0005-8718-5435"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Nikita Belko",
      "orcid": "0000-0002-9926-3462"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Tuomas Kilpeläinen"
    },
    {
      "affs": [
        4
      ],
      "name": "Olga Neustroeva"
    },
    {
      "affs": [
        5
      ],
      "name": "Agnieszka Słowik"
    },
    {
      "affs": [
        5
      ],
      "name": "Nikolaus Plesnila"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Aurel Popa-Wagner"
    },
    {
      "affs": [
        7,
        8
      ],
      "name": "Jacopo Zini"
    },
    {
      "affs": [
        4,
        7
      ],
      "name": "Francesco Piga"
    },
    {
      "affs": [
        9
      ],
      "name": "Saara Zini"
    },
    {
      "affs": [
        9
      ],
      "name": "Pia Damlin"
    },
    {
      "affs": [
        4
      ],
      "name": "Emma Gribchenko"
    },
    {
      "affs": [
        4
      ],
      "name": "Tarja Malm"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Polina Kuzhir"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bad3kbjnd5zgt.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15011020/v1",
  "fulltext_url": null,
  "id": "bad3kbjnd5zgt",
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  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15011020/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1304|Spectroscopy Techniques in Biomedical and Chemical Research"
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  "openalex": "W7223705078",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15011020/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-25",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/bad3kbjnd5zgt.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:26Z",
      "native_id": "10.26434/chemrxiv.15011020",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15011020/v1"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "openalex:1304|Spectroscopy Techniques in Biomedical and Chemical Research",
      "subfield": "biophysics"
    }
  ],
  "title": "Participant-level Raman spectroscopy of circulating EV-enriched fractions reveals distributed spectral differences in ischemic stroke patients",
  "title_text": "Participant-level Raman spectroscopy of circulating EV-enriched fractions reveals distributed spectral differences in ischemic stroke patients",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:26Z",
  "url": "https://research.draconitic.com/paper/bad3kbjnd5zgt",
  "venue": "ChemRxiv",
  "versions": []
}