Iranian Journal of Basic Medical Sciences

Iranian Journal of Basic Medical Sciences

Controlled stepwise serum deprivation enhances physicochemical properties and biocompatibility of small extracellular vesicle-enriched particles derived from adipose mesenchymal stem cells

Articles in Press

Document Type : Original Article

Authors
Pegah Rajabi 1
Nazanin Akbari 2
Hanieh Jafari 1
Azadeh Soltani 3
Banafsheh Heidari 4
1 Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 Department of Biology, Shahid Beheshti University, Tehran, Iran
3 Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
4 Department of Photo Healing and Regeneration, Medical Laser Research Center, Yara Institute, ACECR, Tehran, Iran
10.22038/ijbms.2026.97865.21046
Abstract
Objective(s): This study assessed how controlled, sequential serum deprivation affects adipose-derived mesenchymal stromal cells (AdMSCs) and the physicochemical properties and biocompatibility of their extracellular vesicle-enriched particles.
Materials and Methods: AdMSCs from five healthy donors were cultured under stepwise serum deprivation (from 10% exosome-depleted FBS to 5%, then 1%) and standard control conditions (10% exosome-depleted FBS) for 36 hr. The effects of these culture conditions on AdMSC density, apoptosis, migration, and stemness were assessed. AdMSC-derived sEV-enriched particles were isolated and characterized for morphological, biochemical, and structural features using field emission scanning electron microscopy (FESEM), TEM, FTIR, DLS, Zeta potential, and Bradford assays, performed in triplicate. Biocompatibility was evaluated using MTT, and in vivo irritation, sensitization, and acute systemic toxicity tests were conducted.
Results: No significant differences were observed in AdMSC cell number, viability, apoptosis, or stemness; however, stepwise serum starvation significantly enhanced migration. FESEM and TEM analyses revealed improved quality, greater structural uniformity, and significantly reduced aggregation in serum-starved sEV-enriched particles. Starved particles showed a distinct dry-size peak of 47±15 to 49±13 nm, whereas controls had a broader average of 340±14 to 350±12 nm. Controls were polydisperse (80% at 223.7±45.7nm, 20% at 50.8±5.7nm), whereas starved particles were monodisperse (34.1±3.1nm). Starved particles exhibited higher zeta potential (-4.9 mV vs -9.0 mV) and protein content (4.35 vs 2.18 mg/ml; P≤0.05). Both groups showed acceptable biocompatibility, with no cytotoxicity, irritation, sensitization, or microbial contamination (P>0.05).
Conclusion: Stepwise serum starvation significantly improved the morphological, biochemical, and structural properties of AdMSC-derived sEV-enriched particles without compromising their overall safety profile.
Keywords
Cell movement
Culture media
Extracellular vesicles
Mesenchymal stem cells
Particle size
Regenerative medicine
Serum-free
Toxicity tests
Subjects
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Iranian Journal of Basic Medical Sciences

Articles in Press, Accepted Manuscript
Available Online from 10 November 2026