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Updated: Mar 7, 2026
Preparation of Pooled Human Platelet Lysate pHPL as an Efficient Supplement for Animal Serum-Free Human Stem Cell Cultures
Published on: October 30, 2009
Standardizing the freeze-thaw preparation of growth factors from platelet lysate
Gabriel Strandberg1, Felix Sellberg1, Pehr Sommar2
1Department of Immunology, Genetics and Pathology, Section of Clinical Immunology, Uppsala University, Uppsala, Sweden.
Background:
Over the past decades, the focus on the regenerative properties of platelets (PLTs) has intensified and many PLT-derived growth factors are readily used in medical settings. A general lack of standardization in the preparation of these growth factors remains, however, and this study therefore examines the dynamics of growth factors throughout the freeze-thaw procedure.
Study Design And Methods:
Plateletpheresis (PA) and PLT-poor plasma (PPP) samples were collected from 10 healthy donors. PA was lysed to produce PLT lysate (PL) for 1, 3, 5, 10, and 30 freeze-thaw cycles. The resulting growth factor and cytokine concentrations from PPP, PA, and PL of different cycles were analyzed and compared using enzyme-linked immunosorbent assay and multiplex bead assays.
Results:
PL produced by the freeze-thaw procedure resulted in approximately four- to 10-fold enrichment of transforming growth factor-β1, epidermal growth factor, PLT-derived growth factor (PDGF)-AB/BB, PLT factor-4, and fibroblast growth factor-2. The increase in concentrations plateaued at Cycles 3 and 5 and in some cases declined with further cycles. The concentrations of insulin-like growth factor-1, hepatocyte growth factor, vascular endothelial growth factor, and bone morphogenetic protein-2 in PL were essentially comparable to those in PPP.
Conclusion:
Using the freeze-thaw method, optimal preparation of PL with regard to the concentration of growth factors was achieved at Cycles 3 to 5. Based on our findings, the clinical significance of using a greater number of cycles is likely limited.
