Comparative analyses of industrial‐scale human platelet lysate preparations

Abstract

Background Efforts are underway to eliminate fetal bovine serum (FBS) from mammalian cell cultures for clinical use. An emerging viable replacement option for FBS is human platelet lysate (PL) either as a plasma (PL-P) or serum (PL-S) based product. Study Design and Methods Nine industrial scale PL-S manufacturing runs (i.e. lots) were performed that consisted of an average volume of 24.6±2.2 liters of pooled platelet-rich-plasma (PRP) units that were obtained from apheresis donors. Manufactured lots were compared by evaluating various biochemical and functional test results. Comprehensive cytokine profiles of PL lots and product stability testing was performed. Global gene expression profiles of Mesenchymal Stromal Cells (MSCs) when cultured with PL-S or PL-P were compared with FBS. Results Electrolyte and protein levels were relatively consistent among all PL-S lots with only slight variations in glucose and calcium levels. All nine lots were as good as or better than FBS in expanding MSCs. PL-S stored at −80°C remained stable over two years. Quantitative cytokine arrays showed similarities as well as dissimilarities in the proteins present in PL-S. Greater differences in MSC gene expression profiles were attributable to the starting cell source than as to whether PL or FBS were used as culture supplements. Conclusion Using a large-scale standardized method, lot-to-lot variations were noted for industrial scale preparations of PL-S. However, all lots were as good as or better than FBS in supporting MSC growth. Together these data indicate that off-the-shelf PL is a feasible substitute for FBS in MSC cultures.

Human Platelet Lysate Can Replace Fetal Calf Serum as a Protein Source to Promote Expansion and Osteogenic Differentiation of Human Bone-Marrow-Derived Mesenchymal Stromal Cells

“…hPL is generally produced out of a varying number of pooled human platelet concentrates [13,18,[42][43][44][45] after platelet lysis by freezing-thawing cycles [20,[43][44][45] or activation by thrombin [13,42] to liberate the substances required for cell culture that are stored in platelet granules [14,15]. However, there is no good manufacturing practice statement concerning the platelet lysis method in hPL production [13].…”

“…However, there is no good manufacturing practice statement concerning the platelet lysis method in hPL production [13]. The hPL available for scientific purposes can be produced out of outdated platelet concentrates having no clinical use whilst being still suitable for (in-vitro research) cell culture [13,20,43]. Furthermore, the hPL composition creates a milieu closer to the physiological milieu of the human body than FCS does [8][9][10][11].…”

“…Many preliminary studies evaluated the effects of hPL-supplemented ESM on MSC in order to assess whether hPL changes MSC characteristics during expansion. Most of these studies evaluated the immunophenotype of the cells after expansion by analyzing cell surface markers with fluorescence-activated cell sorting (FACS): stem cell defining surface markers [46] were analyzed in almost any study; the consistent results were that expansion of MSC in hPL-supplemented ESM does not alter the expression of stem cell defining surface markers in comparison to MSC expanded in FCS-supplemented ESM [16][17][18]22,23,26,28,29,43,44,47]. Viau et al [18] and Reis et al [47] assessed the expression of further surface markers, revealing that the expression of some surface markers differs significantly between MSC expanded in hPL or FCS, but the majority of the markers are only mildly influenced by the source of protein supplement in ESM.…”

Gaps in the knowledge of human platelet lysate as a cell culture supplement for cell therapy: a joint publication from the AABB and the International Society for Cell & Gene Therapy

“…There are challenges with sourcing of starting material for hPL production. 85 Can the industry meet the demand for hPL? Should it be widely adopted as a larger number of commercial cell products come to market and the demand increases?…”

“…More recently it has been shown that serum-converted hPL solutions are stable at −80 C for 2 years. 85 Mojica-Henshaw and coworkers 74 showed that hPL could be maintained for 4 weeks at 4 C without significant loss of activity.…”