Characterization of Lyophilized and Spray-Dried Platelet Lysate as Xeno-Free Serum Alternatives for Regenerative Medicine

Abstract

Human platelet lysate is a promising xeno-free alternative to fetal bovine serum (FBS) for cell culture in regenerative medicine. This thesis focused on the production and characterization of pathogen-inactivated platelet lysate (PIPL) in three formulations: liquid (PIPL), lyophilized (L-PIPL), and spray-dried (S-PIPL). The spray-drying process was optimized to produce three variants based on temperature - low (S-PIPL-L), moderate (S-PIPL-M), and high (S-PIPL-H).The bioactivity of these formulations was evaluated using mesenchymal stem cell (MSC) cultures through viability and cytotoxicity assays. Stability studies were conducted on samples stored at –80 °C, 25 °C, and 40 °C over 31 and 60 days, assessing total protein content (BCA), retention of growth factors and human serum albumin (ELISA), protein structure (SDS-PAGE), and powder morphology (SEM).L-PIPL demonstrated good solubility and preserved structural integrity, while S-PIPL-M showed the strongest biological performance, with high MSC viability and low cytotoxicity. S-PIPL-H exhibited the best stability, maintaining total protein, albumin, and growth factor levels under stress conditions.Overall, these findings support spray-dried PIPL—especially S-PIPL-M and S-PIPL-H as stable and effective xeno-free serum alternatives for applications in regenerative medicine.