Metabolomic Fingerprints of L-PRP and P-PRP: Formulation differences and Storage-induced Shifts

Platelet-rich plasma (PRP) preparation and storage conditions are thought to influence its clinical efficacy in osteoarthritis; however, molecular evidence supporting this assumption remains limited. This study aimed to compare the metabolomic profiles of leukocyte- rich PRP (L-PRP) and pure/leukocyte-poor PRP (P-PRP) and to evaluate the effect of shortterm frozen storage on their metabolite composition.

L-PRP and P-PRP samples were collected from six healthy male donors and analysed using untargeted quadrupole time-of-flight liquid chromatography-mass spectrometry (Q-TOF LC/MS)-based metabolomics. Each sample was analysed immediately after preparation and after one week of storage at -20 °C. Multivariate and univariate statistical analyses were performed to identify formulation-specific and storage-related metabolic alterations.

Distinct metabolomic differences were observed between L-PRP and P-PRP. L-tyrosine, D-glucuronic acid, nicotinamide ribotide, and epinephrine were among the metabolites that best discriminated the two formulations. Frozen storage induced formulation-dependent metabolic changes. In L-PRP, nicotinamide ribotide and prostaglandin H2 changed, whereas P-PRP showed alterations in phosphocreatine, citric acid, and glutathione. These changes were consistent across all donors.

Both PRP formulation and frozen storage influenced metabolite composition, indicating that biochemical differences extend beyond platelet and leukocyte content. Although the clinical significance of these alterations remains unclear, they may contribute to differences in PRP biological activity. Further studies integrating metabolomic and proteomic analyses are needed.

Short-term frozen storage induces reproducible, formulation-dependent metabolomic changes in PRP. These findings emphasize the importance of storage conditions and provide a basis for future studies investigating their impact on PRP therapeutic efficacy.