Solvent/detergent treatment of platelet concentrates enhances the release of growth factors

BACKGROUND: Platelet (PLT) growth factors released by thrombin activation of autologous PLT concentrates (PCs) are used in clinics as PLT gels or releasates for tissue repair and wound healing applications. If allogeneic products are to be used for clinical or cell culture applications, a method of viral inactivation of the PC source of growth factors is desirable. STUDY DESIGN AND METHODS: PLT-derived growth factor-AB (PDGF-AB), transforming growth factor-β1 (TGF-β1), epidermal growth factor (EGF), and insulinlike growth factor-1 (IGF-1) in apheresis PC subjected to solvent/detergent (S/D) treatment with or without prior activation by CaCl₂ and/or bovine thrombin were measured. RESULTS: Mean (± standard deviation) PDGF-AB, TGF-β1, EGF, and IGF-1 content was 13.8 ± 14.3, 16.6 ± 14.3, less than 0.0007, and 83.4 ± 33.4 ng per mL, respectively, in the starting PC. They increased to 184.4 ± 80.2, 192.2 ± 37.4, 2.2 ± 1.6, and 88.4 ± 33.5 after 1 percent tri-n-butyl phosphate (TnBP)-1 percent Triton X-45 treatment, respectively. Mean content was 84.6 ± 35.5, 63.8 ± 14.1, 0.9 ± 0.6, and 117.2 ± 34.9 ng per mL, respectively, in CaCl₂-activated PC and remained stable after subsequent S/D treatment (88.3 ± 45.9, 68.6 ± 27.2, 1.40 ± 1.0, and 112.4 ± 39.7 ng/mL, respectively). Two percent TnBP treatment yielded similar release as with TnBP-Triton X-45. Addition of bovine thrombin did not increase the release of growth factors. CONCLUSION: S/D treatment efficiently releases PDGF-AB, TGF-β1, and EGF from nonactivated apheresis PCs and may be of interest to prepare virally inactivated allogeneic growth factors for clinical and cell culture applications.