Hence, current security regulations prescribe the screening of cell banks and downstream cell cultures for the presence of viable mycoplasma. and regulatory requirements of whole blood donation and details of human platelet lysate AZD1283 manufacturing are offered. International guidelines for raw materials are discussed, and defined quality controls, as well as release criteria for safe and GMP-compliant HPL production, are summarized. others as requiredNegative by approved test systemAll blood donations Sterility Bacteria and fungiNegative by approved test systemAll models Final volume 40 mL per0.6 1011 plateletsAccording to SPC Biochemical analysis pH 6.4 at the end of storageAccording to SPC Cell amount Platelets *2 1011/unitAccording to SPCResidual leukocytes * 1 106/unitAccording to SPC Open in a separate window Due to (re-)emerging pathogens, the increased screening for selected pathogens is an economic and time-consuming burden [49] and still cannot assurance complete security of AZD1283 blood products [50]. Despite sophisticated pathogen screening technologies, there still exists an inevitable diagnostic windows for detection of various infectious diseases. Fortunately, various pathogen reduction (PR) strategies are now available to minimize the contamination risk, not only for plasma products, but also for platelet concentrates. This further processing step is not yet mandatory, but frequently performed. The most common PR techniques are based on illumination with ultraviolet light, with or without addition of photoactive chemicals, for inducing nucleic acid damage and inhibiting replication of pathogens [51]. PR significantly reduces contamination with bacteria, enveloped viruses and protozoa, but may be insufficient for spores, non-enveloped viruses and prions. You will find contradictory data in the AZD1283 literature concerning the adverse effects of PR on platelet biology and function. The in vivo hemostatic function of PR-treated platelets was reported to be comparable to untreated platelets [52]. In addition, the support of in vitro cell proliferation by HPL prepared from PR-treated platelet concentrates was found to be at least comparable to FBS [53,54,55,56,57]. In contrast, affected platelet metabolism and function and increased storage lesions were observed in platelet concentrates after PR treatment [58,59]. Consequently, efficacy and potency of HPL produced from PR-treated platelet concentrates may be affected, although security may be increased. For a final assessment, more data will be required, including a direct comparison of HPL product aliquots prepared from PR-treated vs. untreated platelet concentrates. 4. Preparation of HPL Only platelet concentrates previously released as clinical blood products are included in the HPL manufacturing procedure. For prevention of lethal transfusion-associated graft-versus-host disease, particularly in immunocompromised patients, platelet concentrates are routinely gamma-irradiated at 25 TNFRSF10D Gray (Gy) without significant effects on platelet function [60]. Freshly prepared or expired platelet concentrates are suitable starting materials for HPL preparation, as demonstrated previously [18,61,62,63]. Platelets contain a wide range of growth factors and other bioactive molecules in their specific granules [18]. Efficient platelet lysis may be induced physically via repeated freeze/thaw cycles [15], sonication [64] or by solvent/detergent (S/D) treatment [65]. In contrast, the release of growth factors and cytokines after CaCl2- [66], human- or recombinant thrombin-induced platelet activation [67] may be insufficient, as shown previously [16], and regulatory approval of these substances for GMP-compliant manufacture may be difficult [18]. In Figure 1, the procedure of platelet lysis and HPL preparation is depicted. First, buffy coat-derived platelet concentrates are frozen at ?30 C for at least 24 h and thawed at 37 C to induce lysis. Due to the variable content of serum proteins, growth factors and cytokines in individual platelet concentrates [68], the efficacy of single HPL units may also vary [69]. Notably, in various blood centers HPL pool sizes ranged from a few to more.