Extensive characterization of the composition and functional activities of five preparations of human platelet lysates for dedicated clinical uses

Human platelet lysates (HPLs), rich in various growth factors and cell growth-promoting molecules, encompass a new range of blood products that are being used for regenerative medicine, cell therapies, and tissue engineering. Well-characterized dedicated preparations, tailor-made to best fit specific therapeutic applications, are needed for optimal clinical efficacy and safety. Here, five types of HPL were prepared from the same platelet concentrates and extensively characterized to determine and compare their proteins, growth factors, cytokines, biochemical profiles, thrombin-generating capacities, thrombin-associated proteolytic activities, phospholipid-associated procoagulant potential, contents of extracellular vesicles expressing phosphatidylserine and tissue factor, and antioxidative properties. Our results revealed that all five HPL preparations contained detectable supraphysiological levels, in the ca. 0.1 ~ 350-ng/ml range, of all growth factors assessed, except insulin-like growth factor-1 detected only in HPL containing plasma. There were significant differences observed among these HPLs in total protein content, fibrinogen, complement components C3 and C4, albumin, and immunoglobulin G, and, most importantly, in their functional coagulant and procoagulant activities and antioxidative capacities. Our data revealed that the biochemical and functional properties of HPL preparations greatly vary depending upon their mode of production, with potential impacts on the safety and efficacy for certain clinical indications. Modes of preparation of HPLs should be carefully designed, and the product properties carefully evaluated based on the intended therapeutic use to ensure optimal clinical outcomes.

人血小板裂解物（Human platelet lysates, HPLs）富含多种生长因子与促细胞生长分子，是一类新兴血液制品，目前已应用于再生医学、细胞治疗与组织工程领域。为实现最佳临床疗效与安全性，需开发经过充分表征的定制化专用制剂，以适配特定治疗用途。
本研究从同一批次的血小板浓缩物中制备了五种类型的人血小板裂解物，并对其进行了全面表征，以检测并对比其蛋白质组、生长因子、细胞因子、生化谱、凝血酶生成能力、凝血酶相关蛋白水解活性、磷脂相关促凝活性、表达磷脂酰丝氨酸与组织因子的细胞外囊泡含量，以及抗氧化特性。
研究结果显示，除仅在含血浆的人血小板裂解物中检出的胰岛素样生长因子-1外，其余所有待测生长因子在五种制剂中均达到可检测的超生理水平，浓度范围约为0.1~350 ng/ml。
五种制剂在总蛋白含量、纤维蛋白原、补体成分C3与C4、白蛋白以及免疫球蛋白G水平上均存在显著差异；尤为关键的是，其功能性凝血活性、促凝活性与抗氧化能力也存在显著区别。
本研究数据表明，人血小板裂解物制剂的生化与功能特性随制备工艺存在显著差异，这可能对部分临床适应症的治疗安全性与疗效产生影响。
因此，需针对预期治疗用途精心设计人血小板裂解物的制备工艺，并严格评估产品特性，以保障最佳临床结局。