Division of Cellular and Gene Therapies, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA.
Qureator, Inc., San Diego, CA, USA.
Biomaterials. 2022 Nov;290:121826. doi: 10.1016/j.biomaterials.2022.121826. Epub 2022 Sep 27.
Mesenchymal stromal cells (MSCs) continue to be proposed for use in clinical trials to treat various diseases due to their therapeutic potential to pleiotropically influence endogenous regenerative processes, such as vasculogenesis. However, the functional heterogeneity of MSCs has hampered their clinical success and poses a significant manufacturing challenge with respect to MSC quality control. Here, we evaluated and qualified a quantitative bioassay based on an enhanced-throughput, microphysiological system to measure the specific paracrine bioactivity of MSCs to stimulate vasculogenesis as a measure of MSC potency. Using this novel bioassay, MSCs derived from multiple donors at different passages were co-cultured with human umbilical vein endothelial cells (HUVECs) and exhibited significant heterogeneity in vasculogenic potency between donors and cell passage. Using our microphysiological system (MPS)-based platform, we demonstrated that variations in MSC vasculogenic bioactivity were maintained when assayed across laboratories and operators. The differences in MSC vasculogenic bioactivity were also correlated with the baseline expression of several genes involved in vasculogenesis (hepatocyte growth factor (HGF), angiopoietin-1 (ANGPT)) or the production of matricellular proteins (fibronectin (FN), insulin-like growth factor-binding protein 7 (IGFBP7)). These findings emphasize the significant functional heterogeneity of MSCs in vasculogenic bioactivity and suggest that changes in baseline gene expression of vasculogenic or matricellular protein genes during manufacturing may affect this bioactivity. The development of a reliable and functionally relevant potency assay for measuring the specific vasculogenic bioactivity of manufactured MSCs will help to reliably assure their quality when used in appropriate clinical trials.
间充质基质细胞（MSCs）由于其多效性影响内源性再生过程的治疗潜力，如血管生成，继续被提议用于临床试验中治疗各种疾病。然而，MSCs 的功能异质性阻碍了它们的临床成功，并对 MSC 质量控制提出了重大的制造挑战。在这里，我们评估并确定了一种基于高通量、微生理系统的定量生物测定法，以测量 MSCs 刺激血管生成的特定旁分泌生物活性，作为 MSC 效力的衡量标准。使用这种新的生物测定法，来自多个供体的 MSCs 在不同传代时与人脐静脉内皮细胞（HUVEC）共培养，显示出供体和细胞传代之间血管生成效力的显著异质性。使用我们的微生理系统（MPS）平台，我们证明了在不同实验室和操作人员中进行测定时，MSC 血管生成生物活性的变化得以维持。MSC 血管生成生物活性的差异也与参与血管生成的几个基因（肝细胞生长因子（HGF）、血管生成素-1（ANGPT））或细胞外基质蛋白（纤维连接蛋白（FN）、胰岛素样生长因子结合蛋白 7（IGFBP7））的基础表达相关。这些发现强调了 MSCs 在血管生成生物活性方面的显著功能异质性，并表明在制造过程中血管生成或细胞外基质蛋白基因的基础表达变化可能会影响这种生物活性。开发一种可靠的、具有功能相关性的效力测定法，用于测量制造的 MSCs 的特定血管生成生物活性，将有助于在适当的临床试验中可靠地保证其质量。
