Mesenchymal stromal cells (MSCs), present in the stromal component of several tissues, include multipotent stem cells, progenitors, and differentiated cells. MSCs have quickly attracted considerable attention in the clinical field for their regenerative properties and their ability to promote tissue homeostasis following injury. In recent years, MSCs mainly isolated from bone marrow, adipose tissue, and umbilical cord—have been utilized in hundreds of clinical trials for the treatment of various diseases. However, in addition to some successes, MSC-based therapies have experienced several failures. The number of new trials with MSCs is exponentially growing; still, complete results are only available for a limited number of trials. This dearth does not help prevent potentially inefficacious and unnecessary clinical trials. Results from unsuccessful studies may be useful in planning new therapeutic approaches to improve clinical outcomes. In order to bolster critical analysis of trial results, we reviewed the state of art of MSC clinical trials that have been published in the last six years. Most of the 416 published trials evaluated MSCs’ effectiveness in treating cardiovascular diseases, GvHD, and brain and neurological disorders, although some trials sought to treat immune system diseases and wounds and to restore tissue. We also report some unorthodox clinical trials that include unusual studies.

Graphical abstract

中文翻译：

---

基于间充质基质细胞的临床试验呈指数增长：近年来我们在哪里？

间充质基质细胞 (MSCs) 存在于几种组织的基质成分中，包括多能干细胞、祖细胞和分化细胞。间充质干细胞因其再生特性和促进损伤后组织稳态的能力而迅速在临床领域引起了相当大的关注。近年来，主要从骨髓、脂肪组织和脐带中分离出的 MSCs 已在数百项临床试验中用于治疗各种疾病。然而，除了一些成功之外，基于 MSC 的疗法也经历了几次失败。MSCs 的新试验数量呈指数增长；尽管如此，完整的结果仅适用于有限数量的试验。这种缺乏无助于防止可能无效和不必要的临床试验。不成功研究的结果可能有助于规划新的治疗方法以改善临床结果。为了加强对试验结果的批判性分析，我们回顾了过去六年发表的 MSC 临床试验的最新进展。尽管一些试验试图治疗免疫系统疾病和伤口以及恢复组织，但已发表的 416 项试验中的大多数评估了 MSCs 在治疗心血管疾病、GvHD 以及脑和神经系统疾病方面的有效性。我们还报告了一些非正统的临床试验，其中包括不寻常的研究。尽管一些试验试图治疗免疫系统疾病和伤口以及恢复组织，但已发表的 416 项试验中的大多数评估了 MSCs 在治疗心血管疾病、GvHD 以及脑和神经系统疾病方面的有效性。我们还报告了一些非正统的临床试验，其中包括不寻常的研究。尽管一些试验试图治疗免疫系统疾病和伤口以及恢复组织，但已发表的 416 项试验中的大多数评估了 MSCs 在治疗心血管疾病、GvHD 以及脑和神经系统疾病方面的有效性。我们还报告了一些非正统的临床试验，其中包括不寻常的研究。

图形概要