Berger Dustin R, Centeno Christopher J, Kisiday John D, McIlwraith C Wayne, Steinmetz Neven J
Research and Development, Regenexx, LLC, Broomfield, Colorado, USA.
Centeno-Schultz Clinic, Broomfield, Colorado, USA.
Am J Sports Med. 2021 Oct;49(12):3404-3413. doi: 10.1177/03635465211031275. Epub 2021 Aug 16.
Umbilical cord (UC) connective tissues contain plastic-adherent, colony forming unit-fibroblasts (CFU-Fs) amenable to culture expansion for potential therapeutic use. Recently, UC-derived allograft products have been made available to practitioners in orthopaedics and other specialties, by companies purporting "stem cell"-based healing. However, such marketing claims conflict with existing regulations for these human tissues, generating questions over the cellular and protein composition of current commercially available UC allograft products.
To evaluate commercial UC allograft products for viable cells, CFU-Fs, and protein makeup.
Descriptive laboratory study.
Five commercial UC allograft products claiming to contain viable, undescribed "stem cells," 2 obtained from UC blood (UCB) and 3 from UC tissue (UCT), were analyzed. Image-based methods were used to measure cell concentration and viability, a traditional CFU-F assay was used to evaluate in vitro behavior indicative of a connective tissue progenitor cell phenotype often referred to as mesenchymal stem/stromal cells, and quantitative immunoassay arrays were used to measure a combination of cytokines and growth factors. Bone marrow concentrate (BMC) and plasma derived from the blood and bone marrow of middle-aged individuals served as comparative controls for cell culture and protein analyses, respectively.
Viable cells were identified within all 5 UC allograft products, with those derived from UCB having greater percentages of living cells (40%-59%) than those from UCT (1%-22%). Compared with autologous BMC (>95% viability and >300 million living cells), no CFU-Fs were observed within any UC allograft product (<15 million living cells). Moreover, a substantial number of proteins, particularly those within UCB allograft products, were undetectable or present at lower concentrations compared with blood and bone marrow plasma controls. Interestingly, several important growth factors and cytokines, including basic fibroblast growth factor, hepatocyte growth factor, interleukin-1 receptor antagonist, and osteoprotegerin, were most prevalent in 1 or more UCT allograft products as compared with blood and bone marrow plasma.
CFU-Fs, often referred to as stem cells, were not found within any of the commercial UC allograft products analyzed, and clinicians should remain wary of marketing claims stating otherwise.
Any therapeutic benefit of current UC allograft products in orthopaedic medicine is more likely to be attributed to their protein composition (UCT > UCB) or inclusion of cells without colony forming potential (UCB > UCT).
脐带（UC）结缔组织含有可贴壁生长、具有成纤维细胞集落形成单位（CFU-F）的细胞，适合培养扩增以用于潜在的治疗用途。最近，一些声称基于“干细胞”治疗的公司向骨科及其他专科的从业者提供了源自脐带的同种异体移植产品。然而，此类营销宣传与这些人体组织的现有规定相冲突，引发了人们对当前市售脐带同种异体移植产品的细胞和蛋白质组成的质疑。
评估市售脐带同种异体移植产品中的活细胞、CFU-F以及蛋白质组成。
描述性实验室研究。
分析了5种声称含有活的、未描述的“干细胞”的市售脐带同种异体移植产品，其中2种来自脐带血（UCB），3种来自脐带组织（UCT）。采用基于图像的方法测量细胞浓度和活力，使用传统的CFU-F测定法评估体外行为，这些行为表明结缔组织祖细胞表型（通常称为间充质干/基质细胞），并使用定量免疫分析阵列测量细胞因子和生长因子的组合。分别从中年个体的血液和骨髓中提取的骨髓浓缩物（BMC）和血浆用作细胞培养和蛋白质分析的对照。
在所有5种脐带同种异体移植产品中均鉴定出活细胞，其中源自脐带血的产品活细胞百分比（40%-59%）高于源自脐带组织的产品（1%-22%）。与自体骨髓浓缩物（活力>95%，活细胞>3亿个）相比，在任何脐带同种异体移植产品中均未观察到CFU-F（活细胞<1500万个）。此外，与血液和骨髓血浆对照相比，大量蛋白质，特别是脐带血同种异体移植产品中的蛋白质，无法检测到或浓度较低。有趣的是，与血液和骨髓血浆相比，几种重要的生长因子和细胞因子，包括碱性成纤维细胞生长因子、肝细胞生长因子、白细胞介素-1受体拮抗剂和骨保护素，在1种或多种脐带组织同种异体移植产品中最为普遍。
在所分析的任何市售脐带同种异体移植产品中均未发现通常称为干细胞的CFU-F，临床医生应警惕其他相反的营销宣传。
当前脐带同种异体移植产品在骨科医学中的任何治疗益处更可能归因于其蛋白质组成（脐带组织>脐带血）或包含无集落形成潜力的细胞（脐带血>脐带组织）。
