PURPOSE Articular chondroprogenitors, a suitable contender for cell-based therapy in cartilage repair, routinely employ fetal bovine serum (FBS) for expansion and differentiation. The possibility of transplant rejections or zoonoses transmissions raise a need for xeno-free alternatives. Use of human platelet lysate (hPL), a nutrient supplement abundant in growth factors, has not been reported for human chondroprogenitor expansion thus far. Our aim was to compare the biological profile of chondroprogenitors grown in hPL versus FBS. METHODS Chondroprogenitors were isolated from 3 osteoarthritic knee joints. Following differential fibronectin adhesion assay, passage 0 cells grown in (a) 10% FBS and (b) 10% hPL were considered for assessment of growth kinetics, surface marker expression, gene expression, and trilineage differentiation. Latent transforming growth factor-β1 (TGFβ1) levels were also measured for each culture medium used. RESULTS Cellular proliferation was significantly higher in cells grown with hPL (P < 0.01). Surface marker expression was comparable except in CD-146 where hPL group had significantly higher values (P = 0.03). Comparison of mRNA expression revealed notably low values of collagen I, collagen X, aggrecan, and collagen II (P < 0.05). Trilineage differentiation was seen in both groups with higher alizarin red uptake noted in hPL. There were also significantly higher levels of latent TGFβ1 in the medium containing hPL as compared to FBS. CONCLUSIONS This is the first in vitro xeno-free study to affirm that hPL can serve as an optimal growth supplement for expansion of articular chondroprogenitors, although an in-depth assessment of resident growth factors and evaluation of different dilutions of hPL is required to assess suitability for use in translational research.

中文翻译：

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人血小板裂解物与胎牛血清对人关节软骨源性软骨祖细胞扩增的比较。

目的 关节软骨祖细胞是软骨修复中基于细胞的治疗的合适竞争者，通常使用胎牛血清 (FBS) 进行扩增和分化。移植排斥或人畜共患病传播的可能性提高了对无异源替代品的需求。迄今为止，尚未报道使用人血小板裂解物 (hPL)，一种富含生长因子的营养补充剂，用于人软骨祖细胞的扩增。我们的目的是比较在 hPL 和 FBS 中生长的软骨祖细胞的生物学特征。方法 软骨祖细胞从 3 个骨关节炎膝关节中分离出来。在差异纤连蛋白粘附测定后，考虑在 (a) 10% FBS 和 (b) 10% hPL 中生长的第 0 代细胞用于评估生长动力学、表面标记表达、基因表达和三系分化。还测量了所用每种培养基的潜在转化生长因子-β1 (TGFβ1) 水平。结果 用 hPL 培养的细胞的细胞增殖明显更高（P < 0.01）。表面标记表达是可比的，除了在 CD-146 中 hPL 组具有显着更高的值 (P = 0.03)。mRNA 表达的比较显示胶原蛋白 I、胶原蛋白 X、聚集蛋白聚糖和胶原蛋白 II 的值显着降低（P < 0.05）。两组均观察到三系分化，在 hPL 中注意到较高的茜素红摄取。与 FBS 相比，含有 hPL 的培养基中的潜在 TGFβ1 水平也显着升高。结论 这是第一个证实 hPL 可以作为关节软骨祖细胞扩增的最佳生长补充剂的体外无异种研究