Palo Alto, Calif. From the Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, and the Section of Plastic Surgery, Veterans Affairs Palo Alto Health Care System.
Plast Reconstr Surg. 2012 Feb;129(2):479-489. doi: 10.1097/PRS.0b013e31823aeb94.
Tissue-engineered flexor tendon grafts may allow reconstruction of severe tendon losses. One critical factor is the optimization of cell proliferation and reseeding. Use of growth factors--basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF)-1, and platelet-derived growth factor (PDGF)-BB--may improve culture conditions for human fibroblasts, tenocytes, and adipose-derived stem cells and increase repopulation of a tendon scaffold.
All cell types were plated at a density of 10,000 cells per well and cultured in F12 media supplemented with varying concentrations of bFGF, IGF-1, and PDGF-BB. After 72 hours, cell proliferation was determined using the CellTiter assay. Human flexor tendon segments were acellularized and reseeded in a cell suspension of 5 × 10(5) cells/ml. After 5 days, tendon repopulation was determined using the MTS assay and histology. Statistical significance was determined with analysis of variance and a t test.
For all cell types, there was enhanced proliferation with growth factors. Among single growth factors, PDGF-BB at 50 ng/ml was the most efficient stimulator of proliferation. With multiple growth factors, the optimal concentration was determined to be 5 ng/ml bFGF, 50 ng/ml IGF-1, and 50 ng/ml PDGF-BB (increase when compared with control: fibroblasts, 2.92-fold; tenocytes, 2.3-fold; and adipose-derived stem cells, 2.4-fold; p < 0.05). Tendons reseeded with this optimal combination of growth factors showed improved reseeding compared with the control group (fibroblasts, 2.01-fold; tenocytes, 1.78-fold; and adipose-derived stem cells, 1.76-fold; p < 0.05).
bFGF, IGF-1, and PDGF-BB can be used to improve cellular proliferation and repopulation of an acellularized scaffold. The use of growth factors may be an important step in the tissue engineering of human flexor tendons.
组织工程化的屈肌腱移植物可用于重建严重的肌腱损失。一个关键因素是优化细胞增殖和再播种。使用生长因子——碱性成纤维细胞生长因子（bFGF）、胰岛素样生长因子（IGF-1）和血小板衍生生长因子（PDGF-BB）——可能改善人成纤维细胞、肌腱细胞和脂肪来源干细胞的培养条件，并增加肌腱支架的再定植。
所有细胞类型均以 10,000 个细胞/孔的密度接种，并在补充有不同浓度 bFGF、IGF-1 和 PDGF-BB 的 F12 培养基中培养。72 小时后，使用 CellTiter 测定法测定细胞增殖。将人屈肌腱段去细胞化并在 5×10（5）个细胞/ml 的细胞悬浮液中重新播种。5 天后，使用 MTS 测定法和组织学测定肌腱再定植。通过方差分析和 t 检验确定统计学意义。
对于所有细胞类型，生长因子均可增强增殖。在单一生长因子中，50ng/ml 的 PDGF-BB 是增殖的最有效刺激物。使用多种生长因子时，确定最佳浓度为 5ng/ml bFGF、50ng/ml IGF-1 和 50ng/ml PDGF-BB（与对照组相比增加：成纤维细胞 2.92 倍；肌腱细胞 2.3 倍；脂肪来源干细胞 2.4 倍；p<0.05）。用这种最佳生长因子组合重新播种的肌腱与对照组相比，再播种得到改善（成纤维细胞 2.01 倍；肌腱细胞 1.78 倍；脂肪来源干细胞 1.76 倍；p<0.05）。
bFGF、IGF-1 和 PDGF-BB 可用于改善去细胞化支架的细胞增殖和再定植。生长因子的使用可能是人类屈肌腱组织工程的重要步骤。
