Effects of transforming growth factor beta1 on bonelike tissue formation in three-dimensional cell culture. II: Osteoblastic differentiation

We supplemented rat marrow stromal cells (rMSCs) seeded on poly(L-lactic-co-glycolic acid) fiber meshes with transforming growth factor beta1 (TGF-beta1) to improve bone tissue formation for tissue engineering. Whereas our first study (Lieb, E., et al. Tissue Eng. 10, 1399-1413, 2004) investigated the effects of TGF-beta1 on matrix formation and mineralization, this second study focused on the differentiation of rMSCs to the osteoblastic phenotype in dynamic cell culture (orbital shaker). We assessed a series of bone markers to determine a dosing regimen for TGF-beta1 that enhances collagenous matrix formation and preserves or increases osteoblastic differentiation. Bone sialoprotein and osteonectin formation were investigated immunohistochemically and by RT-PCR. For alkaline phosphatase activity (ALP), we employed an enzyme assay. Osteocalcin was examined by RT-PCR as well as by an immunoassay. Whereas bone sialoprotein appeared to be dose-dependently increased in the immunochemistical stainings after supplementation with TGF-beta1, osteonectin remained unchanged. Both ALP activity and osteocalcin were suppressed by high doses of TGF-beta1, such as single doses of 10 ng/mL or four doses of 1 ng/mL added once a week. Considering the effects of TGF-beta1 both on differentiation and on matrix formation and mineralization, TGF-beta1 at 1 ng/mL, added once a week in the first 1 to 2 weeks, was selected as an effective dose to improve bonelike tissue formation in vitro.     

蛇床子素干预人增生性瘢痕成纤维细胞增殖及转化生长因子β1的表达

背景：蛇床子素对体外培养人增生性瘢痕成纤维细胞增殖和细胞分泌的转化生长因子β1有抑制作用,但其具体作用机制尚待进一步研究。 目的：体外观察蛇床子素对人增生性瘢痕成纤维细胞增殖以及对细胞转化生长因子β1的影响。 方法：体外原代培养人增生性瘢痕成纤维细胞,以不同浓度的蛇床子素作用于成纤维细胞,观察细胞形态的变化,应用MTT法和生长曲线法检测蛇床子素对细胞增殖活性的影响。免疫组织化学检测细胞转化生长因子β1的表达。 结果与结论：蛇床子素能明显抑制人增生性瘢痕成纤维细胞的生长。MTT法检测的IC50为(15.2±2.0) μmol/L,可以明显下调细胞转化生长因子β1的表达(P < 0.05)。说明蛇床子素对人增生性瘢痕成纤维细胞有很强的生长抑制作用并可以下调转化生长因子β1的表达。     

软骨形成过程中的转化生长因子β2

背景：转化生长因子β2是一族多肽类生长因子,具有多重生物学效应,对骨髓间充质干细胞增殖分化功能有一定促进作用,是调节骨髓间充质干细胞增殖和向软骨细胞方向分化的最主要因子之一。 目的：探讨转化生长因子β2 的分子结构特点及其在软骨形成方面的作用。 方法：应用计算机检索中国期刊全文数据CNKI、中国期刊全文数据维普中文科技期刊数据库(VIP)和PubMed数据库(1995-01/2011-08)与骨组织工程中转化生长因子β2 诱导软骨形成有关的文章,检索词分别为“转化生长因子β2;软骨细胞分化;骨组织工程”和“TGF-β2;cartilage formation;tissue engineering”。纳入所述内容与转化生长因子β2 分子结构特点,转化生长因子β2信号转导通路,软骨细胞的诱导性分化,软骨性疾病的生物性治疗进展有关。排除综述文献、重复研究、观点陈旧的文章。 结果与结论：初检得到302篇文献,排除262篇不符合标准的文献,共纳入40篇符合标准的文献。经分析得出转化生长因子β2通过促进骨髓间充质干细胞分化为软骨细胞促进软骨特异性基质如Ⅱ型胶原及蛋白多糖的合成,从而发挥软骨诱导作用。转化生长因子β2 与其他因子共同作用调节软骨细胞生长分化,使临床上永久性修复软骨组织缺损的治疗变为可能。     

Effect of transforming growth factor beta 1 on neonatal rat latent transforming growth factor beta binding protein 2 in cardiomyocytes

目的 探讨转化生长因子β1 (TGF-β1)在诱导心肌细胞表达转化生长因子结合蛋白2(LTBP2)中的作用及信号传导通路.方法 培养乳鼠心肌细胞;实时定量聚合酶链式反应、蛋白质印迹和免疫细胞化学方法检测不同时间和不同浓度的TGF-β1对大鼠乳鼠心肌细胞LTBP2基因及蛋白表达的影响;用TGF-β1相关信号通路阻断剂探讨TGF-β1调节LTBP2表达改变的信号传导机制.结果 LTBP2基因表达随着TGF-β1浓度增加(0、2、5及10 μg/L)而明显升高,在5μg/L时刺激最强(P＜0.05);5μg/L的TGF-β1刺激下心肌细胞内LTBP2基因和蛋白表达的升高呈时间依赖性,均在12 h最高,24 h开始呈下降趋势(P＜0.05或P＜0.01);免疫细胞化学结果显示TGF-β1明显升高LTBP2的表达.信号传导通路研究显示TGF-β1在心肌细胞内主要通过ERK信号通路和PI3K信号通路诱导LTBP2的表达.结论TGF-β1在乳鼠心肌细胞内通过ERK信号通路和PI3K信号通路上调LTBP2的表达.     

转化生长因子β1对乳鼠心肌细胞转化生长因子结合蛋白2表达的影响

 目的：探讨转化生长因子β1（TGF-β1）在诱导心肌细胞表达转化生长因子结合蛋白2（LTBP2）中的作用及信号传导通路。 方法：培养乳鼠心肌细胞;实时定量聚合酶链式反应（Real-time PCR）、蛋白质印迹和免疫细胞化学方法检测不同时间和不同浓度的TGF-β1对大鼠乳鼠心肌细胞LTBP2基因及蛋白表达的影响;用TGF-β1相关信号通路阻断剂探讨TGF-β1调节LTBP2表达改变的信号传导机制。 结果：LTBP2基因表达随着TGF-β1浓度增加（0、2、5、10 ng/mL）而明显升高,在5 ng/mL时刺激最强（P < 0.05）;5 ng/mL的TGF-β1刺激下心肌细胞内LTBP2基因和蛋白表达的升高呈时间依赖性,均在12 h最高,24 h开始呈下降趋势（P < 0.05或P<0.01）;免疫细胞化学结果显示TGF-β1明显升高LTBP2的表达。信号传导通路研究显示TGF-β1在心肌细胞内主要通过ERK信号通路和PI3K信号通路诱导LTBP2的表达。 结论：TGF-β1在乳鼠心肌细胞内通过ERK信号通路和PI3K信号通路上调LTBP2的表达。     

转化生长因子β1对横纹肌肉瘤RD细胞系的生长调节及机制探讨

目的 研究转化生长因子(TGF)-β1对横纹肌肉瘤RD细胞系的生长调节及作用机制。方法^3H-thymidine掺入实验、四甲基偶氮唑盐(MTT)实验和生长曲线检测经TGF-β1处理不同时间的RD细胞生长活力的变化;应用流式细胞术榆测RD细胞周期的改变;激光扫描共聚焦显微镜观察细胞周期抑制蛋白p15、p21和p27在RD中分布的变化;逆转录一聚合酶链反应(RT-PCR)和Western bolt检测RD细胞中细胞周期抑制蛋白P15、p21、p27mRNA和蛋白水平的变化：结果TGF-β1处理RD细胞后,其牛长活力明显降低,并出现G1期停滞。p21,p27在mRNA和蛋白水平表达上升,且p21南胞核表达改变为胞核胞质内均有表达。p15在mRNA和蛋白水平上均无明显改变。结论 TGF-β1对RD细胞具有生长抑制作用,促使细胞G1期停滞。TGF-β1可在mRNA和蛋白水平上调RD细胞中p21、p27的表达。TGF-β1可能通过上调p2和p27而非p15抑制RD细胞生长。     

Fibroblast growth factor 2 and transforming growth factor beta1 synergism in human bronchial smooth muscle cell proliferation

Bronchial smooth muscle cell (BSMC) hyperplasia is a typical feature of airway remodeling and contributes to airway obstruction and hyperresponsiveness in asthma. Fibroblast growth factor 2 (FGF-2) and transforming growth factor beta1 (TGF-beta1) are sequentially upregulated in asthmatic airways after allergic challenge. Whereas FGF-2 induces BSMC proliferation, the mitogenic effect of TGF-beta1 remains controversial, and the effect of sequential FGF-2 and TGF-beta1 co-stimulation on BSMC proliferation is unknown. This study aimed to assess the individual and sequential cooperative effects of FGF-2 and TGF-beta1 on human BSMC proliferation and define the underlying mechanisms. Mitogenic response was measured using crystal violet staining and [3H]-thymidine incorporation. Steady-state mRNA and protein levels were measured by semiquantitative RT-PCR, Western blot, and ELISA, respectively. TGF-beta1 (0.1-20 ng/ml) alone had no effect on BSMC proliferation, but increased the proliferative effect of FGF-2 (2 ng/ml) in a concentration-dependent manner (up to 6-fold). Two distinct platelet-derived growth factor receptor (PDGFR) inhibitors, AG1296 and Inhibitor III, as well as a neutralizing Ab against PDGFRalpha, partially blocked the synergism between these two growth factors. In this regard, TGF-beta1 increased PDGF-A and PDGF-C mRNA expression as well as PDGF-AA protein expression. Moreover, FGF-2 pretreatment increased the mRNA and protein expression of PDGFRalpha and the proliferative effect of exogenous PDGF-AA (140%). Our data suggest that FGF-2 and TGF-beta1 synergize in BSMC proliferation and that this synergism is partially mediated by a PDGF loop, where FGF-2 and TGF-beta1 upregulate the receptor (PDGFRalpha) and the ligands (PDGF-AA and PDGF-CC), respectively. This powerful synergistic effect may thus contribute to the hyperplastic phenotype of BSMC in remodeled asthmatic airways.     

Differential regulation of mouse B cell development by transforming growth factor beta1

Transforming growth factor beta (TGFbeta) can inhibit the in vitro proliferation, survival and differentiation of B cell progenitors, mature B lymphocytes and plasma cells. Here we demonstrate unexpected, age-dependent reductions in the bone marrow (BM) B cell progenitors and immature B cells in TGFbeta1-/- mice. To evaluate TGFbeta responsiveness during normal B lineage development, cells were cultured in interleukin 7 (IL7) +/- TGFbeta. Picomolar doses of TGFbeta1 reduced pro-B cell recoveries at every timepoint. By contrast, the pre-B cells were initially reduced in number, but subsequently increased compared to IL7 alone, resulting in a 4-fold increase in the growth rate for the pre-B cell population. Analysis of purified BM sub-populations indicated that pro-B cells and the earliest BP1- pre-B cells were sensitive to the inhibitory effects of TGFbeta1. However, the large BP1+ pre-B cells, although initially reduced, were increased in number at days 5 and 7 of culture. These results indicate that TGFbeta1 is important for normal B cell development in vivo, and that B cell progenitors are differentially affected by the cytokine according to their stage of differentiation.     

树突细胞与转化生长因子β1在食管癌组织中表达的研究

目的 通过检测食管癌组织中树突细胞（dendrtic cell,DC）与转化生长因子β1（TGF-β1）的表达水平,探讨食管癌病人发生免疫逃逸的原因。方法采用酶标记的链霉亲和素生物素法（LSAB）对94例食管癌组织进行抗S100、抗TGF-β1表达的检测以及采用RT-PCR技术进行CD1a、TGF-β1 mRNA表达的检测。结果食管癌组织分化程度越高,癌组织内S100蛋白阳性DC密度及DC的标记分子CD1a mRNA的表达水平越高（P=0．026,0．0001）;肿瘤分化程度越低,TGF-β1 蛋白及mRNA的表达水平达越显著（P=0．041,0．0001）。TGF-β1蛋白及mRNA的表达越显著,癌组织内S100蛋白阳性DC的密度及DC的标记分子CD1a mRNA的表达越低（P=0．024,0．0001）。结论TGF-β1抑制DC表面分子CD1a mRNA的表达,影响DC的分化与成熟,使肿瘤组织中参与抗肿瘤免疫的DC数量减少,进而抑制机体的免疫系统,是肿瘤细胞逃逸免疫系统监视的重要原因之一。     

Effects of insulin-like growth factor I on transforming growth factor beta1 induced chondrogenesis of synovium-derived mesenchymal stem cells cultured in a polyglycolic acid scaffold

The aim of this study was to demonstrate the induction of chondrogenesis by transforming growth factor (TGF)-beta1 from synovium-derived mesenchymal stem cells in a three-dimensional polyglycolic acid (PGA) scaffold, and to evaluate the effects of insulin-like growth factor (IGF)-I on TGF-beta1-induced chondrogenesis. Adult human synovial membranes were obtained from the knees of patients with osteoarthritis or rheumatoid arthritis. Cells were expanded in monolayers, seeded onto a PGA scaffold, and cultured for 4 or 8 weeks in chondrogenic medium containing TGF-beta1 with or without IGF-I. As a control, the cells were cultured in chondrogenic medium without TGF-beta1. The glycosaminoglycan content was quantified using dimethylmethylene blue dye-binding assay, and the DNA content was measured fluorometrically. Histological examination was also performed using safranin-O staining. The expression of mRNA for aggrecan and collagen type II was confirmed by RT-PCR. After 4 weeks of cultivation with TGF-beta1, the cells differentiated to a chondrocytic phenotype, and these chondrogeneses were more potent when cultured for 8 weeks. The combination of IGF-I and TGF-beta1 produced higher amounts of glycosaminoglycan than TGF-beta1 alone at 8 weeks. In conclusions, chondrogenesis from human synovium-derived mesenchymal cells was identified, and IGF-I plays a role in maintaining the extracellular matrix in combination with TGF-beta1.     

Bovine transforming growth factor beta. Purification and characterization

Polypeptide growth factor isolated from bovine platelets was classified on the basis of its physico-chemical and biological properties to be transforming growth factor type beta (TGF beta). This growth factor was completely purified from platelet lysate by acid ethanol extraction, Bio-Gel P-60 filtration, ion-exchange chromatography on CM-Sephadex followed by two successive gel filtrations on Bio-Gel P-10 and Sephadex G-100. After the last gel filtration over 35,000-fold purified TGF beta was obtained. The purity of the preparation was confirmed by SDS-polyacrylamide gel electrophoresis, which revealed a single protein band with Mr of 25,000-27,000. Further studies showed that native TGF beta consists of two Mr 13,000 polypeptide chains held together by disulfide bonds.     

The role of transforming growth factor beta1 in the vascular system.

The transforming growth factor beta (TGFbeta) family of cytokines exert pleiotropic effects upon a wide variety of cell types. TGFbeta1 has been demonstrated to be of fundamental importance in the development, physiology and pathology of the vascular system. As the role of TGFbeta1 in these processes becomes clearer, influencing its activity for therapeutic benefit is now beginning to be investigated. This review presents an overview of the role of TGFbeta1 in the vasculature. The cellular and extracellular biology of the TGFbeta family is first addressed, followed by an overview of the function of TGFbeta1 during vascular development, atherogenesis, hypertension, and vessel injury.     

Relationship of transforming growth factor beta 1 to angiogenesis in gastric carcinoma.

Transforming growth factor-beta (TGF-beta) comprises a group of multifunctional regulatory proteins, whose effects include angiogenesis. The expression of TGF-beta 1 in gastric carcinomas (70 cases) has been determined and related to pathological features and microvessel count by immunohistochemical staining for TGF-beta 1 and Factor VIII related antigen. Prominent reactivity for TGF-beta 1 was associated with the depth of invasion (r = 0.2; p < 0.05) and increased microvessel count (r = 0.5; p < 0.05). Also, the microvessel count had a significant correlation with invasiveness (r = 0.34; p < 0.05) and lymph node metastasis (r = 0.28; p < 0.05). These findings indicate that TGF-beta 1 may have a role in tumor invasion and angiogenesis.     

Effects of basic fibroblast growth factor and transforming growth factor-beta on maturation of human pediatric aortic cell culture for tissue engineering of cardiovascular structures

Optimal in vitro conditions are necessary for the development of a strong, well structured, and functional tissue engineered cardiovascular structure eventually designed for implantation. To further optimize in vitro conditions for cell proliferation and extracellular matrix formation in tissue engineering of cardiovascular structures, in this study, ascorbic acid and growth factors as additives to standard cell culture medium were evaluated for their effect on tissue development in vitro. Biodegradable polymer patches [polyglycolic acid (PGA) coated with poly-4-hydroxybutyrate (P4HB)] were seeded with human pediatric aortic cells and cultured for 7 and 28 days. Group A was cultured with standard medium (DMEM with 10% fetal calf serum and 1% antibiotics) supplemented with ascorbic acid; group B was cultured with standard medium plus ascorbic acid and basic fibroblast growth factor (bFGF); group C was cultured with standard medium adding ascorbic acid and transforming growth factor (TGF). Analysis of the cell seeded polymer constructs included DNA assay, collagen assay, and histologic and immunohistochemical examination for cell proliferation and collagen formation. After 7 and 28 days of culture, group B and group C showed a significantly higher DNA content compared with group A. The addition of bFGF (group B) led to a markedly higher collagen synthesis after 28 days of culture compared with the additives in groups C and A. The histologic and immunohistochemical examination also revealed a more dense, organized tissue development with pronounced matrix protein formation in the tissue engineered structures in group B after 28 days of culture. When seeded on to the polymeric scaffold, human vascular cells proliferate and form organized cell tissue after 28 days of culture. The addition of bFGF and ascorbic acid to the standard medium enhances cell proliferation and collagen synthesis on the biodegradable polymer, which leads to the formation of more mature, well organized tissue engineered structures.     

Effects of transforming growth factor beta1 and dexamethasone on the growth and chondrogenic differentiation of adipose-derived stromal cells

The effects of soluble mediators and medium supplements commonly used to induce chondrogenic differentiation in different cell culture systems were investigated to define their dose-response profiles and potentially synergistic effects on the chondrogenic differentiation of adipose-derived adult stromal (ADAS) cells. Human ADAS cells were suspended within alginate beads and cultured in basal medium with insulin, transferrin, and selenious acid (ITS+) or fetal bovine serum (FBS) and treated with different doses and combinations of TGF-beta1 (0, 1, and 10 ng/mL) and dexamethasone (0, 10, and 100 nM). Cell growth and chondrogenic differentiation were assessed by measuring DNA content, protein and proteoglycan synthesis rates, and proteoglycan accumulation. The combination of ITS+ and TGF-beta1 significantly increased cell proliferation. Protein synthesis rates were increased by TGF-beta1 and dexamethasone in the presence of ITS+ or FBS. While TGF-beta1 significantly increased proteoglycan synthesis and accumulation by 1.5- to 2-fold in the presence of FBS, such effects were suppressed by dexamethasone. In summary, the combination of TGF-beta1 and ITS+ stimulated cell growth and synthesis of proteins and proteoglycans by human ADAS cells. The addition of dexamethasone appeared to amplify protein synthesis but had suppressive effects on proteoglycan synthesis and accumulation.     

转化生长因子β1在兔房水中的浓度变化

背景：转化生长因子β1可参与角膜损伤后的修复。 目的：观察转化生长因子β1滴眼液滴眼后房水中的浓度变化规律。 方法：将新西兰大白兔随机分为5组,分别给予PBS和质量浓度为0.5,1.0,2.0,4.0 mg/L的转化生长因子β1滴眼液滴右眼。 结果与结论：通过裂隙灯观察兔角膜和结膜结构,各组兔眼均无结膜分泌物、球结膜充血、角膜水肿增厚、角膜后沉着物、前房炎性反应及晶状体混浊改变。ELISA检测结果显示,与PBS组比较,质量浓度2.0和4.0 mg/L转化生长因子β1滴眼液能有效提高兔眼房水中转化生长因子β1的质量浓度(P < 0.01),角膜穿透性良好,在房水中可以达到有效的治疗浓度。     

Role of transforming growth factor beta 1 on hepatic regeneration and apoptosis in liver diseases.

AIMS--To investigate the effects of transforming growth factor beta 1 (TGF-beta 1) on regeneration and induction of apoptosis of liver cell and bile duct in various liver diseases. METHODS--Formalin fixed paraffin wax sections of 18 liver tissue samples were obtained by needle biopsy, surgery, or necropsy; these included six liver cirrhosis, three obstructive jaundice; five fulminant hepatitis, one subacute hepatitis, and three normal liver. Expression of TGF-beta 1, apoptosis related Le(y) antigen, Fas antigen, a receptor for tumour necrosis factor, and biotin nick end labelling with terminal deoxynucleotidyl transferase mediated dUTP (TUNEL) for locating DNA fragmentation, was investigated histochemically. RESULTS--TGF-beta 1 was expressed in areas of atypical bile duct proliferation, where bile duct continuously proliferated from liver cells. In occlusive jaundice and fulminant hepatitis, TUNEL was positive in nuclei and cytoplasm of metaplastic cells which formed incomplete bile ducts, and these cells appeared to extend from TGF-beta 1 expressing liver cells. Fas antigen was found only on the cell membrane of proliferated bile duct in fulminant hepatitis, which differed from TGF-beta 1 and TUNEL positive areas. Le(y) antigen was expressed in liver cell and bile duct at the areas with atypical bile duct proliferation, but its coexpression with TUNEL was rare. CONCLUSIONS--TGF-beta 1 plays a role in the arrest of liver cell regeneration and atypical bile duct proliferation, and in areas of rapidly progressing atypical bile duct proliferation, such as in fulminant hepatitis or bile retention. Apoptosis appears to be induced by TGF-beta 1. This phenomenon may account for the inadequate hepatic regeneration that occurs with liver disease.     

人转化生长因子β3、结缔组织生长因子和基质金属蛋白酶抑制剂1基因重组慢病毒多表达质粒的构建及活性检测*

背景：前期试验显示单个病毒载体介导的多基因共表达系统能够显著提高椎间盘退变转基因疗效。 目的：构建人转化生长因子β3、结缔组织生长因子和基质金属蛋白酶抑制剂1基因重组慢病毒多表达质粒。 方法：应用全基因合成技术,以“自剪切多肽2A”串联目的基因,并克隆到慢病毒表达质粒构建重组慢病毒质粒Lenti-TGF-β3-P2A-CTGF-T2A-TIMP1。转染293细胞后,应用RT-PCR和Western-Blot技术分别检测转染后不同时间点目的基因mRNA和蛋白质表达水平。 结果与结论：RT-PCR和Western-blot技术检测结果显示重组质粒成功表达了3种目的基因,并于转染后48 h左右达到峰值,“2A”结构下游基因蛋白质表达量约为上游基因的80%。说明成功构建了携带人转化生长因子β3、结缔组织生长因子和基质金属蛋白酶抑制剂1基因的慢病毒多表达质粒。     

Effects of exogenous transforming growth factor beta on Trypanosoma congolense infection in mice

The socioeconomic implications of trypanosomosis in sub-Saharan Africa and the limitations of its current control regimes have stimulated research into alternative control methods. Considering the pro- and anti-inflammatory properties of transforming growth factor beta1 (TGF-beta1) and its potential to enhance immunity against protozoan parasites, we examined the effects of intraperitoneally delivered TGF-beta1 in C57BL/6 mice infected with Trypanosoma congolense, the hemoprotozoan parasite causing nagana in cattle. A triple dose of 10 ng TGF-beta1 significantly reduced the first parasitemic peak and delayed mortality of infected mice. Furthermore, exogenous TGF-beta1 significantly decreased the development of trypanosome-induced anemia and splenomegaly. The apparent TGF-beta1-induced antitrypanosome protection, occurring mainly during the early stage of infection, correlated with an enhanced parasite antigen-specific Th1 cell response characterized by a skewed type I cytokine response and a concomitant stronger antitrypanosome immunoglobulin G2a antibody response. Infected TGF-beta1-pretreated mice exhibited a significant reduction in the trypanosome-induced hyperexpansion of B cells. Furthermore, evidence is provided herein that exogenous TGF-beta1 activates macrophages that may contribute to parasite control. Collectively, these data indicate that exogenous TGF-beta1 is immunostimulative, inducing partial protection against T. congolense infection, possibly through mechanisms involving innate immune responses.     

The influence of transforming growth factor beta1 on mesenchymal cell repair of full-thickness cartilage defects

To repair full-thickness articular cartilage defects in rabbit knees, we transplanted periosteal cells in a fibrin gel and determined the influence of transforming growth factor beta (TGF-beta) in vitro. Alginate served as a temporary supportive matrix component and was removed prior to transplantation. The defects were analyzed macroscopically, histologically, and electron microscopically, and evaluated with a semi-quantitative score system. Periosteal cell transplants showed a chondrogenic differentiation, which results in the development of embryonic-like cartilage tissue after 4 weeks and complete resurfacing of the patellar groove after 12 weeks. In the control groups, no repair was observed. Under the influence of TGF-beta1 we observed a reduction of the cartilage layer, whereas the osteochondral integration and the zonal architecture were improved. Periosteal cell-beads are stable cartilage transplants and have stiffness and elasticity enough for easy and sufficient transplant fixation. Further investigations are necessary to optimize the application of TGF-beta1 for cartilage repair.