Blom E J, Klein-Nulend J, Klein C P, Kurashina K, van Waas M A, Burger E H
Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam-Vrije Universiteit, Van der Boechorststraat 7, 1081 BT Amsterdam, The
J Biomed Mater Res. 2000 Apr;50(1):67-74. doi: 10.1002/(sici)1097-4636(200004)50:1<67::aid-jbm10>3.0.co;2-e.
Growth stimulation of periimplant tissues by growth factors like transforming growth factor-beta1 (TGF-beta1) may increase the indication for and success of implant use. Calcium phosphate as a material for implants or for coating of implants is known for its good biologic interaction with bone. Therefore, calcium phosphate implants combined with TGF-beta1 might improve osseointegration. In this study we hypothesise that the addition of recombinant human TGF-beta1 (rhTGF-beta1) to calcium phosphate cement (CPC) affects the differentiation of bone cells growing on the cement layer. rhTGF-beta1 incorporated during setting in a CPC layer at 20 ng rhTGF-beta1/60 mg cement was found to be gradually released into tissue culturing medium leading to a 20% release after 24 h. Two cell populations were obtained from collagenase-treated fragments of adult rat long bones: preosteoblastic cells, which were released by the collagenase treatment, and osteoblastic cells, which grew from the collagenase-stripped bone fragments. Both cell populations were tested for their osteoblastic characteristic phenotype by measuring their alkaline phosphatase (ALP) activity after vitamin D treatment and cyclic AMP after parathyroid hormone stimulation. After preculture the cells were plated on a layer of CPC containing 0 (control), 10, or 20 ng rhTGF-beta1/60 mg CPC. Bone cell differentiation was analyzed after 10 days by measuring the ALP activity, as well as the protein content of the cell layer. Incorporation of rhTGF-beta1 in the CPC did not change the ALP activity in osteoblastic cells, but a significant (analyzed by multivariate analysis of variance) increase was observed in preosteoblastic cells. Incorporation of 10 ng of rhTGF-beta1 in 60 mg of CPC increased the ALP activity in preosteoblastic cells by threefold and 20 ng rhTGF-beta1/60 mg CPC increased it by fivefold. The total protein content was not affected by rhTGF-beta1 in either of the cell populations. We conclude that rhTGF-beta1 incorporated during setting in CPC stimulates the differentiation of preosteoblastic cells in vitro. These results provide a basis for further studies on the use of this combination as an implant material in vivo.
诸如转化生长因子-β1（TGF-β1）等生长因子对种植体周围组织的生长刺激作用，可能会增加种植体使用的适应症并提高其成功率。磷酸钙作为一种种植体材料或种植体涂层材料，因其与骨具有良好的生物相互作用而闻名。因此，磷酸钙种植体与TGF-β1联合使用可能会改善骨结合。在本研究中，我们假设向磷酸钙骨水泥（CPC）中添加重组人TGF-β1（rhTGF-β1）会影响在骨水泥层上生长的骨细胞的分化。发现在固化过程中以20 ng rhTGF-β1/60 mg骨水泥掺入CPC层中的rhTGF-β1会逐渐释放到组织培养基中，24小时后释放率达20%。从成年大鼠长骨经胶原酶处理的碎片中获得了两种细胞群体：经胶原酶处理释放出的前成骨细胞，以及从经胶原酶处理剥离的骨碎片上生长的成骨细胞。通过测量维生素D处理后的碱性磷酸酶（ALP）活性以及甲状旁腺激素刺激后的环磷酸腺苷，对这两种细胞群体的成骨细胞特征表型进行了检测。预培养后，将细胞接种在含有0（对照）、10或20 ng rhTGF-β1/60 mg CPC的CPC层上。10天后，通过测量ALP活性以及细胞层的蛋白质含量来分析骨细胞分化情况。在CPC中掺入rhTGF-β1并未改变成骨细胞中的ALP活性，但在前成骨细胞中观察到显著增加（通过多变量方差分析）。在60 mg CPC中掺入10 ng rhTGF-β1使前成骨细胞中的ALP活性增加了三倍，而20 ng rhTGF-β1/60 mg CPC则使其增加了五倍。两种细胞群体中的总蛋白质含量均不受rhTGF-β1的影响。我们得出结论，在固化过程中掺入CPC的rhTGF-β1在体外可刺激前成骨细胞的分化。这些结果为进一步研究将这种组合用作体内植入材料提供了依据。
