Otsuka Makoto, Kuninaga Tomoaki, Otsuka Kuniko, Higuchi William I
Research Institute of Pharmaceutical Sciences, Faculty of Pharmacy, Musashino University, Shinmachi 1-1-20, Nishitokyo-shi, Tokyo 202-8585, Japan.
J Biomed Mater Res B Appl Biomater. 2006 Oct;79(1):176-84. doi: 10.1002/jbm.b.30528.
Apatite cement and collagen were combined by a mechanochemical method to create a new self-setting apatite/collagen composite cement, and menatetrenone (VK2) was loaded into a drug-delivery system to test biocompatibility in rats. Powder X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and electron probe microanalyzer (EPMA) were performed to characterize the physicochemical properties of apatite/collagen composite cements. The XRD results suggested that ground apatite/collagen cement was completely transformed into bone-like hydroxyapatite, but that without grinding was incomplete. The SEM and EPMA results suggested that ground apatite/collagen cement was homogeneously dispersed of nanoapatite crystals in collagen matrices, similar to that in natural bone. In contrast, the cement without grinding was heterogeneously distributed. To evaluate in-vivo cement density (CMM), microradiograms were measured for 72 days after implanting apatite/collagen composite cements in intramuscular tissue on the backs of rats, and cross sections of the cements and surrounding soft tissues were observed by microscope. The CMM results of the apatite/collagen composite cements suggested that the biodegradation rate was dependent on the cement quality and nanogeometrical structure. The CMM result of VK2-loaded apatite/collagen cements suggested that the biodegradation rates of the cements were significantly dependent on their formulation. The CMM of ground apatite/collagen cement increased until 7 days and then decreased, and bone-like cells penetrated deeply in the center. The microphotograph and CMM results of apatite/collagen without grinding indicated that a lot of bone-like cells penetrated into the cement and the cement shape was totally deformed.
采用机械化学方法将磷灰石水泥与胶原蛋白相结合，制备出一种新型的自固化磷灰石/胶原蛋白复合水泥，并将维生素K2（VK2）负载到药物递送系统中，以测试其在大鼠体内的生物相容性。通过粉末X射线衍射分析（XRD）、扫描电子显微镜（SEM）和电子探针微分析仪（EPMA）对磷灰石/胶原蛋白复合水泥的物理化学性质进行表征。XRD结果表明，研磨后的磷灰石/胶原蛋白水泥完全转化为类骨羟基磷灰石，而未研磨的则不完全转化。SEM和EPMA结果表明，研磨后的磷灰石/胶原蛋白水泥中纳米磷灰石晶体均匀分散在胶原蛋白基质中，类似于天然骨中的情况。相比之下，未研磨的水泥分布不均匀。为了评估体内水泥密度（CMM），在大鼠背部肌肉组织中植入磷灰石/胶原蛋白复合水泥后72天测量微射线照片，并通过显微镜观察水泥及其周围软组织的横截面。磷灰石/胶原蛋白复合水泥的CMM结果表明，生物降解率取决于水泥质量和纳米几何结构。负载VK2的磷灰石/胶原蛋白水泥的CMM结果表明，水泥的生物降解率显著取决于其配方。研磨后的磷灰石/胶原蛋白水泥的CMM在7天前增加，然后下降，类骨细胞深入中心。未研磨的磷灰石/胶原蛋白的显微照片和CMM结果表明，大量类骨细胞侵入水泥，水泥形状完全变形。
