Effects of Electrical Polarization of Hydroxyapatite ceramics on Bone Conduction

实验1。质子输运极化可以在羟基磷灰石（HAp）陶瓷表面诱导较大的电荷，但由于β-磷酸三钙（β-TCP）的极化率较低，因此对其不产生影响。我们希望通过颅骨骨缺损模型来研究带正负表面电荷的HAp和HAp/TCP板在成骨细胞活性和新骨生长方面的差异。在第一组大鼠中，测试片的正电荷面朝下放置在硬脑膜上。在第二组中，测试片的负电荷面朝下放置在硬脑膜上。第三组接受的是不带电的测试片。组织学检查，包括成骨细胞和破骨细胞的酶染色。虽然在颅周未观察到骨形成，但颅骨碎片上的直接骨形成和新骨生长从损伤部位的边缘扩展到正电荷和新电荷之间。HAp和HAp/TCP板的正电荷表面出现更多。植入板的电极化，包括正电荷，导致成骨细胞活性增强，尽管在带正电荷的板表面可以看到破骨细胞活性下降。因此，HAp陶瓷的极化可以调节新骨的形成和吸收。实验2。羟基磷灰石陶瓷作为植入物用于修复受损/移除的骨，在体内，负或正电极化分别增强成骨细胞活性和降低破骨细胞活性。我们比较了电极化和非极化羟基磷灰石与互联孔（IPHA）种植体促进骨生长的能力。将极化或未处理的IPHAs分别植入兔左右股骨髁（每组10只），于植入后3周和6周进行组织学检查，包括成骨细胞和破骨细胞的酶染色。我们观察到极化种植体的骨长入改善和成骨细胞活性增加，早在手术后三周，骨完全渗透到极化种植体中。相比之下，非极化种植体在手术后6周未完全骨化。此外，与带负电荷或不带电荷的区域相比，带正电荷的植入区域的破骨细胞活性降低。我们提出了两个不同的模型来解释这些观察结果。少

Experiment 1.Large surface charges can be induced on hydroxyapatite (HAp) ceramics by proton transport polarization, but this does not affect β-tricalcium phosphate (β-TCP) because of its low polarizability. We wished to examine differences in osteogenic cell activity and new bone growth between positively or negatively surface charged HAp and HAp/TCP plates using a calvarial bone defect model. In the first group of rats, test pieces were placed with their positively charged surfaces face down on the dura mater. In a second group, test pieces were placed with their negatively charged surfaces face down on the dura mater. A third group received non-charged test pieces. Histological examination, including enzymatic staining for osteoblasts and osteoclasts, was carried out. While no bone formation was observed at the pericranium, direct bone formation on the cranial bone debris and new bone growth expanded from the margins of the sites of injury to bridge across both the positively and ne … More gatively charged surfaces of HAp and HAp/TCP plates occurred. Electrical polarization of implanted plates, including positive charge, led to enhanced osteoblast activity, though decreased osteoclast activity was seen on the positively charged plate surface. Thus, polarization of HAp ceramics may modulate new bone formation and resorption.Experiment 2.Hydroxyapatite ceramics are used as implants to repair damaged/removed bone, and negative or positive electrical polarization enhances osteoblast and decreases osteoclast activity, respectively, in vivo. We compared the ability of electrically polarized and non-polarized hydroxyapatite with interconnected pores (IPHA) implants to promote bone growth. Polarized or non-treated IPHAs were implanted into the right or left femoral condyle of rabbits (N=10 in each group), and we performed histological examination, including enzymatic staining for osteoblasts and osteoclasts, three and six weeks after implantation. We observed improved bone ingrowth and increased osteoblast activity in polarized implants with complete bone penetration into polarized implants occurring as early as three weeks after surgery. In contrast, non-polarized implants were not fully ossified at six weeks after surgery. Furthermore, positively charged implant regions had decreased osteoclast activity compared to negatively charged or uncharged regions. We propose two different models to explain these observations. Less