Department of Veterinary Surgery, College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea.
Onnuri Animal Medical Center, Cheongju, Republic of Korea.
In Vivo. 2020 Jul-Aug;34(4):1857-1862. doi: 10.21873/invivo.11980.
BACKGROUND/AIM: Many cases of bone damage are due to trauma and metabolic diseases. This study aimed to evaluate bone regeneration into a porous hydroxyapatite (HA) scaffold using dexamethasone (DM)-loaded polymeric microspheres.
Four adult dogs were used to evaluate the in vivo performance of DM-loaded microspheres immobilized on the surfaces of porous HA scaffolds. Two 5-mm drill holes were created in both the left and right femurs of each dog. The experimental groups included a control group (drill holes filled with HA scaffold alone), a DM 20 group (holes filled with DM-loaded HA scaffold with 20 mg DM per scaffold), and a DM 100 group (hole filled with DM-loaded HA scaffold with 100 mg DM per scaffold). Resulting bone volume percentages and bone mineral densities were calculated by examing micro-computed tomographic (CT) images.
The DM-loaded HA scaffold groups showed a gradual periosteal reaction two weeks after insertion of the HA scaffold into the femoral drill holes. Four weeks after HA scaffold insertion, the periosteal reaction in the femoral drill holes became denser. Eight weeks after insertion of DM-loaded HA scaffolds, clear images of the scaffold were observed in micro-CT images of the femoral drill hole. The DM 100 group had better bone healing tendencies (bone mineral density, bone mass, trabecular volume, bone surface, and trabecular thickness) than the DM 20 group.
DM-loaded HA scaffolds are suitable platforms for distributing bioactive molecules during osteogenesis in femoral drill holes.
背景/目的：许多骨损伤是由创伤和代谢疾病引起的。本研究旨在评估载地塞米松（DM）的聚合物微球在多孔羟基磷灰石（HA）支架上的骨再生情况。
使用 4 只成年犬来评估 DM 负载微球固定在多孔 HA 支架表面的体内性能。在每只狗的左右股骨上各钻 2 个 5mm 的孔。实验组包括对照组（仅填充 HA 支架的孔）、DM20 组（填充载有 20mgDM/支架的 DM 负载 HA 支架的孔）和 DM100 组（填充载有 100mgDM/支架的 DM 负载 HA 支架的孔）。通过检查微计算机断层扫描（CT）图像计算骨体积百分比和骨矿物质密度。
DM 负载 HA 支架组在将 HA 支架插入股骨钻孔后两周表现出逐渐的骨膜反应。在 HA 支架插入四周后，股骨钻孔的骨膜反应变得更加密集。在插入 DM 负载 HA 支架 8 周后，在股骨钻孔的微 CT 图像中可以清楚地观察到支架的图像。DM100 组的骨愈合趋势（骨矿物质密度、骨量、小梁体积、骨表面和小梁厚度）优于 DM20 组。
DM 负载 HA 支架是在股骨钻孔中成骨过程中分布生物活性分子的合适平台。
