目的 从影像学、组织学评估聚柠檬酸复合纳米羟基磷灰石（POC-Click-HA）可吸收螺钉治疗比格犬股骨外髁骨折的适用性及其作用机制。 方法 健康成年比格犬9只，制备双侧股骨外髁骨折（AO分型33.B1型）模型。右侧采用POC-click-HA可吸收松质骨螺钉固定，为实验组；左侧采用聚消旋乳酸PDLLA可吸收松质骨螺钉固定，为对照组。术后4周、8周及12周分别取材行Micro-CT扫描及骨组织学染色分析。并体外观察三羧酸循环抑制剂CPI-613和外源性柠檬酸对MC3T3-E1细胞成骨作用的影响。 结果 Micro-CT显示术后4周POC-click-HA螺钉与骨组织结合弱于PDLLA螺钉；8周两组螺钉与周围骨组织逐渐整合，差异不明显；12周两组螺钉-骨组织均键合良好，新形成的骨小梁围绕螺钉螺纹生长。组织学染色发现：实验组螺钉周围逐渐形成新生骨，螺钉在降解，有新骨长入；而对照组螺钉周围仍有较多胶原纤维，仅见少量新骨，螺钉毫无降解。细胞培养结果显示加入CPI-613后培养基内内源性柠檬酸显著减少；抑制剂浓度越高，ALP染色阳性细胞形成数量越少；柠檬酸浓度越高，钙结节形成越多。 结论 POC-click-HA骨螺钉较PDLLA骨螺钉具有更强骨诱导能力和更快骨降解性，适于治疗比格犬股骨外髁骨折。柠檬酸材料促进骨折愈合的机制可能与促进成骨细胞分化有关。
Abstract
Objective To evaluate the applicability and mechanism of citric acid copolymer - hydroxyapatite (POC-click-HA) screws in treatment of lateral femoral condyle fracture of canine. Methods Nine adult male Beagles (weighing 9~12 kg) were selected to prepare the models (AO classification type B1) of bilateral lateral femoral condyle fracture, the right side was fixed with POC-click-HA absorbable cannulated screws as an experimental group and left side with Poly-DL-Lactic acid(PDLLA) screws as a control group. At 4 weeks, 8 weeks, and 12 weeks after operation，Micro-CT and histological analysis were taken to observe the fracture healing. The osteogenesis effect of MC3T3 E1 cell were observed by the Kreb’s cycle inhibitors of the CPI-613 and exogenous citric acid (CA). Results Micro-CT result showed that the combination of POC-click-HA screw and bone was weaker than PDLLA screw at 4 weeks after surgery. At 8 weeks, the two groups of screws were gradually integrated with the surrounding bone tissue, with no significant difference. At 12 weeks, the screw-bone tissues of both groups were well bonded. Histological staining analysis result showed that new bone was gradually formed around the screws in experimental group. The screws were degrading and new bone was growing in. However, there were still more collagen fibers around the screws in the control group, only a few new bones were seen, and the screws were not degraded. The results of cell culture showed that the citric acid in the medium significantly reduced after the addition of cpi-613 inhibitor. The higher concentration of inhibitor, the fewer ALP positive cells were formed. The higher the citric acid concentration, the more calcium nodules formed. Conclusions Compared with PLLA screw, POC -click-HA bone screw has stronger bone induction ability and faster bone degradation，which can be better utilized for Beagles’ lateral femoral condyle B1 fractures. The mechanism for Citric acid material to promote fracture healing may be related to the TCA cycle.
关键词
可降解骨螺钉 /
股骨外髁骨折 /
柠檬酸 /
影像学 /
组织学
Key words
Biodegradable bone screws； Lateral femoral epicondyle fracture； Citric acid； /
Imaging； /
/
Histology
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] Alidadi S, Oryan A, Bigham-Sadegh A, et al. Comparative study on the healing potential of chitosan, polymethylmethacrylate, and demineralized bone matrix in radial bone defects of rat[J]. Carbohydr Polym, 2017, 166: 236-248. DOI: 10.1016/j.carbpol.2017.02.087.
[2] Tang JJ, Guo JS, Li Z, et al. Fast degradable citrate-based bone scaffold promotes spinal fusion[J]. J Mater Chem B, 2015, 3(27): 5569-5576. DOI: 10.1039/C5TB00607D.
[3] Guo JS, Xie ZW, Tran RT, et al. Click chemistry plays a dual role in biodegradable polymer design[J]. Adv Mater, 2014, 26(12): 1906-1911. DOI: 10.1002/adma.201305162.
[4] Chung EJ, Kodali P, Laskin W, et al. Long-term in vivo response to citric acid-based nanocomposites for orthopaedic tissue engineering[J]. J Mater Sci Mater Med, 2011, 22(9): 2131-2138. DOI: 10.1007/s10856-011-4393-5.
[5] Sun DW, Chen YH, Tran RT, et al. Citric acid-based hydroxyapatite composite scaffolds enhance calvarial regeneration[J]. Sci Rep, 2014, 4: 6912. DOI: 10.1038/srep06912.
[6] Guo Y, Tran RT, Xie DH, et al. Citrate-based biphasic scaffolds for the repair of large segmental bone defects[J]. J Biomed Mater Res A, 2015, 103(2): 772-781. DOI: 10.1002/jbm.a.35228.
[7] 马剑雄, 高峰, 柏豪豪, 等. 可降解生物材料在骨科内固定中的研究及应用进展[J]. 生物医学工程与临床, 2016, 20(3): 323-327. DOI: 10.13339/j.cnki.sglc.20160510.022.
[8] Zachar Z, Marecek J, Maturo C, et al. Non-redox-active lipoate derivates disrupt cancer cell mitochondrial metabolism and are potent anticancer agents in vivo[J]. J Mol Med (Berl), 2011, 89(11): 1137-1148. DOI: 10.1007/s00109-011-0785-8.
[9] Costello LC, Franklin RB. Plasma citrate homeostasis: how it is regulated; and its physiological and clinical implications. An important, but neglected, relationship in medicine[J]. HSOA J Hum Endocrinol, 2016, 1(1): 5. DOI: 10.24966/HE-9640/100005.
[10] Williams NC, O'Neill LAJ. A role for the Krebs cycle intermediate citrate in metabolic reprogramming in innate immunity and inflammation[J]. Front Immunol, 2018, 9: 141. DOI: 10.3389/fimmu.2018.00141.
[11] Zhong YL, Li XL, Ji YS, et al. Pyruvate dehydrogenase expression is negatively associated with cell stemness and worse clinical outcome in prostate cancers[J]. Oncotarget, 2017, 8(8): 13344-13356. DOI: 10.18632/oncotarget.14527.
[12]Kara B, Genç HM, Uyur-Yalçın E, et al. Pyruvate dehydrogenase-E1alpha deficiency presenting as recurrent acute proximal muscle weakness of upper and lower extremities in an 8-year-old boy[J]. Neuromuscul Disord, 2017, 27(1): 94-97. DOI: 10.1016/j.nmd.2016.11.001.
[13] Xie D, Guo J, Mehdizadeh M, et al. Development of injectable citrate-based bioadhesive bone implants[J]. J Mater Chem B, 2015, 3: 387-398. DOI: 10.1039/C4TB01498G.
[14] Zhang SX, Zhang XN, Zhao CL, et al. Research on an Mg-Zn alloy as a degradable biomaterial[J]. Acta Biomater, 2010, 6(2): 626-640. DOI: 10.1016/j.actbio.2009.06.028.
[15]Burdick JA, Frankel D, Dernell WS, et al. An initial investigation of photocurable three-dimensional lactic acid based scaffolds in a critical-sized cranial defect[J]. Biomaterials, 2003, 24(9): 1613-1620. DOI: 10.1016/s0142-9612(02)00538-0.
[16]Gunatillake P, Mayadunne R, Adhikari R. Recent developments in biodegradable synthetic polymers[J]. Biotechnol Annu Rev, 2006, 12: 301-347. DOI: 10.1016/S1387-2656(06)12009-8.
京ICP备08002354号-3
