万古霉素阳离子脂质体复合纳米羟基磷灰石/壳聚糖/魔芋葡甘聚糖治疗兔慢性感染性骨缺损

目的检验阳离子脂质体包封万古霉素复合纳米羟基磷灰石/壳聚糖/魔芋葡甘聚糖(nanohydroxyapatite/chitosan/koniac glucomannan,n-HA/CS/KGM)支架体内抗感染及骨修复活性。方法取6月龄健康新西兰大白兔51只,体重1.5～3.0kg,用金黄色葡萄球菌制备慢性感染性双侧胫骨骨缺损模型。将造模后4周存活的48只兔随机分为4组,每组12只。根据以下分组方法,分别于双侧骨缺损处植入相应支架。A组;清创后不作任何处理;B组:n-HA/CS/KGM空白支架组;C组:万古霉素复合n-HA/CS/KGM支架组;D组:万古霉素阳离子脂质体复合n-HA/CS/KGM支架组。治疗后8周行大体、骨缺损修复、组织学观察以及X线片、细菌学检查。结果实验动物造模后4周X线片显示明显骨质缺损、低密度影及软组织肿胀影,Norden评分均>3分,为(3.83±0.52)分。治疗后8周大体观察:C、D组窦道已愈合,A、B组仍有窦道;大体观察病理评分C、D组明显优于A、B组(P<0.05)。骨缺损修复观察:D组骨缺损已修复,骨缺损最长径显著优于A、B、C组(P<0.05)。X线片检查:C、D组可见新骨形成,A、B组可见骨膜反应及髓腔低密度影;Norden评分D组明显小于A、B、C组(P<0.05)。组织学观察:HE染色示C、D组可见大量骨小梁形成,纤维增生,未见明显感染迹象,A、B组仍可见中性粒细胞积聚;Smeltzer评分C、D组明显优于A、B组(P<0.05)。细菌学检查:C、D组阴性率明显高于A、B组(P<0.05)。结论万古霉素阳离子脂质体复合n-HA/CS/KGM支架可很好治疗兔慢性感染性胫骨骨缺损,为临床上治疗慢性感染性骨缺损提供了新思路。

Vancomycin cationic liposome combined with nano-hydroxyapatite/chitosan/konjac glucomannan scaffold for treatment of infected bone defects in rabbits

Objective To investigate the anti-infection and bone repair effects of cationic liposome-encapsulated vancomycin combined with the nano-hydroxyapatite/chitosan/konjac glucomannan(n-HA/CS/KGM) composite scaffold in vivo.Methods Fifty-one 6-month-old New Zealand white rabbits,weighing 1.5-3.0 kg,were selected to prepare chronic infectious tibia bone defect model by using Staphylococcus aureus.After 4 weeks,48 survival rabbits were randomly divided into 4 groups(n=12).After debridement,defect was treated with nothing in group A,with n-HA/CS/KGM composite scaffold in group B,with vancomycin and n-HA/CS/KGM composite scaffold in group C,and with cationic liposome-encapsulated vancomycin and n-HA/CS/KGM composite scaffold in group D.After 8 weeks of treatment,general observation,X-ray,HE staining,the bacterial culture,and the measurement of the longest diameter of bone defect were done.Results At 4 weeks after modeling, 48 rabbits were diagnosed as having osteomyelitis,including periosteal new bone formation,destruction of bone,and soft tissue swelling.The Norden score was 3.83±0.52.At 8 weeks after treatment,sinus healed in groups C and D,but sinus was observed in groups A and B;the gross bone pathologieal scores of group D were significantly better than those of groups A and B(P < 0.05). Bone defects were repaired completely in group D,the results of the longest diameter of bone defects in group D was significantly better than those in the other 3 groups(P < 0.05).New bone formation was observed in groups C and D,but periosteal reaction and marrow low-density shadow were observed in groups A and B;Norden score in group D was significantly better than those in groups A,B,and C(P < 0.05).HE staining showed that there were a large number of trabecular bone formation and fibrosis, with no obvious signs of infection in groups C and D,but neutrophil accumulation was observed in groups A and B;Smeltzer scores in groups C and D were significantly better than those in groups A and B(P < 0.05).Bacteriological results showed higher negative rate in groups C and D than in groups A and B(P < 0.05).Conclusion Cationic liposome-encapsulated vancomycin and n-HA/CS/KGM composite scaffold can be a good treatment for infectious bone defects in rabbits,providing a new strategy for the therapy of bone defects in chronic infection.