Experimental study of the treatment of spinal tuberculosis in rabbit with isoniazid and rifampicin loaded albumin nanoparticles in rabbits

English Keywords:Albumin  Nanoparticles  Isoniazid  Rifampicin  Spinal tuberculosis

English Abstract:

  【Abstract】 Objectives: To observe the clinical efficacy of isoniazid(INH) and rifampicin(RFP) loaded albumin nanoparticles in the treatment of spinal tuberculosis in rabbits. Methods: New Zealand white rabbits with the standard strain of Mycobacterium tuberculosis H37Rv were selected to establish the spinal tuberculosis model. Thirty-five New Zealand White Rabbits were divided into 3 groups: experimental group(14 rabbits), control group(14 rabbits) and blank control group(7 rabbits). INH and RFP loaded albumin nanoparticles were administrated forthe rabbits of group A(INH 3mg/kg, RFP 4mg/kg, once per week for a total of 12 weeks). Ordinary INH and RFP were administrated for the rabbits of group B(INH 3mg/kg, RFP 4mg/kg, once per day for a total of 12 weeks). Normal saline was administrated for the rabbits of blank control group(7mg/kg, once per day for a total of 12 weeks). The body weight was measured and CT scan was performed for all the rabbits in the 3 groups at 6 weeks and 12 weeks after treatment started, and 3 rabbits in each group were sacrificed. The concentrations of INH and RFP in blood, infected vertebral body, normal vertebral body and muscle tissue were tested by high performance liquid chromatography(HPLC). The efficacy of INH and RFP loaded albumin nanoparticles in the treatment of spinal tuberculosis in rabbit model was evaluated. Results: For group A, after 6 weeks of treatment, the weight of the rabbits increased by 0.44±0.09kg, and 0.27±0.07kg after 12 weeks of treatment. After 6 weeks of treatment, the pathological result showed inflammatory repair after bone destruction in the backgroud, together with a large number of lymphocytes, eosinophils and some plasma cellsaccumulating. After 12 weeks of treatment, a large number of osteoblasts and trabecular bone formation were observed in group A. CT showed bone fragments disappeared and abscess and necrosis were replaced by normal bone tissue. In group B, all the 14 rabbits survived and 4 had neurological symptoms of hind leg paralysis. There was no significant increase in body weight after 6 weeks of treatment, the average body weight was maintained at 2.5±0.2kg. Only 6 rabbits had increased weight of an average of 0.30±0.07kg after 12 weeks of treatment. At 6 weeks, vertebral bone destruction and severe inflammation were observed as well as massive necrosis and fibrin formation. CT scan revealed partial repair of the infected vertebrae, but there were still debris signs. After 12 weeks of treatment, a lot of osteoclasts, mesenchymal cells and capillaries were found at the infected vertebrae, indicating the repair of lesion. CT showed incomplete repair of the lesion represented by disappearance of bone fragments and cavities formation surrounded by sclerosis band. 6 weeks of treatment, there was a significant difference in plasma concentration of INH and RFP between two groups(P<0.05). The concentrations of INH and RFP were measured at the infected vertebraewhich were significantly different from those of group B. Muscle tissue INH, RFP measured of the tissue concentration were no significant difference compared with the group B. 12 weeks of treatment, there was a significant difference in plasma concentration of INH and RFP between two groups(P<0.05). The concentrations of INH and RFP were measured at the infected vertebraewhich were significantly different from those of group B. Muscle tissue INH, RFP measured of the tissue concentration were no significant difference compared with the group B. Rabbits in group C died within 45-60 days of the placebo normal saline administration. Conclusions: Compared with control group, the INH-RFP loaded albumin nanoparticles have good sustained release characteristics in vivo and effective biodistribution in the infected bone tissue. Its rapeutic effect in spinal tuberculosis in rabbit model is significantly better than that of conventional preparation.