Release of isoniazid and rifampicin ano-hydroxyapatite-calcium-sulfate-chitosan artificial bone in rabbit spinal tuberculosis model

English Keywords:Spinal tuberculosis  Isoniazid  Rifampin  Artificial bone  Slow-release in vivo

English Abstract:

  【Abstract】 Objectives: To study drug release characteristics of isoniazid(INH) and rifampicin(RFP) nano-hydroxyapatite(nHA)-calcium sulfate(CSH)-chitosan(CTS) artificial bone in rabbit spinal tuberculosis model. Methods: By using standard strain of Mycobacterium tuberculosis H37Rv, 27 rabbit spinal tuberculosis models were established by lateral ventral approach, 15 females and 12 males, 3 months old, with an average body weight of 2.50±0.25kg, each model rabbit was implanted with artificial bone materials after spinal tuberculosis debridement. According to the time points, the models were divided into 24h, 72h and 1, 2, 4, 6, 8, 10, 12 weeks, a total of nine groups, with 3 rabbits in each group. High performance liquid chromatography(HPLC) was used to determine the concentration of INH and RFP in focal bone tissue and focal muscle tissue of animal models at different time points, and the relationship between concentration and time was studied. Results: The concentration of INH in focal bone tissue at 24h, 72h and 1 week, 2 weeks, 4 weeks, 6 weeks and 8 weeks was 75.66±1.95μg/g, 48.46±2.34μg/g, 30.69±2.74μg/g, 20.34±1.63μg/g, 9.36±1.17μg/g, 5.19±1.40μg/g and 2.73±1.19μg/g respectively， no drug concentration was detected after 10 weeks, the concentration of INH in focal muscle tissue was 39.51±2.25μg/g, 23.65±1.55μg/g, 16.39±2.10μg/g, 10.38±1.44μg/g, 3.66±0.79μg/g, 1.89±0.73μg/g, 0.26±0.10μg/g respectively， no drug concentration was detected after 10 weeks. Comparison of drug concentrations of INH in two different tissues at the same time showed statistical significance(P<0.05). At 24h, 72h and 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks and 10 weeks, the drug concentration of RFP in focal bone tissue was 10.85±2.45μg/g, 22.47±1.94μg/g, 38.32±1.73μg/g, 24.22±1.45μg/g, 17.85±1.50μg/g, 9.81±1.30μg/g, 6.35±1.30μg/g, 5.11±0.53μg/g, 1.32±0.33μg/g respectively. The drug concentration of RFP in focal muscle tissue was 5.39±1.50μg/g, 20.66±1.29μg/g, 48.72±2.24μg/g, 32.27±1.63μg/g, 15.58±1.88μg/g, 8.69±0.79μg/g, 3.43±0.39μg/g respectively. No drug concentration was detected after 10 weeks. The concentrations of RFP in two different tissues were significantly different at other time points except 72h, 4 weeks and 6 weeks(P<0.05). Conclusions: INH-RFP nano hydroxyapatite-calcium sulfate-chitosan artificial bone can sustainably and effectively release anti-tuberculosis drugs in the focal tissues of rabbit spinal tuberculosis model.