OBJECTIVETo fabricate a new composite scaffold material as an implant for sustained delivery of rifampicin and evaluate its performance of sustained drug release and biocompatibility.

METHODSThe composite scaffold material was prepared by loading poly(lactic-co-glycolic) acid (PLGA) microspheres that encapsulated rifampicin in a biphasic calcium composite material with a negative surface charge. The in vitro drug release characteristics of the microspheres and the composite scaffold material were evaluated; the in vivo drug release profile of the composite scaffold material implanted in a rat muscle pouch was evaluated using high-performance liquid chromatography. The biochemical parameters of the serum and liver histopathologies of the rats receiving the transplantation were observed to assess the biocompatibility of the composite scaffold material.

RESULTSThe encapsulation efficiency and drug loading efficiency of microspheres were (56.05±5.33)% and (29.80±2.88)%, respectively. The cumulative drug release rate of the microspheres in vitro was (94.19±5.4)% at 28 days, as compared with the rate of (82.23±6.28)% of composite scaffold material. The drug-loaded composite scaffold material showed a good performance of in vivo drug release in rats, and the local drug concentration still reached 16.18±0.35 µg/g at 28 days after implantation. Implantation of the composite scaffold material resulted in transient and reversible liver injury, which was fully reparred at 28 days after the implantation.

CONCLUSIONThe composite scaffold material possesses a good sustained drug release capacity and a good biocompatibility, and can serve as an alternative approach to conventional antituberculous chemotherapy.

Animals ; Biocompatible Materials ; chemistry ; Delayed-Action Preparations ; Drug Carriers ; chemistry ; Drug Liberation ; Lactic Acid ; chemistry ; Microspheres ; Polyglycolic Acid ; chemistry ; Rats ; Rifampin ; administration & dosage

OBJECTIVETo investigate the association between vitamin D receptor (VDR) gene Apa I polymorphism and the susceptibility to bone and joint tuberculosis in Chinese Han population.

METHODSBetween May, 2015 and June, 2016, 100 patients with bone and joint tuberculosis and 100 healthy volunteers were recruited concomitantly in Heyuan Hospital of Traditional Chinese Medicine. Vitamin D receptor gene Apa I polymorphisms in these subjects were analyzed using SNaPshot.

RESULTThe genotype frequencies of Apa I-AA, Apa I-Aa and Apa I-aa were 51%, 41%, and 8% in the case group and 33%, 55%, and 12% in the control group, respectively, showing significant differences between the two groups (P<0.05). The genotype of Apa I-AA was significantly higher in the case group with an odds ratio (OR) of 2.073 (95% CI: 1.142-3.763).

CONCLUSIONThe Apa I polymorphisms of the VDR gene are associated with the susceptibility to bone and joint tuberculosis in Chinese Han population, and individuals with a Apa I-AA genotype are at greater risks to develop bone and joint tuberculosis.