No abstract

Background:Polymethyl methacrylate (PMMA) antibiotic beads though have proved their utility as a local antibiotic delivery system, however, there are limitations. Decalcified bone matrix (DBM) as a vehicle of antibiotics can serve the purpose, provided a minimum inhibitory concentration is sustained. Healing of the defect and avoiding the second surgery is another advantage. We studied the DBM as the delivery vehicle for vancomycin in controlling the methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis as well as healing of the cavity simultaneously in an experimental study.Materials and Methods:An in vitro study was conducted to optimize vancomycin impregnation in the DBM. For the in vivo study, a unicortical defect was created in the metaphysis of the distal femur in 18 rabbits. After contaminating the defect with MRSA, rabbits were divided into three groups. Group I (eight limbs) received no graft. Defects in group II (11 limbs) were filled with plain DBM chips and in group III (14 limbs), cavities were implanted with vancomycin-impregnated decal bone chips. Rabbits were assessed by clinical, radiological, histological, gross examination and bacterial load assay. High Performance Liquid Chromatography HPLC analysis of vancomycin in group III was done to assess the concentration in DBM chips.Results:In group I, the infection persisted throughout the period of the study. Group II showed the fulminated infection at the grafted site with DBM chips sequestrating out. Vancomycin-impregnated decal chips in group III did not show any sign of infection and eventually incorporated. The bacterial load study showed a progressive load change and HPLC revealed an effective antibiotic concentration up to 3 weeks in both in vitro and in vivo.Conclusion:Decal bone chips were effective as the local antibiotic delivery vehicle in preventing the MRSA osteomyelitis model. It eluted vancomycin significantly and the graft uptake was also excellent. Allogeneic decal grafts eliminated the need for second surgery and acted as an excellent delivery vehicle for antibiotics.

Recently, the nephroprotective property of Pueraria tuberosa DC. tuber (PT) has been reported by our group. Here, PT-embedded biscuits were prepared and tested on cisplatin-induced nephrotoxicity in Swiss albino mice. The PT powder was characterized by RAPD (random amplified polymorphic DNA) to ascertain its authenticity and PT biscuits were prepared in different concentrations (1, 2, or 4 g of PT powder). These biscuits were given as diet for a total of 10 days, but on the 7th day cisplatin injection (8 mg/kg bw, i.p.) was given. On the 10th day animals were killed to collect kidneys for assessment of antioxidant status. Blood samples were collected on both the 7th and 10th days for assessment of liver and kidney functions. In mice, PT biscuit showed significant protection against cisplatin-induced nephrotoxicity, but there was a transient rise in alanine aminotransferase and aspartate aminotransferase at the dose of 4 g PT biscuit. Therefore, it is suggested that PT biscuit might be an effective food supplement for cancer patients undergoing cisplatin-chemotherapy. However, periodical liver function monitoring is required, especially when PT is used for longer periods or at higher doses.