ObjectiveThe full name of vertebroplasty is percutaneous vertebroplasty (PVP). It is a clinical technique that injects bone cement into the diseased vertebral body to achieve strengthening of the vertebra. The research on the safety and efficacy of bone cement is the basis for clinical application. In this study, vertebroplasty is used to evaluate and compare the safety and efficacy of Tecres and radiopaque bone cement in experimental pigs, and to determine the puncture method suitable for pigs and the pre-clinical evaluation method for the safety and efficacy of bone cement. MethodsTwenty-four experimental pigs (with a body weight of 60-80 kg) were randomly divided into an experimental group (Group A) and a control group (Group B). Group A was the Tecres bone cement group, and Group B was the radiopaque bone cement group, with 12 pigs in each group. Under the monitoring of a C-arm X-ray machine, the materials were implanted into the 1st lumbar vertebra (L1) and 4th lumbar vertebra (L4) of the pigs via percutaneous puncture using the unilateral pedicle approach. The animals were euthanized at 4 weeks and 26 weeks after the operation, respectively. The L4 vertebrae were taken for compressive strength testing, and the L1 vertebrae were taken for hard tissue pathological examination to observe the inflammatory response, bone necrosis, and degree of osseointegration at the implantation site. ResultsThe test results of compressive strength between groups A and B showed no significant difference at 4 weeks and 26 weeks after bone cement implantation (P > 0.05). Observation under an optical microscope (×100) revealed that at 4 weeks postoperatively, both groups A and B showed that the bone cement was surrounded by proliferative fibrous tissue, with lymphocyte infiltration around it. The bone cement was combined with bone tissue, the trabecular arrangement was disordered, and osteoblasts and a small amount of osteoid were formed. At 26 weeks postoperatively, bone cement was visible in both groups A and B. The new bone tissue was mineralized, the trabeculae were fused, the trabecular structure was regular and dense with good continuity, and no obvious inflammatory reaction was observed. ConclusionIn experimental pig vertebrae, there were no significant differences observed in the compressive strength, inflammation response, bone destruction, and integration with the bone between Tecres and non-radiopaque bone cement. Both exhibited good biocompatibility and osteogenic properties. It indicates that using vertebroplasty to evaluate the safety and efficacy of bone cement in pigs is scientifically sound.

Objective To observe toxic symptoms and signs , toxic damage extents and reversibility in rats after oral administration of Tangwang Mingmu granules .Methods Four dose groups with 40 rats in each group were designed in this study, including control group fed with distilled water and three groups at different dosages of the test drug .Tangwang Mingmu granules were orally administered to SD rats at the dosage of 8.4, 4.2 and 2.1 g/kg for 3 weeks and 14.0, 8.4 and 4.2 g/kg for 23 weeks, for 26 consecutive weeks .The general state of the rats was observed every day , while body mass and food consumption were calculated once a week .Halfway through and at the end of the administration (13 and 26 weeks) and after four weeks of recovery, parameters of body mass, hematology, hematological biochemistry, organ/body mass ratio and histopathology were measured .Results Compared with the control group at the same time-point, body mass of male rats in the other three groups was slightly reduced .Food consumption in high and medium dose groups was reduced (P<0.05), MCHC, ALT, TBIL and Na +in high dose group were decreased (P<0.05), TP, ALB and D-BIL were increased (P<0.05), the mean body mass and relative organ weight of thymus in medium dose male rats were decreased (P<0.05), relative organ weight of the liver and kidney in high dose male rats was increased (P<0.05), and focal chronic inflammation to different extent was observed in the liver , kidney and prostate gland .No dose-effect relationship was found in these perturbations that were all within the normal range of animals .No significant drug-related pathological changes were found.Conclusion The NOAEL of Tangwang Mingmu granules is considered to be 14.0 g/kg body mass/day (equal to 50 times the proposed clinical adult dosage ) for the 26-week repeated dose oral toxicity study in male andfemale rats.