Data from: Enhancement of apoptosis by titanium alloy internal fixations during microwave treatments for fractures: an animal study

Objective: Microwaves are used in one method of physical therapy and can increase muscle tissue temperature which is useful for improving muscle, tendon and bone injuries. In the study, we sought to determine whether titanium alloy internal fixations influence apoptosis in tissues subjected to microwave treatments at 2,450 MHz and 40 W during the healing of fractures because this issue is not yet fully understood. Methods: In this study, titanium alloy internal fixations were used to treat 3.0-mm transverse osteotomies in the middle of New Zealand rabbits’ femurs. After the operation, 30-day microwave treatments were applied to the 3.0 mm transverse osteotomies 3 days after the operation. The changes in the temperatures of the muscle tissues in front of the implants or the 3.0 mm transverse osteotomies were measured during the microwave treatments. To characterize the effects of titanium alloy internal fixations on apoptosis in the muscles after microwave treatment, we performed TUNEL assays, fluorescent real-time (quantitative) PCR, western blotting analyses, reactive oxygen species (ROS) detection and transmission electron microscopy examinations. Results: The temperatures were markedly increased in the animals with the titanium alloy implants. Apoptosis in the muscle cells of the implanted group was significantly more extensive than that in the non-implanted control group at different time points. Transmission electron microscopy examinations of the skeletal muscles of the implanted groups revealed muscular mitochondrial swelling, vacuolization. ROS, Bax and Hsp70 were up-regulated, and Bcl-2 was down-regulated in the implanted group. Conclusion: Our results suggest that titanium alloy internal fixations caused greater muscular tissue cell apoptosis following 2,450 MHz, 40 W microwave treatments in this rabbit femur fracture models.研究目标：微波是物理治疗的常用手段之一，可升高肌肉组织温度，有助于改善肌肉、肌腱及骨骼损伤。本研究旨在探究2450 MHz、40 W的微波治疗过程中，钛合金内固定物（titanium alloy internal fixations）对骨折愈合过程中受微波作用的组织细胞凋亡（apoptosis）的影响，该问题目前尚未完全阐明。 研究方法：本研究对新西兰兔股骨中段实施3.0 mm横行截骨术，并采用钛合金内固定物进行固定。术后第3天起，对截骨部位进行为期30天的微波治疗。微波治疗期间，实时检测植入物前方肌肉组织或截骨部位的温度变化。为表征钛合金内固定物对微波治疗后肌肉组织细胞凋亡的影响，本研究开展了TUNEL检测（TUNEL assays）、荧光实时（定量）聚合酶链反应（fluorescent real-time (quantitative) PCR）、蛋白质印迹（western blotting）分析、活性氧（reactive oxygen species, ROS）检测以及透射电子显微镜（transmission electron microscopy）检查。 研究结果：植入钛合金内固定物的动物，其肌肉组织温度显著升高。在不同时间点，植入组的肌肉细胞凋亡程度均显著高于未植入对照组。对植入组骨骼肌的透射电子显微镜检查显示，肌细胞出现线粒体肿胀、空泡化现象。植入组的活性氧（ROS）、Bcl-2相关X蛋白（Bax）及热休克蛋白70（Hsp70）表达上调，而B细胞淋巴瘤-2蛋白（Bcl-2）表达下调。 研究结论：本研究结果表明，在本兔股骨骨折模型中，经2450 MHz、40 W的微波治疗后，钛合金内固定物会加剧肌肉组织细胞的凋亡。