Objective: To investigate the therapeutic effects and mechanisms of Ultrasound-targeted microbubble destruction (UTMD) technology combined with CoQ10 loaded PEGylated nanoliposomes (CoQ10-PEG-lips) on diabetic cardiomyopathy (DCM) in rats. Methods: CoQ10-PEG-lips were prepared using the thin-film dispersion method combined with ultrasonic hydration, followed by quality assessment. Sixty healthy and clean male SD rats were selected, and 50 were randomly chosen using a random number table to establish a type 1 diabetes mellitus (DM) model via a single intraperitoneal injection of streptozotocin. The remaining 10 rats were assigned as the normal control group. A total of 47 rats successfully developed the DM model, and 40 were selected using the random number table method. Based on different intervention methods, these rats were then randomly divided into DM model group, CoQ10 solution group, CoQ10-PEG-Lips group, and CoQ10-PEG-Lips+UTMD group (n=10 per group). Normal control group and DM model group rats were injected with 1 ml of normal saline through caudal vein. CoQ10 solution group and CoQ10-PEG-Lips group were injected with 1 ml of CoQ10 solution or CoQ10-PEG-Lips solution containing 10 mg/kg of CoQ10 through caudal vein, respectively. Rats in the CoQ10-PEG-Lips+UTMD group were injected with 1 ml of CoQ10-PEG-Lips solution containing 10 mg/kg of CoQ10+100 mg of freeze-dried ultrasound microbubble powder through caudal vein and were given UTMD treatment at the same time, with the intervention given twice a week. After 12 weeks of intervention, cardiac function indexes [left ventricular end-systolic diameter (LVEDs), left ventricular end-diastolic diameter (LVEDd), and left ventricular ejection fraction (LVEF)]of each group were measured by ultrasonic cardiac function detection in vivo. Simultaneously, ex-vivo histopathological examination was conducted to assess myocardial cell morphology, cross-sectional area, collagen volume fraction (CVF), and apoptosis index (AI) in each group. Additionally, molecular biology techniques were employed to measure oxidative stress-related indicators and the expression of apoptosis-related pathway proteins. Results: The prepared CoQ10-PEG-lips had a well-rounded morphology, good dispersibility, and a high encapsulation efficiency of 87.45%±3.23%. After 12 weeks of intervention, the myocardial cell morphology in the CoQ10-PEG-Lips+UTMD group was intact, with orderly arrangement, closely resembling that of the normal control group. There were no statistically significant differences between the two groups in terms of LVEDs [(1.53±0.07) mm vs (1.42±0.04) mm], LVEDd [(2.93±0.15) mm vs (2.81±0.05) mm], or LVEF (80.76%±3.42% vs 84.60%±2.10%) (all P>0.05). Similarly, there were no significant differences between the two groups in myocardial cell cross-sectional area, CVF, or AI (all P>0.05). The CoQ10-PEG-Lips+UTMD group showed statistically significant differences in the above-mentioned indicators compared to the DM group, CoQ10 solution group, and CoQ10-PEG-Lips group (all P<0.05). In the CoQ10-PEG-Lips+UTMD group, the levels of myocardial superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the expression of the anti-apoptotic protein B-cell lymphoma-2 (Bcl-2) were significantly higher compared to the DM model group, CoQ10 solution group, and CoQ10-PEG-Lips group (all P<0.05), while malondialdehyde levels and the expression of Bcl-2-associated X protein (Bax) and caspase-3 were lower (all P<0.05). Conclusions: Using PEG-lips to encapsulate the poorly soluble drug CoQ10 in combination with UTMD technology enables targeted delivery of the drug to the myocardium, which can help reduce myocardial cell damage, fibrosis, and apoptosis caused by diabetes mellitus (DM) by inhibiting oxidative stress damage and the Bcl-2/Bax/caspase-3 apoptosis signaling pathway, ultimately improving cardiac function in DCM rats.
目的： 探讨超声靶向微泡爆破（UTMD）技术结合包载辅酶Q10（CoQ10）新型聚乙二醇化长循环纳米脂质体（PEG-lips）对于大鼠糖尿病心肌病（DCM）的治疗效果及其机制。 方法： 应用薄膜分散技术结合超声水合法制备CoQ10-PEG-lips并进行质量考察。选取60只健康清洁级雄性SD大鼠，应用随机数字表法选取50只，通过单次腹腔注射链脲佐菌素建立大鼠1型糖尿病（DM）动物模型，剩余10只大鼠作为正常对照组，共47只大鼠DM模型建模成功，应用随机数字表法选取40只，根据干预方式的不同再次应用随机数字表法分成DM模型组、CoQ10溶液组、CoQ10-PEG-Lips组、CoQ10-PEG-Lips+UTMD组（各组n=10）。正常对照组与DM模型组大鼠尾静脉注射1 ml生理盐水，CoQ10溶液组及CoQ10-PEG-Lips组分别大鼠尾静脉注射1 ml CoQ10溶液或者CoQ10-PEG-Lips溶液包含CoQ10 10 mg/kg，CoQ10-PEG-Lips+UTMD组大鼠尾静脉注射1 ml CoQ10-PEG-Lips溶液包含CoQ10 10 mg/kg+100 mg超声微泡冻干粉同时给予UTMD技术治疗，每周干预2次。连续干预12周应用超声心功能检测在体测定各组大鼠的各项心功能指标［左心室收缩末期直径（LVEDs）、左心室舒张末期直径（LVEDd）、左心室射血分数（LVEF）］。同时应用离体组织病理学检查方法分别测定各组大鼠的心肌细胞形态和横截面积、胶原容积分数（CVF）及凋亡指数（AI）等。另外应用分子生物学检测技术测定氧化应激相关指标及细胞凋亡相关通路蛋白的表达。 结果： 制备的CoQ10-PEG-lips形态圆整，分散性好，包封率高达87.45%±3.23%。干预12周后，CoQ10-PEG-lips+UTMD组大鼠心肌细胞形态完整，排列整齐，接近正常对照组，两组LVEDs［（1.53±0.07）mm比（1.42±0.04）mm］、LVEDd［（2.93±0.15）mm比（2.81±0.05）mm］、LVEF（80.76%±3.42%比84.60%±2.10%）差异均无统计学意义（均P>0.05）；两组心肌细胞横截面积、CVF及AI差异亦均无统计学意义（均P>0.05）。CoQ10-PEG-lips+UTMD组以上指标与DM组、CoQ10溶液组及CoQ10-PEG-lips组比较差异均有统计学意义（均P<0.05）。CoQ10-PEG-lips+UTMD组大鼠心肌超氧化物歧化酶、谷胱甘肽过氧化物酶含量及抗凋亡相关蛋白B淋巴细胞瘤-2（Bcl-2）表达较DM模型组、CoQ10溶液组及CoQ10-PEG-lips组升高（均P<0.05），而丙二醛及Bcl-2相关X蛋白（Bax）、半胱氨酸蛋白酶-3（caspase-3）表达下降（均P<0.05）。 结论： 应用PEG-lips包载难溶性药物CoQ10结合UTMD技术可以实现药物的心肌靶向递送，使得其通过抑制DM导致的氧化应激损伤及Bcl-2/Bax/caspase-3细胞凋亡信号通路减轻DM引起的心肌细胞损伤、纤维化及凋亡，最终改善DCM大鼠的心脏功能。.