[Experimental study on the treatment of diabetic cardiomyopathy in rats by using ultrasound-targeted microbubble destruction combined with coenzyme Q10 loaded long-circulating nanoliposomes].

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. 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 (=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. 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 >0.05). Similarly, there were no significant differences between the two groups in myocardial cell cross-sectional area, CVF, or AI (all >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 <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 <0.05), while malondialdehyde levels and the expression of Bcl-2-associated X protein (Bax) and caspase-3 were lower (all <0.05). 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.