Study of Metoprolol-Loaded Poly(Lactic-co-Glycolic Acid)–Poly (Trimethylene Carbonate)–Poly(Glycolic Acid) Drug-Eluting Stents for Coronary Heart Disease

Background and Objective: Drug-eluting stents (DES) have become a crucial strategy for improving the outcomes of patients with coronary artery disease (CAD). This work aimed to evaluates the therapeutic efficacy of metoprolol-loaded poly (lactic-co-glycolic acid)–poly(trimethylene carbonate)–poly (glycolic acid) (PLGA–PTMC–PGA) DES (Meto-PLGA/PTMC DES) in a rabbit model of CAD. Methods: A total of 30 New Zealand white rabbits (male, weighing 4–6 kg) were randomly divided into three groups: Sham group (chest suturing without intervention), Model group (CAD animal model without DES), and stent group (treatment with the Meto-PLGA/PTMC DES). The blood samples were collected at regular intervals to assess the serum inflammatory markers, cardiac function parameters, hemodynamic parameters and coronary remodeling. Statistical analysis was performed using One-way analysis of variance (ANOVA), followed by a post hoc Tukey’s test to compare the differences between groups (p < 0.05 indicated statistically significance). Results: The Meto-PLGA/PTMC DES, through its unique co-polymer structure, achieved stable Meto loading in vivo. This stent enabled the gradual release of Meto, thus maintaining sustained drug concentrations and optimizing CAD treatment. The animal experiment results indicated that the sent group (Meto-loaded DES) exhibited markedly lower levels of interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-α), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) relative to the model group (p < 0.05). In terms of cardiac function, compared with the model group, the stent group exhibited significantly elevated left ventricular systolic pressure (LVSP), ±dp/dtmax, arterial systolic blood pressure (BPs), and diastolic blood pressure (BPd), along with a marked reduction in left ventricular end-diastolic pressure (LVEDP) compared with the model group (p < 0.05). The coronary tissue morphology in the stent group revealed notably reduced intimal thickness, intimal area and degree of stenosis versus the Model group, with a prominent increase in lumen area (p < 0.05). Conclusion: The Meto-PLGA/PTMC DES not only effectively provides sustained drug release and exhibits superior mechanical properties and excellent blood compatibility. Animal experiments further validated the crucial role of the Meto-PLGA/PTMC DES in reducing inflammatory responses, improving cardiac function and alleviating coronary artery stenosis.