Myocardial infarction (MI), one of the leading causes of global mortality and disability among cardiovascular diseases, has long been a focal point in medical research concerning its pathological mechanisms and therapeutic strategies [1]. From a pathophysiological perspective, MI triggers a complex cascade of events: initial ischemia and hypoxia induce cardiomyocyte necrosis, subsequently activating inflammatory responses that exacerbate ventricular remodeling and functional deterioration [2]. Within this process, oxidative stress and inflammatory reactions form a vicious cycle that critically aggravates tissue damage [3]. Excessive production of reactive oxygen species (ROS) directly injures cardiomyocytes and activates pro-inflammatory pathways such as NF-κB, further amplifying tissue injury [4]. Concurrently, sustained inflammation promotes additional ROS generation, establishing a detrimental positive feedback loop [5]. Conventional MI pharmacotherapy primarily includes antiplatelet agents (e.g., aspirin), β-blockers, and angiotensin-converting enzyme inhibitors [6], [7], [8], which mainly alleviate symptoms by improving hemodynamics or inhibiting thrombogenesis. However, these drugs exhibit limited efficacy in myocardial repair and microenvironmental modulation [9]. With advancing insights into MI pathology, therapeutic strategies are evolving from mere “blood flow reconstruction” toward a multifaceted approach integrating “microenvironmental regulation + tissue repair” [10], [11]. For instance, our research group developed a miRNA-based delivery system (P-MSN/miRNA nanoparticles) for post-ischemic cardiomyocyte reprogramming to enhance contractility and prevent apoptosis [12]. In this context, biomaterials, particularly dynamic-responsive self-assembled hydrogels, demonstrate unique advantages [13]. For example, Tang et al. achieved enzyme-regulated Hofmeister effect-mediated supramolecular gel self-assembly, enabling precise spatiotemporal control over material formation [14]. Such gels can serve as “artificial extracellular matrices” [15], providing structural support and pathological microenvironment modulation through their intrinsic bioactivity or loaded therapeutic agents. By disrupting the ROS-inflammation vicious cycle, these materials create a pro-regenerative niche conducive to myocardial repair [16].
Self-assembled hydrogels constitute a class of functional materials that spontaneously organize into three-dimensional network structures through non-covalent interactions such as hydrogen bonding, hydrophobic effects, and π-π stacking, and have garnered significant attention in biomedical applications in recent years [17], [18]. These materials possess unique dynamic reversibility, excellent biocompatibility, and tunable physicochemical properties, making them ideal candidates for drug delivery and tissue engineering [14], [19]. From a molecular design perspective, the formation mechanism of self-assembled hydrogels involves complex intermolecular interaction networks, which collectively determine the material’s final structure and functional characteristics [20]. Researchers have developed various self-assembled hydrogel systems based on peptides, polysaccharides, synthetic polymers, and other building blocks, achieving notable progress in wound healing, nerve regeneration, and other fields [21], [22], [23], [24]. For instance, Wu et al. employed peptide self-assembly technology to construct a well-defined, granzyme B (GrB)-responsive gel adjuvant system, which was injected into post-tumor-resection cavities to achieve personalized adjuvant immunotherapy [22]. Zhou et al. systematically investigated the biological effects of hierarchical chirality in peptide-based supramolecular gels in modulating immune responses and neural repair in the nervous system [25]. However, the application of self-assembled hydrogels in MI therapy remains challenging [26]. The post-MI myocardial microenvironment is highly complex, involving intertwined pathological processes such as hypoxia, oxidative stress, inflammatory responses, and extracellular matrix (ECM) remodeling [27]. An ideal therapeutic gel should exhibit the following characteristics: (1) mechanical properties mimicking the native myocardial ECM, (2) controllable degradation kinetics, (3) stimuli-responsive release of therapeutic factors, and (4) the ability to modulate cellular behavior [15]. Although a few studies have explored the application of hydrogels in MI, self-assembled hydrogel systems that are precisely molecularly engineered to target the characteristics of the post-MI microenvironment remain extremely rare [28], particularly with regard to systematic investigations into the relationship between their assembly mechanisms and biological functions, as well as their dynamic regulatory effects on the pathological microenvironment.
Choline chloride (ChCl), a naturally occurring quaternary ammonium salt, participates in various critical physiological processes in vivo [29]. Its pharmacological effects are primarily manifested in three aspects: (1) As a precursor of acetylcholine, ChCl modulates autonomic nervous function via the cholinergic system [30]; (2) As a methyl donor, it participates in phospholipid metabolism, influencing cell membrane integrity and signal transduction [31]; (3) Recent studies have revealed its anti-inflammatory [32] and antioxidant [33] properties, demonstrating potential in alleviating ischemia-reperfusion injury. In the context of MI, these characteristics of ChCl are particularly valuable, as they can suppress inflammasome activation to reduce pro-inflammatory cytokine (e.g., IL-1β) release while upregulating antioxidant enzyme expression to mitigate oxidative stress damage [32], [33]. However, ChCl monotherapy exhibits limitations such as relatively narrow therapeutic targets and short in vivo half-life, which restrict its therapeutic efficacy. Ammonium glycyrrhizinate (AG), the primary active component of licorice, possesses diverse pharmacological activities [34]. Its core mechanisms include: (1) exerting anti-inflammatory effects by inhibiting NF-κB and MAPK signaling pathways [35]; (2) enhancing antioxidant defense through free radical scavenging and upregulation of the Nrf2/HO-1 pathway [36]; and (3) suppressing myocardial fibrosis by modulating the CXCR4/SDF1 and TGF-β/p38MAPK signaling axes [37]. AG exhibits multi-target regulatory effects on post-infarction hyperactivated inflammatory responses, simultaneously influencing inflammation initiation, amplification, and resolution phases [38]. Nevertheless, its clinical application is constrained by poor aqueous solubility and low bioavailability [39], [40]. Theoretically, constructing a ChCl-AG composite gel system via a self-assembly strategy could achieve multiple synergistic effects: (1) Pharmacodynamically, their anti-inflammatory and antioxidant activities may mutually potentiate; (2) Pharmacokinetically, the gel system could prolong drug retention and enable controlled release; (3) Material-wise, molecular interactions between the two components may generate novel assembly structures with emergent functional properties. This natural molecule-based self-assembly approach circumvents potential toxicity associated with synthetic materials and achieves functional optimization through molecular synergy, representing a promising novel therapeutic strategy for MI.
This study proposes the construction of a ChCl-AG self-assembled hydrogel system to develop a novel therapeutic material capable of actively modulating the MI microenvironment. Adopting an interdisciplinary research strategy, we integrated methodologies from materials science, computational chemistry, and molecular biology. We successfully developed a self-assembled hydrogel system with optimal physicochemical properties through systematic component screening and process optimization. Mechanistic investigations employing advanced characterization techniques and theoretical simulations revealed that hydrophobic interactions, electrostatic forces, and hydrogen-bonding networks synergistically drive the dynamic self-assembly process in the ChCl-AG system. Notably, cryo-electron microscopy successfully captured the near-native nanostructural features of the gel, providing direct visual evidence for understanding its structure-function relationship. In the biological evaluation, we established in vitro and in vivo MI models that simulate clinical pathological conditions, and used high-throughput transcriptomics to comprehensively elucidate the cardioprotective mechanisms of ChCl-AG self-assembled hydrogels on cardiomyocytes. This work establishes a new paradigm for the structural design of self-assembled hydrogels. It lays a solid theoretical foundation for developing novel myocardial repair materials with microenvironment-modulating capabilities, offering significant scientific value and clinical potential for advancing MI treatment strategies.