Applications of elastic and conductive hydrogels in myocardial infarction repair

An anisotropic cardiac patch with barbed microneedles for enhanced tissue anchorage and myocardial repair.

Myocardial infarction (MI) is a leading cause of mortality among cardiovascular diseases. Following MI, the damaged myocardium is progressively being replaced by fibrous scar tissue, which exhibits poor electrical conductivity, ultimately resulting in arrhythmias and adverse cardiac remodeling. Due to their extracellular matrix-like structure and excellent biocompatibility, hydrogels are emerging as a focal point in cardiac tissue engineering. However, traditional hydrogels lack the necessary conductivity to restore electrical signal transmission in the infarcted regions. Imparting conductivity to hydrogels while also enhancing their adhesive properties enables them to adhere closely to myocardial tissue, establish stable electrical connections, and facilitate synchronized contraction and myocardial tissue repair within the infarcted area. This paper reviews the strategies for constructing conductive and adhesive hydrogels, focusing on their application in MI repair. Furthermore, the challenges and future directions in developing adhesive and conductive hydrogels for MI repair are discussed.

Myocardial infarction (MI) results in an impaired heart function. Conductive hydrogel patch-based therapy has been considered as a promising strategy for cardiac repair after MI. In our study, we fabricated a three-dimensional (3D) printed conductive hydrogel patch made of fibrinogen scaffolds and mesenchymal stem cells (MSCs) combined with graphene oxide (GO) flakes (MSC@GO), capitalizing on GO's excellent mechanical property and electrical conductivity. The MSC@GO hydrogel patch can be attached to the epicardium via adhesion to provide strong electrical integration with infarcted hearts, as well as mechanical and regeneration support for the infarcted area, thereby up-regulating the expression of connexin 43 (Cx43) and resulting in effective MI repair in vivo. In addition, MI also triggers apoptosis and damage of cardiomyocytes (CMs), hindering the normal repair of the infarcted heart. GO flakes exhibit a protective effect against the apoptosis of implanted MSCs. In the mouse model of MI, MSC@GO hydrogel patch implantation supported cardiac repair by reducing cell apoptosis, promoting gap connexin protein Cx43 expression, and then boosting cardiac function. Together, this study demonstrated that the conductive hydrogel patch has versatile conductivity and mechanical support function and could therefore be a promising candidate for heart repair.

A tunable self-healing ionic hydrogel with microscopic homogeneous conductivity as a cardiac patch for myocardial infarction repair

Engineered neutrophil apoptotic bodies ameliorate myocardial infarction by promoting macrophage efferocytosis and inflammation resolution

Myocardial infarction (MI) remains one of the leading causes of death globally, necessitating innovative therapeutic strategies for effective repair. Conventional treatment methods such as pharmacotherapy, interventional surgery, and cardiac transplantation, while capable of reducing short-term mortality rates, still face significant challenges in post-MI repair including the restoration of intercellular biological and electrical signaling. This study presents a novel exosome-loaded conductive hydrogel designed to enhance myocardial repair by concurrently improving biological and electrical signals. Adipose-derived stem cell (ADSC) exosomes, encapsulated within a hyaluronic acid-dopamine (HA-DA) hydrogel, were employed to promote angiogenesis and inhibit inflammation. Incorporating black phosphorus (BP) into the hydrogel improved its electrical conductivity, thereby restoring electrical signal transmission in the infarcted myocardium and preventing arrhythmias. In vitro and in vivo experiments demonstrated that the exosome-loaded conductive hydrogel significantly enhanced cardiac function recovery by accelerating angiogenesis, reducing inflammation, and increasing electrical activity between myocardial cells. The hydrogel exhibited excellent biocompatibility, biodegradability, and sustained release of exosomes, ensuring prolonged therapeutic effects. This integrated approach resulted in notable improvements in the left ventricular ejection fraction, reduced fibrosis, and increased neovascularization. The combination of bioactive exosomes and a conductive hydrogel presents a promising therapeutic strategy for myocardial infarction repair.

Despite impressive advances in the last decade at treating coronary atherosclerosis, myocardial infarction remains the number one cause of death and disability in industrialized countries. A great deal of effort has been expended over the last 25 years toward identifying strategies to limit the amount of myocardium lost to infarction [4, 5]. Although infarct size limitation remains a highly desirable goal, it has been extremely difficult to achieve clinically. Over the last 5 years, our group has become increasingly interested in working on strategies to enhance the repair phase of myocardial infarction [31-33, 42, 43]. Our long-term goals are to induce muscular regeneration of the infarcted region. An intermediate goal, however, is to understand the molecular biology of infarct healing and to find strategies to prevent complications of infarction such as ventricular dilation that contribute to heart failure. This chapter will review the pathobiology of myocardial infarction and infarct repair, and then summarize some of our recent work in cardiomyocyte transplantation for creation of new myocardium.

An injectable silk sericin hydrogel promotes cardiac functional recovery after ischemic myocardial infarction

Advances and challenges in conductive hydrogels: From properties to applications

Background:Myocardial infarction (MI) remains a leading cause of morbidity and mortality worldwide, necessitating advanced therapeutic strategies for cardiac repair. Conventional treatments often fail to restore cardiac function effectively, highlighting the need for innovative biomaterials. Smart bioactive hydrogels have emerged as promising candidates due to their ability to provide structural support, controlled drug delivery, electroconductivity, and real-time biosensing capabilities.Objective:This review explores the multifunctional role of smart bioactive hydrogels in MI repair, focusing on their stimuli-responsive drug delivery, electroconductive properties, and biosensing potential.Methods:This narrative review synthesized recent advances in multifunctional smart bioactive hydrogels for MI repair, focusing on systems integrating stimuli-responsive drug delivery, electroconductivity, and real-time biosensing. A comprehensive literature search was conducted in PubMed, Scopus, Web of Science, and Google Scholar for studies published between 2010 and 2025 using relevant keywords. Articles were included if they addressed hydrogel-based platforms featuring at least one of the following: responsive drug release (e.g., pH, temperature, and enzymatic), conductive components (e.g., carbon nanotubes and graphene), or embedded biosensing technologies. Studies limited to conventional hydrogels without multifunctionality were excluded. Relevant data were extracted and thematically categorized by material composition, functional properties, regenerative potential, and translational applicability, with emphasis on preclinical cardiac models. No quantitative synthesis was performed due to heterogeneity across study designs.Results:Smart bioactive hydrogels have demonstrated significant potential for MI repair by integrating stimuli-responsive drug delivery, electroconductivity, and biosensing within a single therapeutic platform. pH-, ROS-, and enzyme-sensitive systems enable localized, on-demand release of angiogenic factors or cardioprotective drugs, leading to 20–45% infarct size reduction and 1.5–2.3-fold increases in neovascular density in preclinical models. Incorporation of conductive materials such as graphene oxide (GO), polypyrrole, or carbon nanotubes (CNT) has been shown to restore electrical coupling, improve connexin-43 expression, and enhance left ventricular ejection fraction by 8–15%, while narrowing QRS complex duration by ~15 ms in large-animal studies. Emerging biosensing-enabled hydrogels permit real-time monitoring of local biochemical cues, such as pH, oxygen levels, and inflammatory cytokines, maintaining stable signal fidelity for up to 4 weeks without adverse tissue reactions. Advances in 3D/4D bioprinting now allow spatially patterned integration of these functionalities, enabling region-specific therapeutic release and conductivity optimization. Collectively, these multifunctional hydrogels exhibit superior regenerative outcomes compared to conventional scaffolds and hold strong translational promise, although variability in experimental design, lack of standardized endpoints, and limited long-term clinical data remain challenges to widespread adoption.Conclusion:Smart bioactive hydrogels represent a transformative approach in MI repair by combining structural support with multifunctional properties. Their ability to deliver therapeutics on demand, enhance electroconductivity, and enable real-time biosensing offers new possibilities for precision cardiac medicine.

Bioadhesive hydrogels of favorable tribological attributes have attracted intensive attention for their potential usage due to the large benefits they can bring to surgical critical care. We report an all-natural polymer-based and bilayer-integrated asymmetrical Janus hydrogel bioadhesive patch for efficient myocardial infarction (MI) repair. We developed a low-friction polyelectrolyte composite biohydrogel (Bio-PEC hydrogel), CA, using naturally occurring cationic chitosan quaternary ammonium salt (HACC) and anionic sodium hyaluronate (HA). We further developed a high-adhesion Bio-PEC hydrogel, TA@CA, by incorporating tannic acid (TA). Ultimately, we integrated them into a bilayer asymmetrical Janus hydrogel bioadhesive, CA|TA@CA, which exhibited excellent bulk mechanical properties and favorable one-sided adequate adhesion to myocardial tissue (fracture strength 0.98 MPa, fracture strain 330%, and interfacial toughness 50.87 J/m2). Additionally, the in vivo myocardial repair surgery using the CA|TA@CA Janus hydrogel has been shown to inhibit ventricular remodeling more effectively. Such CA|TA@CA Janus hydrogel bioadhesives may have high potential as medical patches for MI repair.

The goal of tissue engineering scaffolds is to simulate the physiological microenvironment, in which the electrical microenvironment is an important part. Hydrogel is an ideal material for tissue engineering scaffolds because of its soft, porous, water-bearing, and other extracellular matrix-like properties. However, the hydrogel matrix is usually not conductive and can hinder the communication of electrical signals between cells, which promotes researchers' attention to conductive hydrogels. Conductive hydrogels can promote the communication of electrical signals between cells and simulate the physiological microenvironment of electroactive tissues. Hydrogel formation is an important step for the application of hydrogels in tissue engineering. In situ forming of injectable hydrogels and customized forming of three-dimensional (3D) printing hydrogels represent two most potential advanced forming processes, respectively. In this review, we discuss (i) the classification, properties, and advantages of conductive hydrogels, (ii) the latest development of conductive hydrogels applied in myocardial, nerve, and bone tissue engineering, (iii) advanced forming processes, including injectable conductive hydrogels in situ and customized 3D printed conductive hydrogels, (iv) the challenges and opportunities of conductive hydrogels for tissue engineering. Impact Statement Biomimetic construction of electro-microenvironment is a challenge of tissue engineering. The development of conductive hydrogels provides possibility for the construction of biomimetic electro-microenvironment. However, the importance of conductive hydrogels in tissue engineering has not received enough attention so far. Herein, various conductive hydrogels and their tissue engineering applications are systematically reviewed. Two potential methods of conductive hydrogel forming, in situ forming of injectable conductive hydrogels and customized forming of three-dimensional printing conductive hydrogels, are introduced. The current challenges and future development directions of conductive hydrogels are comprehensively overviewed. This review provides a guideline for tissue engineering applications of conductive hydrogels.

Recent years, cardiac vascular disease has arisen owing to acute myocardial infarction (MI) and heart failure leading to death worldwide. Various treatments are available for MI in modern medicine such as implantation of devices, pharmaceutical therapy, and transplantation of organs, nonetheless, it has many complications in finding an organ donor, devices for stenosis, high intrusiveness and long-time hospitalization. To overcome these problems, we have designed and developed a novel hydrogel material with a combination of Se NPs loaded poly(ethylene glycol)/tannic acid (PEG/TA) hydrogel for the treatment of acute MI repair. Herein, Se NPs were characterized by effective analytical and spectroscopic techniques. In vitro cell compatibility and anti-oxidant analyses were examined on human cardiomyocytes in different concentrations of Se NPs and appropriate Se NPs loaded hydrogel samples to demonstrate its greater suitability for in vivo cardiac applications. In vivo investigations of MI mice models injected with Se hydrogels established that LV wall thickness was conserved significantly from the value of 235.6 µm to 390 µm. In addition, the relative scar thickness (33.6%) and infarct size (17.1%) of the MI model were enormously reduced after injection of Se hydrogel when compared to the Se NPs and control (MI) sample, respectively, which confirmed that Se introduced hydrogel have greatly influenced on the restoration of the infarcted heart. Based on the investigated results of the nanoformulation samples, it could be a promising material for future generations treatment of acute myocardial infarction and cardiac repair applications.

Mesenchymal stem cells encapsulated in a reactive oxygen species-scavenging and O2-generating injectable hydrogel for myocardial infarction treatment

To achieve synchronous repair and real-time monitoring the infarcted myocardium based on an integrated ion-conductive hydrogel patch is challenging yet intriguing. Herein, a novel synthetic strategy is reported based on core-shell-structured curcumin-nanocomposite-reinforced ion-conductive hydrogel for synchronous heart electrophysiological signal monitoring and infarcted heart repair. The nanoreinforcement and multisite cross-linking of bioactive curcumin nanoparticles enable well elasticity with negligible hysteresis, implantability, ultrahigh mechanoelectrical sensitivity (37ms), and reliable sensing capacity (over 3000 cycles) for the nanoreinforced hydrogel. Results of in vitro and in vivo experiments demonstrate that such solely physical microenvironment of electrophysiological and biomechanical characteristics combining with the role of bioactive curcumin exert the synchronous benefit of regulating inflammatory microenvironment, promoting angiogenesis, and reducing myocardial fibrosis for effective myocardial infarction (MI) repair. Especially, the hydrogel sensors offer the access for achieving accurate acquisition of cardiac signals, thus monitoring the whole MI healing process. This novel bioactive and electrophysiological-sensing ion-conductive hydrogel cardiac patch highlights a versatile strategy promising for synchronous integration of in vivo real-time monitoring the MI status and excellent MI repair performance.