Injectable Conductive Hydrogel Research Articles

Injectable conductive hydrogel remodeling microenvironment and mimicking neuroelectric signal transmission after spinal cord injury

Severe spinal cord injury (SCI) leads to dysregulated neuroinflammation and cell apoptosis, resulting in axonal die-back and the loss of neuroelectric signal transmission. While biocompatible hydrogels are commonly used in SCI repair, they lack the capacity to support neuroelectric transmission. To overcome this limitation, we developed an injectable silk fibroin/ionic liquid (SFMA@IL) conductive hydrogel to assist neuroelectric signal transmission after SCI in this study. The hydrogel can form rapidly in situ under ultraviolet (UV) light. The mechanical supporting and neuro-regenerating properties are provided by silk fibroin (SF), while the conductive capability is provided by the designed ionic liquid (IL). SFMA@IL showed attractive features for SCI repair, such as anti-swelling, conductivity, and injectability. In vivo, SFMA@IL hydrogel used in rats with complete transection injuries was found to remodel the microenvironment, reduce inflammation, and facilitate neuro-fiber outgrowth. The hydrogel also led to a notable decrease in cell apoptosis and the achievement of scar-free wound healing, which saved 45.6 ± 10.8 % of spinal cord tissue in SFMA@IL grafting. Electrophysiological studies in rats with complete transection SCI confirmed SFMA@IL's ability to support sensory neuroelectric transmission, providing strong evidence for its signal transmission function. These findings provide new insights for the development of effective SCI treatments.

Injectable Conductive Hydrogel with Self-Healing, Motion Monitoring, and Bacteria Theranostics for Bioelectronic Wound Dressing.

Wounds at joints are difficult to treat and tend to recover more slowly due to the frequent motions. When using traditional hydrogel dressings, they are easy to crack and undergo bacterial infection, difficult to match and monitor the irregular wounds. Integrating multiple functions within a hydrogel dressing to achieve intelligent wound monitoring and healing remains a significant challenge. In this research, a multifunctional hydrogel is developed based on polysaccharide biopolymer, poly(vinyl alcohol), and hydroxylated graphene through dynamic borate ester bonding and supramolecular interaction. The prepared hydrogel not only exhibits rapid self-healing (within 60 s), injectable, conductive and motion monitoring properties, but also realizes in situ bacterial sensing and killing functions. It shows excellent bacterial sensitivity (within 15 min) and killing ability via the changes of electrical signals and photothermal therapy, avoiding the emergence of drug-resistant bacteria. In vivo experiments prove that the hydrogel can promote wound healing effectively. In addition, it displays great electromechanical performance to achieve real-time monitoring and prevent re-tearing of the wound at human joints. The injectable pH-responsive hydrogel with good biocompatibility demonstrates considerable potential as multifunctional bioelectronic dressing for the detection, treatment, management, and healing of infected joint wounds.

Injectable MXene conductive hydrogel improves myocardial infarction through scavenging ROS and repairing myocardium electrical integrity

Myocardial infarction (MI) caused by ischemia and hypoxia microenvironment leads to irreversible death of cardiomyocytes, in which excessive oxidative stress plays a key role. Moreover, MI breaks the effective conduction of electrical signals in myocardial tissue, leading to cardiac systolic and diastolic dysfunction, and subsequently adverse ventricular remodeling. Therefore, scavenging reactive oxygen species (ROS) and repairing myocardium electrical integrity are two key issues in MI treatment. In this study, we embedded MXene nanosheets (Ti3C2) into temperature-sensitive extracellular matrix (ECM) hydrogels to prepare antioxidant/conductive hydrogels (E-MXene). E-MXene efficiently eliminated ROS in vitro, and improved calcium signaling synchronization of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) because of remarkable antioxidant and conductivity properties. Meanwhile, the upregulation of Connexin43(Cx43) confirmed that MXenes enhanced electrical conduction between hiPSC-CMs. The injection of E-MXene in the MI region of mice soon after surgery was found to reduce ROS and cardiomyocyte apoptosis in the early stage of MI, as well as enhanced the electrical signal transmission in infarcted tissue during the late stage of MI. The cardiac function and structure were improved 28 days post-MI. Therefore, the E-MXene combined ROS scavenging with tissue electrical integrity improvement, thus providing theoretical bases and new ideas for the treatment of MI.

Injectable Mesh-Like Conductive Hydrogel Patch for Elimination of Atrial Fibrillation.

Irregular electrical impulses in atrium are the leading cause of atrial fibrillation (AF), resulting in fatal arrhythmia and sudden cardiac death. Traditional medication and physical therapies are widely used, but generally suffer problems in serious physical damage and high surgical risks. Flexible and soft implants have great potential to be a novel approach for heart diseases therapy. A conductive hydrogel-based mesh cardiac patch is developed for application in AF elimination. The designed mesh patch with rhombic-shaped structure exhibits excellent flexibility, surface conformability, and deformation compliance, making it fit well with heart surface and accommodate to the deformation during heart beating. Moreover, the mechanical elastic and shape-memory properties of the mesh patch enable a minimally invasive injection of the patch into living animals. The mesh patch is implanted on the atrium surface for one month, indicating good biocompatibility and stability. Furthermore, the conductive patch can effectively eliminate AF owing to the conductivity and high charge storage capability (CSC) of the hydrogel. The proposed scheme of cardiac bioelectric signal modulation using conductive hydrogel brings new possibility for the treatment of arrhythmia diseases.

An injectable conductive hydrogel with dual responsive release of rosmarinic acid improves cardiac function and promotes repair after myocardial infarction.

Myocardial infarction (MI) causes irreversible damage to the heart muscle, seriously threatening the lives of patients. Injectable hydrogels have attracted extensive attention in the treatment of MI. By promoting the coupling of mechanical and electrical signals between cardiomyocytes, combined with synergistic therapeutic strategies targeting the pathological processes of inflammation, proliferation, and fibrotic remodeling after MI, it is expected to improve the therapeutic effect. In this study, a pH/ROS dual-responsive injectable hydrogel was developed by modifying xanthan gum and gelatin with reversible imine bond and boronic ester bond double crosslinking. By encapsulating polydopamine-rosmarinic acid nanoparticles to achieve on-demand drug release in response to the microenvironment of MI, thereby exerting anti-inflammatory, anti-apoptotic, and anti-fibrosis effects. By adding conductive composites to improve the conductivity and mechanical strength of the hydrogel, restore electrical signal transmission in the infarct area, promote synchronous contraction of cardiomyocytes, avoid induced arrhythmias, and induce angiogenesis. Furthermore, the multifunctional hydrogel promoted the expression of cardiac-specific markers to restore cardiac function after MI. The in vivo and in vitro results demonstrate the effectiveness of this synergistic comprehensive treatment strategy in MI treatment, showing great application potential to promote the repair of infarcted hearts.

The effect of conductive aligned fibers in an injectable hydrogel on nerve tissue regeneration

Injectable hydrogels are a promising treatment option for nervous system injuries due to the difficulty to replace lost cells and nervous factors but research on injectable conductive hydrogels is limited and these scaffolds have poor electromechanical properties. This study developed a chitosan/beta-glycerophosphate/salt hydrogel and added conductive aligned nanofibers (polycaprolactone/gelatin/single-wall carbon nanotube (SWCNT)) for the first time and inspired by natural nerve tissue to improve their biochemical and biophysical properties. The results showed that the degradation rate of hydrogels is proportional to the regrowth of axons and these hydrogels’ mechanical (hydrogels without nanofibers or SWCNTs and hydrogels containing these additions have the same Young's modulus as the brain and spinal cord or peripheral nerves, respectively) and electrical properties, and the interconnective structure of the scaffolds have the ability to support cells.

Injectable Conductive Hydrogel Containing Black Phosphorus Nanosheets Inhibits the Oxidative Stress-Inflammation Chain during Myocardial Infarction

Injectable Conductive Hydrogel Containing Black Phosphorus Nanosheets Inhibits the Oxidative Stress-Inflammation Chain during Myocardial Infarction

Spider-web inspired self-healing, adhesive, injectable conductive hydrogel for human motion monitoring and shape recognition

Conductive hydrogels have received significant attention in fabricating wearable strain sensors, electronic skins, and human-machine interface applications, but suffer the poor cycling capacity and hard to be applied in complex sensing applications. Herein a spider web-inspired poly (stearyl methacrylate-co-acrylic acid) and polyvinyl alcohol interpenetrating network conductive hydrogel was synthesized via one-step in-situ polymerization to address these challenges aforementioned. The as-obtained hydrogels exhibit good mechanical strength (111 kPa stress), high stretchability (1029% strain), strong adhesiveness, high conductivity, injectability, and rapid self-healing performance (the healing efficiency of 87.3% at room temperature within 4 h). Attributing to excellent self-healing properties, the hydrogels were easily reprocessed four times at room temperature without losing their intrinsic characteristics. Additionally, high strain sensitivity (GF = 4.28 in the wide strain-sensing range 1–500%) and real time monitoring large/tiny human motions have been also realized. Most importantly, a assembled sensing array has been demonstrated via the injectable behaviour to detect the mass and contact shape of the target We believe that this study will definitely broaden the practical applications of a new generation of hydrogel-based wearable strain sensor.

Injectable polyaniline nanorods/alginate hydrogel with AAV9-mediated VEGF overexpression for myocardial infarction treatment

Intramyocardial injection of hydrogels possesses great potential in the minimally invasive treatment of myocardial infarction (MI), but the current injectable hydrogels lack conductivity, long-term angiogenesis inductive ability, and reactive oxygen species (ROS)-scavenging ability, which are essential for myocardium repair. In this study, lignosulfonate-doped polyaniline (PANI/LS) nanorods and adeno-associated virus encoding vascular endothelial growth factor (AAV9-VEGF) are incorporated in the calcium-crosslinked alginate hydrogel to develop an injectable conductive hydrogel with excellent antioxidative and angiogenic ability (Alg-P-AAV hydrogel). Due to the special nanorod morphology, a conductive network is constructed in the hydrogel with the conductivity matching the native myocardium for excitation conduction. The PANI/LS nanorod network may also have large specific surfaces and effectively scavenges ROS to protect cardiomyocytes from oxidative stress damage. AAV9-VEGF transfects the surrounding cardiomyocytes for continuously expressing VEGF, which significantly promotes the proliferation, migration and tube formation of endothelial cells. After injecting the Alg-P-AAV hydrogel around the MI area in rats, the generation of gap junctions and angiogenesis are greatly improved with reduced infarct area and recovered cardiac function. The remarkable therapeutic effect indicates the promising potential of this multi-functional hydrogel for MI treatment.

Worldwide productivity and research trend of publications concerning electroactive materials and spinal cord injury: A bibliometric study.

Purpose: We investigated the current state and trends in the area during the previous 10years using bibliometric approaches to evaluate the global scientific output of research on electroactive materials and spinal cord injury. Methods: Studies on spinal cord injury in electroactive materials that were published between 2012 and 2022 were located using the Web of science (WOS) datebase. The software programs bibliometrix R-package and CiteSpace were used to do quantitative analyses of annual publications, nation, author, institution, journal source, co-cited references, and keywords. The studies were categorized by the research's main points using a qualitative analysis, and publications having more than 10 citations each year. Results: In the final analysis, 1,330 relevant papers or reviews were included. There is an increased tendency in both the average annual citation rate and the number of publications in the discipline. The United States and the University of Toronto are the countries and institutions that have contributed the most to this discipline, respectively. The majority of authors are from the China and United States. Zhang Y is the author with the most published articles and holds the top position in the cited author h-index species. The journal with the highest number of published articles is "Disability and rehabilitation"; the journal is divided into four main areas including physics, materials, chemistry, molecular, and biology. The keyword analysis revealed a shift in research hotspots from schwann cell, fracture, and urinary disorders to carbon-based materials, functional recovery, and surgery. Analysis of qualitative data revealed that the role and mechanism of injectable conductive hydrogels in spinal cord healing after damage is a hot topic of current study, with the mechanism primarily focusing on the inhibition of oxidative stress (Nrf2) and apoptosis (Casepase 3). Conclusion: Our bibliometric analysis indicates that research on electroactive materials for spinal cord injury remains an active field of study. Moreover, contemporary research is concentrated on carbon-based materials, functional rehabilitation, and surgery.

Injectable Conductive Hydrogels with Tunable Degradability as Novel Implantable Bioelectrodes.

Bioelectrodes have been developed to efficiently mediate electrical signals of biological systems as stimulators and recording devices. Recently, conductive hydrogels have garnered great attention as emerging materials for bioelectrode applications because they can permit intimate/conformal contact with living tissues and tissue-like softness. However, administration and control over the in vivo lifetime of bioelectrodes remain challenges. Here, injectable conductive hydrogels(ICHs) with tunable degradability as implantable bioelectrodes are developed. ICHswereconstructed via thiol-ene reactions using poly(ethylene glycol)-tetrathiol and thiol-functionalized reduced graphene oxide with either hydrolyzable poly(ethylene glycol)-diacrylate or stable poly(ethylene glycol)-dimaleimide, the resultant hydrogels of which are degradable and nondegradable, respectively. The ICH electrodeshadconductivities of 21-22 mS cm-1 and Young's moduli of 15-17kPa, and showed excellent cell and tissue compatibility. The hydrolyzable conductive hydrogels disappeared 3 days after in vivo administration, while the stable conductive hydrogels maintained their shapes for up to 7 days.Ourproof-of-concept studies reveal that electromyography signals with significantly improved sensitivity from rats could be obtained from the injected ICH electrodes compared to skin electrodes and injected nonconductive hydrogel electrodes. The ICHs, offering convenience in use, controllable degradation and excellent signal transmission, will have great potential to develop various bioelectronics devices.

Injectable and tissue-conformable conductive hydrogel for MRI-compatible brain-interfacing electrodes

The development of flexible and stretchable materials has led to advances in implantable bio-integrated electronic devices that can sense physiological signals or deliver electrical stimulation to various organs in the human body. Such devices are particularly useful for neural interfacing systems that monitor neurodegenerative diseases such as Parkinson’s disease or epilepsy in real time. However, coupling current brain-interfacing devices with magnetic resonance imaging (MRI) remains a practical challenge due to resonance frequency variations from inorganic metal-based devices. Thus, organic conductive materials, such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), have recently been considered as promising candidates. Nonetheless, their conformability on curvilinear tissues remains questionable. In this study, we developed an injectable conductive hydrogel (ICH) composed of tyramine-conjugated hyaluronic acid (HATYR) and PEDOT:PSS for MRI-compatible brain-interfacing electrodes. Our ICH produced low impedance around 5 kΩ even under 10 Hz, demonstrating high confidence volumetric capacitance. Due to HATYR’s biocompatibility, histological and cytotoxicity assays showed almost no inflammation and toxicity, respectively; in addition, ICH was able to degrade into 40% of its original volume within four weeks in vivo. An electrocorticogram (ECoG) array was also patternable by syringe injections of ICH on a stretchable and flexible elastomeric substrate layer that conformed to curvy brain tissues and successfully recorded ECoG signals under light stimulation. Furthermore, MRI imaging of implanted devices did not show any artifacts, indicating the potential of the MRI-compatible hydrogel electrodes for advanced ECoG arrays. This study provides a promising solution for MRI-compatible neural electrodes, enabling the advancement of chronic neural interfacing systems for monitoring neurodegenerative diseases.

Graphene oxide-based injectable conductive hydrogel dressing with immunomodulatory for chronic infected diabetic wounds

The main challenges of chronic wounds represented by diabetic wounds are that the infection is not easily controlled and the healing is difficult, mainly due to the high-glucose microenvironment, M1 macrophage aggregation, and persistent inflammation. Previous studies inspired by endogenous electric fields have demonstrated that conductive materials can promote cell proliferation, migration, etc., to promote wound healing. However, no study has been conducted on the effect of conductive materials on local immunity. To this end, this study designed a graphene oxide-based conductive hydrogel to repair infected diabetic wounds. Self-healing injectable conductive hydrogels were synthesized by dynamic Schiff-base reaction and electrostatic interactions between oxidized hyaluronic acid, N-carboxyethyl chitosan, graphene oxide, and polymyxin B. The study found that the hydrogel has good biocompatibility and antibacterial properties. In addition, in vivo experiments confirmed that the hydrogel could modulate macrophage polarization to improve the local inflammatory microenvironment, promote neovascularization, and significantly accelerate the healing of diabetic wounds. Most notably, graphene oxide-based conductive hydrogels can modulate local immunity in diabetic wounds to promote healing. This study provides new guidelines for expanding research on conductive materials and new directions for promoting healing in infected diabetic wounds.

An injectable conductive hydrogel restores electrical transmission at myocardial infarct site to preserve cardiac function and enhance repair.

Myocardial infarction (MI) leads to massive cardiomyocyte death and deposition of collagen fibers. This fibrous tissue disrupts electrical signaling in the myocardium, leading to cardiac systolic and diastolic dysfunction, as well as arrhythmias. Conductive hydrogels are a promising therapeutic strategy for MI. Here, we prepared a highly water-soluble conductive material (GP) by grafting polypyrrole (PPy) onto non-conductive gelatin. This component was added to the gel system formed by the Schiff base reaction between oxidized xanthan gum (OXG) and gelatin to construct an injectable conductive hydrogel. The prepared self-healing OGGP3 (3 wt% GP) hydrogel had good biocompatibility, elastic modulus, and electrical conductivity that matched the natural heart. The prepared biomaterials were injected into the rat myocardial scar tissue 2 days after MI. We found that the cardiac function of the rats treated with OGGP3 was improved, making it more difficult to induce arrhythmias. The electrical resistivity of myocardial fibrous tissue was reduced, and the conduction velocity of myocardial tissue was increased. Histological analysis showed reduced infarct size, increased left ventricular wall thickness, increased vessel density, and decreased inflammatory response in the infarcted area. Our findings clearly demonstrate that the OGGP3 hydrogel attenuates ventricular remodeling and inhibits infarct dilation, thus showing its potential for the treatment of MI.

Conductive nanocomposite hydrogel and mesenchymal stem cells for the treatment of myocardial infarction and non-invasive monitoring via PET/CT.

BackgroundInjectable hydrogels have great promise in the treatment of myocardial infarction (MI); however, the lack of electromechanical coupling of the hydrogel to the host myocardial tissue and the inability to monitor the implantation may compromise a successful treatment. The introduction of conductive biomaterials and mesenchymal stem cells (MSCs) may solve the problem of electromechanical coupling and they have been used to treat MI. In this study, we developed an injectable conductive nanocomposite hydrogel (GNR@SN/Gel) fabricated by gold nanorods (GNRs), synthetic silicate nanoplatelets (SNs), and poly(lactide-co-glycolide)-b-poly (ethylene glycol)-b-poly(lactide-co-glycolide) (PLGA-PEG-PLGA). The hydrogel was used to encapsulate MSCs and 68Ga3+ cations, and was then injected into the myocardium of MI rats to monitor the initial hydrogel placement and to study the therapeutic effect via 18F-FDG myocardial PET imaging.ResultsOur data showed that SNs can act as a sterically stabilized protective shield for GNRs, and that mixing SNs with GNRs yields uniformly dispersed and stabilized GNR dispersions (GNR@SN) that meet the requirements of conductive nanofillers. We successfully constructed a thermosensitive conductive nanocomposite hydrogel by crosslinking GNR@SN with PLGA2000-PEG3400-PLGA2000, where SNs support the proliferation of MSCs. The cation-exchange capability of SNs was used to adsorb 68Ga3+ to locate the implanted hydrogel in myocardium via PET/CT. The combination of MSCs and the conductive hydrogel had a protective effect on both myocardial viability and cardiac function in MI rats compared with controls, as revealed by 18F-FDG myocardial PET imaging in early and late stages and ultrasound; this was further validated by histopathological investigations.ConclusionsThe combination of MSCs and the GNR@SN/Gel conductive nanocomposite hydrogel offers a promising strategy for MI treatment.Graphical Supplementary InformationThe online version contains supplementary material available at 10.1186/s12951-022-01432-7.

Injectable conductive and angiogenic hydrogels for chronic diabetic wound treatment

Chronic diabetic wounds are lack of angiogenesis and susceptible to bacterial infections due to their high sugar microenvironment, making them difficult to heal. Here, a conductive and intrinsically antibacterial hydrogel with pH responsiveness has been developed. This hydrogel has good mechanical properties, self-healing ability and biocompatibility, and can smartly release the pro-angiogenic drug, deferoxamine. Application of the hydrogel promotes the proliferation and migration of endothelial cells and enhances vascularization by upregulating the expression of hypoxia-inducible factor-1α and vascular endothelial growth factor. The hydrogel dressing combined with electrical stimulation improves angiogenesis and significantly accelerates the healing of infected diabetic wounds, which would lead to a promising therapeutic strategy.

Graphene Oxide-Based Injectable Conductive Hydrogel Dressing with Immunomodulatory for Chronic Infected Diabetic Wounds

Graphene Oxide-Based Injectable Conductive Hydrogel Dressing with Immunomodulatory for Chronic Infected Diabetic Wounds

Restoring Cardiac Functions after Myocardial Infarction-Ischemia/Reperfusion via an Exosome Anchoring Conductive Hydrogel.

Both myocardial infarction (MI) and the follow-up reperfusion will lead to an inevitable injury to myocardial tissues, such as cardiac dysfunctions, fibrosis, and reduction of intercellular cell-to-cell interactions. Recently, exosomes (Exo) derived from stem cells have demonstrated a robust capability to promote angiogenesis and tissue repair. However, the short half-life of Exo and rapid clearance lead to insufficient therapeutic doses in the lesion area. Herein, an injectable conductive hydrogel is constructed to bind Exo derived from human umbilical cord mesenchymal stem cells to treat myocardial injuries after myocardial infarction-ischemia/reperfusion (MI-I/R). To this end, a hyperbranched epoxy macromer (EHBPE) grafted by an aniline tetramer (AT) was synthesized to cross-link thiolated hyaluronic acid (HA-SH) and thiolated Exo anchoring a CP05 peptide via an epoxy/thiol "click" reaction. The resulting Gel@Exo composite system possesses multiple features, such as controllable gelation kinetics, shear-thinning injectability, conductivity matching the native myocardium, soft and dynamic stability adapting to heartbeats, and excellent cytocompatibility. After being injected into injured hearts of rats, the hydrogel effectively prolongs the retention of Exo in the ischemic myocardium. The cardiac functions have been considerably improved by Gel@Exo administration, as indicated by the enhancing ejection fraction and fractional shortening, and reducing fibrosis area. Immunofluorescence staining and reverse transcription-polymerase chain reaction (RT-PCR) results demonstrate that the expression of cardiac-related proteins (Cx43, Ki67, CD31, and α-SMA) and genes (VEGF-A, VEGF-B, vWF, TGF-β1, MMP-9, and Serca2a) are remarkably upregulated. The conductive Gel@Exo system can significantly improve cell-to-cell interactions, promote cell proliferation and angiogenesis, and result in a prominent therapeutic effect on MI-I/R, providing a promising therapeutic method for injured myocardial tissues.

Engineering conductive antioxidative antibacterial nanocomposite hydrogel scaffolds with oriented channels promotes structure-functional skeletal muscle regeneration

It remains a challenge for the structure–function regeneration of volumetric skeletal muscle loss, in addition to the conservative treatment. Herein, we report an injectable conductive antioxidant antibacterial nanocomposite hydrogel scaffolds for the structural and functional regeneration of full-thickness skeletal muscle tissues. The nanocomposites hydrogel scaffolds (FPAu) were fabricated through the double crosslinking of F127-CHO network using ultrasmall gold@polymine nanoparticles and polydopamine nanoparticles. FPAu hydrogel scaffolds showed the good antioxidant activity, antibacterial ability, electroconductive activity and well-ordered porous structure, which significantly upregulated the myogenic genes and myosin heavy chain (MHC) protein expression of C2C12 myoblasts, as well as the myotube formation in vitro. Importantly, by a rat tibialis anterior muscle defect model, FPAu scaffolds facilitated the skeletal muscle tissue formation, restored the mechanical and electrophysiological functions of skeletal muscle tissues. This work suggests that engineering the injectable conductive antioxidant scaffolds with good porous structure is a promising strategy for in situ muscle tissue engineering.

One zwitterionic injectable hydrogel with ion conductivity enables efficient restoration of cardiac function after myocardial infarction

An injectable zwitterionic polymer with an intrinsic ionic conductivity prepared from Michael addition reaction between acrylate-modified carboxybetaine macromonomer and DTT demonstrates an anti-oxidant/anti-inflammatory, vascularization-promoting activity. The betaine can down-regulate homocysteine level and its ever under-exploited conductivity is harnessed to facilitate transmission of electrical signal. • A polyzwitterion hydrogel is prepared via in situ Michael addition reaction. • This hydrogel is capable of promoting angiogenesis and suppressing fibrosis. • The conductivity of polyzwitterion is explored to treat MI for the first time. Conventional strategies for constructing an injectable conductive hydrogel for treatment of myocardial infarction (MI) are mostly involved with complicated bioactive modification and incorporation of external conductive materials or cells/therapeutic drugs, severely restraining its medical translation. Herein, a cell-free and therapeutic drug-free injectable zwitterionic hydrogel is fabricated by thiol-acrylate Michael addition reaction between acrylate modified polycarboxybetaine macromonomer and dithiothreitol (DTT), where the free DTT and the tethered-DTT endow the hydrogel with an antioxidant ability. The zwitterionic hydrogel is optimized to exhibit an appropriate gelation time and injectability. Intriguingly, the cation-anion ion pair on the side chain affords an intrinsic conductive property similar to the native myocardium. After injection into the infarcted region of rats, the hydrogel can downregulate level of inflammatory factors, and upregulate the expressions of cardiac-related factors, angiogenic factors, and transmission electrical signal-relevant Cx-43, accompanied by suppression of oxidant stress and cardiac fibrosis and increased vessel density, supposedly due to inherent antifouling, vascularization-promoting and conductive properties. Echocardiography and histological analyses demonstrate a remarkable improvement of the functions and structure of infarcted myocardium in rats in terms of 2.17/2.80-fold increase in ejection fraction/fractional shortening, 3.62-fold decline in end-systolic volume, and 2.39-fold decrease in fibrosis area, compared to MI group. This cell-free and therapeutic drug-free injectable zwitterionic hydrogel represents a new approach to seek a simplified but holistic biomaterial for treating myocardial infarction.