Wet adhesive hydrogel cardiac patch loaded with anti-oxidative, autophagy-regulating molecule capsules and MSCs for restoring infarcted myocardium

Bibliometrics of trends in global research on the roles of stem cells in myocardial fibrosis therapy

BACKGROUND

Myocardial fibrosis, a condition linked to several cardiovascular diseases, is associated with a poor prognosis. Stem cell therapy has emerged as a potential treatment option and the application of stem cell therapy has been studied extensively. However, a comprehensive bibliometric analysis of these studies has yet to be conducted.

AIM

To map thematic trends, analyze research hotspots, and project future directions of stem cell-based myocardial fibrosis therapy.

METHODS

We conducted a bibliometric and visual analysis of studies in the Web of Science Core Collection using VOSviewer and Microsoft Excel. The dataset included 1510 articles published between 2001 and 2024. Countries, organizations, authors, references, keywords, and co-citation networks were examined to identify evolving research trends.

RESULTS

Our findings revealed a steady increase in the number of publications, with a projected increase to over 200 publications annually by 2030. Initial research focused on stem cell-based therapy, particularly for myocardial infarction and heart failure. More recently, there has been a shift toward cell-free therapy, involving extracellular vesicles, exosomes, and microRNAs. Key research topics include angiogenesis, inflammation, apoptosis, autophagy, and oxidative stress.

CONCLUSION

This analysis highlights the evolution of stem cell therapies for myocardial fibrosis, with emerging interest in cell-free approaches. These results are expected to guide future scientific exploration and decision-making.

Stem Cell-Laden Engineered Patch: Advances and Applications in Tissue Regeneration

Stem cell-based therapies are emerging as significant approaches in tissue engineering and regenerative medicine, applicable to both fundamental scientific research and clinical practice. Despite remarkable results in clinical studies, challenges such as poor standardization of graft tissues, limited sources, and reduced functionality have hindered the effectiveness of these therapies. In this review, we summarize the engineering approaches involved in fabricating stem cell assisted patches and the substantial strategies for designing stem cell-laden engineered patches (SCP) to complement the existing stem cell-based therapies. We then outline the potential applications of SCP in advancing tissue regeneration and regenerative medicine. By combining living stem cells with engineered patches, SCP can enhance the functions of both components, particularly for tissue engineering applications. Finally, we addressed current challenges, such as ethical considerations, high costs, and regulatory hurdles and proposed future research directions to overcome these barriers.

A Multifunctional Anisotropic Patch Manufactured by Microfluidic Manipulation for the Repair of Infarcted Myocardium

Engineered hydrogel patches have shown promising therapeutic effects in the treatment of myocardial infarction (MI), especially anisotropic patches that mimic the characteristics of native myocardium have attracted widespread attention. However, it remains a great challenge to develop cardiac patches with long-range and orderly electrical conduction based on an effective, mild, and rapid strategy. Here, a multifunctional anisotropic cardiac patch is presented based on microfluidic manipulation. The anisotropic alginate-gelatin methacrylate hydrogel patches are easily and rapidly prepared through microfluidic focusing, ion-photocrosslinking, and parallel packing processes. The fluid-based anisotropic realization process does not involve complex machining and strong field stimulation and is compatible with the loading of macromolecular biological agents. The anisotropic hydrogel patch can mimic the anisotropy of the myocardium and guide the directional polarization of cardiomyocytes. In animal model experiments, it also exhibits significant effects in inhibiting ventricular remodeling, fibrosis, and enhancing cardiac function recovery after MI. These comprehensive features make the multifunctional hydrogel patch a promising candidate for cardiac tissue repair and future provide a new paradigm for expanding microfluidic technology to solve tissue engineering challenges.

Autophagy accompanying the developmental process of male germline stem cells

Germline stem cells are a crucial type of stem cell that can stably pass on genetic information to the next generation, providing the necessary foundation for the reproduction and survival of organisms. Male mammalian germline stem cells are unique cell types that include primordial germ cells and spermatogonial stem cells. They can differentiate into germ cells, such as sperm and eggs, thereby facilitating offspring reproduction. In addition, they continuously generate stem cells through self-renewal mechanisms to support the normal function of the reproductive system. Autophagy involves the use of lysosomes to degrade proteins and organelles that are regulated by relevant genes. This process plays an important role in maintaining the homeostasis of germline stem cells and the synthesis, degradation, and recycling of germline stem cell products. Recently, the developmental regulatory mechanism of germline stem cells has been further elucidated, and autophagy has been shown to be involved in the regulation of self-renewal and differentiation of germline stem cells. In this review, we introduce autophagy accompanying the development of germline stem cells, focusing on the autophagy process accompanying the development of male spermatogonial stem cells and the roles of related genes and proteins. We also briefly outline the effects of autophagy dysfunction on germline stem cells and reproduction.

Genetically modified mesenchymal stromal cells: a cell-based therapy offering more efficient repair after myocardial infarction

Myocardial infarction (MI) is a serious complication of coronary artery disease. This condition is common worldwide and has a profound impact on patients' lives and quality of life. Despite significant advances in the treatment of heart disease in modern medicine, the efficient treatment of MI still faces a number of challenges. Problems such as scar formation and loss of myocardial function after a heart attack still limit patients' recovery. Therefore, the search for a new therapeutic tool that can promote repair and regeneration of myocardial tissue has become crucial. In this context, mesenchymal stromal cells (MSCs) have attracted much attention as a potential therapeutic tool. MSCs are a class of adult stem cells with multidirectional differentiation potential, derived from bone marrow, fat, placenta and other tissues, and possessing properties such as self-renewal and immunomodulation. The application of MSCs may provide a new direction for the treatment of MI. These stem cells have the potential to differentiate into cardiomyocytes and vascular endothelial cells in damaged tissue and to repair and protect myocardial tissue through anti-inflammatory, anti-fibrotic and pro-neovascularization mechanisms. However, the clinical results of MSCs transplantation for the treatment of MI are less satisfactory due to the limitations of the native function of MSCs. Genetic modification has overcome problems such as the low survival rate of transplanted MSCs in vivo and enhanced their functions of promoting neovascularization and differentiation into cardiomyocytes, paving the way for them to become an effective tool for repair therapy after MI. In previous studies, MSCs have shown some therapeutic potential in experimental animals and preliminary clinical trials. This review aims to provide readers with a comprehensive and in-depth understanding to promote the wider application of engineering MSCs in the field of MI therapy, offering new hope for recovery and improved survival of cardiac patients.

Advances in Functionalized Hydrogels in the Treatment of Myocardial Infarction and Drug-Delivery Strategies

Myocardial infarction (MI) is a serious cardiovascular disease with high morbidity and mortality rates, posing a significant threat to patient's health and quality of life. Following a MI, the damaged myocardial tissue is typically not fully repaired, leading to permanent impairment of myocardial function. While traditional treatments can alleviate symptoms and reduce pain, their ability to repair damaged heart muscle tissue is limited. Functionalized hydrogels, a broad category of materials with diverse functionalities, can enhance the properties of hydrogels to cater to the needs of tissue engineering, drug delivery, medical dressings, and other applications. Recently, functionalized hydrogels have emerged as a promising new therapeutic approach for the treatment of MI. Functionalized hydrogels possess outstanding biocompatibility, customizable mechanical properties, and drug-release capabilities. These properties enable them to offer scaffold support, drug release, and tissue regeneration promotion, making them a promising approach for treating MI. This paper aims to evaluate the advancements and delivery methods of functionalized hydrogels for treating MI, while also discussing their potential and the challenges they may pose for future clinical use.

Advanced Cardiac Patches for the Treatment of Myocardial Infarction

Myocardial infarction is a cardiovascular disease characterized by a high incidence rate and mortality. It leads to various cardiac pathophysiological changes, including ischemia/reperfusion injury, inflammation, fibrosis, and ventricular remodeling, which ultimately result in heart failure and pose a significant threat to global health. Although clinical reperfusion therapies and conventional pharmacological interventions improve emergency survival rates and short-term prognoses, they are still limited in providing long-lasting improvements in cardiac function or reversing pathological progression. Recently, cardiac patches have gained considerable attention as a promising therapy for myocardial infarction. These patches consist of scaffolds or loaded therapeutic agents that provide mechanical reinforcement, synchronous electrical conduction, and localized delivery within the infarct zone to promote cardiac restoration. This review elucidates the pathophysiological progression from myocardial infarction to heart failure, highlighting therapeutic targets and various cardiac patches. The review considers the primary scaffold materials, including synthetic, natural, and conductive materials, and the prevalent fabrication techniques and optimal properties of the patch, as well as advanced delivery strategies. Last, the current limitations and prospects of cardiac patch research are considered, with the goal of shedding light on innovative products poised for clinical application.

Dough-Kneading-Inspired Design of an Adhesive Cardiac Patch to Attenuate Cardiac Fibrosis and Improve Cardiac Function via Regulating Glycometabolism

Recently, hydrogel adhesive patches have been explored for treating myocardial infarction. However, achieving secure adhesion onto the wet beating heart and local regulation of pathological microenvironment remains challenging. Herein, a dough-kneading-inspired design of hydrogel adhesive cardiac patch is reported, aiming to improve the strength of prevalent powder-formed patch and retain wet adhesion. In mimicking the polysaccharide and protein components of natural flour, methacrylated polyglutamic acid (PGAMA) is electrostatically interacted with hydroxypropyl chitosan (HPCS) to form PGAMA/HPCS coacervate hydrogel. The PGAMA/HPCS hydrogel is freeze-dried and ground into powders, which are further rehydrated with two aqueous solutions of functional drug, 3-acrylamido phenylboronic acid (APBA)/rutin (Rt) complexes for protecting the myocardium from advanced glycation end product (AGEs) injury by reactive oxygen species (ROS) -responsive Rt release, and hypoxanthine-loaded methacrylated hyaluronic acid (HAMA) nanogels for enhancing macrophage targeting ability to regulate glycometabolism for combating inflammation. The rehydrated powders bearing APBA/Rt complexes and HAMA-hypoxanthine nanogels are repeatedly kneaded into a dough-like gel, which is further subjected to thermal-initiated crosslinking to form a stabilized and sticky patch. This biofunctional patch is applied onto the rats' infarcted myocardium, and the outcomes at 28 days post-surgery indicate efficient restoration of cardiac functions and attenuation of cardiac fibrosis.

A cigarette filter-derived biomimetic cardiac niche for myocardial infarction repair

Cell implantation offers an appealing avenue for heart repair after myocardial infarction (MI). Nevertheless, the implanted cells are subjected to the aberrant myocardial niche, which inhibits cell survival and maturation, posing significant challenges to the ultimate therapeutic outcome. The functional cardiac patches (CPs) have been proved to construct an elastic conductive, antioxidative, and angiogenic microenvironment for rectifying the aberrant microenvironment of the infarcted myocardium. More importantly, inducing implanted cardiomyocytes (CMs) adapted to the anisotropic arrangement of myocardial tissue by bioengineered structural cues within CPs are more conducive to MI repair. Herein, a functional Cig/(TA-Cu) CP served as biomimetic cardiac niche was fabricated based on structural anisotropic cigarette filter by modifying with tannic acid (TA)-chelated Cu2+ (TA-Cu complex) via a green method. This CP possessed microstructural anisotropy, electrical conductivity and mechanical properties similar to natural myocardium, which could promote elongation, orientation, maturation, and functionalization of CMs. Besides, the Cig/(TA-Cu) CP could efficiently scavenge reactive oxygen species, reduce CM apoptosis, ultimately facilitating myocardial electrical integration, promoting vascular regeneration and improving cardiac function. Together, our study introduces a functional CP that integrates multimodal cues to create a biomimetic cardiac niche and provides an effective strategy for cardiac repair.

3D Printed Conductive Hydrogel Patch Incorporated with MSC@GO for Efficient Myocardial Infarction Repair

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.

Hydrogel-based cardiac repair and regeneration function in the treatment of myocardial infarction

A life-threatening illness that poses a serious threat to human health is myocardial infarction. It may result in a significant number of myocardial cells dying, dilated left ventricles, dysfunctional heart function, and ultimately cardiac failure. Based on the development of emerging biomaterials and the lack of clinical treatment methods and cardiac donors for myocardial infarction, hydrogels with good compatibility have been gradually applied to the treatment of myocardial infarction. Specifically, based on the three processes of pathophysiology of myocardial infarction, we summarized various types of hydrogels designed for myocardial tissue engineering in recent years, including natural hydrogels, intelligent hydrogels, growth factors, stem cells, and microRNA-loaded hydrogels. In addition, we also describe the heart patch and preparation techniques that promote the repair of MI heart function. Although most of these hydrogels are still in the preclinical research stage and lack of clinical trials, they have great potential for further application in the future. It is expected that this review will improve our knowledge of and offer fresh approaches to treating myocardial infarction.

Transplantation of Stem Cell Spheroid-Laden 3-Dimensional Patches with Bioadhesives for the Treatment of Myocardial Infarction

Myocardial infarction (MI) is treated with stem cell transplantation using various biomaterials and methods, such as stem cell/spheroid injections, cell sheets, and cardiac patches. However, current treatment methods have some limitations, including low stem cell engraftment and poor therapeutic effects. Furthermore, these methods cause secondary damage to heart due to injection and suturing to immobilize them in the heart, inducing side effects. In this study, we developed stem cell spheroid-laden 3-dimensional (3D) patches (S_3DP) with biosealant to treat MI. This 3D patch has dual modules, such as open pockets to directly deliver the spheroids with their paracrine effects and closed pockets to improve the engraft rate by protecting the spheroid from harsh microenvironments. The spheroids formed within S_3DP showed increased viability and expression of angiogenic factors compared to 2-dimensional cultured cells. We also fabricated gelatin-based tissue adhesive biosealants via a thiol-ene reaction and disulfide bond formation. This biosealant showed stronger tissue adhesiveness than commercial fibrin glue. Furthermore, we successfully applied S_3DP using a biosealant in a rat MI model without suturing in vivo, thereby improving cardiac function and reducing heart fibrosis. In summary, S_3DP and biosealant have excellent potential as advanced stem cell therapies with a sutureless approach to MI treatment.

Platelet Membrane-Encapsulated Nanocomplexes Based on Profundity Scavenging ROS Strategy for Myocardial Infarction Therapy

Ischemia-induced myocardial injury has become a serious threat to human health, and its treatment remains a challenge. The occurrence of ischemic events leads to a burst release of reactive oxygen species (ROS), which triggers extensive oxidative damage and leads to dysfunctional autophagy, making it difficult for cells to maintain homeostasis. Antioxidants and modulation of autophagy have thus become promising strategies for the treatment of ischemic myocardial injury. This study proposes an antioxidant-activated autophagy therapeutic regimen based on combining melanin (Mel), an excellent antioxidant with metformin mimetic ploymetformin via electrostatic interactions, to obtain a nanocomplex (Met-Mel). The nanocomplex is finally encapsulated with platelet membranes (PMN) to construct a biomimetic nanoparticle (PMN@Met-Mel) capable of targeting injured myocardium. The prepared PMN@Met-Mel has good Mel loading capacity and optimal biosafety. It exhibits excellent antioxidant activity and autophagy activation, rapidly restoring mitochondrial function. Moreover, RNA sequencing (RNA-seq) analysis reveals that PMN@Met-Mel operates mechanistically by triggering the activation of the autophagy pathway. Subsequent in vivo experiments showcase promising cardioprotective effects of these nanoparticles. These discoveries present a newly devised nanoplatform with promising potential for the effective treatment of myocardial infarction.

Ameliorating impaired cardiac function in myocardial infarction using exosome-loaded gallic-acid-containing polyurethane scaffolds

Myocardial infarction (MI) can be tackled by implanting cardiac patches which provide mechanical support to the heart. However, most tissue-engineered scaffolds face difficulty in attenuating oxidative stress, maintaining mechanical stability, and regenerating damaged cardiomyocytes. Here, we fabricated elastic cryogels using polyurethane modified with antioxidant gallic acid in its backbone (PUGA) and further coated them with decellularized extracellular matrix (dECM) to improve adhesiveness, biocompatibility and hemocompatibility. The scaffold was functionalized with exosomes (EXO) isolated from adipose-derived stem cells having regenerative potential. PUGA-dECM + EXO was tested in a rat model with induced MI where echocardiography after 8 weeks of implantation showed significant recovery in treatment group. Histological analysis revealed a decrease in fibrosis after application of patch and promotion of angiogenesis with reduced oxidative stress was shown by immunostaining. Expression of cardiac tissue contractile function marker was also observed in treatment groups. Thus, the proposed biomaterial has a promising application to be utilized as a patch for cardiac regeneration. More detailed studies with larger animal species are needed for using these observations for specific applications.

Progress of polysaccharide-based tissue adhesives

Recently, polymer-based tissue adhesives (TAs) have gained the attention of scientists and industries as alternatives to sutures for sealing and closing wounds or incisions because of their ease of use, low cost, minimal tissue damage, and short application time. However, poor mechanical properties and weak adhesion strength limit the application of TAs, although numerous studies have attempted to develop new TAs with enhanced performance. Therefore, next-generation TAs with improved multifunctional properties are required. In this review, we address the requirements of polymeric TAs, adhesive characteristics, adhesion strength assessment methods, adhesion mechanisms, applications, advantages and disadvantages, and commercial products of polysaccharide (PS)-based TAs, including chitosan (CS), alginate (AL), dextran (DE), and hyaluronic acid (HA). Additionally, future perspectives are discussed.

ROS/pH dual responsive PRP-loaded multifunctional chitosan hydrogels with controlled release of growth factors for skin wound healing

Platelet-rich plasma (PRP) contains a variety of growth factors (GFs) and has been used in the treatment of a variety of diseases, including skin lesions. In particular, PRP with low immunogenicity will be more widely used. However, the explosive release of GFs limits its further application. In order to achieve controlled release of GFs, a multifunctional and reactive oxygen species (ROS)/pH dual responsive hydrogel was developed to load PRP derived from human cord blood for the treatment of skin wound healing. Based on the hydrogen bond and Schiff base interaction, carboxymethyl chitosan (CMCS), oxidized dextran (Odex) and oligomeric procyanidins (OPC) were crosslinked to form CMCS/Odex/OPC/PRP hydrogel with good injectability, self-healing, adhesion, ROS scavenging, antibacterial activity, controlled and sustained release of GFs. In vitro cell experiments suggested that this hydrogel possessed excellent biocompatibility and could promote the proliferation and migration of L929. In vivo healing of full-layer skin wounds further indicated that the prepared hydrogel could regulate inflammation and promote epithelialization, collagen deposition, and angiogenesis. In summary, this present study demonstrates that CMCS/Odex/OPC/PRP hydrogel may serve as a promising multifunctional dressing for skin wound healing.

A Biomimetic Cardiac Fibrosis-on-a-Chip as a Visible Disease Model for Evaluating Mesenchymal Stem Cell-Derived Exosome Therapy

Cardiac fibrosis acts as a serious worldwide health issue due to its prevalence in numerous forms of cardiac disease and its essential link to cardiac failure. Considering the efficiency of stem cell therapy for cardiac fibrosis, great efforts have been dedicated to developing accurate models for investigating their underlying therapeutic mechanisms. Herein we present an elaborate biomimetic cardiac fibrosis-on-a-chip based on Janus structural color film (SCF) to provide microphysiological visuals for stem cell therapeutic studies. By coculturing cardiomyocytes (CMs) and cardiac fibroblasts (FBs) on Janus SCF with fibrosis induction, the chip can recreate physiological intercellular crosstalk within the fibrotic microenvironment, elucidating the physiological alterations of fibrotic hearts. In particular, the Janus structural color film possesses superior perceptual capabilities for capturing and responding to a weak cardiac force, demonstrating synchronized structural color shifts. Based on these features, we have not only explored the dynamic relationship between color mapping and the evaluated disease phenotype but also demonstrated the self-reporting capacity of the cardiac fibrosis-on-a-chip for the assessment of mesenchymal stem cell-derived exosome therapy. These features suggest that such a chip can potentially facilitate the evolution of precision medicine strategies and create a protocol for preclinical cardiac drug screening.

Flexible Conductive Decellularized Fish Skin Matrix as a Functional Scaffold for Myocardial Infarction Repair

Engineering cardiac patches are proven to be effective in myocardial infarction (MI) repair, but it is still a tricky problem in tissue engineering to construct a scaffold with good biocompatibility, suitable mechanical properties, and solid structure. Herein, decellularized fish skin matrix is utilized with good biocompatibility to prepare a flexible conductive cardiac patch through polymerization of polydopamine (PDA) and polypyrrole (PPy). Compared with single modification, the double modification strategy facilitated the efficiency of pyrrole polymerization, so that the patch conductivity is improved. According to the results of experiments in vivo and in vitro, the scaffold can promote the maturation and functionalization of cardiomyocytes (CMs). It can also reduce the inflammatory response, increase local microcirculation, and reconstruct the conductive microenvironment in infarcted myocardia, thus improving the cardiac function of MI rats. In addition, the excellent flexibility of the scaffold, which enables it to be implanted in vivo through "folding-delivering-re-stretehing" pathway, provides the possibility of microoperation under endoscope, which avoids the secondary damage to myocardium by traditional thoracotomy for implantation surgery.

Hydrogels for Cardiac Restorative Support: Relevance of Gelation Mechanisms for Prospective Clinical Use

PURPOSE OF REVIEW

Cardiac tissue regenerative strategies have gained much traction over the years, in particular those utilizing hydrogels. With our review, and with special focus on supporting post-myocardial infarcted tissue, we aim to provide insights in determining crucial design considerations of a hydrogel and the implications these could have for future clinical use.

RECENT FINDINGS

To date, two hydrogel delivery strategies are being explored, cardiac injection or patch, to treat myocardial infarction. Recent advances have demonstrated that the mechanism by which a hydrogel is gelated (i.e., physically or chemically cross-linked) not only impacts the biocompatibility, mechanical properties, and chemical structure, but also the route of delivery of the hydrogel and thus its effect on cardiac repair. With regard to cardiac regeneration, various hydrogels have been developed with the ability to function as a delivery system for therapeutic strategies (e.g., drug and stem cells treatments), as well as a scaffold to guide cardiac tissue regeneration following myocardial infarction. However, these developments remain within the experimental and pre-clinical realm and have yet to transition towards the clinical setting.

Advances in the design, generation, and application of tissue-engineered myocardial equivalents

Due to the limited regenerative ability of cardiomyocytes, the disabling irreversible condition of myocardial failure can only be treated with conservative and temporary therapeutic approaches, not able to repair the damage directly, or with organ transplantation. Among the regenerative strategies, intramyocardial cell injection or intravascular cell infusion should attenuate damage to the myocardium and reduce the risk of heart failure. However, these cell delivery-based therapies suffer from significant drawbacks and have a low success rate. Indeed, cardiac tissue engineering efforts are directed to repair, replace, and regenerate native myocardial tissue function. In a regenerative strategy, biomaterials and biomimetic stimuli play a key role in promoting cell adhesion, proliferation, differentiation, and neo-tissue formation. Thus, appropriate biochemical and biophysical cues should be combined with scaffolds emulating extracellular matrix in order to support cell growth and prompt favorable cardiac microenvironment and tissue regeneration. In this review, we provide an overview of recent developments that occurred in the biomimetic design and fabrication of cardiac scaffolds and patches. Furthermore, we sift in vitro and in situ strategies in several preclinical and clinical applications. Finally, we evaluate the possible use of bioengineered cardiac tissue equivalents as in vitro models for disease studies and drug tests.

Application of biomedical materials in the diagnosis and treatment of myocardial infarction

Myocardial infarction (MI) is a cardiovascular emergency and the leading cause of death worldwide. Inflammatory and immune responses are initiated immediately after MI, leading to myocardial death, scarring, and ventricular remodeling. Current therapeutic approaches emphasize early restoration of ischemic myocardial reperfusion, but there is no effective treatment for the pathological changes of infarction. Biomedical materials development has brought new hope for MI diagnosis and treatment. Biomedical materials, such as cardiac patches, hydrogels, nano biomaterials, and artificial blood vessels, have played an irreplaceable role in MI diagnosis and treatment. They improve the accuracy and efficacy of MI diagnosis and offer further possibilities for reducing inflammation, immunomodulation, inhibiting fibrosis, and cardiac regeneration. This review focuses on the advances in biomedical materials applications in MI diagnosis and treatment. The current studies are outlined in terms of mechanisms of action and effects. It is addressed how biomedical materials application can lessen myocardial damage, encourage angiogenesis, and enhance heart function. Their clinical transformation value and application prospect are discussed.

Evaluation of in vitro biocompatibility of human pulp stem cells with allogeneic, alloplastic, and xenogeneic grafts under the influence of extracellular vesicles

Therapies using dental pulp stem cells (DPSCs) or stem cell-derived extracellular vesicles (EVs) have shown promising applications for bone tissue engineering. This in vitro experiment evaluated the joint osteogenic capability of DPSCs and EVs on alloplastic (maxresorp), allogeneic (maxgraft), and xenogeneic (cerabone) bone grafts. We hypothesize that osteogenic differentiation and the proliferation of human DPSCs vary between bone grafts and are favorable under the influence of EVs. DPSCs were obtained from human wisdom teeth, and EVs derived from DPSCs were isolated from cell culture medium. DPSCs were seeded on alloplastic, allogeneic, and xenogeneic bone graft substitutes for control, and the same scaffolds were administered with EVs in further groups. The cellular uptake of EVs into DPSC cells was assessed by confocal laser scanning microscopy. Cell vitality staining and calcein acetoxymethyl ester staining were used to evaluate cell attachment and proliferation. Cell morphology was determined using scanning electron microscopy, and osteogenic differentiation was explored by alkaline phosphatase and Alizarin red staining. Within the limitations of an in vitro study without pathologies, the results suggest that especially the use of xenogeneic bone graft substitutes with DPSCS and EVs may represent a promising treatment approach for alveolar bone defects.

The origin, progress, and application of cell-based cardiac regeneration therapy

Cardiovascular disease (CVD) has become a severe threat to human health, with morbidity and mortality increasing yearly and gradually becoming younger. When the disease progresses to the middle and late stages, the loss of a large number of cardiomyocytes is irreparable to the body itself, and clinical drug therapy and mechanical support therapy cannot reverse the development of the disease. To explore the source of regenerated myocardium in model animals with the ability of heart regeneration through lineage tracing and other methods, and develop a new alternative therapy for CVDs, namely cell therapy. It directly compensates for cardiomyocyte proliferation through adult stem cell differentiation or cell reprogramming, which indirectly promotes cardiomyocyte proliferation through non-cardiomyocyte paracrine, to play a role in heart repair and regeneration. This review comprehensively summarizes the origin of newly generated cardiomyocytes, the research progress of cardiac regeneration based on cell therapy, the opportunity and development of cardiac regeneration in the context of bioengineering, and the clinical application of cell therapy in ischemic diseases.

Stem cells derived exosomes and biomaterials to modulate autophagy and mend broken hearts

Autophagy maintains cellular homeostasis and plays a crucial role in managing pathological conditions including ischemic myocardial injury leading to heart failure (HF). Despite treatments, no intervention can replace lost cardiomyocytes. Stem cell therapy offers potential for post-myocardial infarction repair but struggles with poor cell retention due to immune rejection. In the search for effective therapies, stem cell-derived extracellular vesicles (EVs), especially exosomes, have emerged as promising tools. These tiny bioactive molecule carriers play vital roles in intercellular communication and tissue engineering. They offer numerous therapeutic benefits including modulating immune responses, promoting tissue repair, and boosting angiogenesis. Additionally, biomaterials provide a conducive 3D microenvironment for cell, exosome, and biomolecule delivery, and enhance heart muscle strength, making it a comprehensive cardiac repair strategy. In this regard, the current review delves into the intricate application of extracellular vesicles (EVs) and biomaterials for managing autophagy in the heart muscle during cardiac injury. Central to our investigation is the exploration of how these elements interact within the context of cardiac repair and regeneration. Additionally, this review also casts light on the formidable challenges that plague this field, such as the issues of safety, efficacy, controlled delivery, and acceptance of these therapeutic strategies for effective clinical translation. Addressing these challenges is crucial for unlocking the full therapeutic potential of EV and biomaterial-based therapies and ensuring their successful translation from bench to bedside.

Recent progress of antibacterial hydrogels in wound dressings

Hydrogels are essential biomaterials due to their favorable biocompatibility, mechanical properties similar to human soft tissue extracellular matrix, and tissue repair properties. In skin wound repair, hydrogels with antibacterial functions are especially suitable for dressing applications, so novel antibacterial hydrogel wound dressings have attracted widespread attention, including the design of components, optimization of preparation methods, strategies to reduce bacterial resistance, etc. In this review, we discuss the fabrication of antibacterial hydrogel wound dressings and the challenges associated with the crosslinking methods and chemistry of the materials. We have investigated the advantages and limitations (antibacterial effects and antibacterial mechanisms) of different antibacterial components in the hydrogels to achieve good antibacterial properties, and the response of hydrogels to stimuli such as light, sound, and electricity to reduce bacterial resistance. Conclusively, we provide a systematic summary of antibacterial hydrogel wound dressings findings (crosslinking methods, antibacterial components, antibacterial methods) and an outlook on long-lasting antibacterial effects, a broader antibacterial spectrum, diversified hydrogel forms, and the future development prospects of the field.

Extracellular matrix (ECM)-inspired high-strength gelatin-alginate based hydrogels for bone repair

It has always been a huge challenge to construct high-strength hydrogels that are composed entirely of natural polymers. In this study, inspired by the structural characteristics of the extracellular matrix (ECM), gelatin and hydrazide alginate were employed to mimic the composition of collagen and glycosaminoglycans (GAGs) in the ECM, respectively, to develop natural polymer (NP) high-strength hydrogels crosslinked by physical and covalent interactions (Gelatin-HAlg-DN). First, HAlg and gelatin can form physically crosslinked hydrogels (Gelatin-HAlg) due to electrostatic and hydrogen bond interactions. Then, the Gelatin-HAlg hydrogels can be further covalently crosslinked in the presence of 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) to obtain Gelatin-HAlg-DN hydrogels. The obtained Gelatin-HAlg-DN hydrogels exhibit considerably enhanced mechanical properties (tensile strength: 0.9 MPa; elongation at break: 177%) with a maximum 16- and 3.2-fold increase in tensile strength and elongation at break, respectively, compared with gelatin methacrylate (GelMA) hydrogels. Importantly, the Gelatin-HAlg-DN hydrogels exhibit excellent biodegradability and swelling stability under physiological conditions, and the capability to support cell adhesion and proliferation. In a rat critical size bone defect model, Gelatin-HAlg-DN hydrogels loaded with psoralen could effectively promote bone regeneration, showing appealing potential as tissue engineering scaffolds.

Cyclodextrin regulated natural polysaccharide hydrogels for biomedical applications-a review

Cyclodextrin and its derivative (CDs) are natural building blocks for linking with other components to afford functional biomaterials. Hydrogels are polymer network systems that can form hydrophilic three-dimensional network structures through different cross-linking methods and are developing as potential materials in biomedical applications. Natural polysaccharide hydrogels (NPHs) are widely adopted in biomedical field with good biocompatibility, biodegradability, low cytotoxicity, and versatility in emulating natural tissue properties. Compared with conventional NPHs, CD regulated natural polysaccharide hydrogels (CD-NPHs) maintain good biocompatibility, while improving poor mechanical qualities and unpredictable gelation times. Recently, there has been increasing and considerable usage of CD-NPHs while there is still no review comprehensively introducing their construction, classification, and application of these hydrogels from the material point of view regarding biomedical fields. To draw a complete picture of the current and future development of CD-NPHs, we systematically overview the classification of CD-NPHs, and provide a holistic view on the role of CD-NPHs in different biomedical fields, especially in drug delivery, wound dressing, cell encapsulation, and tissue engineering. Moreover, the current challenges and prospects of CD-NPHs are discussed rationally, providing an insight into developing vibrant fields of CD-NPHs-based biomedicine, and facilitating their translation from bench to clinical medicine.

The Role of Hydrogel in Cardiac Repair and Regeneration for Myocardial Infarction: Recent Advances and Future Perspectives

A myocardial infarction (MI) is the leading cause of morbidity and mortality, seriously threatens human health, and becomes a major health burden of our society. It is urgent to pursue effective therapeutic strategies for the regeneration and restore myocardial function after MI. This review discusses the role of hydrogel in cardiac repair and regeneration for MI. Hydrogel-based cardiac patches and injectable hydrogels are the most commonly used applications in cardiac regeneration medicine. With injectable hydrogels, bioactive compounds and cells can be delivered in situ, promoting in situ repair and regeneration, while hydrogel-based cardiac patches reduce myocardial wall stress, which passively inhibits ventricular expansion. Hydrogel-based cardiac patches work as mechanically supportive biomaterials. In cardiac regeneration medicine, clinical trials and commercial products are limited. Biomaterials, biochemistry, and biological actives, such as intelligent hydrogels and hydrogel-based exosome patches, which may serve as an effective treatment for MI in the future, are still under development. Further investigation of clinical feasibility is warranted. We can anticipate hydrogels having immense translational potential for cardiac regeneration in the near future.

Engineered Tissue for Cardiac Regeneration: Current Status and Future Perspectives

Heart failure (HF) is the leading cause of death worldwide. The most effective HF treatment is heart transplantation, the use of which is restricted by the limited supply of donor hearts. The human pluripotent stem cell (hPSC), including human embryonic stem cell (hESC) and the induced pluripotent stem cells (hiPSC), could be produced in an infinite manner and differentiated into cardiomyocytes (CMs) with high efficiency. The hPSC-CMs have, thus, offered a promising alternative for heart transplant. In this review, we introduce the tissue-engineering technologies for hPSC-CM, including the materials for cell culture and tissue formation, and the delivery means into the heart. The most recent progress in clinical application of hPSC-CMs is also introduced. In addition, the bottleneck limitations and future perspectives for clinical translation are further discussed.