Calcium Hydride-Based Dressing to Promote Wound Healing

Zinc sulfide nanoparticles serve as gas slow-release bioreactors for H2S therapy of ischemic stroke

Stroke is one of the leading causes of death and disability in the world. Ischemic stroke causes overproduction of reactive oxygen/nitrogen species (RONS) after reperfusion, triggering inflammatory responses that further leads to cell damage. In order to develop novel neuroprotective materials, we synthesized zinc sulfide nanoparticles (ZnS NPs) to function as gas slow-release bioreactors, showcasing stable and sustained H2S release while effectively removing RONS. In cultured cells, ZnS NPs can reduce the oxidative damage caused by oxygen-glucose deprivation and reoxygenation (OGD/R), promote the expression of p-AMPK, enhance microglia M2 polarization, decrease inflammatory factors and reduce neuronal apoptosis. Additionally, it increases the proliferation and migration of endothelial cells, promoting the formation of new neurovascular units by regulating the protein of p-AKT. In mice with ischemic stroke induced by middle cerebral artery occlusion/reperfusion (MCAO/R), ZnS NPs significantly reduce the infarct area and restore the mobility of mice owing to the slow release of H2S. In summary, our results indicate that ZnS NPs can be used as H2S slow-release bioreactors, offering a potentially innovative approach to treat ischemia-reperfusion injury caused by stroke.

Catalytic Biomaterials-Activated In Situ Chemical Reactions: Strategic Modulation and Enhanced Disease Treatment

Chemical reactions underpin biological processes, and imbalances in critical biochemical pathways within organisms can lead to the onset of severe diseases. Within this context, the emerging field of "Nanocatalytic Medicine" leverages nanomaterials as catalysts to modulate fundamental chemical reactions specific to the microenvironments of diseases. This approach is designed to facilitate the targeted synthesis and localized accumulation of therapeutic agents, thus enhancing treatment efficacy and precision while simultaneously reducing systemic side effects. The effectiveness of these nanocatalytic strategies critically hinges on a profound understanding of chemical kinetics and the intricate interplay of reactions within particular pathological microenvironments to ensure targeted and effective catalytic actions. This review methodically explores in situ catalytic reactions and their associated biomaterials, emphasizing regulatory strategies that control therapeutic responses. Furthermore, the discussion encapsulates the crucial elements-reactants, catalysts, and reaction conditions/environments-necessary for optimizing the thermodynamics and kinetics of these reactions, while rigorously addressing both the biochemical and biophysical dimensions of the disease microenvironments to enhance therapeutic outcomes. It seeks to clarify the mechanisms underpinning catalytic biomaterials and evaluate their potential to revolutionize treatment strategies across various pathological conditions.

Recent Trends in the Development and Application of Nano-Antioxidants for Skin-Related Disease

Skin is a vital barrier for the human body, protecting against external environmental influences and maintaining internal homeostasis. In addition, an imbalance of oxidative stress and antioxidant mechanisms can lead to skin-related diseases. Thus, for treating skin-related diseases, antioxidant therapy may be an important strategy to alleviate these symptoms. However, traditional drug therapies have limitations in treating these conditions, such as lack of lasting effect and insufficient skin permeability. Recently, nano-antioxidants, with their good permeability, sustained-release ability, multifunctionality, and other beneficial characteristics, have showed their advances in the exploration of skin-related diseases from research on safe therapies to clinical practice. Hereby, we review the latest research and advancements in nano-antioxidants for skin-related diseases. We categorize skin-related diseases into four main groups: skin inflammatory diseases, skin damage caused by ultraviolet rays, skin wound healing, and other skin-related conditions. Additionally, we summarize the prospects and potential future directions for nano-antioxidant drugs in treating skin-related diseases.

Metal ion formulations for diabetic wound healing: Mechanisms and therapeutic potential

Metals are vital in human physiology, which not only act as enzyme catalysts in the processes of superoxide dismutase and glucose phosphorylation, but also affect the redox process, osmotic adjustment, metabolism and neural signals. However, metal imbalances can lead to diseases such as diabetes, which is marked by chronic hyperglycemia and affects wound healing. The hyperglycemic milieu of diabetes impairs wound healing, posing significant challenges to patient quality of life. Wound healing encompasses a complex cascade of hemostasis, inflammation, proliferation, and remodeling phases, which are susceptible to disruption in hyperglycemic conditions. In recent decades, metals have emerged as critical facilitators of wound repair by enhancing antimicrobial properties (e.g., iron and silver), providing angiogenic stimulation (copper), promoting antioxidant activity and growth factor synthesis (zinc), and supporting wound closure (calcium and magnesium). Consequently, research has pivoted towards the development of metal ion-based therapeutics, including innovative formulations such as nano-hydrogels, nano-microneedle dressings, and microneedle patches. Prepared by combining macromolecular materials such as chitosan, hyaluronic acid and sodium alginate with metals, aiming at improving the management of diabetic wounds. This review delineates the roles of key metals in human physiology and evaluates the application of metal ions in diabetic wound management strategies.

Sandwich-Structured Nanofiber Dressings Containing MgB2 and Metformin Hydrochloride With ROS Scavenging and Antibacterial Properties for Wound Healing in Diabetic Infections

The treatment of chronic diabetic wounds is a major challenge due to oxidative stress, persistent hyperglycemia, and susceptibility to bacterial infection. In this study, multifunctional sandwich-structured nanofiber dressings (SNDs) are prepared via electrospinning. The SNDs consisted of an outer layer of hydrophobic polylactic acid (PLA) fibers encapsulating MgB2 nanosheets (MgB2 NSs), a middle layer of PLA and polyvinylpyrrolidone (PVP) fibers encapsulating the MgB2 NSs and metformin hydrochloride complex (MgB2-Met), and an inner layer of water-soluble PVP fibers encapsulating MgB2-Met. Because of their special sandwich structure, SNDs have high photothermal conversion efficiency (24.13%) and photothermal cycle performance. SNDs also exhibit a photothermal effect, bacteria-targeting effect of MgB2, electrostatic attraction ability of metformin hydrochloride (Met), and strong antibacterial activity against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA). SNDs can eliminate intracellular reactive oxygen species (ROS) by regulating the hydrogen release from MgB2. In addition, SNDs have good biocompatibility, can effectively inhibit the inflammatory factor Interleukin-6 (IL-6), and promote granulation tissue formation, collagen deposition, and diabetic wound healing. These findings offer a promising approach for clinical treatment of diabetic wounds.

Bioactive Calcium Hydride-Driving "Triple" Hydrogen/Alkaline/Calcium Therapy for Efficient Treatment of Osteomyelitis

Osteomyelitis with high mortality and disability rates is a common clinical disease caused by a bacterial infection that is difficult to cure. Considering the stubborn nature and depth of tissue infection, rapid and effective treatments for osteomyelitis remain an enormous challenge. Calcium hydride (CaH2), as efficient hydrogen/alkaline/calcium donors, is employed for combined osteomyelitis therapy. CaH2 reacts with water to sufficiently generate a strong alkali environment with hydroxide anions (OH-) to inhibit bacterial proliferation and induce bacterial death. The released calcium ions (Ca2+) induce calcium overload to kill bacteria first and then serves as calcium source to promote new bone formation. Another byproduct, hydrogen enhances the bacterial membrane permeability and scavenges excess reactive oxygen species (ROS). After incubation with bacteria, CaH2 significantly increases the permeability of the bacterial membrane, therefore increasing the entry of OH- and Ca2+ into bacterial cells, thereby leading to significant bacterial death. After being applied to S. aureus-infected mouse tibia osteomyelitis, CaH2 materials efficiently kill bacteria, relieve local inflammation, and promote new bone formation in a short time. Overall, bioactive metal hydride-associated "triple" hydrogen/alkaline/calcium therapy provides a new idea for the treatment of deep-site bacterial infection, which is beneficial for relieving the pressure caused by antibiotic-resistant bacteria.

Nanotechnology-Mediated Immunomodulation Strategy for Inflammation Resolution

Inflammation serves as a common characteristic across a wide range of diseases and plays a vital role in maintaining homeostasis. Inflammation can lead to tissue damage and the onset of inflammatory diseases. Although significant progress is made in anti-inflammation in recent years, the current clinical approaches mainly rely on the systemic administration of corticosteroids and antibiotics, which only provide short-term relief. Recently, immunomodulatory approaches have emerged as promising strategies for facilitating the resolution of inflammation. Especially, the advanced nanosystems with unique biocompatibility and multifunctionality have provided an ideal platform for immunomodulation. In this review, the pathophysiology of inflammation and current therapeutic strategies are summarized. It is mainly focused on the nanomedicines that modulate the inflammatory signaling pathways, inflammatory cells, oxidative stress, and inflammation targeting. Finally, the challenges and opportunities of nanomaterials in addressing inflammation are also discussed. The nanotechnology-mediated immunomodulation will open a new treatment strategy for inflammation therapy.

Calcium‐dependent antimicrobials: Nature‐inspired materials and designs

Bacterial infection remains a major complication answering for the failures of various implantable medical devices. Tremendous extraordinary advances have been published in the design and synthesis of antimicrobial materials addressing this issue; however, the clinical translation has largely been blocked due to the challenge of balancing the efficacy and safety of these materials. Here, calcium's biochemical features, natural roles in pathogens and the immune systems, and advanced uses in infection medications are illuminated, showing calcium is a promising target for developing implantable devices with less infection tendency. The paper gives a historical overview of biomedical uses of calcium and summarizes calcium's merits in coordination, hydration, ionization, and stereochemistry for acting as a structural former or trigger in biological systems. It focuses on the involvement of calcium in pathogens' integrity, motility, and metabolism maintenance, outlining the potential antimicrobial targets for calcium. It addresses calcium's uses in the immune systems that the authors can learn from for antimicrobial synthesis. Additionally, the advances in calcium's uses in infection medications are highlighted to sketch the future directions for developing implantable antimicrobial materials. In conclusion, calcium is at the nexus of antimicrobial defense, and future works on taking advantage of calcium in antimicrobial developments are promising in clinical translation.

Hydrogen therapy: recent advances and emerging materials

Hydrogen therapy, leveraging its selective attenuation of hydroxyl radicals (˙OH) and ONOO-, has emerged as a pivotal pathophysiological modulator with antioxidant, anti-inflammatory, and antiapoptotic attributes. Hydrogen therapy has been extensively studied both preclinically and clinically, especially in diseases with an inflammatory nature. Despite the substantial progress, challenges persist in achieving high hydrogen concentrations in target lesions, especially in cancer treatment. A notable breakthrough lies in water/acid reactive materials, offering enhanced hydrogen generation and sustained release potential. However, limitations include hydrogen termination upon material depletion and reduced bioavailability at targeted lesions. To overcome these challenges, catalytic materials like photocatalytic and sonocatalytic materials have surfaced as promising solutions. With enhanced permeability and retention effects, these materials exhibit targeted delivery and sustained stimuli-reactive hydrogen release. The future of hydrogen therapy hinges on continuous exploration and modification of catalytic materials. Researchers are urged to prioritize improved catalytic efficiency, enhanced lesion targeting effects, and heightened biosafety and biocompatibility in future development.

Poly(ionic liquid)-Flocculated Chlorella Loading Bactericidal and Antioxidant Hydrogel as a Biological Hydrogen Therapy for Diabetic Wound Dressing

Infection and oxidative stress seriously hinder the healing of diabetic wounds, resulting in various serious health and clinical problems. Herein, a sustainable biological hydrogen (H2)-producing hyaluronic acid-based hydrogel patch (HAP-Chl) was constructed by loading an imidazolium-based poly(ionic liquid) (PIL) flocculated live Chlorella as a diabetic wound dressing. The PIL can flocculate Chlorella through electrostatic interactions between PIL and Chlorella to form Chlorella agglomerates, endowing the Chlorella in the central agglomerates with the ability to continuously produce H2 for 24 h under mild conditions. Combining the membrane disruption-related bactericidal mechanism of PIL and the antioxidant properties of the produced H2, HAP-Chl was determined to be antibacterial and antioxidant. In addition to exhibiting biocompatible and nontoxic activities, subsequent Staphylococcus aureus-infected chronic wound studies revealed that HAP-Chl is capable of promoting the healing of chronic wounds by effectively killing bacteria, reducing extensive ROS, relieving inflammation, and promoting the deposition of mature collagen and angiogenesis. This study provides a new strategy for constructing an in situ sustainable H2-producing hydrogel, enabling the formation of novel antibacterial and antioxidant material platforms with potential for wound dressing applications.

Biomaterials for immunomodulation in wound healing

The substantial economic impact of non-healing wounds, scarring, and burns stemming from skin injuries is evident, resulting in a financial burden on both patients and the healthcare system. This review paper provides an overview of the skin's vital role in guarding against various environmental challenges as the body's largest protective organ and associated developments in biomaterials for wound healing. We first introduce the composition of skin tissue and the intricate processes of wound healing, with special attention to the crucial role of immunomodulation in both acute and chronic wounds. This highlights how the imbalance in the immune response, particularly in chronic wounds associated with underlying health conditions such as diabetes and immunosuppression, hinders normal healing stages. Then, this review distinguishes between traditional wound-healing strategies that create an optimal microenvironment and recent peptide-based biomaterials that modulate cellular processes and immune responses to facilitate wound closure. Additionally, we highlight the importance of considering the stages of wounds in the healing process. By integrating advanced materials engineering with an in-depth understanding of wound biology, this approach holds promise for reshaping the field of wound management and ultimately offering improved outcomes for patients with acute and chronic wounds.

Anti-adhesive and antibacterial chitosan/PEO nanofiber dressings with high breathability for promoting wound healing

Wound dressings are crucial for wound healing. Ideal wound dressings should possess many functions such as wettability, antibacterial activity and anti-adherent property to promote wound healing. In the present study solution blown spinning (SBS) technology was applied to prepare chitosan/polyethylene oxide (CS/PEO) nanofiber dressings in high efficiency. The obtained nanofiber dressings were treated with anhydrous ethanol to improve the fiber structure and enhance the functionality of the fiber dressings. The results show that the treated nanofibers had higher crystallinities and higher CS contents. The CS/PEO nanofiber dressings fabricated by using no additives and crosslinking had excellent wettability, water stability and antibacterial activity against Escherichia coli and Staphylococcus aureus reached to over 99.99 %. In addition, the CS/PEO nanofiber dressings exhibited high breathability, antioxidant activity and anti-adhesion function. The in vivo animal experiment confirmed that the nanofiber dressings enhanced cell proliferation and significantly accelerated the wound healing within 10 days. The developed CS/PEO nanofiber dressings have great potential in the clinical field of wound healing.

Recent Advances in Metal-Hydride-Based Disease Treatment

In comparison to traditional antioxidant treatment methods, the use of hydrogen to eliminate reactive oxygen species from the body has the advantages of high biological safety, strong selectivity, and high clearance rate. As an energy storage material, metal hydrides have been extensively studied and used in transporting hydrogen as clean energy, which can achieve a high hydrogen load and controlled hydrogen release. Considering the antioxidant properties of hydrogen and the delivery ability of metal hydrides, metal-hydride-based disease treatment strategies have attracted widespread attention. Up to now, metal hydrides have been reported for the treatment of tumors and a range of inflammation-related diseases. However, limited by the insufficient investment, the use of metal hydrides in disease treatment still has many shortcomings, such as low targeting efficiency, limited therapeutic activity, and complex material preparation process. Particularly, metal hydrides have been found to have a series of optical, acoustic, and catalytic properties when scaled up to the nanoscale, and these properties are also widely used to promote disease treatment effects. From this new perspective, we comprehensively summarize the very recent research progress on metal-hydride-based disease treatment in this review. Ultimately, the challenges and prospects of such a burgeoning cancer theranostics modality are outlooked to provide inspiration for the further development and clinical translation of metal hydrides.

Enhancing wound healing and adhesion through dopamine-assisted gelatin-silica hybrid dressings

Gelatin, widely employed in hydrogel dressings, faces limitations when used in high fluid environments, hindering effective material adhesion to wound sites and subsequently reducing treatment efficacy. The rapid degradation of conventional hydrogels often results in breakdown before complete wound healing. Thus, there is a pressing need for the development of durable adhesive wound dressings. In this study, 3-glycidoxypropyltrimethoxysilane (GPTMS) was utilized as a coupling agent to create gelatin-silica hybrid (G-H) dressings through the sol-gel method. The coupling reaction established covalent bonds between gelatin and silica networks, enhancing structural stability. Dopamine (DP) was introduced to this hybrid (G-H-D) dressing to further boost adhesiveness. The efficacy of the dressings for wound management was assessed through in-vitro and in-vivo tests, along with ex-vivo bioadhesion testing on pig skin. Tensile bioadhesion tests demonstrated that the G-H-D material exhibited approximately 2.5 times greater adhesion to soft tissue in wet conditions compared to pure gelatin. Moreover, in-vitro and in-vivo wound healing experiments revealed a significant increase in wound healing rates. Consequently, this material shows promise as a viable option for use as a moist wound dressing.

Ferrite bismuth-based nanomaterials: From ferroelectric and piezoelectric properties to nanomedicine applications

Bismuth ferrite (BiFeO3), a perovskite-type oxide, possesses unique morphology and multiferroicity, rendering it highly versatile for various applications. Recent investigations have demonstrated that BiFeO3 exhibits enhanced Fenton-like and photocatalytic behaviors, coupled with its piezoelectric/ferroelectric properties. BiFeO3 can catalytically generate highly oxidative reactive oxygen species (ROS) when exposed to hydrogen peroxide or light irradiation. Consequently, bismuth ferrite-based nanomaterials have emerged as promising candidates for various biomedical applications. However, the precise fabrication of BiFeO3-based materials with controllable features and applications in diverse biomedical scenarios remains a formidable challenge. In this review, we initially summarize the Fenton reaction property, ferroelectric, and piezoelectric properties of BiFeO3. We further survey the current methodologies for synthesizing BiFeO3 nanomaterials with diverse morphologies. Subsequently, we explore the effects of element doping and heterojunction formation on enhancing the photocatalytic activity of BiFeO3, focusing on microstructural, electronic band structure, and modification approaches. Additionally, we provide an overview of the recent advancements of BiFeO3-based nanomaterials in biomedicine. Finally, we discuss the prevailing obstacles and prospects of BiFeO3 for biomedical applications, offering valuable insights and recommendations for forthcoming research endeavors.

Cu-GA-coordination polymer nanozymes with triple enzymatic activity for wound disinfection and accelerated wound healing

During the past few years, bacterial infection and oxidative stress have become important issues for wound healing. However, the emergence of numerous drug-resistant superbugs has had a serious impact on the treatment of infected wounds. Presently, the development of new nanomaterials has become one of the most important approaches to the treatment of drug-resistant bacterial infections. Herein, coordination polymer copper-gallic acid (Cu-GA) nanorods with multi-enzyme activity is successfully prepared for efficient wound treatment of bacterial infection, which can effectively promote wound healing. Cu-GA can be efficiently prepared by a simple solution method and had good physiological stability. Interestingly, Cu-GA shows enhanced multienzyme activity (peroxidase, glutathione peroxidase, and superoxide dismutase), which can produce a large number of reactive oxygen species (ROS) under acidic conditions while scavenging ROS under neutral conditions. In acidic environment, Cu-GA possesses POD (peroxidase)-like and glutathione peroxidase (GSH-Px)-like catalytic activities that is capable of killing bacteria; but in neutral environment, Cu-GA exhibits superoxide dismutase (SOD)-like catalytic activity that can scavenge ROS and promote wound healing. In vivo studies show that Cu-GA can promote wound infection healing and have good biosafety. Cu-GA contributes to the healing of infected wounds by inhibiting bacterial growth, scavenging reactive oxygen species, and promoting angiogenesis. STATEMENT OF SIGNIFICANCE: Cu-GA-coordinated polymer nanozymes with multienzyme activity were successfully prepared for efficient wound treatment of bacterial infection, which could effectively promote wound healing. Interestingly, Cu-GA exhibited enhanced multienzyme activity (peroxidase, glutathione peroxidase, and superoxide dismutase), which could produce a large number of reactive oxygen species (ROS) under acidic conditions and scavenge ROS under neutral conditions. In vitro and in vivo studies demonstrated that Cu-GA was capable of killing bacteria, controlling inflammation, and promoting angiogenesis.