CuCeO Bimetallic Oxide Rapidly Treats Staphylococcus aureus-Infected Osteomyelitis through Microwave Strengthened Microwave Catalysis and Fenton-Therapy

Multiscale metal-based nanocomposites for bone and joint disease therapies

Bone and joint diseases are debilitating conditions that can result in significant functional impairment or even permanent disability. Multiscale metal-based nanocomposites, which integrate hierarchical structures ranging from the nanoscale to the macroscale, have emerged as a promising solution to this challenge. These materials combine the unique properties of metal-based nanoparticles (MNPs), such as enzyme-like activities, stimuli responsiveness, and photothermal conversion, with advanced manufacturing techniques, such as 3D printing and biohybrid systems. The integration of MNPs within polymer or ceramic matrices offers a degree of control over the mechanical strength, antimicrobial efficacy, and the manner of drug delivery, whilst concomitantly promoting the processes of osteogenesis and chondrogenesis. This review highlights breakthroughs in stimulus-responsive MNPs (e.g., photo-, magnetically-, or pH-activated systems) for on-demand therapy and their integration with biocomposite hybrids containing cells or extracellular vesicles to mimic the native tissue microenvironment. The applications of these composites are extensive, ranging from bone defects, infections, tumors, to degenerative joint diseases. The review emphasizes the enhanced load-bearing capacity, bioactivity, and tissue integration that can be achieved through hierarchical designs. Notwithstanding the potential of these applications, significant barriers to progress persist, including challenges related to long-term biocompatibility, regulatory hurdles, and scalable manufacturing. Finally, we propose future directions, including machine learning-guided design and patient-specific biomanufacturing to accelerate clinical translation. Multiscale metal-based nanocomposites, which bridge nanoscale innovations with macroscale functionality, are a revolutionary force in the field of biomedical engineering, providing personalized regenerative solutions for bone and joint diseases.

Biotechnology-assisted cancer therapy using metal sulfides based on their optical and thermophysical properties

Two-dimensional transition metal sulfides (2D-TMSs) have received considerable attention in recent years owing to their exceptional features and diverse applications. Two-dimensional nanostructures of transition metal sulfides exhibit highly anisotropic properties, excellent mechanical strength, biocompatibility, a large surface area, and the ability to enhance functionality through surface modification methods. These features make them an ideal and attractive material for developing multifunctional platforms. In this review, we provide a comprehensive introduction to various configurations of nanostructures based on 2D-TMSs, including their modified structures such as vacancies and nanoflowers, as well as their composites, which encompass doped structures, alloyed structures, particles/dots on sheets, 2D-TMS-based heterojunctions, and core-shell nanostructures. This chemistry and configuration of 2D-TMSs have captured the attention of many researchers, driving them to delve into the diverse applications of these materials in the biomedical field, especially in drug delivery, photothermal therapy, sonodynamic therapy, and ferroptosis. Finally, the review summarizes the opportunities, challenges, and prospects of 2D-TMSs, emphasizing their crucial role in shaping the future of technology, medicine, and cancer therapy. The distinctive properties of 2D-TMSs make them promising contenders for various applications, and their continued exploration holds tremendous potential for scientific and technological progress.

Hemoglobin-loaded hollow mesoporous carbon-gold nanocomposites enhance microwave ablation through hypoxia relief

Microwave ablation, as a critical minimally invasive technique for tumor treatment, remains challenging in achieving an optimal balance between incomplete and excessive ablation. In addition to selectively elevating the temperature of tumor lesions through the microwave thermal effect, microwave-responsive nanoparticles can also improve the efficacy of single-session ablation by generating reactive oxygen species (ROS) via the microwave dynamic effect, thereby mitigating the thermal damage to normal tissues caused by high temperature. In this study, ultra-small gold nanoparticles anchored hollow mesoporous carbon nanoparticles (HMCNs) are loaded with hemoglobin (Hb) to serve as microwave ablation nano-sensitizers (HMCN/Au@Hb), which will amplify the microwave dynamic effect by alleviating the hypoxic microenvironment of tumors. Upon microwave irradiation, HMCN/Au@Hb not only improves the microwave-thermal conversion efficiency of tumor lesion but also promotes the ROS generation by increasing oxygen content in the hypoxic tumor microenvironment. More importantly, we found that the hypoxia relief will improve the antitumor response and further enhance the clearance of residual tumor after ablation. Nearly complete ablation was achieved in certain tumor-bearing mice, with no recurrence of the primary tumor observed up to 33 days post-ablation. In comparison to traditional microwave ablation, the survival time of the tumor-bearing mice was significantly extended. Therefore, this work presents an innovative ablation sensitization strategy based on the hypoxia relief and provides a nanosensitizer for microwave ablation integrating great microwave-thermal and dynamic effects along with immune modulation capabilities.

Advances in copper-containing biomaterials for managing bone-related diseases

Bone-related diseases pose a major challenge in contemporary society, with significant implications for both health and economy. Copper, a vital trace metal in the human body, facilitates a wide range of physiological processes by being crucial for the function of proteins and enzymes. Numerous studies have validated copper's role in bone regeneration and protection, particularly in the development and expansion of bone collagen. Owing to copper's numerous biological advantages, an increasing number of scientists are endeavoring to fabricate novel, multifunctional copper-containing biomaterials as an effective treatment strategy for bone disorders. This review integrates the current understanding regarding the biological functions of copper from the molecular and cellular levels, highlighting its potential for bone regeneration and protection. It also reviews the novel fabrication techniques for developing copper-containing biomaterials, including copper-modified metals, calcium phosphate bioceramics, bioactive glasses, bone cements, hydrogels and biocomposites. The fabrication strategies and various applications of these biomaterials in addressing conditions such as fractures, bone tumors, osteomyelitis, osteoporosis, osteoarthritis and osteonecrosis are carefully elaborated. Moreover, the long-term safety and toxicity assessments of these biomaterials are also presented. Finally, the review addresses current challenges and future prospects, in particular the regulatory challenges and safety issues faced in clinical implementation, with the aim of guiding the strategic design of multifunctional copper-based biomaterials to effectively manage bone-related diseases.

Stimuli-responsive mesoporous silica nanoplatforms for smart antibacterial therapies: From single to combination strategies

The demand for new antibacterial therapies is urgent and crucial in the clinical setting because of the growing degree of antibiotic resistance and the limits of conventional antibacterial therapies. Stimuli- responsive nanoplatforms, are sensitive to endogenous or exogenous stimulus (pH, temperature, light, and magnetic fields, etc.) which activate cargo release locally and on-demand, hold great potential in developing next generation personalized precision medicine. For instance, pH-sensitive nanoplatforms can selectively release antibacterial agents in the acidic environment of infection sites. To achieve the stimuli-responsive delivery, mesoporous silica nanoplatforms (MSNs) have demonstrated as prospective candidates for efficient cargo loading and controlled release through strategies such as tunable pore engineering, versatile surface modification/coating, and tailored framework composition. Furthermore, aiming for more precise delivery of MSNs, current research interests are increasingly shifting from single-stimuli antibacterial strategy to integrated strategy that combine multiple-stimulus. In this review, we briefly discuss the microenvironment of bacterial infections and provide a comprehensive summary of current stimuli-responsive strategies, and associated materials design principles of stimuli-responsive mesoporous silica-based smart nanoplatforms (SRMSNs). Additionally, integrative antibacterial strategies with synergistic effects, combining chemodynamic, photodynamic, photothermal, sonodynamic and gas therapies, have also been elaborated. Present research advances and limitations of SRMSNs-based antibacterial therapies, such as limited biodegradability and potential cytotoxicity, have been overviewed with future outlooks presented. This review aims to inspire and guide future research in developing novel antibacterial strategies with integrative solutions.

Emodin Enhanced Microwave-Responsive Heterojunction with Powerful Bactericidal Capacity and Immunoregulation for Curing Bacteria-Infected Osteomyelitis

Eradication of osteomyelitis caused by bacterial infections is still a major challenge. Microwave therapy has the inherent advantage of deep penetration in curing deep tissue infections. However, the antibacterial efficiency of sensitizers is limited by the weak energy of microwaves. Here, a hybrid heterojunction system (Fe3O4/CuS/Emo) is designed for curing bacterially infected osteomyelitis. As an enhanced microwave sensitizer, it shows supernormal microwave response ability. Specifically, Fe3O4 acts as a matrix to mediate magnetic loss. After CuS loading, the heterogeneous interface forms induce significant interfacial polarization, which increasing dielectric loss. On the basis of the heterojunction formed by the two semiconductors, emodin is innovatively introduced to modify it. This integration not only accelerates the movement of charge carriers but also enhances polarization loss due to the numerous functional groups present on the surface. This further optimizes the microwave thermal and catalytic response. In addition, the unique anti-inflammatory properties of emodin confer the ability of hybrid heterojunction to regulate the immune microenvironment. In vivo studies reveal that heterojunction modified by emodin programmed elimination of bacteria and regulation of the immune microenvironment. It offers a revolutionary approach to the treatment of bacterial osteomyelitis.

Oxygen vacancy formation strengthened microwave catalysis of Zn-Zr solid solution for antibiotic-free therapy strategies of bacteria-infected osteomyelitis

Osteomyelitis, a grave deep tissue infection primarily caused by Staphylococcus aureus, results in serious complications such as abscesses and sepsis. With the incidence from open fractures exceeding 30 % and prevalent antibiotic resistance due to extensive treatment regimens, there's an urgent need for innovative, antibiotic-free strategies. Photothermal therapy (PTT) and photodynamic therapy (PDT) renowned for generating localized reactive oxygen species (ROS), face limitations in penetration depth. To overcome this, our method combines the deep penetration attributes of medical microwaves (MW) with the synergistic effects of the ZnO/ZrO2 solid solution. Comprehensive in vitro and in vivo evaluations showcased the solid-solution's potent antibacterial efficacy and biocompatibility. The ZnO/ZrO2 solid solution, especially in a 7:3 M ratio, manifests superior microstructural characteristics, optimizing MW-assisted therapy. Our findings highlight the potential of this integrated strategy as a promising avenue in osteomyelitis management.

Bioclay Enzyme with Bimetal Synergistic Sterilization and Infectious Wound Regeneration

Bacteria invasion is the main factor hindering the wound-healing process. However, current antibacterial therapies inevitably face complex challenges, such as the abuse of antibiotics or severe inflammation during treatment. Here, a drug-free bioclay enzyme (Bio-Clayzyme) consisting of Fe2+-tannic acid (TA) network-coated kaolinite nanoclay and glucose oxidase (GOx) was reported to destroy harmful bacteria via bimetal antibacterial therapy. At the wound site, Bio-Clayzyme was found to enhance the generation of toxic hydroxyl radicals for sterilization via cascade catalysis of GOx and Fe2+-mediated peroxidase mimetic activity. Specifically, the acidic characteristics of the infection microenvironment accelerated the release of Al3+ from kaolinite, which further led to bacterial membrane damage and amplified the antibacterial toxicity of Fe2+. Besides, Bio-Clayzyme also performed hemostasis and anti-inflammatory functions inherited from Kaol and TA. By the combination of hemostasis and anti-inflammatory and bimetal synergistic sterilization, Bio-Clayzyme achieves efficient healing of infected wounds, providing a revolutionary approach for infectious wound regeneration.

Electron Aggregation and Oxygen Fixation Reinforced Microwave Dynamic and Thermal Therapy for Effective Treatment of MRSA-Induced Osteomyelitis

Antibiotics are frequently used to clinically treat osteomyelitis caused by bacterial infections. However, extended antibiotic use may result in drug resistance, which can be life threatening. Here, a heterojunction comprising Fe2O3/Fe3S4 magnetic composite is constructed to achieve short-term and efficient treat osteomyelitis caused by methicillin-resistant Staphylococcus aureus (MRSA). The Fe2O3/Fe3S4 composite exhibits powerful microwave (MW) absorption properties, thereby effectively converting incident electromagnetic energy into thermal energy. Density functional theory calculations demonstrate that Fe2O3/Fe3S4 possesses significant charge accumulation and oxygen-fixing capacity at the heterogeneous interface, which provides more active sites and oxygen sources for trapping electromagnetic hotspots. The finite element analysis indicates that Fe2O3/Fe3S4 displays a larger electromagnetism field enhancement parameter than Fe2O3 owing to a significant increase in electromagnetic hotspots. These hotspots contribute to charge differential accumulation and depletion motions at the interface, thereby augmenting the release of free electrons that subsequently combine with the oxygen adsorbed by Fe2O3/Fe3S4 to generate reactive oxygen species (ROS) and heat. This research, which achieves extraordinary bacterial eradication through the synergistic effect of microwave thermal therapy (MWTT) and microwave dynamic therapy (MDT), presents a novel strategy for treating deep-tissue bacterial infections.

Metal Ion Coordination Improves Graphite Nitride Carbon Microwave Therapy in Antibacterial and Osteomyelitis Treatment

The ability to effectively treat deep bacterial infections while promoting osteogenesis is the biggest treatment demand for diseases such as osteomyelitis. Microwave therapy is widely studied due to its remarkable ability to penetrate deep tissue. This paper focuses on the development of a microwave-responsive system, namely, a zinc ion (Zn2+ ) doped graphite carbon nitride (CN) system (BZCN), achieved through two high-temperature burning processes. By subjecting composite materials to microwave irradiation, an impressive 99.81% eradication of Staphylococcus aureus is observed within 15 min. Moreover, this treatment enhances the growth of bone marrow stromal cells. The Zn2+ doping effectively alters the electronic structure of CN, resulting in the generation of a substantial number of free electrons on the material's surface. Under microwave stimulation, sodium ions collide and ionize with the free electrons generated by BZCN, generating a large amount of energy, which reacts with water and oxygen, producing reactive oxygen species. In addition, Zn2+ doping improves the conductivity of CN and increases the number of unsaturated electrons. Under microwave irradiation, polar molecules undergo movement and generate frictional heat. Finally, the released Zn2+ promotes macrophages to polarize toward the M2 phenotype, which is beneficial for tibial repair.