Ultrasound activatable microneedles for bilaterally augmented sono-chemodynamic and sonothermal antibacterial therapy

Ultrasound-activated sonothermal-catalytic synergistic therapy via asymmetric electron distribution for bacterial wound infections

Antibiotic-resistant bacterial infections present a growing global health challenge, requiring innovative therapeutic solutions to overcome current limitations. We introduce boron-integrated bismuth oxide (B-BiO2) nanosheets with an asymmetrically distributed electronic structure for ultrasound-activated synergistic sonothermal and catalytic therapy. Boron incorporation enhances local electron density distribution, optimizing charge separation and significantly improving sonothermal and catalytic efficiency, as validated by density functional theory calculations. These nanosheets exhibit dual functionality, effectively generating localized heat and reactive oxygen species (ROS) under ultrasound, leading to 99.999 % antibacterial efficacy against multidrug-resistant pathogens by disrupting bacterial membranes, as demonstrated through all-atom simulations and in vitro experiments. The simulations further reveal that sonothermal conversion effects enhance bacterial membrane fluidity and induce structural defects, amplifying ROS-induced oxidative damage and membrane destabilization. In vivo, B-BiO2 nanosheets accelerate wound healing in methicillin-resistant Staphylococcus aureus (MRSA)-infected murine models, achieving 99.8 % closure by day 14 by reducing inflammation and promoting angiogenesis and tissue regeneration. Transcriptomic analysis highlights the activation of extracellular matrix remodeling, angiogenesis, and autophagy pathways, underscoring the nanosheets' therapeutic potential. This study establishes ultrasound-activated B-BiO2 nanosheets as a novel nanotherapeutic platform, leveraging asymmetric electron distribution to synergistically combat drug-resistant infections and promote effective wound healing.

A narrative review: Ultrasound-Assisted drug delivery: Improving treatments via multiple mechanisms

Safe and efficient drug delivery is as important as drug development. Biological barriers, such as cell membranes, present significant challenges in drug delivery, especially for newly developed protein-, nucleic acid-, and cell-based drugs. Ultrasound-mediated drug delivery systems offer a promising strategy to overcome these challenges. Ultrasound, a mechanical wave with energy, produces thermal effects, cavitation, acoustic radiation, and other biophysical effects. Used alone or in combination with microbubbles or sonosensitizers, it breaks biological barriers, enhances targeted drug delivery, reduces adverse reactions, controls drug release, switches on/off drug functions, and ultimately improves therapeutic efficiency. Various ultrasound-mediated drug delivery methods, including transdermal drug delivery, nebulization, targeted microbubble destruction, and sonodynamic therapy, are being actively explored for the treatment of various diseases. This review article introduces the principles, advantages, and applications of ultrasound-mediated drug delivery methods for improved therapeutic outcomes and discusses future prospects in this field.

Emerging synergistic strategies for enhanced antibacterial sonodynamic therapy: Advances and prospects

Antibacterial therapy has been extensively applied in medical field to alleviate the severity and mortality of infection. However, it still exists some issues such as drug side effects, limited efficacy and bacterial resistance. Among the alternative therapies, antibacterial sonodynamic therapy (aSDT) has been explored as a promising approach to tackle those crises. It is meaningful to investigate superior strategy to augment the therapeutic efficacy of aSDT. This review summarizes the potential aSDT-based antibacterial mechanisms and comprehensively discusses the prevailing synergistic strategies, such as nanomaterials-based aSDT antibacterial strategy, aSDT + strategy with physical, chemical and biological methods. Moreover, we also reviewed the medical applications of aSDT strategies. Finally, the perspectives on the current challenges that need be resolved in aSDT are proposed. We expect that this review could provide robust support to expedite the clinical applications of aSDT.

3D-Printed Scaffold Achieves Synergistic Chemo-Sonodynamic Therapy for Tumorous Bone Defect

Various smart scaffolds have recently been developed to address the regeneration of tumor bone defect. However, the recurrence of residual tumor cells poses a serious challenge to postoperative management, highlighting the need for effective therapeutic interventions. In this study, a multifunctional antitumor nanoplatform (Ti3C2/CuO2) for synergistic chemo-sonodynamic tumor therapy was developed and then rationally integrated into a poly(l-lactic acid) (PLLA) scaffold via selective laser sintering. CuO2 not only releases Cu2+ ions to facilitate chemodynamic antitumor therapy through the Fenton reaction but also generates H2O2, which further oxidizes Ti3C2 to produce TiO2 sonosensitizers. More importantly, the carbon-based substrates after oxidation of Ti3C2 have created favorable conditions for carrier transmission in the sonodynamic process, thereby amplifying the sonodynamic therapy. Additionally, moderate local hyperthermia form periodic sonodynamic therapy produces moderate localized heat therapy to further stimulate bone tissue regeneration. Meanwhile, the sustained release of bioactive ions (such as Cu and Ti ions) from the scaffold also fosters vascularization, further accelerating bone regeneration. This work presents a viable approach to developing multifunctional scaffolds for repairing tumorous bone defects.

Multimodal Synergistic Antimicrobial Activity of the Copper-Doped and Oxygen-Defective In Situ Nanocoating on Medical Titanium

To combat escalating antibiotic resistance in titanium implant-associated infections, oxygen-vacancy-rich polydopamine/TiCu nanocoating (PDA/p-TiCu-300 °C) was developed on medical-grade titanium, uniquely enabling synergistic photothermal (PTT), photodynamic (PDT), and sonodynamic (SDT) antimicrobial strategies. Unlike previous dual-modal approaches, this trimodal strategy, activated by near-infrared light and ultrasound, achieved exceptional broad-spectrum bactericidal efficacy against both Escherichia coli (99.19% killing) and Staphylococcus aureus (95.03% killing) via enhanced reactive oxygen species (ROS) generation and membrane disruption. The engineered oxygen vacancies within the PDA/p-TiCu-300 °C nanocoating significantly boosted ROS production, outperforming conventional photocatalytic materials. Crucially, the nanocoatings demonstrated excellent in vitro cytocompatibility. This PTT-PDT-SDT platform exhibits synergistic multimodal bactericidal activity, overcoming the limitations of existing strategies and representing a paradigm shift in implant surface modification with significant translational potential against severe infections.

Zn‐DHM Nanozymes Enhance Muscle Regeneration Through ROS Scavenging and Macrophage Polarization in Volumetric Muscle Loss Revealed by Single‐Cell Profiling

Volumetric muscle loss (VML) is a severe condition in which the loss of skeletal muscle surpasses the body's intrinsic repair capabilities, leading to irreversible functional deficits and potential disability, with persistent inflammation and impaired myogenic differentiation. To address these challenges, a novel zinc‐dihydromyricetin (Zn‐DHM) nanozyme with superoxide dismutase (SOD)‐like activity is developed, designed to neutralize excessive reactive oxygen species (ROS) and restore oxidative balance. Zn‐DHM mitigates oxidative stress and promotes polarization of macrophages from the proinflammatory M1 phenotype to the anti‐inflammatory M2 phenotype, thereby reducing chronic inflammation and creating a conducive environment for muscle repair. Further, Zn‐DHM significantly enhances the myogenic differentiation of C2C12 cells, accelerating wound healing processes. These studies confirm the biosafety and low toxicity of Zn‐DHM. As per a murine tibialis anterior VML model, Zn‐DHM effectively suppresses inflammation and markedly improves skeletal muscle repair outcomes. Single‐cell RNA sequencing reveals that Zn‐DHM treatment increases the expression of M2 macrophage markers and enhances the proliferation and differentiation capacity of muscle stem cells (MuSCs). In addition, intercellular communication analysis reveals interactions between MuSCs and macrophages in the Zn‐DHM treatment group, suggesting that these interactions may drive tissue regeneration through the activation of the GAS and Notch signaling pathways.

Acid-Responsive Bacteria-Targeted Zinc-Porphyrin Based Sonosensitizer with Enhancing Antibacterial Efficacy and Biofilm Eradication for Infected Wounds Healing

Diseases caused by bacterial infections place a significant burden on global public health. Sonodynamic therapy (SDT), as an emerging antibacterial treatment, faces clinical challenges due to the non-polar nature of most sonosensitizers. To address this, an acid-responsive zinc-porphyrin-based sonosensitizer (Zn-TCPP) is developed via a simple thermal reaction, which is then coated with phenylboronic acid-modified hyaluronic acid (B-HA), to fabricate B-HA@Zn-TCPP. While in the mildly acidic microenvironment mimicking an infected wound site, the released B-HA@Zn-TCPP achieves effective SDT activity. The disruption of the bacterial membrane and the levels of intracellular reactive oxygen species (ROS) verified that the inhibition rate can reach 99% within 5 min, without any development of resistance after 15 consecutive generations of culture. Additionally, under ultrasound (US) -mediated cavitation, B-HA@Zn-TCPP exhibits excellent penetration into biofilms, achieving a 90.04% bactericidal rate for bacteria within biofilms. In vivo studies further demonstrated that B-HA@Zn-TCPP can effectively accelerate the healing of bacterial infected wounds with a wound healing rate of 98.65% within 9 days. Therefore, B-HA@Zn-TCPP as a novel sonosensitizer offers a viable strategy to overcome the limitations of traditional sonosensitizers for the bacterial wound infections.

Ultrasound meets nanomedicine: towards disease treatment and medical imaging

As a kind of mechanical wave, ultrasound has been widely employed in the biomedical field due to its superiors of deep tissue penetration, non-destructiveness and non-toxicity. In this review, we highlight current progress and prospects in using ultrasound as a powerful tool for disease treatment and medical imaging, including (1) ultrasound as energy input for driving nano/micromotor in drug delivery, this part first introduces the synthesis and motion behavior of nano/micromotors, then reviews the small molecular and macromolecular compounds that the nano/micromotors are delivering; (2) sonosensitive nanomaterials for disease therapy, the sonodynamic, sonopiezoelectric, sonothermal, and sonomechanical therapy will all be covered; (3) ultrasound as a non-invasive technique for nano/micromotor tracking or medical imaging; (4) the sonoporation of nano/microbubble. Future challenges in using ultrasound for disease treatment or medical imaging will also be described in the conclusion part.

Ultrasound-mediated nanomaterials for the treatment of inflammatory diseases

Sterile and infection-associated inflammatory diseases are becoming increasingly prevalent worldwide. Conventional drug therapies often entail significant drawbacks, such as the risk of drug overdose, the development of drug resistance in pathogens, and systemic adverse reactions, all of which can undermine the effectiveness of treatments for these conditions. Nanomaterials (NMs) have emerged as a promising tool in the treatment of inflammatory diseases due to their precise targeting capabilities, tunable characteristics, and responsiveness to external stimuli. Ultrasound (US), a non-invasive and effective treatment method, has been explored in combination with NMs to achieve enhanced therapeutic outcomes. This review provides a comprehensive overview of the recent advances in the use of US-mediated NMs for treating inflammatory diseases. A comprehensive introduction to the application and classification of US was first presented, emphasizing the advantages of US-mediated NMs and the mechanisms through which US and NMs interact to enhance anti-inflammatory therapy. Subsequently, specific applications of US-mediated NMs in sterile and infection-associated inflammation were summarized. Finally, the challenges and prospects of US-mediated NMs in clinical translation were discussed, along with an outline of future research directions. This review aims to provide insights to guide the development and improvement of US-mediated NMs for more effective therapeutic interventions in inflammatory diseases.

Microneedle technology for enhanced topical treatment of skin infections

Skin infections caused by microbes such as bacteria, fungi, and viruses often lead to aberrant skin functions and appearance, eventually evolving into a significant risk to human health. Among different drug administration paradigms for skin infections, microneedles (MNs) have demonstrated superiority mainly because of their merits in enhancing drug delivery efficiency and reducing microbial resistance. Also, integrating biosensing functionality to MNs offers point-of-care wearable medical devices for analyzing specific pathogens, disease status, and drug pharmacokinetics, thus providing personalized therapy for skin infections. Herein, we do a timely update on the development of MN technology in skin infection management, with a special focus on how to devise MNs for personalized antimicrobial therapy. Notably, the advantages of state-of-the-art MNs for treating skin infections are pointed out, which include hijacking sequential drug transport barriers to enhance drug delivery efficiency and delivering various therapeutics (e.g., antibiotics, antimicrobial peptides, photosensitizers, metals, sonosensitizers, nanoenzyme, living bacteria, poly ionic liquid, and nanomoter). In addition, the nanoenzyme-based multimodal antimicrobial therapy is highlighted in addressing intractable infectious wounds. Furthermore, the MN-based biosensors used to identify pathogen types, track disease status, and quantify antibiotic concentrations are summarized. The limitations of antimicrobial MNs toward clinical translation are offered regarding large-scale production, quality control, and policy guidance. Finally, the future development of biosensing MNs with easy-to-use and intelligent properties and MN-based wearable drug delivery for home-based therapy are prospected. We hope this review will provide valuable guidance for future development in MN-mediated topical treatment of skin infections.

Versatile nanomaterials used in combatting biofilm infections

Microbial infections are a pressing global health issue, exacerbated by the rise of antibiotic-resistant bacteria due to widespread antibiotic overuse. This resistance diminishes the effectiveness of current treatments, intensifying the need for new antimicrobial agents and innovative drug delivery strategies. Nanotechnology presents promising solutions, leveraging the unique properties of nanomaterials such as tunable optical and electronic characteristics, nanoscale size, and high surface-to-volume ratios. These features enhance their effectiveness as innovative antimicrobial agents and versatile drug delivery systems. This minireview classifies antimicrobial nanomaterials into four categories based on their mechanisms of action: thermal generation, reactive oxygen species generation, gas generation, and nanocarrier systems such as liposomes, polymersomes, and metal-organic frameworks. Uniquely, this review integrates a comparative analysis of these mechanisms, highlighting their relative advantages, limitations, and applications across diverse microbial targets. Additionally, it identifies emerging trends in the field, providing a forward-looking perspective on how recent advancements in nanotechnology can be leveraged to address unmet clinical needs. Finally, this article discusses future directions and emerging opportunities in antimicrobial nanotechnology.

Tailoring Design of Microneedles for Drug Delivery and Biosensing

Microneedles (MNs) are emerging as versatile tools for both therapeutic drug delivery and diagnostic monitoring. Unlike hypodermic needles, MNs achieve these applications with minimal or no pain and customizable designs, making them suitable for personalized medicine. Understanding the key design parameters and the challenges during contact with biofluids is crucial to optimizing their use across applications. This review summarizes the current fabrication techniques and design considerations tailored to meet the distinct requirements for drug delivery and biosensing applications. We further underscore the current state of theranostic MNs that integrate drug delivery and biosensing and propose future directions for advancing MNs toward clinical use.

Copper-Based Nanozymes: Potential Therapies for Infectious Wounds

Bacterial infections are a significant obstacle to the healing of acute and chronic wounds, such as diabetic ulcers and burn injuries. Traditional antibiotics are the primary treatment for bacterial infections, but they present issues such as antibiotic resistance, limited efficacy, and potential side effects. This challenge leads to the exploration of nanozymes as alternative therapeutic agents. Nanozymes are nanomaterials with enzyme-like activities. Owing to their low production costs, high stability, scalability, and multifunctionality, nanozymes have emerged as a prominent focus in antimicrobial research. Among various types of nanozymes, metal-based nanozymes offer several benefits, including broad-spectrum antimicrobial activity and robust catalytic properties. Specifically, copper-based nanozymes (CuNZs) have shown considerable potential in promoting wound healing. They exhibit strong antimicrobial effects, reduce inflammation, and enhance tissue regeneration, making them highly advantageous for use in wound care. This review describes the dual functions of CuNZs in combating infection and facilitating wound repair. Recent advancements in the design and synthesis of CuNZs, evaluating their antimicrobial efficacy, healing promotion, and biosafety both in vitro and in vivo on the basis of their core components, are critically important.

Advanced Piezoelectric Materials, Devices, and Systems for Orthopedic Medicine

Harnessing the robust electromechanical couplings, piezoelectric materials not only enable efficient bio-energy harvesting, physiological sensing and actuating but also open enormous opportunities for therapeutic treatments through surface polarization directly interacting with electroactive cells, tissues, and organs. Known for its highly oriented and hierarchical structure, collagen in natural bones produces local electrical signals to stimulate osteoblasts and promote bone formation, inspiring the application of piezoelectric materials in orthopedic medicine. Recent studies showed that piezoelectricity can impact microenvironments by regulating molecular sensors including ion channels, cytoskeletal elements, cell adhesion proteins, and other signaling pathways. This review thus focuses on discussing the pioneering applications of piezoelectricity in the diagnosis and treatment of orthopedic diseases, aiming to offer valuable insights for advancing next-generation medical technologies. Beginning with an introduction to the principles of piezoelectricity and various piezoelectric materials, this review paper delves into the mechanisms through which piezoelectric materials accelerated osteogenesis. A comprehensive overview of piezoelectric materials, devices, and systems enhancing bone tissue repair, alleviating inflammation at infection sites, and monitoring bone health is then provided, respectively. Finally, the major challenges faced by applications of piezoelectricity in orthopedic conditions are thoroughly discussed, along with a critical outlook on future development trends.

Physical stimuli-responsive polymeric patches for healthcare

Many chronic diseases have become severe public health problems with the development of society. A safe and efficient healthcare method is to utilize physical stimulus-responsive polymer patches, which may respond to physical stimuli, including light, electric current, temperature, magnetic field, mechanical force, and ultrasound. Under certain physical stimuli, these patches have been widely used in therapy for diabetes, cancer, wounds, hair loss, obesity, and heart diseases since they could realize controllable treatment and reduce the risks of side effects. This review sketches the design principles of polymer patches, including composition, properties, and performances. Besides, control methods of using different kinds of physical stimuli were introduced. Then, the fabrication methods and characterization of patches were explored. Furthermore, recent applications of these patches in the biomedical field were demonstrated. Finally, we discussed the challenges and prospects for its clinical translation. We anticipate that physical stimulus-responsive polymer patches will open up new avenues for healthcare by acting as a platform with multiple functions.

Smart drug delivery and responsive microneedles for wound healing

Wound healing is an ongoing concern for the medical community. The limitations of traditional dressings are being addressed by materials and manufacturing technology. Microneedles (MNs) are a novel type of drug delivery system that has been widely used in cancer therapy, dermatological treatment, and insulin and vaccine delivery. MNs locally penetrate necrotic tissue, eschar, biofilm and epidermis into deep tissues, avoiding the possibility of drug dilution and degradation and greatly improving administration efficiency with less pain. MNs represent a new direction for wound treatment and transdermal delivery. In this study, we summarise the skin wound healing process and the mechanical stimulation of MNs in the context of the wound healing process. We also introduce the structural design and manufacture of MNs. Subsequently, MNs are categorised according to the loaded drugs, where the design of the MNs according to the traumatic biological/biochemical microenvironment (pH, glucose, and bacteria) and the physical microenvironment (temperature, light, and ultrasound) is emphasised. Finally, the advantages of MNs are compared with traditional drug delivery systems and their prospects are discussed.

Enhancing wound healing through sonodynamic silver/barium titanate heterostructures-loading gelatin/PCL nanodressings

Bacterial infections present a formidable challenge in surgical procedures, and are a major threat to wound healing. Sonodynamic therapy (SDT) is a non-invasive approach for fighting pathogens; however, it is hindered by the efficiency of sonosensitizers and effective antibacterial time. In this study, we developed a biocompatible nanodressing to improve the antibacterial efficacy and accelerate wound healing via SDT. Silver nanoparticles (NPs) were synthesized on tetragonal barium titanate (BTO) NPs to create an Ag@BTO heterostructure of sonosensitizers to improve their piezocatalytic activities, which were then incorporated into gelatin/polycaprolactone (PCL) to form Ag@BTO-gelatin/PCL nanofiber (ABT-gP NFs) dressings. The loading of Ag@BTO NPs resulted in ABT-gP NFs with better mechanical properties and excellent piezocatalysis, which produced reactive oxygen species and Ag+ to kill bacteria during ultrasound (US) irradiation. Additionally, nanodressing released moderate amounts of silver ions without US, prolonging the antibacterial time, while promoting fibroblast migration. This approach was effective in killing Gram-positive and Gram-negative bacteria (100 % and 90.8 %, respectively), promoting cell migration in vitro and accelerating wound healing without adverse effects in vivo. This study extends the potential applications of ultrasound-triggered nanodressing to the field of wound healing.

Dissolving microneedles: standing out in melanoma treatment

Melanoma is one of the most significant and dangerous superficial skin tumors with a high fatality rate, thanks to its high invasion rate, drug resistance and frequent metastasis properties. Unfortunately, researchers for decades have demonstrated that the outcome of using conventional therapies like chemotherapy and immunotherapy with normal drug delivery routes, such as an oral route to treat melanoma was not satisfactory. The severe adverse effects, slow drug delivery efficiency and low drug accumulation at targeted malignancy sites all lead to poor anti-cancer efficacy and terrible treatment experience. As a novel transdermal drug delivery system, microneedles (MNs) have emerged as an effective solution to help improve the low cure rate of melanoma. The excellent characteristics of MNs make it easy to penetrate the stratum corneum (SC) and then locally deliver the drug towards the lesion without drug leakage to mitigate the occurrence of side effects and increase the drug accumulation. Therefore, loading chemotherapeutic drugs or immunotherapy drugs in MNs can address the problems mentioned above, and MNs play a crucial role in improving the curative effect of conventional treatment methods. Notably, novel tumor therapies like photothermal therapy (PTT), photodynamic therapy (PDT) and chemodynamic therapy (CDT) have shown good application prospects in the treatment of melanoma, and MNs provide a valid platform for the combination of conventional therapies and novel therapies by encompassing different therapeutic materials in the matrix of MNs. The synergistic effect of multiple therapies can enhance the therapeutic efficacy compared to single therapies, showing great potential in melanoma treatment. Dissolving MNs have been the most commonly used microneedles in the treatment of melanoma in recent years, mainly because of their simple fabrication procedure and enough drug loading. So, considering the increasing use of dissolving MNs, this review collects research studies published in the last four years (2020-2024) that have rarely been included in other reviews to update the progress of applications of dissolving MNs in anti-melanoma treatment, especially in synergistic therapies. This review also presents current design and fabrication methods of dissolving MNs; the limitations of microneedle technology in the treatment of melanoma are comprehensively discussed. This review can provide valuable guidance for their future development.

Reactive oxygen species-responsive polydopamine-PtCuTe nanoparticle-loaded microneedle system for promoting the healing of infected skin wounds

Nanozymes, known for their high efficiency in scavenging reactive oxygen species (ROS), have received significant attention in promoting the healing of infected wounds. Herein, we reported a novel multifunctional PDA-PtCuTe nanozyme with excellent ROS scavenging, antibacterial, pro-angiogenic, anti-inflammatory, and immune regulatory properties. It was loaded onto microneedles (PTPP-MN) for treating infected wounds. In vitro experiments demonstrated its ability to scavenge ROS and exhibit antioxidant properties. Compared to PT-MN (11.03 ± 3.37 %) and PTP-MN (42.30 ± 2.60 %), the ROS scavenging rate of PTPP-MN reached 63.63 ± 4.42 %. The microneedle exhibits good biocompatibility, stimulating fibroblast migration, endothelial angiogenesis, and M2 macrophage polarization. Additionally, it effectively eliminates ROS and provides antioxidant effects while inhibiting the viability of S. aureus and E. coli. Animal experiments showed that the PTPP-MN group achieved near-complete re-epithelialization by the third day compared to other groups. Histological observations revealed that the PTPP-MN group exhibited enhanced granulation tissue formation, epithelial regeneration, and angiogenesis. After PTPP-MN treatment, the local immune response shifted from a pro-inflammatory state to a pro-regenerative state. Our results indicate that PTPP-MN holds great promise for infected wound healing with reduced scar formation.

Naphthalene Diimide-Based Polycyclic Conjugated Molecule Composite CoFe2O4 Nanohybrids for Photoacoustic Imaging-Mediated Photo-/Sonic Therapy

The complex and harsh tumor microenvironment imped the efficacy of single-modality tumor therapy. With the advantages of biosafety, organic/inorganic nanohybrids have attracted more and more interest of researchers, and it is critical to investigate the development of highly efficient nanohybrids for multimodality combination therapy of cancers. Herein, a naphthalene diimide-based polycyclic conjugated molecule (NDI-S) is designed and synthesized, which has broader light absorption in the near infrared (NIR) region, outstanding photothermal conversion ability, and excellent photostability. Inorganic CoFe2O4 is synthesized via a solvothermal technique, which can produce much more reactive oxygen species (ROS) as a sonosensitizer when activated by ultrasonic (US). NDI-S and CoFe2O4 are then nanoprecipitated to create the organic/inorganic nanohybrids, NDI-S@CoFe2O4. According to the results of in vitro and in vivo experiments, NDI-S@CoFe2O4 can serve as a multifunctional nanoplatform for multimodal treatment of tumors in combination with photothermal/photodynamic/sonodynamic- therapy under the guidance of photoacoustic imaging, which provides a new vision of the development of organic/inorganic nanohybrids for cancer theranostics.

Organic-Inorganic Interfacial Dipole Induced by Energy Level Alignment for Efficient Photocatalytic Sterilization

Photocatalytic molecules are considered to be one of the most promising substitutions of antibiotics against multidrug-resistant bacterial infections. However, the strong excitonic effect greatly restricts their efficiency in antibacterial performance. Inspired by the interfacial dipole effect, a Ti3C2 MXene modified photocatalytic molecule (MTTTPyB) is designed and synthesized to enhance the yield of photogenerated carriers under light irradiation. The alignment of the energy level between Ti3C2 and MTTTPyB results in the formation of an interfacial dipole, which can provide an impetus for the separation of carriers. Under the role of a dipole electric field, these photogenerated electrons can rapidly migrate to the side of Ti3C2 for improving the separation efficiency of photogenerated electrons and holes. Thus, more electrons can be utilized to produce reactive oxygen species (ROS) under light irradiation. As a result, over 97.04% killing efficiency can be reached for Staphylococcus aureus (S. aureus) when the concentration of MTTTPyB/Ti3C2 was 50 ppm under 660 nm irradiation for 15 min. A microneedle (MN) patch made from MTTTPyB/Ti3C2 was used to treat the subcutaneous bacterial infection. This design of an organic-inorganic interface provides an effective method to minimize the excitonic effect of molecules, further expanding the platform of inorganic/organic hybrid materials for efficient phototherapy.

Polysaccharide hydrogels for skin wound healing

Advances in the development and utilization of polysaccharide materials are highly promising, offering prominent applications in the field of tissue engineering for addressing diverse clinical needs, including wound healing, bone regeneration, cartilage repair, and treatment of conditions such as arthritis. Novel polysaccharide materials are popular owing to their inherent stability, biocompatibility, and repeatability. This review presents an overview of the biomedical applications of natural polysaccharide hydrogels and their derivatives. Herein, we discuss the latest advancements in the fabrication, physicochemical properties, and biomedical applications of polysaccharide-based hydrogels, including chitosan, hyaluronic acid, alginate, and cellulose. Various processing techniques applicable to polysaccharide materials are explored, such as the transformation of polysaccharide hydrogels into electrospun nanofibers, microneedles, microspheres, and nanogels. Furthermore, the use of polysaccharide hydrogels in the context of wound-healing applications, including hemostatic effects, antimicrobial activities, anti-inflammatory properties, and promotion of angiogenesis, is presented. Finally, we address the challenges encountered in the development of polysaccharide hydrogels and outline the potential prospects in this evolving field.

Microneedle-mediated drug delivery for neurological diseases

Neurological disorders, including brain injury, brain tumors, and neurodegenerative diseases, rank as the second leading cause of death worldwide. Exploring effective new treatments for neurological disorders has long been a hot research issue in clinical practice. Recently, microneedles (MNs) have attracted much attention due to their designation as a "painless and non-invasive" novel transdermal delivery method, characterized by their biocompatibility and sustainability. The advantages of MNs open an avenue for potential therapeutic interventions targeting neurological disorders. This review presents a concise overview of progress in the field of MNs, with highlights on the application in the treatment of neurological disorders. Notably, trends in the development of MNs and future challenges are also discussed.

Advances in Polysaccharide-Based Microneedle Systems for the Treatment of Ocular Diseases

The eye, a complex organ isolated from the systemic circulation, presents significant drug delivery challenges owing to its protective mechanisms, such as the blood-retinal barrier and corneal impermeability. Conventional drug administration methods often fail to sustain therapeutic levels and may compromise patient safety and compliance. Polysaccharide-based microneedles (PSMNs) have emerged as a transformative solution for ophthalmic drug delivery. However, a comprehensive review of PSMNs in ophthalmology has not been published to date. In this review, we critically examine the synergy between polysaccharide chemistry and microneedle technology for enhancing ocular drug delivery. We provide a thorough analysis of PSMNs, summarizing the design principles, fabrication processes, and challenges addressed during fabrication, including improving patient comfort and compliance. We also describe recent advances and the performance of various PSMNs in both research and clinical scenarios. Finally, we review the current regulatory frameworks and market barriers that are relevant to the clinical and commercial advancement of PSMNs and provide a final perspective on this research area.

Nanozyme-Incorporated Microneedles for the Treatment of Chronic Wounds

Acute wounds are converted to chronic wounds due to advanced age and diabetic complications. Nanozymes catalyze ROS production to kill bacteria without causing drug resistance, while microneedles (MNs) can break through the skin barrier to deliver drugs effectively. Nanozymes can be intergrateded into MNs delivery systems to improve painless drug delivery. It can also reduce the effective dose of drug sterilization while increasing delivery efficiency and effectively killing wounded bacteria while preventing drug resistance. This paper describes various types of metal nanozymes from previous studies and compares their mutual enhancement with nanozymes. The pooled results show that the MNs, through material innovation, are able to both penetrate the scab and deliver nanozymes and exert additional anti-inflammatory and bactericidal effects. The catalytic effect of some of the nanozymes can also accelerate the lysis of the MNs or create a cascade reaction against inflammation and infection. However, the issue of increased toxicity associated with skin penetration and clinical translation remains a challenge. This study reviews the latest published results and corresponding challenges associated with the use of MNs combined with nanozymes for the treatment of wounds, providing further information for future research.

Engineering Magnetic Extracellular Vesicles Mimetics for Enhanced Targeting Chemodynamic Therapy to Overcome Ovary Cancer

Chemodynamic therapy (CDT), employing metal ions to transform endogenous H2O2 into lethal hydroxyl radicals (•OH), has emerged as an effective approach for tumor treatment. Yet, its efficacy is diminished by glutathione (GSH), commonly overexpressed in tumors. Herein, a breakthrough strategy involving extracellular vesicle (EV) mimetic nanovesicles (NVs) encapsulating iron oxide nanoparticles (IONPs) and β-Lapachone (Lapa) was developed to amplify intracellular oxidative stress. The combination, NV-IONP-Lapa, created through a serial extrusion from ovarian epithelial cells showed excellent biocompatibility and leveraged magnetic guidance to enhance endocytosis in ovarian cancer cells, resulting in selective H2O2 generation through Lapa catalysis by NADPH quinone oxidoreductase 1 (NQO1). Meanwhile, the iron released from IONPs ionization under acidic conditions triggered the conversion of H2O2 into •OH by the Fenton reaction. Additionally, the catalysis process of Lapa eliminated GSH in tumor, further amplifying oxidative stress. The designed NV-IONP-Lapa demonstrated exceptional tumor targeting, facilitating MR imaging, and enhanced tumor suppression without significant side effects. This study presents a promising NV-based drug delivery system for exploiting CDT against NQO1-overexpressing tumors by augmenting intratumoral oxidative stress.

Ultrasound-Based Micro-/Nanosystems for Biomedical Applications

Due to the intrinsic non-invasive nature, cost-effectiveness, high safety, and real-time capabilities, besides diagnostic imaging, ultrasound as a typical mechanical wave has been extensively developed as a physical tool for versatile biomedical applications. Especially, the prosperity of nanotechnology and nanomedicine invigorates the landscape of ultrasound-based medicine. The unprecedented surge in research enthusiasm and dedicated efforts have led to a mass of multifunctional micro-/nanosystems being applied in ultrasound biomedicine, facilitating precise diagnosis, effective treatment, and personalized theranostics. The effective deployment of versatile ultrasound-based micro-/nanosystems in biomedical applications is rooted in a profound understanding of the relationship among composition, structure, property, bioactivity, application, and performance. In this comprehensive review, we elaborate on the general principles regarding the design, synthesis, functionalization, and optimization of ultrasound-based micro-/nanosystems for abundant biomedical applications. In particular, recent advancements in ultrasound-based micro-/nanosystems for diagnostic imaging are meticulously summarized. Furthermore, we systematically elucidate state-of-the-art studies concerning recent progress in ultrasound-based micro-/nanosystems for therapeutic applications targeting various pathological abnormalities including cancer, bacterial infection, brain diseases, cardiovascular diseases, and metabolic diseases. Finally, we conclude and provide an outlook on this research field with an in-depth discussion of the challenges faced and future developments for further extensive clinical translation and application.

Metainterface Heterostructure Enhances Sonodynamic Therapy for Disrupting Secondary Biofilms

Implant-related secondary infections are a challenging clinical problem. Sonodynamic therapy (SDT) strategies are promising for secondary biofilm infections by nonsurgical therapy. However, the inefficiency of SDT in existing acoustic sensitization systems limits its application. Therefore, we take inspiration from popular metamaterials and propose the design idea of a metainterface heterostructure to improve SDT efficiency. The metainterfacial heterostructure is defined as a periodic arrangement of heterointerface monoclonal cells that amplify the intrinsic properties of the heterointerface. Herein, we develop a TiO2/Ti2O3/vertical graphene metainterface heterostructure film on titanium implants. This metainterface heterostructure exhibits extraordinary sonodynamic and acoustic-to-thermal conversion effects under low-intensity ultrasound. The modulation mechanisms of the metainterface for electron accumulation and separation are revealed. The synergistic sonodynamic/mild sonothermal therapy disrupts biofilm infections (antibacterial rates: 99.99% for Staphylococcus aureus, 99.54% for Escherichia coli), and the osseointegration ability of implants is significantly improved in in vivo tests. Such a metainterface heterostructure film lays the foundation for the metainterface of manipulating electron transport to enhance the catalytic performance and holding promise for addressing secondary biofilm infections.

Bioinspired multifunctional cellulose film: In situ bacterial capturing and killing for managing infected wounds

Bacterial infection of cutaneous wounds can easily lead to occurrence of chronic wounds and even more serious diseases. Therefore, multifunctional, biodegradable, and reusable wound dressings that can quickly manage wound infection and promote wound healing are urgently desired. Herein, inspired by the "capturing and killing" action of Drosera peltata Thunb., a biomimetic cellulose film was constructed to capture the bacteria (via the rough structure of the film) and kill them (via the combination of photodynamic therapy and chemotherapy) to promote wound tissue remodeling. The film (termed OBC-PR) was simply prepared by chemically crosslinking the oxidized bacterial cellulose (OBC) with polyhexamethylene guanidine hydrochloride (PHGH) and rose bengal (RB). Notably, it could effectively capture Escherichia coli and Staphylococcus aureus bacterial cells with capture efficiencies of ∼99 % and ∼96 %, respectively, within 10 min. Furthermore, the in vivo experiments showed that OBC-PR could effectively promote the macrophage polarization toward the M2 phenotype and adequately induce the reconstruction of blood vessels and nerves, thus promoting wound healing. This study provides a potential direction for designing multifunctional wound dressings for managing infected skin wounds in the future.

Antimicrobial Properties of Carboxymethyl Cellulose/Starch/N'N Methylenebisacrylamide Membranes Endowed by Ultrasound and Their Potential Application in Antimicrobial Packaging

Cellulose is used widely in antimicrobial packaging due to its abundance in nature, biodegradability, renewability, non-toxicity, and low cost. However, how efficiently and rapidly it imparts high antimicrobial activity to cellulose-based packaging materials remains a challenge. In this work, Ag NPs were deposited on the surface of carboxymethyl cellulose/starch/N'N Methylenebisacrylamide film using ultrasonic radiation. Morphology and structure analysis of as-prepared films were conducted, and the antibacterial effects under different ultrasonic times and reductant contents were investigated. These results showed that Ag NPs were distributed uniformly on the film surface under an ultrasonic time of 45 min. The size of Ag NPs changes as the reducing agent content decreases. The composite film demonstrated a slightly better antibacterial effect against E. coli than against S. aureus. Therefore, this work can provide valuable insights for the research on antimicrobial packaging.

Targeting Diverse Wounds and Scars: Recent Innovative Bio-design of Microneedle Patch for Comprehensive Management

Wounds and the subsequent formation of scars constitute a unified and complex phased process. Effective treatment is crucial; however, the diverse therapeutic approaches for different wounds and scars, as well as varying treatment needs at different stages, present significant challenges in selecting appropriate interventions. Microneedle patch (MNP), as a novel minimally invasive transdermal drug delivery system, has the potential for integrated and programmed treatment of various diseases and has shown promising applications in different types of wounds and scars. In this comprehensive review, the latest applications and biotechnological innovations of MNPs in these fields are thoroughly explored, summarizing their powerful abilities to accelerate healing, inhibit scar formation, and manage related symptoms. Moreover, potential applications in various scenarios are discussed. Additionally, the side effects, manufacturing processes, and material selection to explore the clinical translational potential are investigated. This groundwork can provide a theoretical basis and serve as a catalyst for future innovations in the pursuit of favorable therapeutic options for skin tissue regeneration.

Metal natural product complex Ru-procyanidins with quadruple enzymatic activity combat infections from drug-resistant bacteria

Bacterial infection hampers wound repair by impeding the healing process. Concurrently, inflammation at the wound site triggers the production of reactive oxygen species (ROS), causing oxidative stress and damage to proteins and cells. This can lead to chronic wounds, posing severe risks. Therefore, eliminating bacterial infection and reducing ROS levels are crucial for effective wound healing. Nanozymes, possessing enzyme-like catalytic activity, can convert endogenous substances into highly toxic substances, such as ROS, to combat bacteria and biofilms without inducing drug resistance. However, the current nanozyme model with single enzyme activity falls short of meeting the complex requirements of antimicrobial therapy. Thus, developing nanozymes with multiple enzymatic activities is essential. Herein, we engineered a novel metalloenzyme called Ru-procyanidin nanoparticles (Ru-PC NPs) with diverse enzymatic activities to aid wound healing and combat bacterial infections. Under acidic conditions, due to their glutathione (GSH) depletion and peroxidase (POD)-like activity, Ru-PC NPs combined with H2O2 exhibit excellent antibacterial effects. However, in a neutral environment, the Ru-PC NPs, with catalase (CAT) activity, decompose H2O2 to O2, alleviating hypoxia and ensuring a sufficient oxygen supply. Furthermore, Ru-PC NPs possess exceptional antioxidant capacity through their superior superoxide dismutase (SOD) enzyme activity, effectively scavenging excess ROS and reactive nitrogen species (RNS) in a neutral environment. This maintains the balance of the antioxidant system and prevents inflammation. Ru-PC NPs also promote the polarization of macrophages from M1 to M2, facilitating wound healing. More importantly, Ru-PC NPs show good biosafety with negligible toxicity. In vivo wound infection models have confirmed the efficacy of Ru-PC NPs in inhibiting bacterial infection and promoting wound healing. The focus of this work highlights the quadruple enzymatic activity of Ru-PC NPs and its potential to reduce inflammation and promote bacteria-infected wound healing.

Enzyme-triggered on-demand release of a H2O2-self-supplying CuO2@Fe3O4 nanoagent for enhanced chemodyamic antimicrobial therapy and wound healing

Nanoagents for chemodynamic therapy (CDT) hold a promising future in the field of antimicrobials, especially copper peroxide (CuO2) (CP) nanomaterials which have garnered significant attention due to their ability to self-supply H2O2. Nevertheless, the poor stability of CuO2 remains a critical challenge which restricts its practical application in the antibacterial field. In this study, an advanced nano-antimicrobial system HA-CP@Fe3O4 with enzyme-responsive properties is developed by coating hyaluronic acid (HA) on CuO2-loaded iron tetraoxide nanoparticles. The coating of HA not only stabilizes the CuO2 nanomaterials but also provides responsiveness towards the enzyme hyaluronidase, which is typically secreted by some bacteria. The outer layer of HA in HA-CP@Fe3O4 undergoes decomposition in the presence of hyaluronidase-secreting bacteria, resulting in the release of CuO2@Fe3O4. The released CuO2@Fe3O4 then self-supplies H2O2 and generates reactive oxygen species (ROS) within the infected microenvironment through Fenton and Russell effects, to ultimately achieve effective and precise antimicrobial activity. Simultaneously, the magnetic property provided by Fe3O4 allows the substance to be directed towards the infection site. Both in vitro and in vivo tests demonstrated that HA-CP@Fe3O4 exhibited excellent antimicrobial capabilities at low concentration (30 μg mL-1), exceptional biocompatibility and the ability to accelerate wound healing. The findings of this work offer a new and promising approach for targeted and precise CDT.

Carbomer Hydrogel Composed of Cu2O and Hematoporphyrin Monomethyl Ether Promotes the Healing of Infected Wounds

Infectious wounds pose a significant challenge in the field of wound healing primarily due to persistent inflammation and the emergence of antibiotic-resistant bacteria. To combat these issues, the development of an effective wound dressing that can prevent infection and promote healing is of the utmost importance. Photodynamic therapy (PDT) has emerged as a promising noninvasive treatment strategy for tackling antibiotic-resistant bacteria. A biodegradable photosensitizer called hematoporphyrin monomethyl ether (HMME) has shown potential in generating reactive oxygen species (ROS) upon laser activation to combat bacteria. However, the insolubility of HMME limits its antibacterial efficacy and its ability to facilitate skin healing. To overcome these limitations, we have synthesized a compound hydrogel by combining carbomer, HMME, and Cu2O nanoparticles. This compound hydrogel exhibits enhanced antimicrobial ability and excellent biocompatibility and promotes angiogenesis, which is crucial for the healing of skin defects. By integrating the benefits of HMME, Cu2O nanoparticles, and the gel-forming properties of carbomer, this compound hydrogel shows great potential as an effective wound dressing material. In summary, the compound hydrogel developed in this study offers a promising solution for infectious wounds by addressing the challenges of infection prevention and promoting skin healing. This innovative approach utilizing PDT and the unique properties of the compound hydrogel could significantly improve the outcomes of wound healing in clinical settings.

Ultrasound-activatable and skin-associated minimally invasive microdevices for smart drug delivery and diagnosis

Ultrasound-activatable and skin-associated minimally invasive microdevices (USMIMs) have garnered significant attention in the domains of smart drug delivery and biomedical diagnosis for on-demand healthcare, owing to their outstanding wearability, flexibility, and comfort. In this review, we present a comprehensive overview of the noteworthy advancements in USMIMs, with a specific focus on device design, potential applications, challenges, and future prospects. The classification of such microdevices primarily encompasses biointerfacing microsystems, including skin-perforable US-assisted microneedles (MNs), skin-attachable sonophoresis and their combination with microbubbles, as well as non-biointerfacing microsystems for drug delivery. Additionally, US-mediated and skin-attached microtransducers utilized in biomedical diagnosis are classified into imaging-related microtransducers, diagramming detection devices, and their combinative systems with applications on diverse signal detection. Besides, the review also highlights the challenges associated with USMIMs, focusing on aspects such as safety, environmental tolerance, wearability/comfortability, and personalization. Furthermore, it offers insights into future perspectives that address these challenges and discuss potential advancements in the field. It is firmly believed that the proposed USMIMs possess immense potential to significantly improve human lives in the near future.

Manganese Dioxide/Gold-based Active Tumor Targeting Nanoprobes for Enhancing Photodynamic and Low-Temperature-Photothermal Combination Therapy in Lung Cancer

Tumor drug resistance caused by the tumor microenvironment is an extremely difficult problem for researchers to solve. Nanoplatforms that integrate diagnosis and treatment have great advantages in tumor treatment, but the design and synthesis of simple and efficient nanoplatforms still face tremendous challenges. In this study, a novel Mn/Au@ir820/GA-CD133 nanoprobe was developed. The manganese dioxide/gold particles were prepared by coprecipitation/assembly, chemically coupled with CD133 antibody, and finally loaded with the photosensitive drug IR820 and the heat shock protein inhibitor Ganetespib. The nanoprobe demonstrated good tumor-targeting ability, increased the level of singlet oxygen produced from laser irradiation by effectively alleviating tumor hypoxia, and decreased the threshold of heat tolerance by downregulating the expression of HSP90 in tumor tissues. This nanoprobe successfully inhibited the growth and progression of tumor tissues in a tumor-bearing mouse model by improving the effectiveness of photodynamic and low-temperature photothermal combination therapy.

Metallic elements combine with herbal compounds upload in microneedles to promote wound healing: a review

Wound healing is a dynamic and complex restorative process, and traditional dressings reduce their therapeutic effectiveness due to the accumulation of drugs in the cuticle. As a novel drug delivery system, microneedles (MNs) can overcome the defect and deliver drugs to the deeper layers of the skin. As the core of the microneedle system, loaded drugs exert a significant influence on the therapeutic efficacy of MNs. Metallic elements and herbal compounds have been widely used in wound treatment for their ability to accelerate the healing process. Metallic elements primarily serve as antimicrobial agents and facilitate the enhancement of cell proliferation. Whereas various herbal compounds act on different targets in the inflammatory, proliferative, and remodeling phases of wound healing. The interaction between the two drugs forms nanoparticles (NPs) and metal-organic frameworks (MOFs), reducing the toxicity of the metallic elements and increasing the therapeutic effect. This article summarizes recent trends in the development of MNs made of metallic elements and herbal compounds for wound healing, describes their advantages in wound treatment, and provides a reference for the development of future MNs.

Sonodynamic therapy-based nanoplatforms for combating bacterial infections

The rapid spread and uncontrollable evolution of antibiotic-resistant bacteria have already become urgent global to treat bacterial infections. Sonodynamic therapy (SDT), a noninvasive and effective therapeutic strategy, has broadened the way toward dealing with antibiotic-resistant bacteria and biofilms, which base on ultrasound (US) with sonosensitizer. Sonosensitizer, based on small organic molecules or inorganic nanoparticles, is essential to the SDT process. Thus, it is meaningful to design a sonosensitizer-loaded nanoplatform and synthesize the nanoplatform with an efficient SDT effect. In this review, we initially summarize the probable SDT-based antibacterial mechanisms and systematically discuss the current advancement in different SDT-based nanoplatform (including nanoplatform for organic small-molecule sonosensitizer delivery and nanoplatform as sonosensitizer) for bacterial infection therapy. In addition, the biomedical applications of SDT-involved multifunctional nanoplatforms are also discussed. We believe the innovative SDT-based nanoplatforms would become a highly efficient next-generation noninvasive therapeutic tool for combating bacterial infection.

Going below and beyond the surface: Microneedle structure, materials, drugs, fabrication, and applications for wound healing and tissue regeneration

Microneedle, as a novel drug delivery system, has attracted widespread attention due to its non-invasiveness, painless and simple administration, controllable drug delivery, and diverse cargo loading capacity. Although microneedles are initially designed to penetrate stratum corneum of skin for transdermal drug delivery, they, recently, have been used to promote wound healing and regeneration of diverse tissues and organs and the results are promising. Despite there are reviews about microneedles, few of them focus on wound healing and tissue regeneration. Here, we review the recent advances of microneedles in this field. We first give an overview of microneedle system in terms of its potential cargos (e.g., small molecules, macromolecules, nucleic acids, nanoparticles, extracellular vesicle, cells), structural designs (e.g., multidrug structures, adhesive structures), material selection, and drug release mechanisms. Then we briefly summarize different microneedle fabrication methods, including their advantages and limitations. We finally summarize the recent progress of microneedle-assisted wound healing and tissue regeneration (e.g., skin, cardiac, bone, tendon, ocular, vascular, oral, hair, spinal cord, and uterine tissues). We expect that our article would serve as a guideline for readers to design their microneedle systems according to different applications, including material selection, drug selection, and structure design, for achieving better healing and regeneration efficacy.

Copper-Single-Atom Coordinated Nanotherapeutics for Enhanced Sonothermal-Parallel Catalytic Synergistic Cancer Therapy

Phototherapy and sonotherapy are recognized by scientific medicine as effective strategies for treating certain cancers. However, these strategies have limitations such as an inability to penetrate deeper tissues and overcome the antioxidant tumor microenvironment. In this study, a novel "BH" interfacial-confined coordination strategy to synthesize hyaluronic acid-functionalized single copper atoms dispersed over boron imidazolate framework-derived nanocubes (HA-NC_Cu) to achieve sonothermal-catalytic synergistic therapy is reported. Notably, HA-NC_Cu demonstrates exceptional sonothermal conversion performance under low-intensity ultrasound irradiation, attained through intermolecular lattice vibrations. In addition, it shows promise as an efficient biocatalyst, able to generate high-toxicity hydroxyl radicals in response to tumor-endogenous hydrogen peroxide and glutathione. Density functional theory calculations reveal that the superior parallel catalytic performance of HA-NC_Cu originates from the CuN4 C/B active sites. Both in vitro and in vivo evaluations consistently demonstrate that the sonothermal-catalytic synergistic strategy significantly improves tumor inhibition rate (86.9%) and long-term survival rate (100%). In combination with low-intensity ultrasound irradiation, HA-NC_Cu triggers a dual death pathway of apoptosis and ferroptosis in MDA-MB-231 breast cancer cells, comprehensively limiting primary triple-negative breast cancer. This study highlights the applications of single-atom-coordinated nanotherapeutics in sonothermal-catalytic synergistic therapy, which may create new opportunities in biomedical research.

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.

Emerging nanosonosensitizers augment sonodynamic-mediated antimicrobial therapies

With the widespread prevalence of drug-resistant pathogens, traditional antibiotics have limited effectiveness and do not yield the desired outcomes. Recently, alternative antibacterial therapies based on ultrasound (US) have been explored to overcome the crisis of bacterial pathogens. Antimicrobial sonodynamic therapy (aSDT) offers an excellent solution that relies on US irradiation to produce reactive oxygen species (ROS) and achieve antibiotic-free mediated antimicrobial effects. In addition, aSDT possesses the advantage of superior tissue penetrability of US compared to light irradiation, demonstrating great feasibility in treating deep infections. Although existing conventional sonosensitizers can produce ROS for antimicrobial activity, some limitations, such as low penetration rate, nonspecific distribution and poor ROS production under hypoxic conditions, result in suboptimal sterilization in aSDT. Recently, emerging nanosonosensitizers have enormous advantages as high-performance agents in aSDT, which overcome the deficiencies of conventional sonosensitizers as described above. Thus, nanosonosensitizer-mediated aSDT has a bright future for the management of bacterial infections. This review classifies the current available nanosonosensitizers and provides an overview of the mechanisms, biomedical applications, recent advances and perspectives of aSDT.