Combined photothermal and sonodynamic therapy using a 2D black phosphorus nanosheets loaded coating for efficient bacterial inhibition and bone-implant integration

Synergistic photothermal-sonodynamic therapy for antibacterial and immune reprogramming in chronic osteomyelitis

The development of antibiotic resistance and inadequate immune response in chronic inflammation pose significant challenges in treating chronic osteomyelitis. As accepted non-antibiotic antimicrobial therapies, sonodynamic therapy (SDT) and photothermal therapy (PTT) are recognized for their effectiveness in eliminating bacteria and promoting tissue repair, rendering them promising therapeutic strategies for treating bacterial infections and preventing the emergence of drug-resistant bacteria. However, the antimicrobial action and efficacy in promoting tissue repair depend on the activation status of the host immune system. In this study, by encapsulating horseradish peroxidase (HRP)-loaded gold/polydopamine (PDA) nanoparticles within DOTAP/DOPE cationic liposomes (DLPs), a novel multifunctional nanocatalyst, Au/PDA/HRP@DLP (APH@DLP), was developed to achieve antimicrobial effects and immunological reprogramming of chronic osteomyelitis through synergistic SDT and PTT. The impact on immune activation was investigated by assessing the anti-infective and healing effects in osteomyelitis rat models. The release of bacterial-associated antigens during treatment serves as an in situ vaccine, activating antigen-presenting cells and further stimulating adaptive immunity, while also inducing immune memory that significantly reduces the risk of recurrence. Additionally, macrophage phenotypic transformation during SDT and PTT facilitates tissue repair. This study highlights the role of immune activation in SDT/PTT-based antimicrobial therapy and suggests new strategies for treating chronic osteomyelitis.

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.

Black Phosphorus-Loaded Gelatin Methacryloyl Hydrogels Enhance Angiogenesis via Activation of the PEAK1-MAPK Pathway

Repair and regeneration of oral and maxillofacial tissue defects remain significant challenges, mainly due to the limitations of existing treatment approaches. Conventional methods such as transplantation, tissue scaffolds, growth factors, and stem cell therapies often face obstacles, including donor shortages, insufficient vascularization, and safety concerns. There is an urgent need for innovative therapeutic strategies to effectively promote vascular regeneration while minimizing complications. Black phosphorus nanosheets (BPNSs) and hydrogels present significant advantages and broad application potential as tissue regeneration carriers due to their biocompatibility, degradability, and controlled drug release properties. By combining various characterization techniques and detection methods, we conducted a thorough analysis of BPNSs and gelatin methacryloyl (GelMA) scaffolds loaded with BPNSs (BP-GelMA). The results indicate that this study successfully prepared BPNSs with uniform size, good dispersion, and intact structure. Moreover, the BP-GelMA composite demonstrated excellent swelling behavior and structural stability while effectively enabling the controlled release of BPNSs. This study investigated the angiogenic effects of BP-GelMA at concentrations of 0, 12.5, and 25.0 μg/mL. In vitro experiments showed that BP-GelMA significantly enhanced endothelial cell proliferation, migration, and tube formation. In vivo results demonstrated that 12.5 μg/mL and 25.0 μg/mL BP-GelMA did not induce significant developmental toxicity in zebrafish and effectively promoted neovascularization. RNA-Seq analysis revealed that BP-GelMA activates angiogenesis-related biological processes. Mechanistic studies identified PEAK1 as a central regulator, driving vascular formation through activation of the MAPK signaling pathway. These findings highlight the potential of BP-GelMA as a therapeutic strategy for promoting angiogenesis and underscore the importance of optimizing BP-GelMA concentrations to achieve maximum therapeutic efficacy and safety in clinical applications.

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.

Ultrasound-activated inorganic nanomaterials to generate ROS for antibacterial applications

Given the global overuse and misuse of antibiotics, the problem of antibiotic resistance has become increasingly severe, necessitating the urgent development of innovative therapeutic strategies to address bacterial infections. In recent years, nanomaterial-mediated sonodynamic therapy (SDT) has emerged as a promising alternative treatment. This strategy works by generating reactive oxygen species (ROS) to inhibit or kill bacteria, thereby avoiding the risk of antibiotic resistance. This review explores the various mechanisms by which ROS exert antibacterial effects and examines the different methods of generating ROS. It provides an overview of the diverse nanomaterials applied in SDT in recent years, including two-dimensional materials, metal-organic frameworks (MOFs), heterojunctions, and surface-modified bulk materials. Additionally, it discusses other types of nanomaterials such as metal oxides and piezoelectric materials, while also highlighting their specific therapeutic applications in treating infections like skin infections and osteomyelitis. At the conclusion of the review, the development of nanomaterial-mediated SDT is discussed in terms of both its potential and challenges. The article offers valuable theoretical insights and practical references for the preparation of the nanomaterials required for this antibiotic-free therapeutic approach, and proposes new directions for future research aimed at addressing the growing issue of antibiotic resistance.

Self-healing hydrogel based on polyvinyl alcohol/dextran with hyperglycemia-triggered cascade enzyme catalytic activity promotes diabetic wound healing

Bacterial infection, hypoxia and oxidative stress caused by high blood glucose are the main problems in diabetic wound healing. The glucose-activated cascade reaction could fundamentally solve these problems in diabetic wounds by consuming glucose and eliminating bacteria. In this paper, glucose oxidase (GOx) was immobilized on polyethylenimine (PEI) adsorbed molybdenum disulfide (MoS2) to prepare MoS2-PEI-GOx (MPG) composite particles, which were doped into the self-healing hydrogel of polyvinyl alcohol (PVA) and dextran (Dex) for preparing PD@MPG hydrogel. GOx can decompose excessive glucose into H2O2 and gluconic acid, thereby reducing the pH value and improving the microenvironment of the wound. Low pH value enables MoS2 exert a similar role as peroxidase, catalyzing H2O2 to produce hydroxyl radicals (OH) to kill bacteria. After reducing the blood glucose of the wound, MoS2 can play a similar role as catalase, catalyzing the excess H2O2 at the wound converted to O2, thereby alleviating hypoxia and oxidative stress. In addition, the wound healing ability of PD@MPG has been evaluated by in vivo study. The self-healing hydrogels developed in this study hold promise as an innovative dressing for diabetic wound healing.

A nanocatalytic membrane with sono-responsive antibacterial therapy (SRAT) for rapid sterilization and enhanced chronic wound healing

Pathogenic bacteria in infected microenvironments can severely disrupt the normal progression of wound healing. Sono-responsive nanomaterials have emerged as a promising alternative to conventional antibiotics for combating bacterial infections. Despite the advantageous sono-excited antibacterial properties of n-type barium titanate (BaTiO3, BTO), developing bioheterojunctions (bioHJs) with compatible sono-physical characteristics remains a key strategy for achieving superior sono-antibacterial efficiency. Here, we constructed a novel PN-bioHJ by integrating two-dimensional p-type black phosphorus (BP) with three-dimensional n-type cubic BTO and modifying it onto a poly(lactic-co-glycolic acid) (PLGA) spinning membrane to enhance antibacterial performance under ultrasonic (US) stimulation. The successful construction of PN-bioHJs can significantly enhance the yield of ROS production for sono-responsive antibacterial therapy (SRAT). Additionally, the biodegradable PLGA membrane provides a biocompatible and scalable platform for the acoustic activation of the PN-bioHJs while facilitating localized antibacterial therapy. The designed sono-responsive nanocatalytic membrane demonstrates excellent bactericidal performance with antibacterial rates exceeding 99% under US stimulation. In vivo tests further revealed that the proposed membrane shows excellent biocompatibility and the ability to mitigate pathogenic virulence factors, potentially aiding in the regeneration of infected tissues. This work introduces a promising strategy for leveraging acoustically activated membranes in biomedical applications, paving the way for advanced solutions to combat antibiotic resistance.

Glucose-triggered NO-evolving coating bestows orthopedic implants with enhanced anti-bacteria and angiectasis for safeguarding diabetic osseointegration

As a common chronic metabolic disease, diabetes mellitus (DM) features a hyperglycemic micromilieu around implants, resulting in the critical implantation failure and high complications such as peri-implantitis and angiectasis disorder. To address the plaguing issue, we devise and develop a glucose-unlocked NO-evolving orthopedic implant consisted of polyetheretherketone (PEEK), glucose oxidase (GOx) and l-arginine (Arg) with enhanced angiogenesis for boosting diabetic osseointegration. Upon hyperglycemic niche, GOx on implants catalytically exhaust glucose to H2O2, which immediately reacts with Arg to in situ liberate nitric oxide (NO), resulting in enhanced angiogenesis and angiectasis around PEEK implant. Besides, the engineered implant exhibits great anti-bacterial properties against both Gram-positive and Gram-negative bacteria, as well as fortifies osteogenicity of osteoblasts in terms of cell proliferation, alkaline phosphatase activity and calcium matrix mineralization. Intriguingly, in vivo evaluations utilizing diabetic infectious bone defect models of rat further authenticate that the engineered implants substantially augment bone remodeling and osseointegration at weeks 4 and 8 through dampening pathogens, anti-inflammatory as well as promoting angiectasis. Altogether, this work proposed a new tactic to remedy stalled diabetic osseointegration with hyperglycemic micromilieu-responsive therapeutic gas-evolving orthopedic implants.

Polydopamine-Coated Copper-Doped Mesoporous Silica/Gelatin-Waterborne Polyurethane Composite: A Multifunctional GBR Membrane Bone Defect Repair

Guided bone regeneration (GBR) membrane has proven to be a fundamental tool in the realm of bone defect repair. In this study, we develop a mussel-inspired composite biomaterial through polydopamine-assisted, combining gelatin-WPU matrix with the ion-release behavior of Cu-MSNs for augmented bone regeneration. The optimized composite membrane exhibits enhanced mechanical stability, demonstrating a tensile strength of 11.23 MPa (representing a 2.3-fold increase compared to Bio-Gide®), coupled with significantly slower degradation kinetics that retained 73.3% structural integrity after 35-day immersion in physiological solution. Copper ions act as angiogenic agents to promote blood vessel growth and as antimicrobial agents to prevent potential infections. The combined effect of these components creates a biomimetic environment that is ideal for cell adhesion, growth, and differentiation. This research significantly contributes to the development of advanced biomaterials that combine regeneration and infection-prevention functions. It provides a versatile and effective solution for treating bone injuries and defects, offering new hope for patients in need.

Understanding the interplay between pH and charges for theranostic nanomaterials

Nanotechnology has emerged as a highly promising platform for theranostics, offering dual capabilities in targeted imaging and therapy. Interactions between the nanomaterial and biological components determine the in vivo fate of these materials which makes the control of their surface properties of utmost importance. Nanoparticles with neutral or negative surface charge have a longer circulation time while positively charged nanoparticles have higher affinity to cells and better cellular uptake. This trade-off presents a key challenge in optimizing surface charge for theranostic applications. A sophisticated solution is an on-demand switch of surface charge, enabled by leveraging the distinct pH conditions at the target site. In this review, we explore the intricate relationship between pH and charge modulation, summarizing recent advances in pH-induced charge-switchable nanomaterials for theranostics over the past five years. Additionally, we discuss how these innovations enhance targeted drug delivery and imaging contrast and provide perspectives on future directions for this transformative field.

Black Phosphorus Nanosheet-Based Composite Biomaterials for the Enhanced Repair of Infectious Bone Defects

Infectious bone defects pose significant challenges in orthopedic practice, marked by persistent bacterial infection and ongoing inflammatory responses. Recent advancements in bone tissue engineering have led to the development of biomaterials with both antibacterial properties and the ability to promote bone regeneration, offering new solutions to these complex issues. Black phosphorus nanosheets (BPNS), a unique two-dimensional material, demonstrate exceptional biocompatibility, bioactivity, and antibacterial properties. Their combination of osteogenic, antibacterial, and anti-inflammatory effects positions BPNS as an ideal candidate for addressing bone defects complicated by infection. This Review explores the potential of BPNS-based composite biomaterials in repairing infectious bone defects, discussing their molecular mechanisms for antibacterial activity, including intrinsic antibacterial properties, photothermal therapy (PTT), photodynamic therapy (PDT), and drug delivery. The application of BPNS in treating infectious bone defects, through hydrogels, scaffolds, coatings, and fibers, is also discussed. The Review emphasizes the transformative role of BPNS in bone tissue engineering and advocates for continued research and development in this promising field.

Nanocapsuled Neutrophil Extracellular Trap Scavenger Combating Chronic Infectious Bone Destruction Diseases

Chronic infectious bone destruction diseases, such as periodontitis, pose a significant global health challenge. Repairing the bone loss caused by these chronic infections remains challenging. In addition to pathogen removal, regulating host immunity is imperative. The retention of neutrophil extracellular traps (NETs) in chronic infectious niches is found to be a barrier to inflammation resolution. However, whether ruining the existing NETs within the local infectious bone lesions can contribute to inflammation resolve and bone repair remains understudied. Herein, a nanocapsuled delivery system that scavenges NETs dual-responsively to near-infrared light as a switch and to NETs themselves as a microenvironment sensor is designed. Besides, the photothermal and photodynamic effects endow the nanocapsules with antibacterial properties. Together with the ability to clear NETs, these features facilitate the restoration of the normal host response. The immunocorrective properties and inherent pro-osteogenic effects finally promote local bone repair. Together, the NET scavenging nanocapsules address the challenge of impaired bone repair in chronic infections due to biased host response caused by excessive NETs. This study provides new concepts and strategies for repairing bone destruction attributable to chronic infections via correcting biased host responses in chronic infectious diseases.

Prospects of black phosphorus nanosheets in the treatment of peri-implantitis

Peri-implantitis represents an inflammatory condition characterized by the presence of plaque-related soft and hard tissue damage surrounding dental implants, often resulting in progressive alveolar bone loss and, ultimately, implant failure. Black phosphorus (BP), a novel two-dimensional (2D) material that has recently emerged in the biomedical field, has attracted increasing attention due to its unique osteogenic properties and exceptional antibacterial and antioxidant characteristics. Additionally, its outstanding biomedical attributes enhance angiogenesis and nerve regeneration. Compared to other biomaterials, its high specific surface area, high photothermal conversion efficiency, and complete biodegradability make BP a promising candidate for treating infection-related bone defects. This article reviews the biological properties of BP nanosheets (BPNSs) and discusses their potential applications in the context of peri-implantitis, aiming to provide fresh insights for future research and applications of BPNS.

Synthetic nanointerfacial bioengineering of Ti implants: on-demand regulation of implant-bone interactions for enhancing osseointegration

Titanium and its alloys are the most commonly used biometals for developing orthopedic implants to treat various forms of bone fractures and defects, but their clinical performance is still challenged by the unfavorable mechanical and biological interactions at the implant-tissue interface, which substantially impede bone healing at the defects and reduce the quality of regenerated bones. Moreover, the impaired osteogenesis capacity of patients under certain pathological conditions such as diabetes and osteoporosis may further impair the osseointegration of Ti-based implants and increase the risk of treatment failure. To address these issues, various modification strategies have been developed to regulate the implant-bone interactions for improving bone growth and remodeling in situ. In this review, we provide a comprehensive analysis on the state-of-the-art synthetic nanointerfacial bioengineering strategies for designing Ti-based biofunctional orthopedic implants, with special emphasis on the contributions to (1) promotion of new bone formation and binding at the implant-bone interface, (2) bacterial elimination for preventing peri-implant infection and (3) overcoming osseointegration resistance induced by degenerative bone diseases. Furthermore, a perspective is included to discuss the challenges and potential opportunities for the interfacial engineering of Ti implants in a translational perspective. Overall, it is envisioned that the insights in this review may guide future research in the area of biometallic orthopedic implants for improving bone repair with enhanced efficacy and safety.

Programmed surface platform orchestrates anti-bacterial ability and time-sequential bone healing for implant-associated infection

Implant-associated infection (IAI) has become an intractable challenge in clinic. The healing of IAI is a complex physiological process involving a series of spatiotemporal connected events. However, existing titanium-based implants in clinic suffer from poor antibacterial effect and single function. Herein, a versatile surface platform based on the presentation of sequential function is developed. Fabrication of titania nanotubes and poly-γ-glutamic acid (γ-PGA) achieves the efficient incorporation of silver ions (Ag+) and the pH-sensitive release in response to acidic bone infection microenvironment. The optimized PGA/Ag platform exhibits satisfactory biocompatibility and converts macrophages from pro-inflammatory M1 to pro-healing M2 phenotype during the subsequent healing stage, which creates a beneficial osteoimmune microenvironment and promotes angio/osteogenesis. Furthermore, the PGA/Ag platform mediates osteoblast/osteoclast coupling through inhibiting CCL3/CCR1 signaling. These biological effects synergistically improve osseointegration under bacterial infection in vivo, matching the healing process of IAI. Overall, the novel integrated PGA/Ag surface platform proposed in this study fulfills function cascades under pathological state and shows great potential in IAI therapy.

Biophysical stimuli for promoting bone repair and regeneration

Bone injuries and diseases are associated with profound changes in the biophysical properties of living bone tissues, particularly their electrical and mechanical properties. The biophysical properties of healthy bone are attributed to the complex network of interactions between its various cell types (i.e., osteocytes, osteoclast, immune cells and vascular endothelial cells) with the surrounding extracellular matrix (ECM) against the backdrop of a myriad of biomechanical and bioelectrical stimuli arising from daily physical activities. Understanding the pathophysiological changes in bone biophysical properties is critical to developing new therapeutic strategies and novel scaffold biomaterials for orthopedic surgery and tissue engineering, as well as provides a basis for the application of various biophysical stimuli as therapeutic agents to restore the physiological microenvironment of injured/diseased bone tissue, to facilitate its repair and regeneration. These include mechanical, electrical, magnetic, thermal and ultrasound stimuli, which will be critically examined in this review. A significant advantage of utilizing such biophysical stimuli to facilitate bone healing is that these may be applied non-invasively with minimal damage to surrounding tissues, unlike conventional orthopedic surgical procedures. Furthermore, the effects of such biophysical stimuli can be localized specifically at the bone defect site, unlike drugs or growth factors that tend to diffuse away after delivery, which may result in detrimental side effects at ectopic sites.

Nanocatalytic medicine enabled next-generation therapeutics for bacterial infections

The rapid rise of antibiotic-resistant strains and the persistence of biofilm-associated infections have significantly challenged global public health. Unfortunately, current clinical high-dose antibiotic regimens and combination therapies often fail to completely eradicate these infections, which can lead to adverse side effects and further drug resistance. Amidst this challenge, however, the burgeoning development in nanotechnology and nanomaterials brings hopes. This review provides a comprehensive summary of recent advancements in nanomaterials for treating bacterial infections. Firstly, the research progress of catalytic therapies in the field of antimicrobials is comprehensively discussed. Thereafter, we systematically discuss the strategies of nanomaterials for anti-bacterial infection therapies, including endogenous response catalytic therapy, exogenous stimulation catalytic therapy, and catalytic immunotherapy, in order to elucidate the mechanism of nanocatalytic anti-infections. Based on the current state of the art, we conclude with insights on the remaining challenges and future prospects in this rapidly emerging field.

Time-Dependent Electrical Active and Ultrasound-Responsive Calcium Titanate Implant Coating with Immunomodulation, Osteogenesis, and Customized Antibacterial Activity

Surgical site infection and insufficient osseointegration are notable risks factors associated with oral implant surgery. In this study, the development of a polarized calcium titanate (CT-P) coating for titanium surfaces is proposed as a solution to these problems. The coating generated electrical stimulation (ES) can inhibit pro-inflammatory M1-type macrophage polarization and promote anti-inflammatory M2-type macrophage polarization, resulting in favorable bone immunomodulation. The ES generated by the coating can match the physiological electrical potential that will change during bone repair, thereby promoting osseointegration in vivo. In addition, the system can also achieve on-demand antibacterial activity, mainly depending on the CT-P coating responding to ultrasound (US) irradiation to produce reactive oxygen species (ROS) and remove Staphylococcus aureus (S. aureus) on the surface of the implant. In conclusion, this work provides valuable insights for the development and clinical application of highly efficient electroactive coatings, as well as novel solutions for the selective treatment of bacterial infections in the surgical area.

Antibacterial and anti-biofilm activities of gold-curcumin nanohybrids and its polydopamine form upon photo-sonotherapy of Staphylococcus aureus infected implants: In vitro and animal model studies

Implant-related infections are among the major post-surgery problems, and treatment of these infections is challenging due to the formation of biofilms by microorganisms such as Staphylococcus aureus. Herein, a novel gold-curcumin nanohybrid (GCNH) was synthesized for the first time and characterized. GCNH had a band gap energy of 2.41 eV, a zeta potential of -15 mV, and comprised uniform spherical particles with a mean diameter of 8 ± 2 nm. The biological macromolecule of polydopamine was then coated on GCNH to prepare a gold-curcumin-polydopamine nanohybrid (GCDNH). The nanohybrids were employed as novel dual photo-sonosensitizers for bacterial eradication by near-infrared (NIR) light and ultrasound (US) irradiations. GCNH and GCDNH represented photothermal conversion efficiencies of 26 and 32 %, respectively, and GCDNH represented a hemolysis rate of 2.3 % under both near-infrared (NIR) light and ultrasound (US) irradiations. NIR light and US irradiations (photo-sonotherapy) of Staphylococcus aureus using GCDNH depicted anti-bacterial and anti-biofilm efficiencies of 98 and 99 %, respectively, in synergistic manners, which are higher or as high as other sensitizers reported previously. The mechanism of photo-sonotherapy was related to generation of high levels of reactive oxygen species (ROS), and protein and nucleic acid leakages. In an in vivo infection model, NIR light and US irradiations annihilated Staphylococcus aureus on GCDNH-covered implants with high efficiency, without causing damage to normal tissues.

Zinc finger-inspired peptide-metal-phenolic nanointerface enhances bone-implant integration under bacterial infection microenvironment through immune modulation and osteogenesis promotion

Orthopedic and dental implantations under bacterial infection microenvironment face significant challenges in achieving high-quality bone-implant integration. Designing implant coatings that incorporate both immune defense and anti-inflammation is difficult in conventional single-functional coatings. We introduce a multifunctional nanointerface using a zinc finger-inspired peptide-metal-phenolic nanocoating, designed to enhance implant osseointegration under such conditions. Abaloparatide (ABL), a second-generation anabolic drug for treating osteoporosis, can be integrated into the design of a zinc-phenolic network constructed on the implant surface (ABL@ZnTA). Importantly, the phenolic-coordinated Zn2+ ions in ABL@ZnTA can act as zinc finger motif to co-stabilize the configuration of ABL through multiple molecular interactions, enabling high bioactivity, high loading capacity (1.36 times), and long-term release (>7 days) of ABL. Our results showed that ABL@ZnTA can modulate macrophage polarization from the pro-inflammatory M1 towards the anti-inflammatory M2 phenotype, promoting immune osteogenesis with increased OCN, ALP, and SOD 1 expression. Furthermore, the ABL@ZnTA significantly reduces inflammatory fibrous tissue encapsulation and enhances the long-term stability of the implants, indicated by enhanced binding strength (6 times) and functional connectivity (1.5-3 times) in the rat bone defect model infected by S. aureus. Overall, our research offers a nano-enabled synergistic strategy that balances infection defense and osteogenesis promotion in orthopedic and dental implantations.

Nanosonosensitizer Optimization for Enhanced Sonodynamic Disease Treatment

Low-intensity ultrasound-mediated sonodynamic therapy (SDT), which, by design, integrates sonosensitizers and molecular oxygen to generate therapeutic substances (e.g., toxic hydroxyl radicals, superoxide anions, or singlet oxygen) at disease sites, has shown enormous potential for the effective treatment of a variety of diseases. Nanoscale sonosensitizers play a crucial role in the SDT process because their structural, compositional, physicochemical, and biological characteristics are key determinants of therapeutic efficacy. In particular, advances in materials science and nanotechnology have invigorated a series of optimization strategies for augmenting the therapeutic efficacy of nanosonosensitizers. This comprehensive review systematically summarizes, discusses, and highlights state-of-the-art studies on the current achievements of nanosonosensitizer optimization in enhanced sonodynamic disease treatment, with an emphasis on the general design principles of nanosonosensitizers and their optimization strategies, mainly including organic and inorganic nanosonosensitizers. Additionally, recent advancements in optimized nanosonosensitizers for therapeutic applications aimed at treating various diseases, such as cancer, bacterial infections, atherosclerosis, and autoimmune diseases, are clarified in detail. Furthermore, the biological effects of the improved nanosonosensitizers for versatile SDT applications are thoroughly discussed. The review concludes by highlighting the current challenges and future opportunities in this rapidly evolving research field to expedite its practical clinical translation and application.

Intrinsically bioactive multifunctional Poly(citrate-curcumin) for rapid lung injury and MRSA infection therapy

Dysregulated inflammation after trauma or infection could result in the further disease and delayed tissue reconstruction. The conventional anti-inflammatory drug treatment suffers to the poor bioavailability and side effects. Herein, we developed an amphiphilic multifunctional poly (citrate-polyglycol-curcumin) (PCGC) nano oligomer with the robust anti-inflammatory activity for treating acute lung injury (ALI) and Methicillin-resistant staphylococcus aureus (MRSA) infected wound. PCGC demonstrated the sustained curcumin release, inherent photoluminescence, good cellular compatibility, hemocompatibility, robust antioxidant activity and enhanced cellular uptake. PCGC could efficiently scavenge nitrogen-based free radicals, oxygen-based free radicals, and intracellular oxygen species, enhance the endothelial cell migration and reduce the expression of pro-inflammatory factors through the NF-κB signal pathway. Combined the anti-inflammation and antioxidant properties, PCGC can shortened the inflammatory process. In animal model of ALI, PCGC was able to reduce the pulmonary edema, bronchial cell infiltration, and lung inflammation, while exhibiting rapid metabolic behavior in vivo. The MRSA-infection wound model showed that PCGC significantly reduced the expression of pro-inflammatory factors, promoted the angiogenesis and accelerated the wound healing. The transcriptome sequencing and molecular mechanism studies further demonstrated that PCGC could inhibit multiple inflammatory related pathways including TNFAIP3, IL-15RA, NF-κB. This work demonstrates that PCGC is efficient in resolving inflammation and promotes the prospect of application in inflammatory diseases as the drug-loaded therapeutic system.

An updated review of few-layer black phosphorus serving as a promising photocatalyst: synthesis, modification and applications

Semiconductor photocatalysts represent a potential strategy to simultaneously solve the global energy shortage and environmental pollution, and black phosphorus (BP) has gained widespread applications in photocatalysis due to its high hole mobility, strong light trapping capabilities, and adjustable band gap. Nevertheless, the original material exhibits unsatisfactory photocatalytic activity in terms of low carrier separation efficiency, weak environmental stability, and difficult to control layer thickness. The following review briefly presents the fundamental characteristics and extensively discusses the synthesis methods and modification strategies for few-layer black phosphorus (FL-BP). Furthermore, various applications of composite photocatalysts derived from FL-BP such as water splitting, pollutant degradation, the carbon dioxide reduction reaction (CO2RR), phototherapy, bacterial disinfection, N2 fixation, and hydrogenation reactions are reviewed. Finally, the opportunities and challenges for the development and further investigation of advanced FL-BP-based photocatalysts are also presented.

Application of advanced surface modification techniques in titanium-based implants: latest strategies for enhanced antibacterial properties and osseointegration

Titanium-based implants, renowned for their excellent mechanical properties, corrosion resistance, and biocompatibility, have found widespread application as premier implant materials in the medical field. However, as bioinert materials, they often face challenges such as implant failure caused by bacterial infections and inadequate osseointegration post-implantation. Thus, to address these issues, researchers have developed various surface modification techniques to enhance the surface properties and bioactivity of titanium-based implants. This review aims to outline several key surface modification methods for titanium-based implants, including acid etching, sol-gel method, chemical vapor deposition, electrochemical techniques, layer-by-layer self-assembly, and chemical grafting. It briefly summarizes the advantages, limitations, and potential applications of these technologies, presenting readers with a comprehensive perspective on the latest advances and trends in the surface modification of titanium-based implants.

Black phosphorus for bone regeneration: Mechanisms involved and influencing factors

BP has shown good potential for promoting bone regeneration. However, the understanding of the mechanisms of BP-enhanced bone regeneration is still limited. This review first summarizes the recent advances in applications of BP in bone regeneration. We further highlight the possibility that BP enhances bone regeneration by regulating the behavior of mesenchymal stem cells (MSCs), osteoblasts, vascular endothelial cells (VECs), and macrophages, mainly through the regulation of cytoskeletal remodeling, energy metabolism, oxidation resistance and surface adsorption properties, etc. In addition, moderating the physicochemical properties of BP (i.e., shape, size, and surface charge) can alter the effects of BP on bone regeneration. This review reveals the underlying mechanisms of BP-enhanced bone regeneration and provides strategies for further material design of BP-based materials for bone regeneration.

Graphene Oxide/Black Phosphorus Functionalized Collagen Scaffolds with Enhanced Near-Infrared Controlled In Situ Biomineralization for Promoting Infectious Bone Defect Repair through PI3K/Akt Pathway

Infectious bone defects resulting from surgery, infection, or trauma are a prevalent clinical issue. Current treatments commonly used include systemic antibiotics and autografts or allografts. Nevertheless, therapies come with various disadvantages, including multidrug-resistant bacteria, complications arising from the donor site, and immune rejection, which makes artificial implants desirable. However, artificial implants can fail due to bacterial infections and inadequate bone fusion after implantation. Thus, the development of multifunctional bone substitutes that are biocompatible, antibacterial, osteoconductive, and osteoinductive would be of great clinical importance. This study designs and prepares 2D graphene oxide (GO) and black phosphorus (BP) reinforced porous collagen (Col) scaffolds as a viable strategy for treating infectious bone defects. The fabricated Col-GO@BP scaffold exhibited an efficient photothermal antibacterial effect under near-infrared (NIR) irradiation. A further benefit of the NIR-controlled degradation of BP was to promote biomineralization by phosphorus-driven and calcium-extracted phosphorus in situ. The abundant functional groups in GO could synergistically capture the ions and enhance the in situ biomineralization. The Col-GO@BP scaffold facilitated osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSC) by leveraging its mild photothermal effect and biomineralization process, which upregulated heat shock proteins (HSPs) and activated PI3K/Akt pathways. Additionally, systematic in vivo experiments demonstrated that the Col-GO@BP scaffold obviously promotes infectious bone repair through admirable photothermal antibacterial performance and enhanced vascularization. As a result of this study, we provide new insights into the photothermal activity of GO@BP nanosheets, their degradation, and a new biological application for them.

Functional black phosphorus-based sensors for food safety applications: A review

Food safety has garnered global attention, necessitating advanced methods for the quick and accurate detection of contaminants. Sensors, notable for their ease of use, high sensitivity, and fast analysis, are prominent. Two-dimensional (2D) nanomaterials have been employed to improve sensor performance. Particularly, black phosphorus (BP) stands out with its multifunctional capabilities, attributed to unique layered structure, ultra-high charge mobility, easy surface functionalization, enhanced optical absorption, and tunable direct bandgap. These characteristics suggest that BP could significantly enhance sensor selectivity, sensitivity, and response speed for contaminant detection. Despite numerous studies on BP-based sensors in food safety, few reviews have been comprehensively summarized. Moreover, challenges in BP's preparation and stability restrict its wider use. This paper reviews recent research on BP's role in food safety, covering preparation, passivation, and applications. Through analysis of challenges and prospects, this review aims to provide insightful guidance for upcoming research in this area.

Polydopamine-Based Biomaterials in Orthopedic Therapeutics: Properties, Applications, and Future Perspectives

Polydopamine is a versatile and modifiable polymer, known for its excellent biocompatibility and adhesiveness. It can also be engineered into a variety of nanoparticles and biomaterials for drug delivery, functional modification, making it an excellent choice to enhance the prevention and treatment of orthopedic diseases. Currently, the application of polydopamine biomaterials in orthopedic disease prevention and treatment is in its early stages, despite some initial achievements. This article aims to review these applications to encourage further development of polydopamine for orthopedic therapeutic needs. We detail the properties of polydopamine and its biomaterial types, highlighting its superior performance in functional modification on nanoparticles and materials. Additionally, we also explore the challenges and future prospects in developing optimal polydopamine biomaterials for clinical use in orthopedic disease prevention and treatment.

Black Phosphorus Nanosheets-Based Hydrogel for Efficient Bacterial Inhibition and Accelerating Wound Healing

With the swift evolution of multidrug-resistant bacteria resulting from the intense and inappropriate use of antibiotics, there is a pressing need for innovative solutions. In this study, a thermosensitive hydrogel was developed for efficient bacterial inhibition and promotion of wound healing. The antibacterial chitosan (CS) thermosensitive hydrogel, cross-linked with two-dimensional photothermal nanomaterial black phosphorus (BP) nanosheets through electrostatic interactions, effectively encapsulates and sustains the release of angiogenic drug deferoxamine mesylate (DFO). This facilitates the acceleration of re-epithelialization and neovascularization by enhancing cell migration and proliferation. Following near-infrared (NIR) treatment, this hydrogel demonstrates rapid eradication of the most common multidrug-resistant bacteria encountered in clinical settings, achieved through physical disruption of bacterial membranes and photothermal therapies. Noteworthy is the significant upregulation of IL-19 expression via STAT3 signaling pathways by the BP/CS-DFO hydrogel in a full-thickness wound model. This results in the polarization of the anti-inflammatory M2 macrophage phenotype, altering the microenvironment to a pro-healing state and enhancing extracellular matrix deposition and blood vessel formation. In conclusion, the BP/CS-DFO hydrogel shows immense promise as a potential clinical candidate for wound healing and antimicrobial therapy. Its innovative design and multifunctional capabilities position it as a valuable asset in combating antibiotic resistance and enhancing efficiency in wound healing.

In Situ Photoactivated Antibacterial and Antioxidant Composite Materials to Promote Bone Repair

Trauma and tumor removal usually cause bone defects; in addition, the related postoperative infection also shall be carefully considered clinically. In this study, polylactic acid (PLLA) composite fibers containing Cerium oxide (CeO2) are first prepared by electrospinning technology. Then, the PLLA/CeO2@PDA/Ag composite materials are successfully prepared by reducing silver ion (Ag+) to nano-silver (AgNPs)  coating in situ and binding AgNPs to the materials surface by mussel structure liked polydopamine (PDA). In the materials, Ag+ can be slowly released in simulated body fluids. Based on the photothermal performance of AgNPs, the photothermal conversion efficiency of the materials is 21%, under NIR 808 nm illumination. The effective photothermal conversion can help materials fighting with E. coli and S. aureus in 3 h, with an antibacterial rate of 100%. Additionally, the sustained Ag+ release contributes to the antibacterial in long term. Meanwhile, the materials can mimic the bio-behavior of superoxide dismutase and catalase in decreasing the singlet oxygen level and removing the excess reactive oxygen species. Furthermore, the materials are beneficial for cell proliferation and osteogenic differentiation in vitro. In this study, a promising bone-regenerated material with high photothermal conversion efficiency and antibacterial and anti-oxidation properties, is successfully constructed.

Recent Advances in 3D Printing of Smart Scaffolds for Bone Tissue Engineering and Regeneration

The repair and functional reconstruction of bone defects resulting from severe trauma, surgical resection, degenerative disease, and congenital malformation pose significant clinical challenges. Bone tissue engineering (BTE) holds immense potential in treating these severe bone defects, without incurring prevalent complications associated with conventional autologous or allogeneic bone grafts. 3D printing technology enables control over architectural structures at multiple length scales and has been extensively employed to process biomimetic scaffolds for BTE. In contrast to inert and functional bone grafts, next-generation smart scaffolds possess a remarkable ability to mimic the dynamic nature of native extracellular matrix (ECM), thereby facilitating bone repair and regeneration. Additionally, they can generate tailored and controllable therapeutic effects, such as antibacterial or antitumor properties, in response to exogenous and/or endogenous stimuli. This review provides a comprehensive assessment of the progress of 3D-printed smart scaffolds for BTE applications. It begins with an introduction to bone physiology, followed by an overview of 3D printing technologies utilized for smart scaffolds. Notable advances in various stimuli-responsive strategies, therapeutic efficacy, and applications of 3D-printed smart scaffolds are discussed. Finally, the review highlights the existing challenges in the development and clinical implementation of smart scaffolds, as well as emerging technologies in this field.

The Effect of Antibacterial-Osteogenic Surface Modification on the Osseointegration of Titanium Implants: A Static and Dynamic Strategy

Titanium (Ti) and its alloys are widely used biomaterials in bone repair. Although these biomaterials possess stable properties and good biocompatibility, the high elastic modulus and low surface activity of Ti implants have often been associated with infection, inflammation, and poor osteogenesis. Therefore, there is an urgent need to modify the surface of Ti implants, where changes in surface morphology or coatings loading can confer specific functions to help them adapt to the osseointegration formation phase and resist bacterial infection. This can further ensure a healthy microenvironment for bone regeneration as well as the promotion of immunomodulation, angiogenesis, and osteogenesis. Therefore, in this review, we evaluated various functional Ti implants after surface modification, both in terms of static modifications and dynamic response strategies, mainly focusing on the synergistic effects of antimicrobial activities and functionalized osteogenic. Finally, the current challenges and future perspectives are summarized to provide innovative and effective solutions for osseointegration and bone defect repair.

Research progresses on mitochondrial-targeted biomaterials for bone defect repair

In recent years, the regulation of the cell microenvironment has opened up new avenues for bone defect repair. Researchers have developed novel biomaterials to influence the behavior of osteoblasts and immune cells by regulating the microenvironment, aiming to achieve efficient bone repair. Mitochondria, as crucial organelles involved in energy conversion, biosynthesis and signal transduction, play a vital role in maintaining bone integrity. Dysfunction of mitochondria can have detrimental effects on the transformation of the immune microenvironment and the differentiation of stem cells, thereby hindering bone tissue regeneration. Consequently, targeted therapy strategies focusing on mitochondria have emerged. This approach offers a wide range of applications and reliable therapeutic effects, thereby providing a new treatment option for complex and refractory bone defect diseases. In recent studies, more biomaterials have been used to restore mitochondrial function and promote positive cell differentiation. The main directions are mitochondrial energy metabolism, mitochondrial biogenesis and mitochondrial quality control. In this review, we investigated the biomaterials used for mitochondria-targeted treatment of bone defect repair in recent years from the perspective of progress and strategies. We also summarized the micro-molecular mechanisms affected by them. Through discussions on energy metabolism, oxidative stress regulation and autophagy regulation, we emphasized the opportunities and challenges faced by mitochondria-targeted biomaterials, providing vital clues for developing a new generation of bone repair materials.

ZIF-8-Modified Black Phosphorus Nanosheets Incorporated into Injectable Dual-Component Hydrogels for Enhanced Photothermal Antibacterial and Osteogenic Activities

The development of growth factor-free biomaterials for bone tissue regeneration with anti-infection and anti-inflammatory activities remains challenging. Black phosphorus nanosheets (BPNs), with distinctive attributes, including photothermal conversion and calcium ion chelation, offer potential for use in bone tissue engineering and infection prevention. However, BPNs are prone to oxidation and degradation in aqueous environments, and methods to stabilize BPNs for long-term bone repair remain insufficient. Herein, zeolitic imidazolate framework-8 (ZIF-8) was used to stabilize BPNs via in situ crystallization onto the surface of BPNs (BP@ZIF-8 nanocomposite). A novel injectable dual-component hydrogel comprising gelatin methacryloyl (GelMA) and methacrylate-modified hyaluronic acid (HAMA) was used as a BP@ZIF-8 nanocomposite carrier (GelMA/HAMA/BP@ZIF-8). The BP@ZIF-8 nanocomposite could effectively protect internal BPNs from oxidation and enhance the long-term photothermal performance of the hydrogel in both in vitro and in vivo settings. The GelMA/HAMA/BP@ZIF-8 hydrogel was injectable and exhibited outstanding performance for photothermal conversion, mechanical strength, and biodegradability, as well as excellent photothermal antibacterial activity against Staphylococcus aureus and Escherichia coli in vitro and in an in vivo rat model. The GelMA/HAMA/BP@ZIF-8 hydrogel also provided a microenvironment conducive to osteogenic differentiation, promoting the transformation of M2 macrophages and inhibiting inflammatory responses. Furthermore, the hydrogel promoted bone regeneration and had a synergistic effect with near-infrared irradiation in a rat skull-defect model. Transcriptome sequencing analysis revealed that the PI3K-AKT- and calcium-signaling pathways may be involved in promoting osteogenic differentiation induced by the GH-BZ hydrogel. This study presents an innovative, multifaceted solution to the challenges of bone tissue regeneration with antibacterial and anti-inflammatory effects, providing insights into the design of smart biomaterials with dual therapeutic capabilities.

Study on the Antibacterial Activity and Bone Inductivity of Nanosilver/PLGA-Coated TI-CU Implants

Background

Implants are widely used in the field of orthopedics and dental sciences. Titanium (TI) and its alloys have become the most widely used implant materials, but implant-associated infection remains a common and serious complication after implant surgery. In addition, titanium exhibits biological inertness, which prevents implants and bone tissue from binding strongly and may cause implants to loosen and fall out. Therefore, preventing implant infection and improving their bone induction ability are important goals.

Purpose

To study the antibacterial activity and bone induction ability of titanium-copper alloy implants coated with nanosilver/poly (lactic-co-glycolic acid) (NSPTICU) and provide a new approach for inhibiting implant-associated infection and promoting bone integration.

Methods

We first examined the in vitro osteogenic ability of NSPTICU implants by studying the proliferation and differentiation of MC3T3-E1 cells. Furthermore, the ability of NSPTICU implants to induce osteogenic activity in SD rats was studied by micro-computed tomography (micro-CT), hematoxylin-eosin (HE) staining, masson staining, immunohistochemistry and van gieson (VG) staining. The antibacterial activity of NSPTICU in vitro was studied with gram-positive Staphylococcus aureus (Sa) and gram-negative Escherichia coli (E. coli) bacteria. Sa was used as the test bacterium, and the antibacterial ability of NSPTICU implanted in rats was studied by gross view specimen collection, bacterial colony counting, HE staining and Giemsa staining.

Results

Alizarin red staining, alkaline phosphatase (ALP) staining, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis showed that NSPTICU promoted the osteogenic differentiation of MC3T3-E1 cells. The in vitro antimicrobial results showed that the NSPTICU implants exhibited better antibacterial properties. Animal experiments showed that NSPTICU can inhibit inflammation and promote the repair of bone defects.

Conclusion

NSPTICU has excellent antibacterial and bone induction ability, and has broad application prospects in the treatment of bone defects related to orthopedics and dental sciences.

Engineered Niobium Carbide MXenzyme-Integrated Self-Adaptive Coatings Inhibiting Periprosthetic Osteolysis by Orchestrating Osteogenesis-Osteoclastogenesis Balance

Periprosthetic osteolysis induced by the ultrahigh-molecular-weight polyethylene (UHMWPE) wear particles is a major complication associated with the sustained service of artificial joint prostheses and often necessitates revision surgery. Therefore, a smart implant with direct prevention and repair abilities is urgently developed to avoid painful revision surgery. Herein, we fabricate a phosphatidylserine- and polyethylenimine-engineered niobium carbide (Nb2C) MXenzyme-coated micro/nanostructured titanium implant (PPN@MNTi) that inhibits UHMWPE particle-induced periprosthetic osteolysis. The specific mechanism by which PPN@MNTi operates involves the bioresponsive release of nanosheets from the MNTi substrate within an osteolysis microenvironment, initiated by the cleavage of a thioketal-dopamine molecule sensitive to reactive oxygen species (ROS). Subsequently, functionalized Nb2C MXenzyme could target macrophages and escape from lysosomes, effectively scavenging intracellular ROS through its antioxidant nanozyme-mimicking activities. This further achieves the suppression of osteoclastogenesis by inhibiting NF-κB/MAPK and autophagy signaling pathways. Simultaneously, based on the synergistic effect of MXenzyme-integrated coatings and micro/nanostructured topography, the designed implant promotes the osteogenic differentiation of bone mesenchymal stem cells to regulate bone homeostasis, further achieving advanced osseointegration and alleviable periprosthetic osteolysis in vivo. This study provides a precise prevention and repair strategy of periprosthetic osteolysis, offering a paradigm for the development of smart orthopedic implants.

Bacterial lipase-responsive polydopamine nanoparticles for detection and synergistic therapy of wound biofilms infection

Wound biofilms represent an elusive conundrum in contemporary treatment and diagnostic options, accredited to their escalating antibiotic resistance and interference in chronic wound healing processes. Here, we developed mesoporous polydopamine (mPDA) nanoparticles, and grafted with rhodamine B (Rb) as biofilm lipase responsive detection probe, followed by π - π stacking mediated ciprofloxacin (CIP) loading to create mP-Rb@CIP nanoparticles. mPDA NPs with a melanin structure could quench fluorescence emissions of Rb. Once encountering biofilm in vivo, the ester bond in Rb and mPDA is hydrolyzed by elevated lipase concentrations, triggering the liberation of Rb and restore fluorescence emissions to achieve real-time imaging of biofilm-infected wounds. Afterwards, the 808 nm near-infrared (NIR) illumination initiates a spatiotemporal controlled antibacterial photothermal therapy (PTT), boosting its effectiveness through photothermal-triggered CIP release for synergistic biofilm eradication. The mP-Rb@CIP platform exhibits dual diagnostic and therapeutic functions, efficaciously treating biofilm-infected wounds in vivo and in vitro. Particularly, the mP-Rb@CIP/NIR procedure expedites wound-healing by alleviating oxidative stress, modulating inflammatory mediators, boosting collagen synthesis, and promoting angiogenesis. Taken together, the theranostic nanosystem strategy holds significant potential for addressing wound biofilm-associated infections.

A win-win platform: Stabilized black phosphorous nanosheets loading gallium ions for enhancing the healing of bacterial-infected wounds through synergistic antibacterial approaches

Bacterial infection is the most common complication in wound healing, highlighting an urgent need for the development of innovative antibacterial technologies and treatments to address the growing threats posed by bacterial infections. Black phosphorus nanosheets (BPNSs), as a promising two-dimensional nanomaterial, have been utilized in treating infected wounds. However, BP's limited stability restricts its application. In this study, we enhance BP's stability and its antibacterial properties by anchoring gallium ions (Ga3+) onto BP's surface, creating a novel antibacterial platform. This modification reduces BP's electron density and enhances its antibacterial capabilities through a synergistic effect. Under near-infrared (NIR) irradiation, the BP/Ga3+ combination exerts antibacterial effects via photothermal therapy (PTT) and photodynamic therapy (PDT), while also releasing Ga3+. The Ga3+ employ a 'Trojan horse strategy' to disrupt iron metabolism, significantly boosting the antibacterial efficacy of the complex. This innovative material offers a viable alternative to antibiotics and holds significant promise for treating infected wounds and aiding skin reconstruction.

Preparation of nano-silver containing black phosphorus based on quaternized chitosan hydrogel and evaluating its effect on skin wound healing

Hydrogels with favorable biocompatibility and antibacterial properties are essential in postoperative wound hemorrhage care, facilitating rapid wound healing. The present investigation employed electrostatic adsorption of black phosphorus nanosheets (BPNPs) and nano‑silver (AgNPs) to cross-link the protonated amino group NH3+ of quaternized chitosan (QCS) with the hydroxyl group of hyaluronic acid (HA). The electrostatic interaction between the two groups resulted in the formation of a three-dimensional gel network structure. Additionally, the hydrogel containing AgNPs deposited onto BPNPs was assessed for its antibacterial properties and effects on wound healing. Hydrogel demonstrated an outstanding drug-loading capacity and could be employed for wound closure. AgNPs loaded on the BPNPs released silver ions and exhibited potent antibacterial properties when exposed to 808 nm near-infrared (NIR) radiation. The ability of the hydrogel to promote wound healing in an acute wound model was further evaluated. The BPNPs were combined with HA and QCS in the aforementioned hydrogel system to improve adhesion, combine the photothermal and antibacterial properties of the BPNPs, and promote wound healing. Therefore, the reported hydrogels displayed excellent biocompatibility and hold significant potential for application in the field of tissue engineering for skin wound treatment.

Black phosphorus, an advanced versatile nanoparticles of antitumor, antibacterial and bone regeneration for OS therapy

Osteosarcoma (OS) is the most common primary malignant bone tumor. In the clinic, usual strategies for OS treatment include surgery, chemotherapy, and radiation. However, all of these therapies have complications that cannot be ignored. Therefore, the search for better OS treatments is urgent. Black phosphorus (BP), a rising star of 2D inorganic nanoparticles, has shown excellent results in OS therapy due to its outstanding photothermal, photodynamic, biodegradable and biocompatible properties. This review aims to present current advances in the use of BP nanoparticles in OS therapy, including the synthesis of BP nanoparticles, properties of BP nanoparticles, types of BP nanoparticles, and modification strategies for BP nanoparticles. In addition, we have discussed comprehensively the application of BP in OS therapy, including single, dual, and multimodal synergistic OS therapies, as well as studies about bone regeneration and antibacterial properties. Finally, we have summarized the conclusions, limitations and perspectives of BP nanoparticles for OS therapy.

Immunomodulatory nanomedicine for osteoporosis: Current practices and emerging prospects

Osteoporosis results from the disruption of the balance between bone resorption and bone formation. However, classical anti-osteoporosis drugs exhibit several limitations in clinical applications, such as multiple adverse reactions and poor therapeutic effects. Therefore, there is an urgent need for alternative treatment strategies. With the evolution of immunomodulatory nanomedicine, a variety of nanomaterials have been designed for anti-osteoporosis treatment, offering prospects of minimal adverse reactions, enhanced bone induction, and high osteogenic activity. This review initially provides a brief overview of the fundamental principles of bone reconstruction, current osteogenic clinical methods in osteoporosis treatment, and the significance of osteogenic-angiogenic coupling, laying the groundwork for understanding the pathophysiology and therapeutics of osteoporosis. Subsequently, the article emphasizes the relationship between bone immunity and osteogenesis-angiogenesis coupling and provides a detailed analysis of the application of immunomodulatory nanomedicines in the treatment of osteoporosis, including various types of nanomaterials and their integration with carrier biomaterials. Importantly, we discuss the potential of some emerging strategies in immunomodulatory nanomedicine for osteoporosis treatment. This review introduces the innovative applications of immunomodulatory nanomedicine in the treatment of osteoporosis, aiming to serve as a reference for the application of immunomodulatory nanomedicine strategies in osteoporosis treatment. STATEMENT OF SIGNIFICANCE: Osteoporosis, as one of the most prevalent skeletal disorders, poses a significant threat to public health. To date, conventional anti-osteoporosis strategies have been limited in efficacy and plagued with numerous side effects. Fortunately, with the advancement of research in osteoimmunology and nanomedicine, strategies integrating these two fields show great promise in combating osteoporosis. Nanomedicine with immunomodulatory properties exhibits enhanced efficiency, prolonged effectiveness, and increased safety. However, as of now, there exists no comprehensive review amalgamating immunomodulation with nanomedicine to delineate the progress of immunomodulatory nanomedicine in osteoporosis treatment, as well as the future direction of this strategy.

Regulation of band gap and localized surface plasmon resonance by loading Au nanorods on violet phosphene nanosheets for photodynamic/photothermal synergistic anti-infective therapy

In the face of the serious threat to human health and the economic burden caused by bacterial antibiotic resistance, 2D phosphorus nanomaterials have been widely used as antibacterial agents. Violet phosphorus nanosheets (VPNSs) are an exciting bandgap-adjustable 2D nanomaterial due to their good physicochemical properties, yet the study of VPNS-based antibiotics is still in its infancy. Here, a composite of gold nanorods (AuNRs) loaded onto VPNS platforms (VPNS/AuNR) is constructed to maximize the potential of VPNSs for antimicrobial applications. The loading with AuNRs not only enhances the photothermal performance via a localized surface plasmon resonance (LSPR) effect, but also enhances the light absorption capacity due to the narrowing of the band gap of the VPNSs, thus increasing the ROS generation capacity. The results demonstrate that VPNS/AuNR exhibits outstanding antibacterial properties and good biocompatibility. Attractively, VPNS/AuNR is then extensively tested for treating skin wound infections, suggesting promising in vivo antibacterial and wound-healing features. Our findings may open a novel direction to develop a versatile VPNS-based treatment platform, which can significantly boost the progress of VPNS exploration.

Application of antimicrobial sonodynamic therapy as a potential treatment modality in dentistry: A literature review

The accumulation of dental plaque is a precursor to various dental infections, including lesions, inflammation around dental implants, and inflammation under dentures. Traditional cleaning methods involving physical removal and chemical agents often fall short of eliminating bacteria and their protective biofilms. These methods can also inadvertently lead to bacteria that resist drugs and upset the mouth's microbial harmony. To counter these issues, a new approach is needed that can target and clear away dental plaque, minimize biofilms and bacteria, and thus support sustained dental health. Enter antimicrobial sonodynamic therapy (aSDT), a supplementary treatment that uses gentle ultrasound waves to trigger a sonosensitizer compound, destroying bacterial cells. This process works by generating heat, mechanical pressure, initiating chemical reactions, and producing reactive oxygen species (ROS), offering a fresh tactic for managing dental plaque and biofilms. The study reviews how aSDT could serve as an innovative dental treatment option to enhance oral health.

Engineering Copper-Containing Nanoparticles-Loaded Silicene Nanosheets with Triple Enzyme Mimicry Activities and Photothermal Effect for Promoting Bacteria-Infected Wound Healing

Skin wounds accompanied by bacterial infections threaten human health, and conventional antibiotic treatments are ineffective for drug-resistant bacterial infections and chronically infected wounds. The development of non-antibiotic-dependent therapeutics is highly desired but remains a challenging issue. Recently, 2D silicene nanosheets with considerable biocompatibility, biodegradability, and photothermal-conversion performance have received increasing attention in biomedical fields. Herein, copper-containing nanoparticles-loaded silicene (Cu2.8O@silicene-BSA) nanosheets with triple enzyme mimicry catalytic (peroxidase, catalase, and oxidase-like) activities and photothermal function are rationally designed and fabricated for efficient bacterial elimination, angiogenesis promotion, and accelerated wound healing. Cu2.8O@silicene-BSA nanosheets display excellent antibacterial activity through synergistic effects of reactive oxygen species generated from multiple catalytic reactions, intrinsic bactericidal activity of released Cu2+ ions, and photothermal effects, achieving high antibacterial efficiencies on methicillin-resistant Staphylococcus aureus (MRSA) of 99.1 ± 0.7% in vitro and 97.2 ± 1.6% in vivo. In addition, Cu2.8O@silicene-BSA nanosheets exhibit high biocompatibility for promoting human umbilical vein endothelial cell (HUVEC) proliferation and angiogenic differentiation. In vivo experiments reveal that Cu2.8O@silicene-BSA nanosheets with synergistic photothermal/chemodynamic therapeutics effectively accelerate MRSA-infected wound healing by eliminating bacteria, alleviating inflammation, boosting collagen deposition, and promoting angiogenesis. This research presents a promising strategy to engineer photothermal-assisted nanozyme catalysis for bacteria-invaded wound healing.

Improving osseointegration and antimicrobial properties of titanium implants with black phosphorus nanosheets-hydroxyapatite composite coatings for vascularized bone regeneration

For decades, titanium implants have shown impressive advantages in bone repair. However, the preparation of implants with excellent antimicrobial properties as well as better osseointegration ability remains difficult for clinical application. In this study, black phosphorus nanosheets (BPNSs) were doped into hydroxyapatite (HA) coatings using electrophoretic deposition. The coatings' surface morphology, roughness, water contact angle, photothermal properties, and antibacterial properties were investigated. The BP/HA coating exhibited a surface roughness of 59.1 nm, providing an ideal substrate for cell attachment and growth. The water contact angle on the BP/HA coating was measured to be approximately 8.55°, indicating its hydrophilic nature. The BPNSs demonstrated efficient photothermal conversion, with a temperature increase of 42.2°C under laser irradiation. The BP/HA composite coating exhibited a significant reduction in bacterial growth, with inhibition rates of 95.6% and 96.1% against Staphylococcus aureus and Escherichia coli. In addition, the cytocompatibility of the composite coating was evaluated by cell adhesion, CCK8 and AM/PI staining; the effect of the composite coating in promoting angiogenesis was assessed by scratch assay, transwell assay, and protein blotting; and the osteoinductivity of the composite coating was evaluated by alkaline phosphatase assay, alizarin red staining, and Western blot. The results showed that the BP/HA composite coating exhibited superior performance in promoting biological functions such as cell proliferation and adhesion, antibacterial activity, osteogenic differentiation, and angiogenesis, and had potential applications in vascularized bone regeneration.

Advancing piezoelectric 2D nanomaterials for applications in drug delivery systems and therapeutic approaches

Precision drug delivery and multimodal synergistic therapy are crucial in treating diverse ailments, such as cancer, tissue damage, and degenerative diseases. Electrodes that emit electric pulses have proven effective in enhancing molecule release and permeability in drug delivery systems. Moreover, the physiological electrical microenvironment plays a vital role in regulating biological functions and triggering action potentials in neural and muscular tissues. Due to their unique noncentrosymmetric structures, many 2D materials exhibit outstanding piezoelectric performance, generating positive and negative charges under mechanical forces. This ability facilitates precise drug targeting and ensures high stimulus responsiveness, thereby controlling cellular destinies. Additionally, the abundant active sites within piezoelectric 2D materials facilitate efficient catalysis through piezochemical coupling, offering multimodal synergistic therapeutic strategies. However, the full potential of piezoelectric 2D nanomaterials in drug delivery system design remains underexplored due to research gaps. In this context, the current applications of piezoelectric 2D materials in disease management are summarized in this review, and the development of drug delivery systems influenced by these materials is forecast.

Advances in the Application of Black Phosphorus-Based Composite Biomedical Materials in the Field of Tissue Engineering

Black Phosphorus (BP) is a new semiconductor material with excellent biocompatibility, degradability, and optical and electrophysical properties. A growing number of studies show that BP has high potential applications in the biomedical field. This article aims to systematically review the research progress of BP composite medical materials in the field of tissue engineering, mining BP in bone regeneration, skin repair, nerve repair, inflammation, treatment methods, and the application mechanism. Furthermore, the paper discusses the shortcomings and future recommendations related to the development of BP. These shortcomings include stability, photothermal conversion capacity, preparation process, and other related issues. However, despite these challenges, the utilization of BP-based medical materials holds immense promise in revolutionizing the field of tissue repair.

Nanomedicine/materdicine-enabled sonocatalytic therapy

The advent of numerous treatment modalities with desirable therapeutic efficacy has been made possible by the fast development of nanomedicine and materdicine, among which the ultrasound (US)-triggered sonocatalytic process as minimal or non-invasive method has been frequently employed for diagnostic and therapeutic purposes. In comparison to phototherapeutic approaches with inherent penetration depth limitations, sonocatalytic therapy shatters the depth limit of photoactivation and offers numerous remarkable prospects and advantages, including mitigated side effects and appropriate tissue-penetration depth. Nevertheless, the optimization of sonosensitizers and therapies remains a significant issue in terms of precision, intelligence and efficiency. In light of the fact that nanomedicine and materdicine can effectively enhance the theranostic efficiency, we herein aim to furnish a cutting-edge review on the latest progress and development of nanomedicine/materdicine-enabled sonocatalytic therapy. The design methodologies and biological features of nanomedicine/materdicine-based sonosensitizers are initially introduced to reveal the underlying relationship between composition/structure, sonocatalytic function and biological effect, in accompany with a thorough discussion of nanomedicine/materdicine-enabled synergistic therapy. Ultimately, the facing challenges and future perspectives of this intriguing sonocatalytic therapy are highlighted and outlined to promote technological advancements and clinical translation in efficient disease treatment.

Biomaterials for bone defect repair: Types, mechanisms and effects

Bone defects or bone discontinuities caused by trauma, infection, tumours and other diseases have led to an increasing demand for bone grafts and biomaterials. Autologous bone grafts, bone grafts with vascular tips, anastomosed vascular bone grafts and autologous bone marrow components are all commonly used in clinical practice, while oversized bone defects require the use of bone tissue engineering-related biomaterials to repair bone defects and promote bone regeneration. Currently, inorganic components such as polysaccharides and bioceramics, as well as a variety of bioactive proteins, metal ions and stem cells can be loaded into hydrogels or 3D printed scaffold materials to achieve better therapeutic results. In this review, we provide an overview of the types of materials, applications, potential mechanisms and current developments in the repair of bone defects.