Sonodynamic therapy-based nanoplatforms for combating bacterial infections

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.

Ultrasound-switchable piezoelectric BiVO4/fullerene heterostructure for on-demand ROS modulation in MRSA-infected diabetic wound healing

Persistent microbial infections and excessive reactive oxygen species (ROS) accumulation severely impede diabetic wound healing. Herein, we developed an ultrasound-switchable BiVO4/fullerene piezoelectric heterostructure via a one-pot solvothermal method, enabling on-demand transition between bactericidal action and ROS scavenging for treating infected diabetic wounds. Under 8-min ultrasound (US) irradiation, the heterojunction sonosensitizer leveraged piezoelectric polarization to generate substantial ROS in real-time through a narrowed energy band gap and enhanced charge carrier separation and migration efficiency, resulting in the disruption of bacterial membrane integrity and 99.9 % eradication of methicillin-resistant Staphylococcus aureus (MRSA). Upon US withdrawal, the sonosensitizer spontaneously transitioned to an antioxidative state through fullerene-mediated ROS scavenging, effectively neutralizing excess ROS and restoring cellular redox balance. In an MRSA-infected diabetic wound model, this ultrasound-responsive duality effectively suppressed bacterial proliferation, reduced inflammation, enhanced angiogenesis, and ultimately accelerated wound healing within 14 days. This ultrasound-switchable therapeutic strategy offers promising insights for managing drug-resistant infections and other ROS-mediated biomedical challenges.

Fe3O4/MnCO3 microbubbles for efficient elimination of bacterial biofilms by mechanical/sonodynamic effects under ultrasound irradiation and magnetic field targeting

Bacterial biofilms present significant challenges in treatment with traditional antibiotics. Ultrasound (US)-responsive antibacterial agents have emerged as promising alternatives for treating bacterial biofilm infections. However, these agents are often limited by antibiotic dependence, inadequate targeting, and low antibacterial efficacy. Herein, we develop Fe3O4/MnCO3 microbubbles (FMMB) by self-assembly of Fe3O4 nanoparticles (Fe3O4 NPs) and MnCO3 nanoparticles (MnCO3 NPs). Under the direction of the magnetic field (MF), FMMB can be directed toward the methicillin-resistant Staphylococcus aureus (MRSA) biofilm. Under US irradiation, FMMB can disrupt the structure of MRSA biofilms by cavitation-induced mechanical effects and kill bacteria with reactive oxygen species (ROS) generated by MnCO3 NPs through the sonodynamic effect. In a mouse model with catheter-associated MRSA biofilm infection, FMMB removed 58.8% of the biofilm with MF and US, and the bacterial inactivation efficiency reached as high as 4.1 log (99.992%). This work develops multifunctional microbubbles with both US-responsive mechanical and sonodynamic effects for biofilm disruption and MF-responsive properties for biofilm targeting, offering a promising strategy for designing antibiofilm agents to effectively treat bacterial biofilm infections.

Stimulus-responsive nanomaterials for ocular antimicrobial therapy

Nanomaterials exhibit a promising new avenue for treating infectious keratitis, having garnered considerable interest in the ophthalmic medical community due to their unique properties including higher target specificity, enhanced bioactivity of loaded agents, reduced drug dosage, and stimulus-responsive drug release. These stimulus-responsive nanomaterial-mediated therapeutic strategies offer innovative approaches for managing ocular antimicrobial diseases. In this review, we aim to summarize current applications of stimulus-responsive nanotherapeutics for ocular antimicrobial therapy. We briefly introduce the basic ocular structure, ocular barrier, infectious keratitis classification, and its microenvironment. Following this, we summarize the nanotherapeutic antimicrobial strategies employed in treating ocular infections including endogenous stimulus-responsive ocular nanodrugs, sonodynamic therapy, and wearable device-based therapy, focusing on their design principles, developmental progress, and advantages and limitations. Finally, we critically evaluate the biosafety profiles of responsive nanomaterials, specifically addressing cytotoxicity and immune interactions. To conclude, we discuss key challenges in this research field and future opportunities with explicit emphasis on clinical translation and practical medical applications.

Bio-Mimicking Nanoparticle System Facilitates Sonodynamic-Mediated Clearance of Extensively Drug-Resistant Bacteria

The increasing prevalence of carbapenem-resistant and extensively drug-resistant Acinetobacter baumannii (XDR-Ab) poses a critical challenge in treating hospital-acquired pulmonary infections. In this study, we developed a biomimetic neutrophil membrane-coated nanoparticle system, NM@PCN-TIG, for the targeted delivery of tigecycline (TIG). The system utilizes the porphyrin-based metal-organic framework (MOF) PCN-224 as the core of the nanoparticle, encapsulating TIG and coated with a neutrophil membrane (NM) to enhance immune evasion and targeting of infection sites. Its loading efficiency, controlled release properties, cytotoxicity, and bactericidal activity under ultrasound mediation were systematically evaluated in vitro and in vivo. Our results demonstrated that NM@PCN-TIG significantly enhanced the bactericidal efficacy of TIG, increased reactive oxygen species (ROS) production, and promoted macrophage polarization toward an anti-inflammatory phenotype. This innovative biomimetic TIG nanosystem shows great potential as a platform for addressing XDR-Ab-induced pneumonia.

Nanomedicines as disruptors or inhibitors of biofilms: Opportunities in addressing antimicrobial resistance

The problem of antimicrobial resistance (AMR) has caused global concern due to its great threat to human health. Evidences are emerging for a critical role of biofilms, one of the natural protective mechanisms developed by bacteria during growth, in resisting commonly used clinical antibiotics. Advances in nanomedicines with tunable physicochemical properties and unique anti-biofilm mechanisms provide opportunities for solving AMR risks more effectively. In this review, we summarize the five "A" stages (adhesion, amplification, alienation, aging and allocation) of biofilm formation and mechanisms through which they protect the internal bacteria. Aimed at the characteristics of biofilms, we emphasize the design "THAT" principles (targeting, hacking, adhering and transport) of nanomedicines in their interactions with biofilms and internal bacteria. Furthermore, recent progresses in multimodal antibacterial nanomedicines, including biofilms disruption and bactericidal activity, and the types of currently available antibiofilm nanomedicines contained organic and inorganic nanomedicines are outlined and highlighted their potential applications in the development of preclinical research. Last but not least, we offer a perspective for the effectiveness of nanomedicines designed to address AMR and challenges associated with their clinical translation.

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.

Inhalable Polymeric Nanoparticle Containing Triphenylphosphanium Bromide-modified Sonosensitizer for Enhanced Therapy of Acute Bacterial Pneumonia

Sonodynamic therapy (SDT) has good feasibility to deeply seated infections, but SDT alone is insufficient being highly effective against multidrug-resistant (MDR) bacteria. SDT combined with triphenylphosphanium bromide (P+Ph3Br-) is expected to solve this problem. This work develops a pseudo-conjugated polymer PFCPS-P containing cationic P+Ph3Br--modified sonosensitizer FCPS (FCPS-P) and ROS-sensitive thioketal bonds. PFCPS-P is assembled with DSPE-mPEG2000 to generate nanoparticle NPFCPS-P. FCPS has SDT effect and generates ROS under ultrasound (US) stimulation. ROS triggers the degradation of NPFCPS-P and release of FCPS-P, endowing highly favored biosafety. FCPS-P targets to bacterial surface through electrostatic interaction and achieves bacterial killing under a synergistic action of SDT and P+Ph3Br-. In vitro, NPFCPS-P+US gives >90% inhibition rates against MDR ESKAPE pathogens, moreover, it causes bacterial metabolic disorders including inhibited nucleic acid synthesis, disordered energy metabolism, excessive oxidative stress, and suppressed biofilm formation and virulence. In mice, NPFCPS-P+US exhibits a 99.3% bactericidal rate in Pseudomonas aeruginosa-induced sublethal pneumonia and renders a 90% animal survival rate in lethal pneumonia, and additionally immunological staining and transcriptomics analyses reveal that NPFCPS-P+US induces inhibited inflammatory response and accelerated lung injury repair. Taken together, NPFCPS-P+US is a promising antibiotics-alternative strategy for treating deeply seated bacterial infections.

Design and application of antimicrobial nanomaterials in the treatment of periodontitis

Periodontitis is a chronic inflammatory disease induced by the microbiome, leading to the destruction of periodontal structures and potentially resulting in tooth loss. Using local drug delivery systems as an adjunctive therapy to scaling and root planning in periodontitis is a promising strategy. However, this administration method's effectiveness is constrained by the complexity of the periodontal environment. Nanomaterials have demonstrated significant potential in the antibacterial treatment of periodontitis, attributed to their controllable size, shape, and surface charge, high design flexibility, high reactivity, and high specific surface area. In this review, we summarize the complex periodontal microenvironment and the difficulties of local drug delivery in periodontitis, explicitly reviewing the application and design strategies of nanomaterials with unique properties in the distinct microenvironment of periodontitis. Furthermore, the review discusses the limitations of current research, proposes feasible solutions, and explores prospects for using nanomaterials in this context.

Current Research in Drug-Free Cancer Therapies

Cancer treatment has historically depended on conventional methods like chemotherapy, radiation, and surgery; however, these strategies frequently present considerable limitations, including toxicity, resistance, and negative impacts on healthy tissues. In addressing these challenges, drug-free cancer therapies have developed as viable alternatives, utilizing advanced physical and biological methods to specifically target tumor cells while reducing damage to normal tissues. This review examines several drug-free cancer treatment strategies, such as high-intensity focused energy beams, nanosecond pulsed electric fields, and photothermal therapy as well as the use of inorganic nanoparticles to promote selective apoptosis. We also investigate the significance of targeting the tumor microenvironment, precision medicine, and immunotherapy in the progression of personalized cancer therapies. Although these approaches demonstrate significant promise, challenges including scalability, safety, and regulatory obstacles must be resolved for clinical application. This paper presents an overview of current research in drug-free cancer therapies, emphasizing recent advancements, underlying scientific principles, and the steps required for clinical implementation.

Rapid enrichment and SERS differentiation of various bacteria in skin interstitial fluid by 4-MPBA-AuNPs-functionalized hydrogel microneedles

Bacterial infection is a major threat to global public health, and can cause serious diseases such as bacterial skin infection and foodborne diseases. It is essential to develop a new method to rapidly diagnose clinical multiple bacterial infections and monitor food microbial contamination in production sites in real-time. In this work, we developed a 4-mercaptophenylboronic acid gold nanoparticles (4-MPBA-AuNPs)-functionalized hydrogel microneedle (MPBA-H-MN) for bacteria detection in skin interstitial fluid. MPBA-H-MN could conveniently capture and enrich a variety of bacteria within 5 min. Surface enhanced Raman spectroscopy (SERS) detection was then performed and combined with machine learning technology to distinguish and identify a variety of bacteria. Overall, the capture efficiency of this method exceeded 50%. In the concentration range of 1 × 107 to 1 × 1010 colony-forming units/mL (CFU/mL), the corresponding SERS intensity showed a certain linear relationship with the bacterial concentration. Using random forest (RF)-based machine learning, bacteria were effectively distinguished with an accuracy of 97.87%. In addition, the harmless disposal of used MNs by photothermal ablation was convenient, environmentally friendly, and inexpensive. This technique provided a potential method for rapid and real-time diagnosis of multiple clinical bacterial infections and for monitoring microbial contamination of food in production sites.

Oxygenous and biofilm-targeted nanosonosensitizer anchored with Pt nanozyme and antimicrobial peptide in the gelatin/sodium alginate hydrogel for infected diabetic wound healing

Sonodynamic therapy is an emerging therapeutic approach for combating bacterial infections. However, the characteristics of hypoxia, high H2O2 microenvironment, and the formation of persistent biofilms in diabetic wound sites limit its efficacy in this field. To address these issues, we developed a multifunctional antibacterial hydrogel dressing PPCN@Pt-AMPs/HGel with the cross-linked gelatin and sodium alginate as the matrix, where the nanosonosensitizer PCN-224 was decorated with the oxygen-generating Pt nanoenzyme and further coupled with a biofilm-targeting antimicrobial peptide via an interacting polydopamine layer. This nano-composite hydrogel displayed improved mechanical properties as well as good biocompatibility and biodegradability. The catalase-like activity of the nanoparticles facilitated the ultrasound-induced generation of the singlet oxygen due to the catalytic decomposition of the H2O2 into O2. In vitro results showed that the hydrogel dressing exhibited excellent antimicrobial ability under low-intensity ultrasound stimulation, which could effectively inhibit the newly formed biofilm and eliminate the full-grown biofilms. In the infected diabetic wound of rats, PPCN@Pt-AMPs/HGel significantly enhanced the wound healing rate under low-intensity ultrasound stimulation and improved the regeneration outcomes by promoting granulation tissue formation, angiogenesis, and type III collagen deposition. In conclusion, our study provides a novel and effective antibacterial hydrogel dressing for sonodynamic treatment of diabetic wounds.

Nanomaterials for liver cancer targeting: research progress and future prospects

The incidence and mortality rates of liver cancer in China remain elevated. Although early-stage liver cancer is amenable to surgical resection, a significant proportion of patients are diagnosed at advanced stages. Currently, in addition to surgical resection for hepatocellular carcinoma, the primary treatment modalities predominantly include chemotherapy. The widespread use of chemotherapy, which non-selectively targets both malignant and healthy cells, often results in substantial immunosuppression. Simultaneously, the accumulation of chemotherapeutic agents can readily induce drug resistance upon reaching the physiological threshold, thereby diminishing the efficacy of these treatments. Besides chemotherapy, there exist targeted therapy, immunotherapy and other therapeutic approaches. Nevertheless, the development of drug resistance remains an inevitable challenge. To address these challenges, we turn to nanomedicine, an emerging and widely utilized discipline that significantly influences medical imaging, antimicrobial strategies, drug delivery systems, and other related areas. Stable and safe nanomaterials serve as effective carriers for delivering anticancer drugs. They enhance the precision of drug targeting, improve bioavailability, and minimize damage to healthy cells. This review focuses on common nanomaterial carriers used in hepatocellular carcinoma (HCC) treatment over the past five years. The following is a summary of the three drugs: Sorafenib, Gefitinib, and lenvatinib. Each drug employs distinct nanomaterial delivery systems, which result in varying levels of bioavailability, drug release rates, and therapeutic efficacy.

Engineered Nanovesicles for the Precise and Noninvasive Treatment of Deep Osteomyelitis Caused by MRSA Infection with Enhanced Immune Response

The clinical treatment of hospital-acquired persistent osteomyelitis caused by methicillin-resistant Staphylococcus aureus (MRSA) presents two major challenges: ineffective drug delivery into deep tissues and counteracting the rapid establishment of an immunosuppressive microenvironment. Indeed, MRSA can evade immunosurveillance and undermine both innate and adaptive immune responses. Herein, the engineered nanovesicles, functioning by combining sonodynamic therapy (SDT) with immune modulation, were constructed for the precise and noninvasive removal of MRSA in deep tissue and activation of the antimicrobial immune response using a newly engineered nanovesicle. Macrophage-derived M1 phenotypic microvesicles (M1-MW) internalized vancomycin-cross-linked micelles with the acoustic sensitizer indocyanine green (ICG) (VCG micelles). The vesicles of M1-MW were grafted with PEGylated mannose, allowing for targeted accumulation at the infection site. The VCG micelles were responsive to the highly reducing environment and released ICG to generate ROS after exposure to ultrasounds. This effect was combined with the presence of vancomycin to kill MRSA. In an osteomyelitis infection model, we observed an improved survival rate and reprogramming of macrophages to a pro-inflammatory M1 phenotype. The latter promoted T-cell activation and immune defense against MRSA-camouflaged homologous cell-transferred infections. Thus, our study presents a noninvasive and efficient treatment (VCG@MMW) for deep osteomyelitis with improved bacterial clearance and reduced risk of recurrence with enhanced immune response.

[Low-intensity pulsed ultrasound combined with nystatin treatment synergistically inhibits vaginal Candida albicans biofilm infection in rabbits]

OBJECTIVES

To explore the efficacy of low-intensity pulsed ultrasound (LIPUS) combined with nystatin for treatment of vaginal Candida albicans biofilm infection.

METHODS

In vitro cultured Candida albicans biofilm were treated with LIPUS, nystatin, or both, and the minimum inhibitory concentration (MIC) of nystatin was determined. Crystal violet staining, confocal laser microscopy (CLSM) and scanning electron microscopy were used to quantify the biofilm and observe the activity and morphological changes of the biofilms; DCFH-DA was used to detect the changes in reactive oxygen species (ROS). Twenty female New Zealand White rabbits with vaginal inoculation of Candida albicans biofilm were randomized into 4 groups for treatment with normal saline, LIPUS, nystatin, or both LIPUS and nystatin. The changes in vulvar symptoms of the rabbits were observed, and the histopathological and ultrastructural changes of the vagina before and after treatment were observed using HE staining and transmission electron microscopy.

RESULTS

In the combined treatment group, the MIC50 and MIC80 of nystatin in Candida albicans biofilms were both reduced by 50% compared with those in nystatin group, and the biofilm clearance rate increased by 26% and 68% compared with nystatin and LIPUS groups, respectively. Compared with nystatin and LIPUS treatment alone, the combined treatment produced stronger effects for inhibiting biofilm activity, causing structural disruption and promoting ROS production. In the rabbit models, the combined treatment more effectively improved vulvar symptoms and inflammatory infiltration, reduced residual vaginal hyphae/strains, and improved ultrastructure of the vaginal epithelium than LIPUS and nystatin treatment alone.

CONCLUSIONS

LIPUS combined with nystatin produces a significant synergistic antifungal effect against Candida albicans biofilm both in vitro and in vivo.

New strategies to enhance antimicrobial photo-sonodynamic therapy based on nanosensitizers against bacterial infections

The rapid evolution and spread of multidrug resistance among bacterial pathogens has significantly outpaced the development of new antibiotics, underscoring the urgent need for alternative therapies. Antimicrobial photodynamic therapy and antimicrobial sonodynamic therapy have emerged as promising treatments. Antimicrobial photodynamic therapy relies on the interaction between light and a photosensitizer to produce reactive oxygen species, which are highly cytotoxic to microorganisms, leading to their destruction without fostering resistance. Antimicrobial sonodynamic therapy, a novel variation, substitutes ultrasound for light to activate the sonosensitizers, expanding the therapeutic reach. To increase the efficiency of antimicrobial photodynamic therapy and antimicrobial sonodynamic therapy, the combination of these two methods, known as antimicrobial photo-sonodynamic therapy, is currently being explored and considered a promising approach. Recent advances, particularly in the application of nanomaterials, have further enhanced the efficacy of these therapies. Nanosensitizers, due to their improved reactive oxygen species generation and targeted delivery, offer significant advantages in overcoming the limitations of conventional sensitizers. These breakthroughs provide new avenues for treating bacterial infections, especially multidrug-resistant strains and biofilm-associated infections. Continued research, including comprehensive clinical studies, is crucial to optimizing nanomaterial-based antimicrobial photo-sonodynamic therapy for clinical use, ensuring their effectiveness in real-world applications.

Revolutionizing oral care: Reactive oxygen species (ROS)-Regulating biomaterials for combating infection and inflammation

The human oral cavity is home to a delicate symbiosis between its indigenous microbiota and the host, the balance of which is easily perturbed by local or systemic factors, leading to a spectrum of oral diseases such as dental caries, periodontitis, and pulp infections. Reactive oxygen species (ROS) play crucial roles in the host's innate immune defenses. However, in chronic inflammatory oral conditions, dysregulated immune responses can result in excessive ROS production, which in turn exacerbates inflammation and causes tissue damage. Conversely, the potent antimicrobial properties of ROS have inspired the development of various anti-infective therapies. Therefore, the strategic modulation of ROS by innovative biomaterials is emerging as a promising therapeutic approach for oral infection and inflammation. This review begins by highlighting the state-of-the-art of ROS-regulating biomaterials, which are designed to generate, scavenge, or modulate ROS in a bidirectional manner. We then delve into the latest innovations in these biomaterials and their applications in treating a range of oral diseases, including dental caries, endodontic and periapical conditions, periodontitis, peri-implantitis, and oral candidiasis. The review concludes with an overview of the current challenges and future potential of these biomaterials in clinical settings. This review provides novel insights for the ongoing development of ROS-based therapeutic strategies for oral diseases.

Fluorocarbon-Functionalized Polymerization-Induced Self-Assembly Nanoparticles Alleviate Hypoxia to Enhance Sonodynamic Cancer Therapy

Sonodynamic therapy (SDT) is an ultrasound-based, noninvasive cancer treatment that targets tumor cells by triggering reactive oxygen species production. However, the limited accumulation of sonosensitizers and the insufficient supply of O2 to the hypoxic environment at the tumor site greatly limit the effectiveness of SDT. To address these issues, positively charged porphyrin-containing nanoparticles (NPs) from self-assembling of fluorocarbon/polyethylene glycol amphiphilic block copolymer, which is synthesized through reversible addition-fragmentation chain transfer polymerization, are constructed. The NPs with fluorocarbon core and positively charged hydrophilic shells not only stabilize the sonosensitizer and improve its cellular uptake, but also act as an O2 carrier alleviating the hypoxic tumor environment. In vitro and in vivo experiments demonstrate that the NPs effectively deliver O2 to the tumor and supply sufficient O2 to Renca cells after ultrasound treatment. Consequently, the NPs inhibit hypoxia-induced resistance to SDT and significantly produce reactive oxygen species by activated porphyrin moieties, inducing apoptosis in cancer cells. These oxygen-enhanced sonosensitizer NPs hold promise for cancer therapies such as photodynamic therapy, radiotherapy, and chemotherapy by overcoming hypoxia-induced resistance.

Transcytosable and Ultrasound-Activated Liposome Enables Deep Penetration of Biofilm for Surgical Site Infection Management

Biofilm-associated surgical site infection (BSSI) is a common and grievous postoperative complication lacking effective remedies, mainly due to the poor drug accumulation and penetration in the biofilms featured by dense extracellular polymeric substances (EPSs). Here, it is found that the vascular cell adhesion molecule-1 (VCAM1) is highly overexpressed in the vascular cells of BSSI. It is proposed that the combination of VCAM1-mediated transcytosis and ultrasonic cavitation can consecutively overcome the biological barriers of vascular endothelial cells and EPS for biofilm eradication. To demonstrate the feasibility, a VCAM1-targeted and ultrasound (US)-activated liposome (LPCOTML) loaded with a reactive-oxygen-species (ROS)-responsive lipoid prodrug of oleoyl meropenem, sonosensitizer of lipoid Ce6, and perfluoropentane is developed. LPCOTML can recognize the receptors on vascular cells, and initiate receptor-mediated transcytosis for transendothelial transport into the BSSI periphery. LPCOTML subsequently transforms from nanoparticle into microbubble via liquid-gas phase transition under US irradiation, triggering strong ultrasonic cavitation to blow up the EPS and deeply penetrate the biofilms. The sonosensitizer Ce6 induces ROS production under US irradiation and triggers the release of meropenem to induce potent antibacterial effect in a BSSI model. This study presents an effective strategy to tackle the biological barriers in BSSI via combining receptor-mediated transcytosis and ultrasonic cavitation.

Monitoring Apoptosis and Myeloid Differentiation of Acridine Orange-Mediated Sonodynamic Therapy-Induced Human Promyelocytic Leukemia HL60 Cells

OBJECTIVES

In the treatment of acute myeloid leukemia (AML), conventional therapies can lead to severe side effects and drug resistance. There is a need for alternative treatments that do not cause treatment resistance and have minimal or no side effects. Sonodynamic therapy (SDT), due to its noninvasive, multiple repeatability, localized treatment feature and do not cause treatment resistance, emerges as an alternative treatment option. However, it has not received sufficient attention in the treatment of AML especially acute promyelocytic leukemia (APL). The aim of the study was to investigate the potential differentiation and antileukemic effects of acridine orange (AO)-mediated SDT on HL60 cells.

METHODS

Cell viability was determined by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) method in the control, ultrasound, AO concentrations, and ultrasound-exposed AO concentrations groups. Transmission electron microscopy (TEM) was used to determine morphology, and flow cytometry was used to determine apoptosis, DNA cycle, cell volume, mitochondria membrane potential (Δψm), reactive oxygen species (ROS) production, and differentiation markers (CD11b and CD15) expressions. Additionally, toluidine blue staining for semithin sections was used to determine differentiation.

RESULTS

The cytotoxicity of AO-mediated SDT on HL60 cells was significantly higher than other groups, and TEM images showed that it caused various morphological changes typical for apoptosis. Flow cytometry results showed the presence of early apoptosis, subG1 arrest, loss of Δψm, increase of intracellular ROS production, decreased cell volume, and increased expression of CD11b (1.3-fold) antigen and CD15 (1.2-fold) antigen.

CONCLUSION

Data showed that AO-mediated SDT significantly induced apoptosis in HL60 cells. Increased expression of CD11b and CD15 antigens and morphological findings demonstrated that AO-mediated SDT contributes to granulocytic differentiation in HL60 cells. AO-mediated SDT has potential as an alternative treatment of APL.

Engineering Stimuli-Responsive Materials for Precision Medicine

Over the past decade, precision medicine has garnered increasing attention, making significant strides in discovering new therapeutic drugs and mechanisms, resulting in notable achievements in symptom alleviation, pain reduction, and extended survival rates. However, the limited target specificity of primary drugs and inter-individual differences have often necessitated high-dosage strategies, leading to challenges such as restricted deep tissue penetration rates and systemic side effects. Material science advancements present a promising avenue for these issues. By leveraging the distinct internal features of diseased regions and the application of specific external stimuli, responsive materials can be tailored to achieve targeted delivery, controllable release, and specific biochemical reactions. This review aims to highlight the latest advancements in stimuli-responsive materials and their potential in precision medicine. Initially, we introduce disease-related internal stimuli and capable external stimuli, elucidating the reaction principles of responsive functional groups. Subsequently, we provide a detailed analysis of representative pre-clinical achievements of stimuli responsive materials across various clinical applications, including enhancements in the treatment of cancers, injury diseases, inflammatory diseases, infection diseases, and high-throughput microfluidic biosensors. Finally, we discuss some clinical challenges, such as off-target effects, long-term impacts of nano-materials, potential ethical concerns, and offer insights into future perspectives of stimuli-responsive materials.

An In vitro Study on the Antibacterial Effect of a Combined Photodynamic and Sonodynamic Therapy Using IR780 Iodide-loaded Mesoporous Silica Nanoparticles Against P. aeruginosa and Multi-Drug Resistant P. aeruginosa

BACKGROUND

The aim of this study was to investigate the antimicrobial photodynamic, sonodynamic, and combined photodynamic and sonodynamic potentials of IR780 iodide loaded mesoporous silica nanoparticles against gram-negative Pseudomonas aeruginosa (P. aeruginosa) and multi drug resistant Pseudomonas aeruginosa (MDR P. aeruginosa).

METHODS

IR780 iodide loaded mesoporous silica nanoparticles were synthesized, and their antimicrobial photodynamic and sonodynamic potentials against one P. aeruginosa strain, and one MDR P. aeruginosa strain were investigated. Laser irradiation was achieved via a 785 nm diode laser (500 mW/cm2, 5 min). Ultrasound irradiation was achieved via a 1-MHz ultrasound unit (1.5 W/cm2, 50% duty cycle, 3 min). Viable bacterial cells were counted by serial dilution method. Data were analyzed by ANOVA followed by Tukey's test (p ≤ 0.05).

RESULTS

The results revealed that for P. aeruginosa, the combined photodynamic therapy (PDT) and sonodynamic therapy (SDT) showed a 44% reduction in bacterial cell viability as compared to 18% and 31% when exposed to SDT alone and PDT alone, respectively. For MDR. P. aeruginosa, the combined treatment resulted in a 45% reduction in bacterial cell viability, as compared to 14% and 30% when exposed to SDT alone and PDT alone, respectively. The killing effect was mainly due to the photodynamic and sonodynamic effects of the nanoparticles, mainly caused by singlet oxygen. No photothermal effect was involved in the killing.

CONCLUSION

The results of this study demonstrated that IR780 iodide-loaded mesoporous silica nanoparticles have the potential to be utilized as photo/sono therapeutic agents for the inactivation of drug-resistant bacteria.

Helicobacter pylori: Routes of Infection, Antimicrobial Resistance, and Alternative Therapies as a Means to Develop Infection Control

Helicobacter pylori (H. pylori) is a Gram-negative, spiral-shaped bacterium that colonizes the gastric epithelium and is associated with a range of gastrointestinal disorders, exhibiting a global prevalence of approximately 50%. Despite the availability of treatment options, H. pylori frequently reemerges and demonstrates increasing antibiotic resistance, which diminishes the efficacy of conventional therapies. Consequently, it is imperative to explore non-antibiotic treatment alternatives to mitigate the inappropriate use of antibiotics. This review examines H. pylori infection, encompassing transmission pathways, treatment modalities, antibiotic resistance, and eradication strategies. Additionally, it discusses alternative therapeutic approaches such as probiotics, anti-biofilm agents, phytotherapy, phototherapy, phage therapy, lactoferrin therapy, and vaccine development. These strategies aim to reduce antimicrobial resistance and enhance treatment outcomes for H. pylori infections. While alternative therapies can maintain low bacterial levels, they do not achieve complete eradication of H. pylori. These therapies are designed to bolster the immune response, minimize side effects, and provide gastroprotective benefits, rendering them suitable for adjunctive use alongside conventional treatments. Probiotics may serve as adjunctive therapy for H. pylori; however, their effectiveness as a monotherapy is limited. Photodynamic and phage therapies exhibit potential in targeting H. pylori infections, including those caused by drug-resistant strains, without the use of antibiotics. The development of a reliable vaccine is also critical for the eradication of H. pylori. This review identifies candidate antigens such as VacA, CagA, and HspA, along with various vaccine formulations, including vector-based and subunit vaccines. Some vaccines have demonstrated efficacy in clinical trials, while others have shown robust immune protection in preclinical studies. Nevertheless, each of the aforementioned alternative therapies requires thorough preclinical and clinical evaluation to ascertain their efficacy, side effects, cost-effectiveness, and patient compliance.

Advancing Anti-Biofilm Strategies: Innovations to Combat Biofilm-Related Challenges and Enhance Efficacy

Biofilms are complex communities of microorganisms that can cause significant challenges in various settings, including industrial processes, environmental systems, and human health. The protective nature of biofilms makes them resistant to traditional anti-biofilm strategies, such as chemical agents, mechanical interventions, and surface modifications. To address the limitations of conventional anti-biofilm methods, researchers have explored emerging strategies that encompass the use of natural compounds, nanotechnology-based methods, quorum-sensing inhibition, enzymatic degradation, and antimicrobial photodynamic/sonodynamic therapy. There is an increasing focus on combining multiple anti-biofilm strategies to combat resistance and enhance effectiveness. Researchers are continuously investigating the mechanisms of biofilm formation and developing innovative approaches to overcome the limitations of conventional anti-biofilm methods. These efforts aim to improve the management of biofilms and prevent infections while preserving the environment. This study provides a comprehensive overview of the latest advancements in anti-biofilm strategies. Given the dynamic nature of this field, exploring new approaches is essential to stimulate further research and development initiatives. The effective management of biofilms is crucial for maintaining the health of industrial processes, environmental systems, and human populations.

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.

Engineering Sonosensitizer-Derived Nanotheranostics for Augmented Sonodynamic Therapy

Sonodynamic therapy (SDT), featuring noninvasive, deeper penetration, low cost, and repeatability, is a promising therapy approach for deep-seated tumors. However, the general or only utilization of SDT shows low efficiency and unsatisfactory treatment outcomes due to the complicated tumor microenvironment (TME) and SDT process. To circumvent the issues, three feasible approaches for enhancing SDT-based therapeutic effects, including sonosensitizer optimization, strategies for conquering hypoxia TME, and combinational therapy are summarized, with a particular focus on the combination therapy of SDT with other therapy modalities, including chemodynamic therapy, photodynamic therapy, photothermal therapy, chemotherapy, starvation therapy, gas therapy, and immunotherapy. In the end, the current challenges in SDT-based therapy on tumors are discussed and feasible approaches for enhanced therapeutic effects are provided. It is envisioned that this review will provide new insight into the strategic design of high-efficiency sonosensitizer-derived nanotheranostics, thereby augmenting SDT and accelerating the potential clinical transformation.

Biomimetic Metal-Organic Framework Gated Nanoplatform for Sonodynamic Therapy against Extensively Drug Resistant Bacterial Lung Infection

Novel antimicrobial strategies are urgently needed to treat extensively drug-resistant (XDR) bacterial infections due to the high mortality rate and lack of effective therapeutic agents. Herein, nanoengineered human umbilical cord mesenchymal stem cells (hUC-MSCs), named PMZMU, are designed as a sonosensitizer for synergistic sonodynamic-nano-antimicrobial therapy against gram-negative XDR bacteria. PMZMU is composed of a bacterial targeting peptide (UBI29-41) modified hUC-MSCs membrane (MSCm), a sonosensitizer meso-tetra(4-car-boxyphenyl) porphine doped mesoporous organo-silica nanoparticle and an acidity-responsive metal-organic framework ZIF-8. This innovative formulation enables efficient loading of polymyxin B, reduces off-target drug release, increases circulation and targeting efficacy, and generates reactive oxygen species upon ultrasound irradiation. PMZMU exhibits remarkable in vitro inhibitory activity against four XDR bacteria: Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa (PA), and Escherichia coli. Taking advantage of the bacterial targeting ability of UBI29-41 and the inflammatory chemotaxis of hUC-MSC, PMZMU can be precisely delivered to lung infection sites thereby augmenting polymyxin B concentration. PMZMU-mediated sonodynamic therapy significantly reduces bacterial burden, relieves inflammatory damage by promoting the polarization of macrophages toward M2 phenotype, and improves survival rates without introducing adverse events. Overall, this study offers promising strategies for treating deep-tissue XDR bacterial infections, and guides the design and optimization of biomimetic nanomedicine.

Material-based treatment strategies against intraosseous implant biofilm infection

Implant-associated infections present a significant clinical obstacle for orthopedic practitioners, with bacterial biofilm formation serving as a pivotal factor in the initiation, progression, and management of such infections. Conventional approaches have proven inadequate in fully eradicating biofilm-related infections. Consequently, novel material-based therapeutic strategies have been developed, encompassing the utilization of antimicrobial agents, delivery vehicles, and synergistic antibacterial systems. In this review, we provide a succinct overview of recent advancements in anti-biofilm strategies, with the aim of offering insights that may aid in the treatment of intraosseous implant infections.

Design of Ultrasound-Driven Charge Interference Therapy for Wound Infection

Wound infections, especially those caused by pathogenic bacteria, present a considerable public health concern due to associated complications and poor therapeutic outcomes. Herein, we developed antibacterial nanoparticles, namely, PGTP, by coordinating guanidine derivatives with a porphyrin-based sonosensitizer. The synthesized PGTP nanoparticles, characterized by their strong positive charge, effectively disrupted the bacterial biosynthesis process through charge interference, demonstrating efficacy against both Gram-negative and Gram-positive bacteria. Additionally, PGTP nanoparticles generated reactive oxygen species under ultrasound stimulation, resulting in the disruption of biofilm integrity and efficient elimination of pathogens. RNA-seq analysis unveiled the detailed mechanism of wound healing, revealing that PGTP nanoparticles, when coupled with ultrasound, impair bacterial metabolism by interfering with the synthesis and transcription of amino acids. This study presents a novel approach to combatting wound infections through ultrasound-driven charge-interfering therapy, facilitated by advanced antibacterial nanomaterials.

Staphylococcus aureus biofilm: Formulation, regulatory, and emerging natural products-derived therapeutics

Staphylococcus aureus can readily form biofilm which enhances the drug-resistance, resulting in life-threatening infections involving different organs. Biofilm formation occurs due to a series of developmental events including bacterial adhesion, aggregation, biofilm maturation, and dispersion, which are controlled by multiple regulatory systems. Rapidly increasing research and development outcomes on natural products targeting S. aureus biofilm formation and/or regulation led to an emergent application of active phytochemicals and combinations. This review aimed at providing an in-depth understanding of biofilm formation and regulation mechanisms for S. aureus, outlining the most important antibiofilm strategies and potential targets of natural products, and summarizing the latest progress in combating S. aureus biofilm with plant-derived natural products. These findings provided further evidence for novel antibiofilm drugs research and clinical therapies.

Facile fabrication of chitosan/hyaluronic acid hydrogel-based wound closure material Co-loaded with gold nanoparticles and fibroblast growth factor to improve anti-microbial and healing efficiency in diabetic wound healing and nursing care

Generally, diabetic wounds heal very slowly and inefficiently with an increasing risk of infections. Recent nanotechnology and biomaterial advances elaborate developed multi-functional hydrogels and nanoparticles offer promising solutions to accelerate wound healing for diabetic patients. This research work demonstrates to use of solvent diffusion method to develop hydrogel nanocomposites composed of chitosan (CS), hyaluronic acid (HA), gold (Au), and fibroblast growth factors (FGF). The biological analysis of nanocomposites exhibited enhanced wound healing efficiency by incorporating bioactive molecules like FGF and bioactive Au nanoparticles. In vitro, cell compatibility analysis (MTT assay) of prepared hydrogel nanocomposites was studied on fibroblast cell lines NIH-3T3-L1 and L929 and exhibited greater cell survival ability (>90 %), cell proliferation and migration ability, which demonstrated the suitability of nanocomposite for wound healing treatment. In vitro, anti-bacterial analyses established that FGF-Au@CS/HA has strong antibacterial effectiveness against gram-positive and gram-negative pathogens. The observation of the present research revealed that prepared FGF-Au@CS/HA hydrogel composites could be a suitable biomaterial for diabetic wound care, potentially improving its antibacterial and healing efficacies.

The Impact of Periodontal Disease on Preterm Birth and Preeclampsia

This review delves into the possible connection between periodontitis and negative pregnancy outcomes, such as preeclampsia and preterm birth. It highlights the potential influence of an unidentified microbial factor on preeclampsia and the effects of inflammatory responses on the rate of preterm births. Furthermore, it underscores the prevalent occurrence of oral ailments within the populace and their significant repercussions on quality of life. Hormonal fluctuations during pregnancy may exacerbate oral conditions such as pregnancy gingivitis and periodontitis, necessitating bespoke therapeutic approaches that take into account potential fetal ramifications. Periodontal disease, characterized by microbial attack and inflammatory response, results in tissue destruction and tooth loss. The oral cavity's susceptibility to bacterial colonization, which is primarily due to its role as a site for food intake, is highlighted. Furthermore, research indicates a correlation between inflammatory responses and factors such as prostaglandin E2 and IL-1β, and preterm birth. Therapeutic interventions are a focus of international research, with efforts being aimed at optimizing outcomes through larger studies involving pregnant women.