Membrane Disruption Research Articles

Crosstalk between Dysfunctional Mitochondria and Proinflammatory Responses during Viral Infections.

Mitochondria play pivotal roles in sustaining various biological functions including energy metabolism, cellular signaling transduction, and innate immune responses. Viruses exploit cellular metabolic synthesis to facilitate viral replication, potentially disrupting mitochondrial functions and subsequently eliciting a cascade of proinflammatory responses in host cells. Additionally, the disruption of mitochondrial membranes is involved in immune regulation. During viral infections, mitochondria orchestrate innate immune responses through the generation of reactive oxygen species (ROS) and the release of mitochondrial DNA, which serves as an effective defense mechanism against virus invasion. The targeting of mitochondrial damage may represent a novel approach to antiviral intervention. This review summarizes the regulatory mechanism underlying proinflammatory response induced by mitochondrial damage during viral infections, providing new insights for antiviral strategies.

Synergistic Toxicity of Pollutant and Ultraviolet Exposure from a Mitochondrial Perspective.

Ultraviolet (UV) exposure and atmospheric pollution are both independently implicated in skin diseases such as cancer and premature aging. UVA wavelengths, which penetrate in the deep layers of the skin dermis, exert their toxicity mainly through chromophore photosensitization reactions. Benzo[a]pyrene (BaP), the most abundant polycyclic aromatic hydrocarbon originating from the incomplete combustion of organic matter, could act as a chromophore and absorb UVA. We and other groups have previously shown that BaP and UVA synergize their toxicity in skin cells, which leads to important oxidation. Even if mitochondria alterations have been related to premature skin aging and other skin disorders, no studies have focused on the synergy between UV exposure and pollution on mitochondria. Our study aims to investigate the combined effect of UVA and BaP specifically on mitochondria in order to assess the effect on mitochondrial membranes and the consequences on mitochondrial activity. We show that BaP has a strong affinity for mitochondria and that this affinity leads to an important induction of lipid peroxidation and membrane disruption when exposed to UVA. Co-exposure to UVA and BaP synergizes their toxicity to negatively impact mitochondrial membrane potential, mitochondrial metabolism and the mitochondrial network. Altogether, our results highlight the implication of mitochondria in the synergistic toxicity of pollution and UV exposure and the potential of this toxicity on skin integrity.

Bioinspired construction of ATP/Co-Al-Zn LDH nanozyme with enhanced peroxidase-mimic performance for efficient bactericidal activity through membrane disruption

In recent years, overuse of antibiotics has led to emerging antibiotic-resistant strains of bacteria. Consequently, creating new, highly productive antibacterial agents is crucial. In this work, we synthesized copper-aluminum-zinc layered double hydroxide (Co-Al-Zn LDH) and modified it using adenosine triphosphate. After characterization, the enzyme-like activity of the prepared particles was evaluated. The results indicated peroxidase-mimic performance of ATP/Co-Al-Zn LDH with Km values of 0.38 mM and 1.69 mM for TMB (3,3′,5,5′-tetramethylbenzidine) and hydrogen peroxide (H2O2), respectively, which were lower than that of horseradish peroxidase. The highest peroxidase-like activity of ATP/Co-Al-Zn LDH was achieved at 20 °C, pH 4, with a 1.02 mg/mL catalyst, 231 μM TMB, and 1.9 mM H2O2. The bactericidal activity of the developed nanozyme was studied against E. coli and S. aureus. The peroxidase-mimic nanozyme decomposes H2O2 and generates free radicals to kill bacteria in vitro. The minimum inhibitory concentration (MIC) of ATP/Co-Al-Zn LDH was 15 μg/mL and 20 μg/mL for S. aureus and E. coli, respectively. The morphological characteristics of the nanozyme-treated bacterial cells showed dramatic changes in bacterial morphology. Our results revealed higher antibacterial activity of ATP/Co-Al-Zn LDH against S. aureus. Therefore, the developed nanozyme could serve as a substitute for conventional antibiotics.

Evaluation of the removal of cyanobacteria and cyanotoxins with a composite hydrogel based on chemically modified gelatin and PVA-containing graphene oxide nanoparticles

After being applied to pharmaceutics removal from water, the newly synthesized composite hydrogel based on chemically modified gelatin and PVA-containing graphene nanoparticles (CHGP-GOn), was now assessed for another application. The hydrogels were able to interact with Microcystis aeruginosa cells, resulting in the formation of small cell colonies and cell lysis related to exposure time. In the removal tests, the best general removal efficiency of cyanobacterial cells was achieved with the highest adsorbent mass at natural pH, achieving values of removal of 90 % for cells, 75 % chlorophyll-a, 63 % and 43 % for turbidity and visible colour removals, respectively. From the kinetic study, the results showed that cell inactivation has achieved removal equilibrium in 19 h, with a qe of 106 × 106 cells/g of CHGP-GOn. Furthermore, with the results from the other parameters, the tests presented a removal equilibrium of just 14 h, there was a removal of 4670 µg/L of Chlorophyll-a and 6450 µg/L/g of MC-LR microcystin per gram of adsorbent. The experimental data best fitted to the Elovich model, indicating possible removal by chemisorption. Analysis of cellular integrity and morphology showed that within just 12 h, few cyanobacterial cells showed membrane disruption and release of intracellular toxins, with an increase in the toxicity medium related to extended exposure time, and presentation of morphological and superficial cellular damage within 24 h. In addition, other characteristic measurements presented an exceptional mechanical strength and resistance that was slightly reduced after swelling. However, showing good development during adsorption tests under agitation, without any detachment of material and an absence of GO leaching. Therefore, it can be concluded that the synthesized hydrogel should be applied in removing M. aeruginosa cells and their toxins from water treatment, serving as an excellent alternative to traditional adsorbents.

Risk factors for development of hyper-reflective foci overlying drusen in eyes with intermediate age-related macular degeneration

AimsThe aim of this study is to assess baseline characteristics of drusen preceding the development of intraretinal hyper-reflective foci (IHRF) in eyes with intermediate age-related macular degeneration (AMD).MethodsIn this retrospective...

Nonequilibrium Dynamic Phase Diagram for Transmembrane Transport of Active Particles.

In recent years, there has been considerable push toward the biomedical applications with active particles, which have great potential to revolutionize disease diagnostics and therapy. The direct penetration of active particles through the cell membrane leads to more efficient intracellular delivery than previously considered endocytosis processes but may cause membrane disruption. Understanding fundamental behaviors of cell membranes in response to such extreme impacts by active particles is crucial to develop active particle-based biomedical technologies and manage health and safety issues in this emerging field. Unfortunately, the physical principles underlying the nonequilibrium behaviors from endocytosis to direct penetration remain elusive, and experiments are challenging. Here, we present a computed dynamic phase diagram for transmembrane transport of active particles and identify four characteristic dynamic phases in endocytosis and direct penetration according to the particle activity and membrane tension. The boundaries dividing these phases are analytically obtained with theoretical models, elucidating the nonequilibrium physics and criteria for the transition between different phases. Furthermore, we numerically and experimentally show three distinct dynamic regimes related to the interplay between necking and wrapping during the endocytosis process of active particles, which strikingly contrast the regimes for passive particles. Overall, these findings could be useful for sharpening the understanding of basic principles underlying biological issues related to the safe and efficient biomedical applications of such emerging matters.

Magnetic-field-assisted extraction of phycocyanin from Spirulina platensis

Phycocyanin is the major natural pigment of phycobiliproteins produced by Spirulina platensis. Extraction and release of this pigment from cells depend on the disruption of the cell membrane. Extraction of bioactive compounds in magnetic field is a novel extraction method with unique characteristics and cost-effectiveness with high precision. Aim of the present study was to develop an efficient protocol for the extraction of phycocyanin from Spirulina platensis using magnetic-field-assisted extraction. Extraction process of phycocyanin via magnetic-field-assisted method was optimized using response surface methodology of three-level, three-variable central composite design. Results included optimum extraction conditions of solid-to-liquid ratio of 17.11 %, magnetic field intensity of 27.13 mT and extraction time of 49.87 min. Under the highlighted conditions, phycocyanin concentration, yield and purity included 5.44 mg/ml, 26.34 mg/g and 24.32, respectively. The experimental yield under optimal conditions was similar to the predictive yield. Magnetic-field-assisted extraction increased concentration, yield and purity of phycocyanin up to 97.7, 91.5 and 28.32 %, compared to conventional methods.

Production and characterisation of antioxidant and antibacterial polymeric nanoparticles loaded with Oenocarpus bataua phenolic extract

SummaryOne recent trend in the food industry is using natural antioxidants and antimicrobials as additives for developing multi‐functional packaging. In this study, phenolic compounds from patawa (PEP), a neglected Amazon palm tree, were extracted and encapsulated in nanoparticles based on acetylated cashew gum polysaccharide (acCGP) and chitosan (CS) using a nanoprecipitation technique. The primary objective was to evaluate the antioxidant activity and antibacterial properties of PEP and acCGP/CS@PEP. Results from HPLC‐MS showed that PEP is mainly composed of epicatechin, naringenin and rutin. acCGP/CS@PEP nanoparticles showed a spheric and smooth microstructure, observed with 40.1% PEP encapsulation into the nanoparticles. The main encapsulated phenolics were luteolin, quercetin and epicatechin. Also, FTIR spectroscopy, X‐ray diffraction and differential scanning calorimetry analyses evidenced the success of PEP encapsulation. Results from antioxidant activity evidenced that acCGP/CS@PEP has a DPPH scavenging activity 45‐fold higher than the unencapsulated PEP, a 5‐fold higher ferric reducing power and 20‐fold higher antioxidant potential against ABTS. Similarly, acCGP/CS@PEP had higher antibacterial activity against Escherichia coli (MIC = 2.24 mg mL−1), Salmonella enteritis (MIC = 4.48 mg mL−1) and Staphylococcus aureus (MIC = 4.48 mg mL−1). Analysis by SEM evidenced that acCGP/CS@PEP had a potent destructive effect with disruption of the bacterial cell membrane and liberation of cytoplasmic content. These findings demonstrated that PEP could be efficiently encapsulated in acCGP/CS nanoparticles, and this strategy could improve the efficiency of PEP as a bioactive compound for developing active packaging.

3D DNA origami pincers that multitask on giant unilamellar vesicles.

Proteins self-assemble to function in living cells. They may execute essential tasks in the form of monomers, complexes, or supramolecular cages via oligomerization, achieving a sophisticated balance between structural topology and functional dynamics. The modularity and programmability make DNA origami unique in mimicking these key features. Here, we demonstrate three-dimensional reconfigurable DNA origami pincers (DOPs) that multitask on giant unilamellar vesicles (GUVs). By programmably adjusting their pinching angle, the DOPs can dynamically control the degree of GUV remodeling. When oligomerized on the GUV to form origami cages, the DOP units interact with one another and undergo reorganization, resulting in the capture, compartmentalization, and detachment of lipid fragments. This oligomerization process is accompanied with membrane disruptions, enabling the passage of cargo across the membrane. We envisage that interfacing synthetic cells with engineered, multifunctional DNA nanostructures may help to confer customized cellular properties, unleashing the potential of both fields.

Membrane-localized magnetic hyperthermia promotes intracellular delivery of cell-impermeant probes.

In this work, we report the disruptive use of membrane-localized magnetic hyperthermia to promote the internalization of cell-impermeant probes. Under an alternating magnetic field, magnetic nanoparticles (MNPs) immobilized on the cell membrane via bioorthogonal click chemistry act as nanoheaters and lead to the thermal disruption of the plasma membrane, which can be used for internalization of different types of molecules, such as small fluorescent probes and nucleic acids. Noteworthily, no cell death, oxidative stress and alterations of the cell cycle are detected after the thermal stimulus, although cells are able to sense and respond to the thermal stimulus through the expression of different types of heat shock proteins (HSPs). Finally, we demonstrate the utility of this approach for the transfection of cells with a small interference RNA (siRNA), revealing a similar efficacy to a standard transfection method based on the use of cationic lipid-based reagents (such as Lipofectamine), but with lower cell toxicity. These results open the possibility of developing new procedures for "opening and closing" cellular membranes with minimal disturbance of cellular integrity. This on-demand modification of cell membrane permeability could allow the direct intracellular delivery of biologically relevant (bio)molecules, drugs and nanomaterials, thus overcoming traditional endocytosis pathways and avoiding endosomal entrapment.

Marine biofouling mitigation of PDMS-based network coating with cross-linked contact- and release-active organoalkoxysilane

Poly (dimethylsiloxane) (PDMS) elastomer is one of key polymer resins for fouling release (FR) coatings, but it shows extremely poor antifouling (AF) activity in seawater since bacteria and diatoms could readily attach to surface. Modifying PDMS-based coatings via incorporating antifouling additives is effective for enhancing overall FR and AF activity. In this work, we prepared a well-defined organoalkoxysilane coating additive with quaternary ammonium and benzoisothiazolinone pendent groups, and the synthesized copolymers were covalently conjugated onto PDMS network in a one-pot reaction. AF and FR activities of the modified PDMS coatings were studied against soft fouling microorganisms. When microorganisms come into contact the coating surface, contact-active action mode works, quaternary ammonium groups could cause bacteria cell membrane disruption and microalgae photosynthesize inhibition via positive charge. Unexpectedly, a surprisingly lasting antimicrobial efficiency could be still observed in the neighboring coating, even the top-surface was completely covered with bacteria biofilm. Chemically conjugated benzoisothiazolinone could be sustainably released via side-group hydrolysis, thus, repelling and preventing the planktonic foulings from approaching the coating surface via release-active action mode. The modified PDMS coating with dual antifouling action modes could inhibit the biofilm formation at solid-liquid-air three-phase contact line, and could find valuable applications in marine transportation, water treatment and other antifouling fields.

Self-Assembling and Pore-Forming Peptoids as Antimicrobial Biomaterials.

Bacterial infections have been a serious threat to mankind throughout history. Natural antimicrobial peptides (AMPs) and their membrane disruption mechanism have generated immense interest in the design and development of synthetic mimetics that could overcome the intrinsic drawbacks of AMPs, such as their susceptibility to proteolytic degradation and low bioavailability. Herein, by exploiting the self-assembly and pore-forming capabilities of sequence-defined peptoids, we discovered a family of low-molecular weight peptoid antibiotics that exhibit excellent broad-spectrum activity and high selectivity toward a panel of clinically significant Gram-positive and Gram-negative bacterial strains, including vancomycin-resistant Enterococcus faecalis (VREF), methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Tuning the peptoid side chain chemistry and structure enabled us to tune the efficacy of antimicrobial activity. Mechanistic studies using transmission electron microscopy (TEM), bacterial membrane depolarization and lysis, and time-kill kinetics assays along with molecular dynamics simulations reveal that these peptoids kill both Gram-positive and Gram-negative bacteria through a membrane disruption mechanism. These robust and biocompatible peptoid-based antibiotics can provide a valuable tool for combating emerging drug resistance.

Synergism of colistin and globular endolysins against multidrug-resistant gram-negative bacteria

Endolysins (lysins), a novel class of antibacterial agents derived from bacteriophages, efficiently lyse bacteria by degrading the peptidoglycan layer within the bacterial wall. Colistin, a classic peptide antibiotic with the ability to permeabilize the outer membrane, has recently shown great promise in synergizing with lysins against gram-negative bacteria. However, the exact mechanisms responsible for their synergy remain unclear. Here, we first demonstrated the synergistic bacterial killing of various lysin and colistin combinations. With a model lysin, LysAB2, we then confirmed that there is a threshold concentration of colistin causing sufficient permeabilization of the outer membrane for lysin to access the peptidoglycan layer and subsequently exert its lytic ability. The threshold colistin concentrations were found to range 0.2−0.8 μM for the tested bacteria, with the exact value largely depending on the density of lipopolysaccharides on the outer membrane. Beyond the threshold colistin level, LysAB2 could synergize with colistin at a concentration as low as 0.31 μM. Next, we proved for the first time that lysin-induced degradation of the peptidoglycan layer facilitated the disruption of cytoplasmic membrane by colistin, elevated the level of reactive oxygen species in bacterial cells, and boosted the killing effect of colistin. Additionally, the colistin-lysin combination could effectively eliminate established biofilms due to the biofilm dispersal ability of lysin. The in-vivo efficacy was preliminary confirmed in a Galleria mellonella infection model for combination with colistin doses (≥ 1.8 μg/larvae), which could reach beyond the threshold concentration, and a fixed LysAB2 dose (10 μg/larvae). In summary, our study provided the first experimental evidence unravelling the mechanisms behind the synergy of colistin and lysins. All these findings provided important insights in guiding the dosing strategy for applying this combination in future development.

The Potential Therapeutic Effects of Botulinum Neurotoxins on Neoplastic Cells: A Comprehensive Review of In Vitro and In Vivo Studies.

A systematic review of the literature found fifteen articles on the effect of a botulinum toxin on neoplastic cell lines and eight articles on in vivo neoplasms. The reported in vitro effects rely on high doses or the mechanical disruption of cell membranes to introduce the botulinum neurotoxin into the cell cytoplasm. The potency of the botulinum neurotoxin to intoxicate non-neuronal cells (even cell lines expressing an appropriate protein receptor) is several orders of magnitude lower compared to that to intoxicate the primary neurons. The data suggest that the botulinum toxin disrupts the progression of cancer cells, with some studies reporting apoptotic effects. A majority of the data in the in vivo studies also showed similar results. No safety issues were disclosed in the in vivo studies. Limited studies have suggested similar anti-neoplastic potential for the clostridium difficile. New modes of delivery have been tested to enhance the in vivo delivery of the botulinum toxin to neoplastic cells. Careful controlled studies are necessary to demonstrate the efficacy and safety of this mode of anti-neoplastic treatment in humans.

Unraveling the effective inhibition of α-terpinol and terpene-4-ol against Aspergillus carbonarius: Antifungal mechanism, ochratoxin A biosynthesis inhibition and degradation perspectives

Aspergillus carbonarius, a common food-contaminating fungus, produces ochratoxin A (OTA) and poses a risk to human health. This study aimed to assess the inhibitory activity of tea tree essential oil and its main components, Terpene-4-ol (T4), α-terpineol (αS), and 3-carene (3C) against A. carbonarius. The study showed αS and T4 were the main antifungal components of tea tree essential oil, which primarily inhibit A. carbonarius growth through cell membrane disruption, reducing antioxidant enzyme activities (catalase, peroxidase, superoxide dismutase) and interrupting the tricarboxylic acid cycle. Furthermore, αS and T4 interacted with enzymes related to OTA biosynthesis. Molecular docking and molecular dynamics show that they bound mainly to P450 with a minimum binding energy of −7.232 kcal/mol, we infered that blocking the synthesis of OTA precursor OTβ. Our hypothesis was preliminarily verified by the detection of key substances in the OTA synthesis pathway. The results of UHPLC-QTOF-MS2 analysis demonstrated that T4 achieved a degradation rate of 43 % for OTA, while αS reached 29.6 %, resulting in final breakdown products such as OTα and phenylalanine. These results indicated that α-terpinol and Terpene-4-ol have the potential to be used as naturally safe and efficient preservatives or active packaging to prevent OTA contamination.

Structure-dependent destructive adsorption of organophosphate flame retardants on lipid membranes

The widespread use of organophosphate flame retardants (OPFRs), a serious type of pervasive environmental contaminants, has led to a global concern regarding their diverse toxicities to living beings. Using a combination of experimental and theoretical approaches, we systematically studied the adsorption, accumulation, and influence of a series of OPFRs on the lipid membranes of bacteria and cells. Our results revealed that OPFRs can aggregate in lipid membranes, leading to the destruction of membrane integrity. During this process, the molecular structure of the OPFRs is a dominant factor that significantly influences the strength of their interaction with the lipid membrane, resulting in varying degrees of biotoxicity. Triphenyl phosphate (TPHP), owing to its large molecular size and strong hydrophobicity, causes severe membrane disruption through the formation of nanoclusters. The corresponding severe toxicity originates from the phase transitions of the lipid membranes. In contrast, smaller OPFRs such as triethyl phosphate (TEP) and tris(2-chloroethyl) phosphate (TCEP) have weaker hydrophobicity and induce minimal membrane disturbance and ineffective damage. In vivo, gavage of TPHP induced more severe barrier damage and inflammatory infiltration in mice than TEP or TCEP, confirming the higher toxicity of TPHP. Overall, our study elucidates the structure-dependent adsorption of OPFRs onto lipid membranes, highlighting their destructive interactions with membranes as the origin of OPFR toxicity.

Cholesterol-Dependent Membrane Deformation by Metastable Viral Capsids Facilitates Entry.

Nonenveloped viruses employ unique entry mechanisms to breach and infect host cells. Understanding these mechanisms is crucial for developing antiviral strategies. Prevailing perspective suggests that nonenveloped viruses release membrane pore-forming peptides to breach host membranes. However, the precise involvement of the viral capsid in this entry remains elusive. Our study presents direct observations elucidating the dynamically distinctive steps through which metastable reovirus capsids disrupt host lipid membranes as they uncoat into partially hydrophobic intermediate particles. Using both live cells and model membrane systems, our key finding is that reovirus capsids actively deform and permeabilize lipid membranes in a cholesterol-dependent process. Unlike membrane pore-forming peptides, these metastable viral capsids induce more extensive membrane perturbations, including budding, bridging between adjacent membranes, and complete rupture. Notably, cholesterol enhances subviral particle adsorption, resulting in the formation of pores equivalent to the capsid size. This cholesterol dependence is attributed to the lipid condensing effect, particularly prominent at an intermediate cholesterol level. Furthermore, our results reveal a positive correlation between membrane disruption extent and efficiency of viral variants in establishing infection. This study unveils the crucial role of capsid-lipid interaction in nonenveloped virus entry, providing new insights into how cholesterol homeostasis influences virus infection dynamics.

Validated DNA isolation method ensuring successful long-read sequencing of cattle semen genome.

Obtaining high-quality DNA suitable for long-read sequencing can be difficult for many types of tissues and cells, and it is a key step in current genomic studies. The challenge is even greater when it comes to isolating genomic DNA from mammalian spermatozoa, as DNA is tightly packed into a cell with a robust membrane rich in disulfide bonds. Here we describe a method for isolating high molecular weight DNA from Bovine commercial semen straws. This protocol includes a cleaning step to remove diluents and preservatives used for the long-term storage of the semen, which may affect long read sequencing. It is based on a simple salting-out method and avoid the use of spin columns, strong mixing or intensive centrifugation, in order to limit DNA fragmentation. However, we have adapted this protocol to facilitate the disruption of cell membranes and disulfide bonds with strong chaotropic and reducing agents. The average size of the fragments produced was approximately 49 kb, ranging from 25 to 85 kb, according to the femto pulse profiles.This method was used to isolate DNA from semen straws, more than 80 of them were successfully sequenced using the Continuous Long-Read (CLR) sequencing mode on the PacBio SequelII platform to study genome diversity and notably to detect large structural variations within genomes.

Integrating electromagnetic cancer stress with immunotherapy: a therapeutic paradigm.

An array of published cell-based and small animal studies have demonstrated a variety of exposures of cancer cells or experimental carcinomas to electromagnetic (EM) wave platforms that are non-ionizing and non-thermal. Overall effects appear to be inhibitory, inducing cancer cell stress or death as well as inhibition in tumor growth in experimental models. A variety of physical input variables, including discrete frequencies, amplitudes, and exposure times, have been tested, but drawing methodologic rationale and mechanistic conclusions across studies is challenging. Nevertheless, outputs such as tumor cytotoxicity, apoptosis, tumor membrane electroporation and leak, and reactive oxygen species generation are intriguing. Early EM platforms in humans employ pulsed electric fields applied either externally or using interventional tumor contact to induce tumor cell electroporation with stromal, vascular, and immunologic sparing. It is also possible that direct or external exposures to non-thermal EM waves or pulsed magnetic fields may generate electromotive forces to engage with unique tumor cell properties, including tumor glycocalyx to induce carcinoma membrane disruption and stress, providing novel avenues to augment tumor antigen release, cross-presentation by tumor-resident immune cells, and anti-tumor immunity. Integration with existing checkpoint inhibitor strategies to boost immunotherapeutic effects in carcinomas may also emerge as a broadly effective strategy, but little has been considered or tested in this area. Unlike the use of chemo/radiation and/or targeted therapies in cancer, EM platforms may allow for the survival of tumor-associated immunologic cells, including naïve and sensitized anti-tumor T cells. Moreover, EM-induced cancer cell stress and apoptosis may potentiate endogenous tumor antigen-specific anti-tumor immunity. Clinical studies examining a few of these combined EM-platform approaches are in their infancy, and a greater thrust in research (including basic, clinical, and translational work) in understanding how EM platforms may integrate with immunotherapy will be critical in driving advances in cancer outcomes under this promising combination.

Ultrasound-Activated Probiotics Vesicles Coating for Titanium Implant Infections Through Bacterial Cuproptosis-Like Death and Immunoregulation.

Implant-associated infections (IAIs) are the main cause of prosthetic implant failure. Bacterial biofilms prevent antibiotic penetration, and the unique metabolic conditions in hypoxic biofilm microenvironment may limit the efficacy of conventional antibiotic treatment. Escaping survival bacteria may not be continually eradicated, resulting in the recurrence of IAIs. Herein, a sonosensitive metal-organic framework of Cu-TCPP (tetrakis(4-carboxyphenyl) porphyrin) nanosheets and tinidazole doped probiotic-derived membrane vesicles (OMVs) with high-penetration sonodynamic therapy (SDT), bacterial metabolic state interference, and bacterial cuproptosis-like death to eradicate IAIs is proposed. The Cu-TCPP can convert O2 to toxic 1O2 through SDT in the normoxic conditions, enhancing the hypoxic microenvironment and activating the antibacterial activity of tinidazole. The released Cu(II) under ultrasound can be converted to Cu(I) by exogenous poly(tannic acid) (pTA) and endogenous glutathione. The disruption of the bacterial membrane by SDT can enhance the Cu(I) transporter activity. Transcriptomics indicate that the SDT-enhanced Cu(I) overload and hypoxia-activated therapy hinder the tricarboxylic acid cycle (TCA), leading to bacterial cuproptosis-like death. Moreover, the OMVs-activated therapy can polarize macrophages to a M2-like phenotype and facilitate bone repair. The sonodynamic biofilm microenvironment modulation strategy, whereby the hypoxia-enhanced microenvironment is potentiated to synergize SDT with OMVs-activated therapy, provides an effective strategy for antibacterial and osteogenesis performance.