Bioresponsive Nanoparticles Targeted to Infectious Microenvironments for Sepsis Management

Chemoproteomics unveils Sofalcone targeting ribosomal proteins to inhibit protein synthesis in Staphylococcus aureus

The escalating threat of antibiotic resistance, particularly in Staphylococcus aureus (including methicillin-resistant strains, MRSA), underscores the urgent need for novel therapeutics. Sofalcone (Sof), a chalcone derivative from Sophora subprostrata with established anti-inflammatory and anti-ulcer properties, exhibits promising yet underexplored antibacterial activity. Here, we demonstrate that Sof potently inhibits S. aureus and MRSA while showing minimal cytotoxicity in human cells. Notably, Sof synergized with amoxicillin, and significantly reduced the pathogenicity of S. aureus through inhibiting biofilm formation addressing key virulence factors. Through chemoproteomic profiling using a clickable Sof-derived probe, ribosomal proteins, specifically the 50S subunit protein rplB, were identified as primary targets. Sof covalently binds to rplB via cysteine residues, as validated by cellular thermal shift assays, microscale thermophoresis, and competition assays. Bio-orthogonal noncanonical amino acid tagging revealed that Sof disrupts bacterial protein synthesis by impairing ribosomal function, a mechanism distinct from conventional antibiotics. In a murine model of S. aureus-induced acute lung injury, Sof greatly reduced bacterial load in lungs, attenuated systemic inflammation, and mitigated histopathological damage. Its dual antibacterial and anti-inflammatory efficacy, coupled with activity against Gram-negative Escherichia coli, highlights broad-spectrum potential. This study unveils a covalent ribosomal-targeting strategy, positioning Sof as a multifaceted candidate against multidrug-resistant infections. Our findings bridge natural product pharmacology and mechanistic antimicrobial discovery, offering a template for combating the global antibiotic resistance crisis.

Citrullination of NF-κB p65 by PAD2 as a Novel Therapeutic Target for Modulating Macrophage Polarization in Acute Lung Injury

Mediating protein citrullination, peptidyl arginine deiminase 2 (PAD2) has recently been reported to influence macrophage phenotypes. However, the mechanisms of PAD2 on macrophage function in Pseudomonas aeruginosa (PA)-induced acute lung injury syndrome (ALI) remains unclear. Utilizing single-cell RNA sequencing and mass spectrometry-based proteomics, a new citrullination site at arginine 171 (R171) is discovered within nuclear factor- κB (NF-κB) p65 catalyzed by PAD2, which modulates PAD2-NF-κB p65-importin α3 pathway and its downstream M1/M2 macrophage polarization. Building on these findings, a cell-specific targeted therapeutic strategy using gold nanoparticles (AuNPs) conjugated with a novel PAD2 inhibitor, AFM41a, and an intercellular adhesion molecule-1 (ICAM-1) antibody is developed. This approach enables the selective delivery of the inhibitor to M1-polarized macrophages in the PA-infected alveolar niche. In vivo, this nanomedicine reduces excessive inflammation and promotes M1-to-M2 polarization to inhibit ALI. This study highlights the role of PAD2-mediated citrullination in macrophage polarization and introduces a promising nanoparticle-based therapy for PA-induced ALI.

Bacteria escape macrophage-mediated phagocytosis via targeting apurinic/apyrimidinic endonuclease 1 in sepsis

Sepsis is a serious disease resulting from an imbalanced host response to bacterial infection, in which macrophages play a crucial role. However, the connection between bacterial infection and macrophage phagocytosis remains largely unknown. Here, we provide evidence supporting the role of apurinic/apyrimidinic endonuclease 1 (APE1) in regulating bacterial infection and macrophage immune function during sepsis. We confirmed down-regulation of APE1 expression in macrophages from both in vitro and in vivo septic models. APE1 deficiency significantly increases the mortality rate of septic mice. Experiments using fluorescent latex beads and Escherichia coli uptake demonstrated that reduced APE1 levels inhibit macrophage phagocytosis. Specifically, APE1 deficiency activates GSK3β, leading to the ubiquitination and subsequent proteasomal degradation of NRF2, thereby reducing the expression of phagocytic receptors. Additionally, APE1 participates in the process through its redox function. In conclusion, APE1 is a critical protein involved in the evasion of macrophage phagocytosis by bacteria. Our study suggests that targeting the APE1/NRF2 axis could serve as a promising therapeutic strategy for sepsis and bacterial infections.

Acid responsive molybdenum (Mo)-based nanoparticles inhibit the cGAS-STING signaling pathway for sepsis therapy

Sepsis, an inflammatory disease caused by bacterial infection, has become a global public health crisis. Excessive reactive oxygen species (ROS) in sepsis patients act as the primary trigger for activating intracellular immune pathways, ultimately leading to multiple organ dysfunction syndrome. The overexpression of acidic metabolites and ROS, characteristic of the infected microenvironment, significantly impedes sepsis treatment. Cyclic GMP-AMP synthase (cGAS), a cytosolic DNA sensor, plays a key role in inflammatory diseases. The detrimental effects of STING in sepsis have been well documented. Here, we developed a pH-responsive nanotherapy platform (DMSNM@C-178/PAA) that combines ROS scavenging with cGAS-STING pathway inhibition for anti-inflammatory therapy. This nanoparticle is selectively released in the infected microenvironment, where reduced molybdenum-based polyoxometalates (Mo-POM) efficiently neutralize toxic ROS in vivo, while C-178 selectively inhibits the cGAS-STING pathway, thereby attenuating the inflammatory response and preventing organ deterioration. In vitro and in vivo studies demonstrate that DMSNM@C-178/PAA treats sepsis by eliminating excess ROS and modulating autoimmune dysfunction via the cGAS-STING pathway, providing a novel therapeutic strategy for sepsis management.

Quaternary ammonium chitosan-functionalized mesoporous silica nanoparticles: A promising targeted drug delivery system for the treatment of intracellular MRSA infection

The limited membrane permeability and bacterial resistance pose significant challenges in the management of intracellular drug-resistant bacterial infections. To overcome this issue, we developed a bacterial-targeted drug delivery system based on quaternary ammonium chitosan-modified mesoporous silica nanoparticles (MSN-NH2-CFP@HACC) for the treatment of intracellular Methicillin-resistant Staphylococcus aureus (MRSA) infections. This system utilizes amino-functionalized mesoporous silica nanoparticles to efficiently load cefoperazone (CFP), and the nanoparticles' surface is coated with 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) to target bacteria and enhance macrophage uptake. The findings indicate that MSN-NH2-CFP@HACC nanoparticles are efficiently internalized by macrophages, demonstrate accelerated drug release in acidic environments, and exhibit enhanced antibacterial properties, effectively suppressing the proliferation and intracellular escape of MRSA. Moreover, HACC enhances the bacterial capture ability of the nanoparticles and reduces resistance by disrupting bacterial membrane structures and inhibiting bacterial β-lactamase activity. In a murine model of MRSA bacteremia, MSN-NH2-CFP@HACC exhibited remarkable antibacterial efficacy and significantly attenuated severe inflammatory responses. In conclusion, MSN-NH2-CFP@HACC represent a promising antibiotic delivery system with exceptional antibacterial efficacy and favorable biocompatibility, thus presenting a novel strategy for addressing intracellular drug-resistant bacterial infections and demonstrating significant potential for clinical application.

Inhalable and bioactive lipid-nanomedicine based on bergapten for targeted acute lung injury therapy via orchestrating macrophage polarization

Acute lung injury (ALI) or its more severe form, acute respiratory distress syndrome, is a life-threatening disease closely associated with an imbalance of M1/M2 macrophage polarization. However, current therapeutic strategies for ALI are controversial due to their side effects, restricted administration routes, or poor targeted delivery. The development of herbal medicine has uncovered numerous anti-inflammatory compounds potentially beneficial for ALI therapy. One such compound is the bergapten, a coumarin, which has been isolated from Ficus simplicissima Lour. However, it's been used as an anti-cancer drug and it's effects on ALI remain unexplored. The poor solubility and biodistribution of bergapten heavily limit its application. In this timely report, we developed a bioactive and lung-targeting lipid-nanomedicine by integrating bergapten and DPPC liposome, named as Ber-lipo. A comprehensive series of in vitro experiments confirmed the anti-inflammatory effects of Ber-lipo and its protective roles in maintaining the homeostasis of macrophage polarization and epithelial-endothelial integrity. In a lipopolysaccharide (LPS)-induced ALI mouse model, Ber-lipo can target inflamed lungs and significantly improve lung edema, tissue injury, and pulmonary function, relieve body weight loss, pulmonary permeability, and proinflammatory status, and especially maintain a balance of M1/M2 macrophage polarization. Furthermore, RNA sequencing analysis showed Ber-lipo's potential in effectively treating inflammatory lung diseases such as pneumonia, inhibiting proinflammatory signals, and altering the transcriptome of M1/M2 macrophages-associated genes in lung tissues. Molecular docking and Western blot analyses validated that Ber-lipo suppressed the activation of the TLR4/MyD88/NF-κB signaling axis responsible for ALI progression. In conclusion, this study demonstrates for the first time that new inhalable nanomedicine (Ber-lipo) can target inflamed lungs and ameliorates ALI by reprogramming macrophage polarization to an anti-inflammatory state via inactivating the TLR4/MyD88/NF-κB pathway, hence providing a promising strategy for enhanced ALI therapy in the clinic.

Polymeric Drug Delivery Systems in Biomedicine

Our review examines the key aspects of using polymeric carriers in biomedicine. The section "Polymers for Biomedicine" provides an overview of different types of polymers, their structural features and properties that determine their use as drug delivery vehicles. The section "Polymeric Carriers" characterizes the role of polymeric delivery systems in modern medicine. The main forms of polymeric carriers are described, as well as their key advantages for drug delivery. The section "Preclinical and Clinical Trials of Polymeric Drug Carriers" reviews the examples of clinical and preclinical studies of polymeric forms used for antitumor therapy, therapy for bacterial and infectious diseases. The final section "Targeted Drug Delivery Systems" is devoted to the discussion of approaches, as well as ligands that provide targeted drug delivery using polymeric carriers. We have paid special attention to modern approaches for increasing the efficacy of antibacterial therapy using vector molecules.

Alginate-based injectable probiotic/squid ink composite hydrogels for accelerated wound healing of MRSA infected abscess through photothermally synergized probiotic therapy

Methicillin-resistant Staphylococcus aureus (MRSA) infections pose great challenges to skin wound care due to the severe drug resistance developed in the clinic. There is an urgent need to exploit next-generation bactericidal therapeutics that are both antibiotic-free and multifunctional for enhanced wound healing. Herein, we designed a Ca2+-crosslinked alginate hydrogel (EcNSIN@Alg) containing two naturally derived bioactive components, probiotics Escherichia coli Nissle1917 (EcN) and Squid ink nanoparticles (SIN), to treat MRSA-infected wounds. The injectable composite hydrogel displayed excellent biocompatibility, photothermal antibacterial activity, and reactive oxygen species (ROS) scavenging property. Importantly, the probiotic EcN can enhance the photothermal SIN to promote immune regulatory activities, shifting pro-inflammatory macrophages (M1) to anti-inflammatory macrophages (M2). In an MRSA-infected abscess model, EcNSIN@Alg can reduce the expression level of wound inflammatory factors and ROS, increase the number of anti-inflammatory macrophages, accelerate collagen deposition and promote wound healing. This work offers a new perspective on developing safe, antibiotic-free, multifunctional bactericides using fully bioderived materials, with potential applications in clinical practice.

Acid-sensitive prodrugs; a promising approach for site-specific and targeted drug release

Drugs administered through conventional formulations are devoid of targeting and often spread to various undesired sites, leading to sub-lethal concentrations at the site of action and the emergence of undesired effects. Hence, therapeutic agents should be delivered in a controlled manner at target sites. Currently, stimuli-based drug delivery systems have demonstrated a remarkable potential for the site-specific delivery of therapeutic moieties. pH is one of the widely exploited stimuli for drug delivery as several pathogenic conditions such as tumor cells, infectious and inflammatory sites are characterized by a low pH environment. This review article aims to demonstrate various strategies employed in the design of acid-sensitive prodrugs, providing an overview of commercially available acid-sensitive prodrugs. Furthermore, we have compiled the progress made for the development of new acid-sensitive prodrugs currently undergoing clinical trials. These prodrugs include albumin-binding prodrugs (Aldoxorubicin and DK049), polymeric micelle (NC-6300), polymer conjugates (ProLindac™), and an immunoconjugate (IMMU-110). The article encompasses a broad spectrum of studies focused on the development of acid-sensitive prodrugs for anticancer, antibacterial, and anti-inflammatory agents. Finally, the challenges associated with the acid-sensitive prodrug strategy are discussed, along with future directions.

Rational design of multifunctional hydrogels targeting the microenvironment of diabetic periodontitis

Periodontitis is a chronic inflammatory disease and is the primary contributor to adult tooth loss. Diabetes exacerbates periodontitis, accelerates periodontal bone resorption. Thus, effectively managing periodontitis in individuals with diabetes is a long-standing challenge. This review introduces the etiology and pathogenesis of periodontitis, and analyzes the bidirectional relationship between diabetes and periodontitis. In this review, we comprehensively summarize the four pathological microenvironments influenced by diabetic periodontitis: high glucose microenvironment, bacterial infection microenvironment, inflammatory microenvironment, and bone loss microenvironment. The hydrogel design strategies and latest research development tailored to the four microenvironments of diabetic periodontitis are mainly focused on. Finally, the challenges and potential solutions in the treatment of diabetic periodontitis are discussed. We believe this review will be helpful for researchers seeking novel avenues in the treatment of diabetic periodontitis.

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.

Advances in bioinspired nanomaterials managing microbial biofilms and virulence: A critical analysis

Microbial virulence and biofilm formation stand as a big concern against the goal of achieving a green and sustainable future. Microbial pathogenesis is the process by which the microbes (bacterial, fungal, and viral) cause illness in their respective host organism. 'Nanotechnology' is a state-of-art discipline to address this problem. The use of conventional techniques against microbial proliferation has been challenging against the environment. To tackle this problem, there has been a revolution in this multi-disciplinary field, to address the aspect of bioinspired nanomaterials in the antibiofilm and antimicrobial sector. Bioinspired nanomaterials prove to be a potential antibiofilm and antimicrobial agent as they are non-hazardous to the environment and mostly synthesized using a single-step reduction protocol. They exhibit synergistic effects against bacterial, fungal, and viral pathogens and thereby, control the virulence. In this literature review, we have elucidated the potential of bioinspired nanoparticles as well as nanomaterials as a promising anti-microbial treatment pedagogy and throw light on the advancements in how smart photo-switchable platforms have been designed to exhibit both bacterial releasing as well as bacterial-killing properties. Certain limitations and possible outcomes of these bio-based nanomaterials have been discussed in the hope of achieving a green and sustainable ecosystem.

Precise antibiotic delivery to the lung infection microenvironment boosts the treatment of pneumonia with decreased gut dysbiosis

Bacterial pneumonia is a common disease with significant health risks. However, the overuse antibiotics in clinics face challenges such as inadequate targeting and limited drug utilization, leading to drug resistance and gut dysbiosis. Herein, a dual-responsive lung inflammatory tissue targeted nanoparticle (LITTN), designed for targeting lung tissue and bacteria, is screened from a series of prepared nanoparticles consisting of permanent cationic lipids, acid-responsive lipids, and reactive oxygen species-responsive and phenylboronic acid-modified lipids with different surface properties. Such nanoparticle is further verified to enhance the adsorption of vitronectin in serum. Additionally, the optimized nanoparticle exhibits more positive charge and coordination of boric acid with cis-diol in the infected microenvironment, facilitating electrostatic interactions with bacteria and biofilm penetration. Importantly, the antibacterial efficiency of dual-responsive rifampicin-loaded LITTN (Rif@LITTN) against methicillin-resistant staphylococcus aureus is 10 times higher than that of free rifampicin. In a mouse model of bacterial pneumonia, the intravenous administration of Rif@LITTN could precisely target the lungs, localize in the lung infection microenvironment, and trigger the responsive release of rifampicin, thereby effectively alleviating lung inflammation and reducing damage. Notably, the targeted delivery of rifampicin helps protect against antibiotic-induced changes in the gut microbiota. This study establishes a new strategy for precise delivery to the lung-infected microenvironment, promoting treatment efficacy while minimizing the impact on gut microbiota. STATEMENT OF SIGNIFICANCE: Intravenous antibiotics play a critical role in clinical care, particularly for severe bacterial pneumonia. However, the inability of antibiotics to reach target tissues causes serious side effects, including liver and kidney damage and intestinal dysbiosis. Therefore, achieving precise delivery of antibiotics is of great significance. In this study, we developed a novel lung inflammatory tissue-targeted nanoparticle that could target lung tissue after intravenous administration and then target the inflammatory microenvironment to trigger dual-responsive antibiotics release to synergistically treat pneumonia while maintaining the balance of gut microbiota and reducing the adverse effects of antibiotics. This study provides new ideas for targeted drug delivery and reference for clinical treatment of pneumonia.

Oxygen-Vacancy-Rich Monolayer BiO2- X Nanosheets for Bacterial Sepsis Management via Dual Physically Antibacterial and Chemically Anti-inflammatory Functions

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. Effective treatment of bacterial sepsis remains challenging due to the rapid progression of infection and the systemic inflammatory response. In this study, monolayer BiO2- X nanosheets (BiO2- X NSs) with oxygen-rich vacancies through sonication-assisted liquid-phase exfoliation are successfully synthesized. Herein, the BiO2- X NSs exhibit a novel nanozyme-enabled intervention strategy for the management of bacterial sepsis, based on its pH dependent dual antibacterial and anti-inflammatory functions. BiO2- X NSs exhibit effective antibacterial by utilizing oxidase (OXD)-like activity. Additionally, BiO2- X NSs can scavenge multiple reactive oxygen species (ROS) and mitigate systemic hyperinflammation by mimicking superoxide dismutase (SOD) and catalase (CAT). These dual capabilities of BiO2- X NSs allow them to address bacterial infection, proinflammatory cytokines secretion and ROS burst collaboratively, effectively reversing the progression of bacterial sepsis. In vivo experiments have demonstrated that BiO2- X NSs significantly reduce bacterial burden, attenuate systemic hyperinflammation, and rapidly rescued organ damage. Importantly, no obvious adverse effects are observed at the administered dose of BiO2- X NSs. This study presents a novel defect engineering strategy for the rational design of high-performance nanozymes and development of new nanomedicines for managing bacterial sepsis.

Dual-Responsive Nanogels with Cascaded Gentamicin Release and Lysosomal Escape to Combat Intracellular Small Colony Variants for Peritonitis and Sepsis Therapies

Intracellular bacteria are the major cause of serious infections including sepsis and peritonitis, but face great challenges in fighting against the stubborn intracellular small colony variants (SCVs). Herein, the authors have developed nanogels (NGs) to destroy both planktonic bacteria and SCVs and eliminate excessive inflammations for peritonitis and sepsis therapies. Free gentamicin (GEN) and hydroxyapatite nanoparticles (NPs) with GEN loading and mannose grafts (mHAG) are inoculated into ε-polylysine NGs to obtain NG@G1-mHAG2 through crosslinking with phenylboronic acid and tannic acid. The H2O2 consumption after reaction with phenylboronic esters and the elimination of free radicals by tannic acid alleviates the escalated inflammatory status to promote sepsis therapy. After mannose-mediated uptake into macrophages, the acid-triggered degradation of mHAG NPs generates Ca2+ to destabilize lysosomes and the efficient lysosomal escape leads to reversion of hypometabolic SCVs into normal phenotype and their sensitivity to GEN. In a peritonitis mouse model, NG@G1-mHAG2 treatment provides strong and persistent bactericidal effects against both extracellular bacteria and intracellular SCVs and extends survival of peritonitis mice without apparent hepatomegaly, splenomegaly, pulmonary edema, and inflammatory cell infiltration. Thus, this study demonstrates a concise and versatile strategy to eliminate SCVs and relieve inflammatory storms for peritonitis and sepsis therapies without infection recurrence.

Polymeric Nanoparticles for Drug Delivery

The recent emergence of nanomedicine has revolutionized the therapeutic landscape and necessitated the creation of more sophisticated drug delivery systems. Polymeric nanoparticles sit at the forefront of numerous promising drug delivery designs, due to their unmatched control over physiochemical properties such as size, shape, architecture, charge, and surface functionality. Furthermore, polymeric nanoparticles have the ability to navigate various biological barriers to precisely target specific sites within the body, encapsulate a diverse range of therapeutic cargo and efficiently release this cargo in response to internal and external stimuli. However, despite these remarkable advantages, the presence of polymeric nanoparticles in wider clinical application is minimal. This review will provide a comprehensive understanding of polymeric nanoparticles as drug delivery vehicles. The biological barriers affecting drug delivery will be outlined first, followed by a comprehensive description of the various nanoparticle designs and preparation methods, beginning with the polymers on which they are based. The review will meticulously explore the current performance of polymeric nanoparticles against a myriad of diseases including cancer, viral and bacterial infections, before finally evaluating the advantages and crucial challenges that will determine their wider clinical potential in the decades to come.

High-performance lung-targeted bio-responsive platform for severe colistin-resistant bacterial pneumonia therapy

Polymyxins are the last line of defense against multidrug-resistant (MDR) Gram-negative bacterial infections. However, this last resort has been threatened by the emergence of superbugs carrying the mobile colistin resistance gene-1 (mcr-1). Given the high concentration of matrix metalloproteinase 3 (MMP-3) in bacterial pneumonia, limited plasma accumulation of colistin (CST) in the lung, and potential toxicity of ionic silver (Ag+), we designed a feasible clinical transformation platform, an MMP-3 high-performance lung-targeted bio-responsive delivery system, which we named "CST&Ag@CNMS". This system exhibited excellent lung-targeting ability (>80% in lungs), MMP-3 bio-responsive release property (95% release on demand), and synergistic bactericidal activity in vitro (2-4-fold minimum inhibitory concentration reduction). In the mcr-1+ CST-resistant murine pneumonia model, treatment with CST&Ag@CNMS improved survival rates (70% vs. 20%), reduced bacteria burden (2-3 log colony-forming unit [CFU]/g tissue), and considerably mitigated inflammatory response. In this study, CST&Ag@CNMS performed better than the combination of free CST and AgNO3. We also demonstrated the superior biosafety and biodegradability of CST&Ag@CNMS both in vitro and in vivo. These findings indicate the clinical translational potential of CST&Ag@CNMS for the treatment of lung infections caused by CST-resistant bacteria carrying mcr-1.

Molecular Weight-Independent "Polysoap" Nanostructure Characterized via In Situ Resonant Soft X-ray Scattering

Studying polymer micelle structure and loading dynamics under environmental conditions is critical for nanocarrier applications but challenging due to a lack of in situ nanoprobes. Here, the structure and loading of amphiphilic polyelectrolyte copolymer micelles, formed by 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and n-dodecyl acrylamide (DDAM), were investigated using a multimodal approach centered around in situ resonant soft X-ray scattering (RSoXS). We observe aqueous micelles formed from polymers of wide-ranging molecular weights and aqueous concentrations. Despite no measurable critical micelle concentration (CMC), structural analyses point toward multimeric structures for most molecular weights, with the lowest molecular weight micelles containing mixed coronas and forming loose micelle clusters that enhance hydrocarbon uptake. The sizes of the micelle substructures are independent of both the concentration and molecular weight. Combining these results with a measured molecular weight-invariant surface charge and zeta potential strengthens the link between the nanoparticle size and ionic charge in solution that governs the polysoap micelle structure. Such control would be critical for nanocarrier applications, such as drug delivery and water remediation.

Bio-Responsive Sliver Peroxide-Nanocarrier Serves as Broad-Spectrum Metallo-β-lactamase Inhibitor for Combating Severe Pneumonia

Metallo-β-lactamases (MBLs) represent a prevalent resistance mechanism in Gram-negative bacteria, rendering last-line carbapenem-related antibiotics ineffective. Here, a bioresponsive sliver peroxide (Ag2 O2 )-based nanovesicle, named Ag2 O2 @BP-MT@MM, is developed as a broad-spectrum MBL inhibitor for combating MBL-producing bacterial pneumonia. Ag2 O2 nanoparticle is first orderly modified with bovine serum albumin and polydopamine to co-load meropenem (MER) and [5-(p-fluorophenyl)-2-ureido]-thiophene-3-carboxamide (TPCA-1) and then encapsulated with macrophage membrane (MM) aimed to target inflammatory lung tissue specifically. The resultant Ag2 O2 @BP-MT@MM effectively abrogates MBL activity by displacing the Zn2+ cofactor in MBLs with Ag+ and displays potent bactericidal and anti-inflammatory properties, specific targeting abilities, and great bioresponsive characteristics. After intravenous injection, the nanoparticles accumulate prominently at infection sites through MM-mediated targeting . Ag+ released from Ag2 O2 decomposition at the infection sites effectively inhibits MBL activity and overcomes the resistance of MBL-producing bacteria to MER, resulting in synergistic elimination of bacteria in conjunction with MER. In two murine infection models of NDM-1+ Klebsiella pneumoniae-induced severe pneumonia and NDM-1+ Escherichia coli-induced sepsis-related bacterial pneumonia, the nanoparticles significantly reduce bacterial loading, pro-inflammatory cytokine levels locally and systemically, and the recruitment and activation of neutrophils and macrophages. This innovative approach presents a promising new strategy for combating infections caused by MBL-producing carbapenem-resistant bacteria.

Multi-functional pH-responsive and biomimetic chitosan-based nanoplexes for targeted delivery of ciprofloxacin against bacterial sepsis

Bacterial sepsis is a mortal syndromic disease characterized by a complex pathophysiology that hinders effective targeted therapy. This study aimed to develop multifunctional, biomimetic and pH-responsive ciprofloxacin-loaded chitosan (CS)/sodium deoxycholic acid (SDC) nanoplexes (CS/SDC) nanoplexes with the ability to target and modulate the TLR4 pathway, activated during sepsis. The formulated nanoplexes were characterized in terms of physicochemical properties, in silico and in vitro potential biological activities. The optimal formulation showed good biocompatibility and stability with appropriate physicochemical parameters. The surface charge changed from negative at pH 7.4 to positive at pH 6.0 accompanied with a significantly faster release of CIP at pH 6.0 compared to 7.4. The biomimicry was elucidated by in silico tools and MST and results confirmed strong binding between the system and TLR4. Furthermore, the system revealed 4- and 2-fold antibacterial enhancement at acidic pH, and 3- and 4-fold better antibiofilm efficacy against Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) respectively, compared to bare CIP. In addition, enhanced bacterial efflux pump inhibition was demonstrated by CS/SDC nanoplexes. Finally, the developed nanosystem showed excellent antioxidant activity against DPPH radicals. Taken together, the study confirmed the multi-functionalities of CS/SDC nanoplexes and their potential benefits in improving bacterial sepsis therapy.

Bacteria-derived extracellular vesicles: endogenous roles, therapeutic potentials and their biomimetics for the treatment and prevention of sepsis

Sepsis is one of the medical conditions with a high mortality rate and lacks specific treatment despite several years of extensive research. Bacterial extracellular vesicles (bEVs) are emerging as a focal target in the pathophysiology and treatment of sepsis. Extracellular vesicles (EVs) derived from pathogenic microorganisms carry pathogenic factors such as carbohydrates, proteins, lipids, nucleic acids, and virulence factors and are regarded as "long-range weapons" to trigger an inflammatory response. In particular, the small size of bEVs can cross the blood-brain and placental barriers that are difficult for pathogens to cross, deliver pathogenic agents to host cells, activate the host immune system, and possibly accelerate the bacterial infection process and subsequent sepsis. Over the years, research into host-derived EVs has increased, leading to breakthroughs in cancer and sepsis treatments. However, related approaches to the role and use of bacterial-derived EVs are still rare in the treatment of sepsis. Herein, this review looked at the dual nature of bEVs in sepsis by highlighting their inherent functions and emphasizing their therapeutic characteristics and potential. Various biomimetics of bEVs for the treatment and prevention of sepsis have also been reviewed. Finally, the latest progress and various obstacles in the clinical application of bEVs have been highlighted.

Carbon Nanosheets-Based Supercapacitor Materials: Recent Advances and Prospects

The need for inexpensive and ecologically sustainable energy storage technologies is rising rapidly along with the severity of the world's environmental challenges as well as with the rising demand for portable electronics and hybrid vehicles. Supercapacitors have drawn a lot of attentions lately in this regard because of their ultrahigh power density, outstanding electrochemical stability, and environmental friendliness. Due to various advantages, carbon materials are the choice of designer for developing commercial electrodes for various applications including devising supercapacitors. Two-dimensional (2D) carbon nanosheets (CNSs) with a large surface area and excellent electronic transport properties have fired up the interest of researchers due to their unique properties and potential applications in energy storage. Such engineered 2D porous CNS may significantly improve the energy storage performance of supercapacitor by enabling fast ion transport and charge transfer kinetics. This article summarizes the most recent and significant advances in the area of activated, porous, graphene-based various CNSs and their composites with a special focus on their use as supercapacitor electrodes. A succinct overview about their syntheses and key characterizations regarding their different structural aspects have been discussed. The present challenges and prospects in using CNS in supercapacitor applications are highlighted.

An Erythrocyte Membrane-Derived Nanosystem for Efficient Reversal of Endothelial Injury in Sepsis

Sepsis is caused by a disordered host immune in response to infection and endothelial cells perform a crucial role in boosting immunity reaction in the pathophysiology of sepsis and septic organ failure. The aim of this study is to construct a novel erythrocyte membrane-derived nanosystems to reverse endothelial damage in sepsis. Herein, an innovative nanometer calcium metal-organic framework (Ca-MOF) is generated for the first time by using chelidonic acid as a ligand and calcium chloride as an ion donor for anti-inflammation. Then, zoliflodacin is loaded into Ca-MOF (CMZ) to sterilize and nanoscale erythrocyte membrane vesicles are prepared by modification with a γ3 peptide on the surface (γ3-RM) for precise targeting. Finally, γ3-RM camouflages the nanocore CMZ, to form novel erythrocyte membrane-camouflaged nanoparticle γ3-RCMZ. The superior performance of novel nanosystem results from its suitable biocompatibility, nontoxicity, specific targeting, and anti-inflammatory and bactericidal effects. Its anti-inflammatory mechanism mainly involves inhibiting the Caspase1-nuclear factor kappa-B (Caspase1-NF-κB) pathway and oxidative stress reduction to alleviate endothelial damage. Moreover, the findings have revealed for the first time that the bactericidal drug zoliflodacin also has anti-inflammatory effects in vivo and in vitro. Therefore, the novel nanosystem (γ3-RCMZ) provides a new nanotherapy strategy for sepsis treatment.

Development and challenges of antimicrobial peptide delivery strategies in bacterial therapy: A review

The escalating global prevalence of antimicrobial resistance poses a critical threat, prompting concerns about its impact on public health. This predicament is exacerbated by the acute shortage of novel antimicrobial agents, a scarcity attributed to the rapid surge in bacterial resistance. This review delves into the realm of antimicrobial peptides, a diverse class of compounds ubiquitously present in plants and animals across various natural organisms. Renowned for their intrinsic antibacterial activity, these peptides provide a promising avenue to tackle the intricate challenge of bacterial resistance. However, the clinical utility of peptide-based drugs is hindered by limited bioavailability and susceptibility to rapid degradation, constraining efforts to enhance the efficacy of bacterial infection treatments. The emergence of nanocarriers marks a transformative approach poised to revolutionize peptide delivery strategies. This review elucidates a promising framework involving nanocarriers within the realm of antimicrobial peptides. This paradigm enables meticulous and controlled peptide release at infection sites by detecting dynamic shifts in microenvironmental factors, including pH, ROS, GSH, and reactive enzymes. Furthermore, a glimpse into the future reveals the potential of targeted delivery mechanisms, harnessing inflammatory responses and intricate signaling pathways, including adenosine triphosphate, macrophage receptors, and pathogenic nucleic acid entities. This approach holds promise in fortifying immunity, thereby amplifying the potency of peptide-based treatments. In summary, this review spotlights peptide nanosystems as prospective solutions for combating bacterial infections. By bridging antimicrobial peptides with advanced nanomedicine, a new therapeutic era emerges, poised to confront the formidable challenge of antimicrobial resistance head-on.

An ultrasound-controllable ROS-responsive nanoplatform for O2 and NO generation to enhance sonodynamic therapy against multidrug-resistant bacterial infections

Antimicrobial sonodynamic therapy (SDT) has broad application potential in the eradication of multidrug-resistant (MDR) bacterial infections due to its non-invasiveness, absence of resistance concern, and high cytotoxicity. However, the hypoxic infection microenvironment and the rapid depletion of O2 during SDT severely limit the therapeutic efficacy of SDT. Herein, an ultrasound-controllable ROS-responsive nanoplatform (FOT/Fe3O4@Lipo-ICG) was constructed and prepared by encapsulating FOT and Fe3O4 nanoparticles (Fe3O4 NPs) within sonosensitiser ICG-modified liposomes. Both in vitro and in vivo, we observed that ICG conjugation on the surface of liposomes could effectively maintain good dispersion and prevent ICG aggregates in complex biological matrices. In addition, liposomes could significantly block the catalytic activity of Fe3O4 NPs, as well as the release of FOT, whereas upon US irradiation, the catalytic activity of Fe3O4 NPs was recovered to catalyse the decomposition of endogenous H2O2 into O2 and ˙OH. Meanwhile, the FOT was successfully released to react with endogenous glutathione to sequentially produce NO. Based on the aforementioned advantages, the FOT/Fe3O4@Lipo-ICG demonstrated potent efficacy in eradicating methicillin-resistant Staphylococcus aureus-induced local infection and sepsis resulting from local infection. Thus, the developed US-controllable nanoplatform offers a promising strategy for enhancing SDT for eradicating MDR bacterial infections.

Cell-Selective Binding Zwitterionic Polymeric Micelles Boost the Delivery Efficiency of Antibiotics

Effective accumulation and penetration of antibiotics in the biofilm are critical issues for bacterial infection treatment. Red blood cells (RBCs) have been widely utilized to hitchhike nanocarriers for drug delivery. It is vital and challenging to find a nanocarrier with an appropriate affinity toward RBCs and bacteria for selective hitchhiking and release that determines the drug delivery efficiency and specificity. Herein, we report a zwitterionic polymer poly(2-(N-oxide-N,N-diethylamino)ethyl methacrylate) (OPDEA)-based micelle, which can hitchhike on RBCs in blood and preferentially release in the infection site. We found that OPDEA could bind to the RBCs cell membrane via phospholipid-related affinity and transfer to Gram-positive bacteria due to nearly an order of magnitude stronger interaction with the bacteria cell wall. The zwitterionic surface and cell-wall affinity of OPDEA-based micelles also promote their penetration in biofilm. The clarithromycin-loaded OPDEA micelles show efficient drug delivery into the infection site, resulting in excellent therapeutic performance in both peritonitis and pneumonia models by intravenous or spray administration. This simple RBC-selective hitchhiking and releasing antibiotic delivery system provides a promising strategy for the design of antibacterial nanomedicines.

Recent advances and prospects in nanomaterials for bacterial sepsis management

Bacterial sepsis is a life-threatening condition caused by bacteria entering the bloodstream and triggering an immune response, underscoring the importance of early recognition and prompt treatment. Nanomedicine holds promise for addressing sepsis through improved diagnostics, nanoparticle biosensors for detection and imaging, enhanced antibiotic delivery, combating resistance, and immune modulation. However, challenges remain in ensuring safety, regulatory compliance, scalability, and cost-effectiveness before clinical implementation. Further research is needed to optimize design, efficacy, safety, and regulatory strategies for effective utilization of nanomedicines in bacterial sepsis diagnosis and treatment. This review highlights the significant potential of nanomedicines, including improved drug delivery, enhanced diagnostics, and immunomodulation for bacterial sepsis. It also emphasizes the need for further research to optimize design, efficacy, safety profiles, and address regulatory challenges to facilitate clinical translation.

Bionanotechnology and bioMEMS (BNM): state-of-the-art applications, opportunities, and challenges

The development of micro- and nanotechnology for biomedical applications has defined the cutting edge of medical technology for over three decades, as advancements in fabrication technology developed originally in the semiconductor industry have been applied to solving ever-more complex problems in medicine and biology. These technologies are ideally suited to interfacing with life sciences, since they are on the scale lengths as cells (microns) and biomacromolecules (nanometers). In this paper, we review the state of the art in bionanotechnology and bioMEMS (collectively BNM), including developments and challenges in the areas of BNM, such as microfluidic organ-on-chip devices, oral drug delivery, emerging technologies for managing infectious diseases, 3D printed microfluidic devices, AC electrokinetics, flexible MEMS devices, implantable microdevices, paper-based microfluidic platforms for cellular analysis, and wearable sensors for point-of-care testing.

An infection-microenvironment-targeted and responsive peptide-drug nanosystem for sepsis emergency by suppressing infection and inflammation

Sepsis is a life-threatening emergency that causes millions of deaths every year due to severe infection and inflammation. Nevertheless, current therapeutic regimens are inadequate to promptly address the vast diversity of potential pathogens. Omiganan, an antimicrobial peptide, has shown promise for neutralizing endotoxins and eliminating diverse pathogens. However, its clinical application is hindered by safety and stability concerns. Herein, we present a nanoscale drug delivery system (Omi-hyd-Dex@HA NPs) that selectively targets infectious microenvironments (IMEs) and responds to specific stimuli for efficient intervention in sepsis. The system consists of omiganan-dexamethasone conjugates linked by hydrazone bonds which self-assemble into nanoparticles coated with a hyaluronic acid (HA). The HA coating not only facilitates IMEs-targeting through interaction with intercellular-adhesion-molecule-1 on inflamed endotheliocytes, but also improves the biosafety of the nanosystem and enhances drug accumulation in primary infection sites triggered by hyaluronidase. The nanoparticles release dual drugs in IMEs through pH-sensitive cleavage of hydrazone bonds to eradicate pathogens and suppress inflammation. In multiple tissue infection and sepsis animal models, Omi-hyd-Dex@HA NPs exhibited rapid source control and comprehensive inflammation reduction, thereby preventing subsequent fatal complications and significantly improving survival outcomes. The bio-responsive and self-delivering nanosystem offers a promising strategy for systemic sepsis treatment in emergencies.

GCH1 reduces LPS-induced alveolar macrophage polarization and inflammation by inhibition of ferroptosis

OBJECTIVE

GTP cyclohydrolase 1(GCH1) was reported to protect against ferroptosis. However, it is not clear whether GCH1 reduced lipopolysaccharide (LPS)-induced macrophage polarization and inflammation by inhibition of ferroptosis.

METHODS

Bioinformatics analysis was used to screen differential expression genes (DEGs) and obtain the different pathways and biological features. Lasso cox regression analysis with ferroptosis related DEGs was established to screen the most relevant genes for disease risk. LPS induced Raw264.7 macrophage polarization model and GCH1-specific siRNA oligos transfection were performed to confirm the function of GCH1. Immunofluorescence staining, western blot and quantitative real-time PCR were performed to detect the expression of iNOS, CD206, GCH1, IL6, SLC2A6, F4/80, IL1β, TNFα, IL10, GPX4, ACSL4, AMPK and p-AMPK in macrophages. The levels of ROS, SOD, MDA and GSH were detected according to the instructions of the reagent kit, respectively.

RESULTS

542 DEGs were screened from GSE40885 microarray. GO and KEGG pathway enrichment analysis showed that the upregulated DEGs induced by LPS in alveolar macrophage were closely associated with inflammatory and immune responses, the downregulated DEGs were related to lipid metabolism, insulin resistance and AMPK signal pathway. Lasso cox regression analysis screened GCH1, IL6, and SLC2A6. Our experimental results showed that the expression of GCH1 and IL6 in the LPS group was higher than that in the control group, but there was no difference in the expression of SLC2A6. Bioinformatics analysis with GSE112720 observed that ferroptosis was enriched in GCHfl/fl + LPS group compared with GCHfl/flTie2cre + LPS group and GCHfl/fl + control group. Silence of GCH1 increased the levels of IL6, TNF-α and IL-1β and decreased IL10 level. Silence of GCH1 increased iNOS level and decreased CD206 level. Moreover, silence of GCH1 raised ferroptosis induced by LPS in macrophages and suppressed the activity of AMPK pathway.

CONCLUSIONS

GCH1 inhibited ferroptosis in LPS-stimulated macrophages, reduced macrophage toward to M1 polarization and inflammatory response.

Exploring release mechanisms by disrupting π-π stacking regions in stable micelles

π-π stacking strategies can enhance the stability performance of delivery platforms but are often restricted by incomplete drug release performance, even with the help of crosslinking strategies. Therefore, there has been considerable interest in enhancing the drug release performance by disrupting the π-π stacking region (structural rearrangements). Herein, we synthesized poly(3-(isobutyloxy)-2-oxopropyl benzoate)-b-poly(2-hydroxybutyl methacrylate)-co-poly((ethylene glycol)methylether methacrylate) [PBOOPMA-b-P(HBMA-co-PEGMA), PHB] and revealed the drug release mechanism of PHB-based micelles. The structural rearrangements derived from the crosslinking strategy were revealed to improve the early release performance by 43-55% using micellar dissolutions. Moreover, the esterase-responsive strategy was elucidated to induce reassembly with 77-79% size variation, intensifying the structural rearrangements, which was also synergistic with the crosslinking strategy. Based on the advantages of improving drug release performance, the esterase-responsive strategy was considered a promising candidate for enhancing late release performance. Meanwhile, it is believed that such responsive modulation (crosslinking, esterase-responsive) in the π-π stacking region will become highly promising for subsequent research. Finally, the biosafety of 95.81% at 400 mg L-1 and drug cytotoxicity of IC50 ≈ 2.5 mg L-1 of PHB-EDE@CPT were also validated, confirming the broad application prospects of PHB-based crosslinked micelles.

Inflammation-responsive drug delivery nanosystems for treatment of bacterial-induced sepsis

Sepsis, a complication of dysregulated host immune systemic response to an infection, is life threatening and causes multiple organ injuries. Sepsis is recognized by WHO as a big contributor to global morbidity and mortality. The heterogeneity in sepsis pathophysiology, antimicrobial resistance threat, the slowdown in the development of antimicrobials, and limitations of conventional dosage forms jeopardize the treatment of sepsis. Drug delivery nanosystems are promising tools to overcome some of these challenges. Among the drug delivery nanosystems, inflammation-responsive nanosystems have attracted considerable interest in sepsis treatment due to their ability to respond to specific stimuli in the sepsis microenvironment to release their payload in a precise, targeted, controlled, and rapid manner compared to non-responsive nanosystems. These nanosystems posit superior therapeutic potential to enhance sepsis treatment. This review critically evaluates the recent advances in the design of drug delivery nanosystems that are inflammation responsive and their potential in enhancing sepsis treatment. The sepsis microenvironment's unique features, such as acidic pH, upregulated receptors, overexpressed enzymes, and enhanced oxidative stress, that form the basis for their design have been adequately discussed. These inflammation-responsive nanosystems have been organized into five classes namely: Receptor-targeted nanosystems, pH-responsive nanosystems, redox-responsive nanosystems, enzyme-responsive nanosystems, and multi-responsive nanosystems. Studies under each class have been thematically grouped and discussed with an emphasis on the polymers used in their design, nanocarriers, key characterization, loaded actives, and key findings on drug release and therapeutic efficacy. Further, this information is concisely summarized into tables and supplemented by inserted figures. Additionally, this review adeptly points out the strengths and limitations of the studies and identifies research avenues that need to be explored. Finally, the challenges and future perspectives on these nanosystems have been thoughtfully highlighted.

Research progress of nanoparticle targeting delivery systems in bacterial infections

Bacterial infection is a huge threat to the health of human beings and animals. The abuse of antibiotics have led to the occurrence of bacterial multidrug resistance, which have become a difficult problem in the treatment of clinical infections. Given the outstanding advantages of nanodrug delivery systems in cancer treatment, many scholars have begun to pay attention to their application in bacterial infections. However, due to the similarity of the microenvironment between bacterial infection lesions and cancer sites, the targeting and accuracy of traditional microenvironment-responsive nanocarriers are questionable. Therefore, finding new specific targets has become a new development direction of nanocarriers in bacterial prevention and treatment. This article reviews the infectious microenvironment induced by bacteria and a series of virulence factors of common pathogenic bacteria and their physiological functions, which may be used as potential targets to improve the targeting accuracy of nanocarriers in lesions.

Efferocytosis-inspired nanodrug treats sepsis by alleviating inflammation and secondary immunosuppression

Uncontrolled inflammation storm induced by sepsis may lead to severe organ dysfunction and secondary immunosuppression, which is one of the main reasons for high mortality and prolonged hospitalization of septic patients. However, there is a lack of effective treatments for it at present. Here, we report an efferocytosis-inspired nanodrug (BCN@M) to treat sepsis and secondary immunosuppression via regulating the macrophage function. Bioactive molecular curcumin was loaded with bovine serum albumin and then coated with the damaged erythrocyte membrane derived from septic mice. It was found that the septic erythrocytes promoted the efferocytosis signal and BCN@M uptake efficiency by macrophages. The well-constructed BCN@M nanodrug reduced the hyperinflammation in sepsis and restored the bacterial clearance ability of macrophage in the secondary immunosuppression state. This study highlights BCN@M as an efferocytosis-inspired nanodrug to alleviate hyperinflammation and secondary immunosuppression of sepsis.

Bioengineered stem cell membrane functionalized nanoparticles combine anti-inflammatory and antimicrobial properties for sepsis treatment

BACKGROUND

Sepsis is a syndrome of physiological, pathological and biochemical abnormalities caused by infection. Although the mortality rate is lower than before, many survivors have persistent infection, which means sepsis calls for new treatment. After infection, inflammatory mediators were largely released into the blood, leading to multiple organ dysfunction. Therefore, anti-infection and anti-inflammation are critical issues in sepsis management.

RESULTS

Here, we successfully constructed a novel nanometer drug loading system for sepsis management, FZ/MER-AgMOF@Bm. The nanoparticles were modified with LPS-treated bone marrow mesenchymal stem cell (BMSC) membrane, and silver metal organic framework (AgMOF) was used as the nanocore for loading FPS-ZM1 and meropenem which was delivery to the infectious microenvironments (IMEs) to exert dual anti-inflammatory and antibacterial effects. FZ/MER-AgMOF@Bm effectively alleviated excessive inflammatory response and eliminated bacteria. FZ/MER-AgMOF@Bm also played an anti-inflammatory role by promoting the polarization of macrophages to M2. When sepsis induced by cecal ligation and puncture (CLP) challenged mice was treated, FZ/MER-AgMOF@Bm could not only reduce the levels of pro-inflammatory factors and lung injury, but also help to improve hypothermia caused by septic shock and prolong survival time.

CONCLUSIONS

Together, the nanoparticles played a role in combined anti-inflammatory and antimicrobial properties, alleviating cytokine storm and protecting vital organ functions, could be a potential new strategy for sepsis management.

Intercellular Adhesion Molecule 1: More than a Leukocyte Adhesion Molecule

Intercellular adhesion molecule 1 (ICAM-1) is a transmembrane protein in the immunoglobulin superfamily expressed on the surface of multiple cell populations and upregulated by inflammatory stimuli. It mediates cellular adhesive interactions by binding to the β2 integrins macrophage antigen 1 and leukocyte function-associated antigen 1, as well as other ligands. It has important roles in the immune system, including in leukocyte adhesion to the endothelium and transendothelial migration, and at the immunological synapse formed between lymphocytes and antigen-presenting cells. ICAM-1 has also been implicated in the pathophysiology of diverse diseases from cardiovascular diseases to autoimmune disorders, certain infections, and cancer. In this review, we summarize the current understanding of the structure and regulation of the ICAM1 gene and the ICAM-1 protein. We discuss the roles of ICAM-1 in the normal immune system and a selection of diseases to highlight the breadth and often double-edged nature of its functions. Finally, we discuss current therapeutics and opportunities for advancements.

Remote Co-loading of amphipathic acid drugs in neutrophil nanovesicles infilled with cholesterol mitigates lung bacterial infection and inflammation

Lung bacterial infections could result in acute lung inflammation/injury (ALI) that propagates to its severe form, acute respiratory distress syndrome (ADRS) leading to the death. The molecular mechanism of ALI is associated with bacterial invasion and the host inflammation response. Here, we proposed a novel strategy to specifically target both bacteria and inflammatory pathways by co-loading of antibiotics (azlocillin, AZ) and anti-inflammatory agents (methylprednisolone sodium, MPS) in neutrophil nanovesicles. We found that cholesterol infilling in the membrane of nanovesicles can maintain a pH gradient between intra-vesicles and outer-vesicles, so we remotely loaded both AZ and MPS in single nanovesicles. The results showed that loading efficiency of both drugs can achieve more than 30% (w/w), and delivery of both drugs using nanovesicles accelerated bacterial clearance and resolved inflammation responses, thus preventing the potential lung damage due to infections. Our studies show that remote loading of multiple drugs in neutrophil nanovesicles which specifically target the infectious lung could be translational to treat ARDS.

A Multifunctional Nanoparticle Mitigating Cytokine Storm by Scavenging Multiple Inflammatory Mediators of Sepsis

Sepsis is a disease caused by infection, which is characterized by a dysregulated immune response in the host and affects more than 30 million people worldwide each year. However, the current single therapeutic approaches are not effective in controlling the progression of sepsis. Here, we synthesize a nanoparticle (TMP) containing tannic acid (TA), Polymyxin B (PMB), and Mn²⁺ (Mn) by a simple one-pot method. TMP has the following characteristics: (1) All components have good biocompatibility; (2) simple preparation process without subsequent processing; (3) antibacterial and remove multiple inflammatory mediators; and (4) effectively mitigating cytokine storm both in the acute lung injury (ALI) and the cecal ligation and puncture (CLP) model. Our results demonstrate the critical role of targeting multiple mediators to mitigate cytokine storms for the treatment of sepsis.

Biodegradable Polymers and Polymer Composites with Antibacterial Properties

Antibiotic resistance is one of the greatest threats to global health and food security today. It becomes increasingly difficult to treat infectious disorders because antibiotics, even the newest ones, are becoming less and less effective. One of the ways taken in the Global Plan of Action announced at the World Health Assembly in May 2015 is to ensure the prevention and treatment of infectious diseases. In order to do so, attempts are made to develop new antimicrobial therapeutics, including biomaterials with antibacterial activity, such as polycationic polymers, polypeptides, and polymeric systems, to provide non-antibiotic therapeutic agents, such as selected biologically active nanoparticles and chemical compounds. Another key issue is preventing food from contamination by developing antibacterial packaging materials, particularly based on degradable polymers and biocomposites. This review, in a cross-sectional way, describes the most significant research activities conducted in recent years in the field of the development of polymeric materials and polymer composites with antibacterial properties. We particularly focus on natural polymers, i.e., polysaccharides and polypeptides, which present a mechanism for combating many highly pathogenic microorganisms. We also attempt to use this knowledge to obtain synthetic polymers with similar antibacterial activity.

Bioengineered extracellular vesicles: future of precision medicine for sepsis

Sepsis is a syndromic response to infection and is frequently a final common pathway to death from many infectious diseases worldwide. The complexity and high heterogeneity of sepsis hinder the possibility to treat all patients with the same protocol, requiring personalized management. The versatility of extracellular vesicles (EVs) and their contribution to sepsis progression bring along promises for one-to-one tailoring sepsis treatment and diagnosis. In this article, we critically review the endogenous role of EVs in sepsis progression and how current advancements have improved EVs-based therapies toward their translational future clinical application, with innovative strategies to enhance EVs effect. More complex approaches, including hybrid and fully synthetic nanocarriers that mimic EVs, are also discussed. Several pre-clinical and clinical studies are examined through the review to offer a general outlook of the current and future perspectives of EV-based sepsis diagnosis and treatment.

A Cascade BIME-Triggered Near-IR Cyanine Nanoplatform for Enhanced Antibacterial Photodynamic Therapy

The long-standing misuse of antibiotics has accelerated the emergence of drug-resistant bacteria, which gives rise to an urgent public health threat. Antibacterial photodynamic therapy (aPDT), as a burgeoning and promising antibacterial strategy, plays an essential role in avoiding the evolution of drug-resistant microbes. However, it is hard for conventional photosensitizers to achieve satisfactory antibacterial efficacy because of the complex bacterial infectious microenvironment (BIME). Herein, a cascade BIME-triggered near-infrared cyanine (HA-CY) nanoplatform has been developed via conjugating cyanine units to biocompatible hyaluronic acid (HA) for enhanced aPDT efficacy. The HA-CY nanoparticles can be dissociated under the overexpressed hyaluronidase in BIME to release a cyanine photosensitizer. Meanwhile, cyanine can be protonated under acidic BIME, where protonated cyanine can efficiently adhere to the surface of a negatively charged bacterial membrane and increase singlet oxygen production due to intramolecular charge transfer (ICT). Experiments in the cellular level and animal model proved that the BIME-triggered activation of aPDT could remarkably boost aPDT efficacy. Overall, this BIME-triggered HA-CY nanoplatform presents great promise for overcoming the dilemma of drug-resistant microbes.

A small-molecule inhibitor of Keap1-Nrf2 interaction attenuates sepsis by selectively augmenting the antibacterial defence of macrophages at infection sites

BACKGROUND

Macrophages at infection sites are considered as the promising therapeutic targets to prevent sepsis development. The Nrf2/Keap1 system acts as a critical modulator of the antibacterial activity of macrophages. Recently, Keap1-Nrf2 protein-protein interaction (PPI) inhibitors have emerged as safer and stronger Nrf2 activators; however, their therapeutic potential in sepsis remains unclear. Herein, we report a unique heptamethine dye, IR-61, as a Keap1-Nrf2 PPI inhibitor that preferentially accumulates in macrophages at infection sites.

METHODS

A mouse model of acute lung bacterial infection was used to investigate the biodistribution of IR-61. SPR study and CESTA were used to detect the Keap1 binding behaviour of IR-61 in vitro and in cells. Established models of sepsis in mice were used to determine the therapeutic effect of IR-61. The relationship between Nrf2 levels and sepsis outcomes was preliminarily investigated using monocytes from human patients.

FINDINGS

Our data showed that IR-61 preferentially accumulated in macrophages at infection sites, enhanced bacterial clearance, and improved outcomes in mice with sepsis. Mechanistic studies indicated that IR-61 potentiated the antibacterial function of macrophages by activating Nrf2 via direct inhibition of the Keap1-Nrf2 interaction. Moreover, we observed that IR-61 enhanced the phagocytic ability of human macrophages, and the expression levels of Nrf2 in monocytes might be associated with the outcomes of sepsis patients.

INTERPRETATIONS

Our study demonstrates that the specific activation of Nrf2 in macrophages at infection sites is valuable for sepsis management. IR-61 may prove to be a Keap1-Nrf2 PPI inhibitor for the precise treatment of sepsis.

FUNDING

This work was supported by the National Natural Science Foundation of China (Major program 82192884), the Intramural Research Project (Grants: 2018-JCJQ-ZQ-001 and 20QNPY018), and the Chongqing National Science Foundation (CSTB2022NSCQ-MSX1222).

An Overview of Drug Delivery Nanosystems for Sepsis-Related Liver Injury Treatment

Sepsis, which is a systemic inflammatory response syndrome caused by infection, has high morbidity and mortality. Sepsis-related liver injury is one of the manifestations of sepsis-induced multiple organ syndrome. To date, an increasing number of studies have shown that the hepatic inflammatory response, oxidative stress, microcirculation coagulation dysfunction, and bacterial translocation play extremely vital roles in the occurrence and development of sepsis-related liver injury. In the clinic, sepsis-related liver injury is mainly treated by routine empirical methods on the basis of the primary disease. However, these therapies have some shortcomings, such as serious side effects, short duration of drug effects and lack of specificity. The emergence of drug delivery nanosystems can significantly improve drug bioavailability and reduce toxic side effects. In this paper, we reviewed drug delivery nanosystems designed for the treatment of sepsis-related liver injury according to their mechanisms (hepatic inflammation response, oxidative stress, coagulation dysfunction in the microcirculation, and bacterial translocation). Although much promising progress has been achieved, translation into clinical practice is still difficult. To this end, we also discussed the key issues currently facing this field, including immune system rejection and single treatment modalities. Finally, with the rigorous optimization of nanotechnology and the deepening of research, drug delivery nanosystems have great potential for the treatment of sepsis-related liver injury.

Antibody-Antimicrobial Conjugates for Combating Antibiotic Resistance

As the development of new antibiotics lags far behind the emergence of drug-resistant bacteria, alternative strategies to resolve this dilemma are urgently required. Antibody-drug conjugate is a promising therapeutic platform to delivering cytotoxic payloads precisely to target cells for efficient disease treatment. Antibody-antimicrobial conjugates (AACs) have recently attracted considerable interest from researchers as they can target bacteria in the target sites and improve the effectiveness of drugs (i.e., reduced drug dosage and adverse effects), abating the upsurge of antimicrobial resistance. In this review, the selection and progress of three essential blocks that compose the AACs: antibodies, antimicrobial payloads, and linkers are discussed. The commonly used conjugation strategies and the latest applications of AACs in recent years are also summarized. The challenges and opportunities of this booming technology are also discussed at the end of this review.

Nanomaterials for Delivering Antibiotics in the Therapy of Pneumonia

Bacterial pneumonia is one of the leading causes of death worldwide and exerts a significant burden on health-care resources. Antibiotics have long been used as first-line drugs for the treatment of bacterial pneumonia. However, antibiotic therapy and traditional antibiotic delivery are associated with important challenges, including drug resistance, low bioavailability, and adverse side effects; the existence of physiological barriers further hampers treatment. Fortunately, these limitations may be overcome by the application of nanotechnology, which can facilitate drug delivery while improving drug stability and bioavailability. This review summarizes the challenges facing the treatment of bacterial pneumonia and also highlights the types of nanoparticles that can be used for antibiotic delivery. This review places a special focus on the state-of-the-art in nanomaterial-based approaches to the delivery of antibiotics for the treatment of pneumonia.

Recent nanoengineered diagnostic and therapeutic advancements in management of Sepsis

COVID-19 acquired symptoms have affected the worldwide population and increased the load of Intensive care unit (ICU) patient admissions. A large number of patients admitted to ICU end with a deadly fate of mortality. A high mortality rate of patients was reported with hospital-acquired septic shock that leads to multiple organ failures and ultimately ends with death. The patients who overcome this septic shock suffer from morbidity that also affects their caretakers. To overcome these situations, scientists are exploring progressive theragnostic techniques with advanced techniques based on biosensors, biomarkers, biozymes, vesicles, and others. These advanced techniques pave the novel way for early detection of sepsis-associated symptoms and timely treatment with appropriate antibiotics and immunomodulators and prevent the undue effect on other parts of the body. There are other techniques like externally modulated electric-based devices working on the principle of piezoelectric mechanism that not only sense the endotoxin levels but also target them with a loaded antibiotic to neutralize the onset of inflammatory response. Recently researchers have developed a lipopolysaccharide (LPS) neutralizing cartridge that not only senses the LPS but also appropriately neutralizes with dual mechanistic insights of antibiotic and anti-inflammatory effects. This review will highlight recent developments in the new nanotechnology-based approaches for the diagnosis and therapeutics of sepsis that is responsible for the high number of deaths of patients suffering from this critical disease.

Stimuli-responsive and biomimetic delivery systems for sepsis and related complications

Sepsis, a consequence of an imbalanced immune response to infection, is currently one of the leading causes of death globally. Despite advances in the discoveries of potential targets and nanotechnology, sepsis still lacks effective drug delivery systems for optimal treatment. Stimuli-responsive and biomimetic nano delivery systems, specifically, are emerging as advanced bio-inspired nanocarriers for enhancing the treatment of sepsis. Herein, we present a critical review of different stimuli-responsive systems, including pH-; enzyme-; ROS- and toxin-responsive nanocarriers, reported in the delivery of therapeutics for sepsis. Biomimetic nanocarriers, utilizing natural pathways in the inflammatory cascade to optimize sepsis therapy, are also reviewed, in addition to smart, multifunctional vehicles. The review highlights the nanomaterials designed for constructing these systems; their physicochemical properties; the mechanisms of drug release; and their potential for enhancing the therapeutic efficacy of their cargo. Current challenges are identified and future avenues for research into the optimization of bio-inspired nano delivery systems for sepsis are also proposed. This review confirms the potential of stimuli-responsive and biomimetic nanocarriers for enhanced therapy against sepsis and related complications.