Macrophage Membrane Research Articles

Simultaneously Modulating HIF-1α and HIF-2α and Optimizing Macrophage Polarization through the Biomimetic Gene Vector toward the Treatment of Osteoarthritis.

In osteoarthritis (OA), articular cartilage is continuously submerged in a hypoxic environment throughout life, and hypoxia-inducible factors (HIFs) play a crucial role in OA progression. Among the various HIF phenotypes, HIF-1α positively contributes to maintaining the stability of the articular cartilage matrix. In contrast, HIF-2α has a detrimental effect, leading to chondrocyte apoptosis and exacerbating inflammation. Notably, there is currently no simultaneous regulation of HIF-1α and HIF-2α for OA treatment. Thus, the biomimetic gene vector (MENP) was developed for co-delivery of siHIF-2α and Mg2+ to the inflamed regions in OA joints, comprising an inner core consisting of siHIF-2α and Mg2+ and an outer M2 macrophage membrane. Invitro and invivo studies demonstrate that MENP effectively targets inflamed areas, efficiently silences HIF-2α, and facilitates HIF-1α-mediated cartilage restoration through Mg2+. Furthermore, it indirectly promotes the polarization of macrophages toward an anti-inflammatory M2 phenotype through its action on inflamed synoviocytes. Overall, MENP is an efficient biomimetic vehicle for alleviating inflammation and promoting cartilage repair, representing an appealing approach for OA treatment.

Genetically Engineered Membrane-Coated Nanoparticles forEnhanced Prostate-Specific Membrane Antigen Targeting and Ferroptosis Treatment of Castration-Resistant Prostate Cancer.

Conventional androgen deprivation therapy (ADT) targets the androgen receptor (AR) inhibiting prostate cancer (PCa) progression; however, it can eventually lead to recurrence as castration-resistant PCa (CRPC), which has high mortality rates and lacks effective treatment modalities. The study confirms the presence of high glutathione peroxidase 4 (GPX4) expression, a key regulator of ferroptosis (i.e., iron-dependent program cell death) in CRPC cells. Therefore, inducing ferroptosis in CRPC cells might be an effective therapeutic modality for CRPC. However, nonspecific uptake of ferroptosis inducers can result in undesirable cytotoxicity in major organs. Thus, to precisely induce ferroptosis in CRPC cells, a genetic engineering strategy is proposed to embed a prostate-specific membrane antigen (PSMA)-targeting antibody fragment (gy1) in the macrophage membrane, which is then coated onto mesoporous polydopamine (MPDA) nanoparticles to produce a biomimetic nanoplatform. The results indicate that the membrane-coated nanoparticles (MNPs) exhibit high specificity and affinity toward CRPC cells. On further encapsulation with the ferroptosis inducers RSL3 and iron ions, MPDA/Fe/RSL3@M-gy1 demonstrates superior synergistic effects in highly targeted ferroptosis therapy eliciting significant therapeutic efficacy against CRPC tumor growth and bone metastasis without increased cytotoxicity. In conclusion, a new therapeutic strategy is reported for the PSMA-specific, CRPC-targeting platform for ferroptosis induction with increased efficacy and safety.

β-Cyclodextrin and Hyaluronic Acid-Modified Targeted Nanodelivery System for Atherosclerosis Prevention.

Natural products have been widely recognized in clinical treatment because of their low toxicity and high activity. It is worth paying attention to modifying the biopolymer into nanostructures to give natural active ingredients additional targeting effects. In this study, based on the multifunctional modification of β-cyclodextrin (β-CD), a nanoplatform encapsulating the unstable drug (-)-epicatechin gallate (ECG) was designed to deliver to atherosclerotic plaques. Acetalization cyclodextrin (PH-CD), which responds to low-pH environments, and hyaluronic acid cyclodextrin, which targets the CD44 receptor on macrophage membranes, were synthesized from β-CD and hyaluronic acid using acetalization and transesterification, respectively. The resulting dual-carrier nanoparticles (Double-NPs) loaded with ECG were prepared using a solvent evaporation method. The Double-NPs effectively scavenged reactive oxygen species, promoted macrophage migration, inhibited macrophage apoptosis, and suppressed abnormal proliferation and migration of vascular smooth muscle cells. Furthermore, the Double-NPs actively accumulated in atherosclerotic plaques in ApoE-/- mice fed with a high-fat diet, leading to a reduced plaque area, inflammatory infiltration, and plaque instability. Our findings demonstrate that the newly developed ECG nanopreparation represents an effective and safe nanotherapy for diseases such as atherosclerosis.

A multi-target and responsive nanoplatform (MM/ZnS/ATV) combining H2S and atorvastatin for enhanced atherosclerosis therapy

Atherosclerosis, a chronic inflammatory disease characterized by the formation of atherosclerotic plaques in the arterial walls. The pathological process of atherosclerosis mainly contains lipid metabolism disorder, endothelial dysfunction, and progressive inflammation. Given the complexity of pathological process, treatments based on a single target might have very limited therapeutic efficacy. Thus, developing a nanoplatform to obtain an enhanced multi-target therapy is promising. Hydrogen sulfide (H2S) has various functions including anti-inflammation, anti-oxidation and endothelial protection. In this study, a responsive multi-target nanoplatform (MM/ZnS/ATV) combining the functions of H2S and atorvastatin was developed. The acidic microenvironment of the plaque can accelerate ZnS hydrolysis to trigger H2S and atorvastatin release. The responsive H2S release from ZnS can overcome the shortcomings of rapid H2S release from H2S donors in vivo. Furthermore, the ZnS hydrolysis-mediated H+ consumption in the microenvironment can reduce acidity to some extent. Results showed macrophage membranes (MM) coating reduced the phagocytosis of nanoparticles and increased the bioavailability. In vitro studies demonstrated that H2S release from MM/ZnS/ATV inhibited ROS-induced endothelial cell apoptosis and repaired the damaged endothelium. Moreover, atorvastatin released from MM/ZnS/ATV regulated lipid metabolism and reduced the blood lipid content. Both in vitro and in vivo studies confirmed MM/ZnS/ATV exhibited excellent therapeutic efficacy. Specifically, in vivo results showed that H2S combined with atorvastatin effectively reduced inflammatory infiltration, and promoted plaque regression and stabilization. Our study provides a promising strategy for atherosclerosis therapy.

Macrophage biomimetic nanoparticle-targeted functional extracellular vesicle micro-RNAs revealed via multiomics analysis alleviate sepsis-induced acute lung injury

Patients who suffer from sepsis typically experience acute lung injury (ALI). Extracellular vesicles (EVs) contain miRNAs, which are potentially involved in ALI. However, strategies to screen more effective EV-miRNAs as therapeutic targets are yet to be elucidated. In this study, functional EV-miRNAs were identified based on multiomics analysis of single-cell RNA sequencing of targeted organs and serum EV (sEV) miRNA profiles in patients with sepsis. The proportions of neutrophils and macrophages were increased significantly in the lungs of mice receiving sEVs from patients with sepsis compared with healthy controls. Macrophages released more EVs than neutrophils. MiR-125a-5p delivery by sEVs to lung macrophages inhibited Tnfaip3, while miR-221-3p delivery to lung neutrophils inhibited Fos. Macrophage membrane nanoparticles (MM NPs) loaded with an miR-125a-5p inhibitor or miR-221-3p mimic attenuated the response to lipopolysaccharide (LPS)-induced ALI. Transcriptome profiling revealed that EVs derived from LPS-stimulated bone marrow-derived macrophages (BMDMs) induced oxidative stress in neutrophils. Blocking toll-like receptor, CXCR2, or TNFα signaling in neutrophils attenuated the oxidative stress induced by LPS-stimulated BMDM-EVs. This study presents a novel method to screen functional EV-miRNAs and highlights the pivotal role of macrophage-derived EVs in ALI. MM NPs, as delivery systems of key sEV-miRNA mimics or inhibitors, alleviated cellular responses observed in sepsis-induced ALI. This strategy can be used to reduce septic organ damage, particularly lung damage, by targeting EVs.

Construction of biomimetic camouflaged neutrophil membrane nanoparticles for precise delivery and augmented glioma cancer treatment

Developing novel nanomedicine formulations that successfully penetrate the blood-brain barrier (BBB) to treat and diagnose glioma effectively is still a significant obstacle. This study presents the development of polymer nanogels camouflaged with macrophage membranes. The nanogels are loaded with manganese dioxide (MnO2) and carboplatin. They are designed for the treatment of glioma using a combination of chemotherapy and chemodynamic therapy (CDT). The precipitation polymerization process was used to create redox-responsive poly(caprolactone) (PCL) nanogels (NGs). These NGs were then loaded with MnO2 and physically encapsulated with carboplatin. The resulting nanogels had an average diameter of 102.52 nm and were covered with macrophage membranes to provide excellent stability. The developed NGs exhibit redox and pH responsiveness, releasing carboplatin and Mn(II) in a controlled manner. NGs may effectively deplete glutathione (GSH) in the tumour milieu. The Mn(II) generated in this process enhances the effectiveness of the loaded carboplatin by exerting its chemotherapeutic action and promoting the formation of reactive oxygen species to improve the efficiency of CDT. The results of our study show a very efficient and promising nanomedicine platform for the treatment and diagnosis of glioma, a type of cancer. This platform is self-adaptive, cooperative, and based on NG technology. Furthermore, this platform can potentially be used for other challenging types of cancer.

Macrophage membrane coated discoidal polymeric particles for evading phagocytosis.

The online version contains supplementary material available at 10.1007/s13534-024-00396-x.

An All‐in‐One Nano‐Biomimetic Polyamidoamine Dendrimer Platform for Treatment of CRKP Pneumonia

AbstractPolymyxin B (PMB) is often considered as the last line of defense for treating carbapenem‐resistantKlebsiella pneumoniae(CRKP). However, its efficacy is hindered by limited penetration across the blood‐air barrier in the lung due to its low lipid solubility. To simultaneously increase PMB in epithelial lining fluid while suppressing the excessive inflammatory response in the lung, a novel nano‐biomimetic system “Siv‐PMB@G4@MM” is designed and fabricated by encapsulating PMB‐ and anti‐inflammatory Sivelestat (Siv)‐loaded G4 PAMAM dendrimers with macrophage membranes (MM). The Siv‐PMB@G4@MM displayed a superior acidic pH‐responsive release property and can target inflamed lung tissues, greatly increasing the concentrations of PMB and Siv at the infection site. Compared with free drugs, Siv‐PMB@G4@MM demonstrated superior synergistic antibacterial and anti‐inflammatory activities. Moreover, due to the ability of MM to sequester lipopolysaccharide (LPS) and some pro‐inflammatory cytokines, Siv‐PMB@G4@MM further enhanced the anti‐inflammatory potential of Siv. In mouse models of LPS‐induced acute lung injury, pulmonary bacterial infection, and sepsis‐induced pneumonia, Siv‐PMB@G4@MM significantly reduced inflammatory responses and/or bacterial burdens, mitigated neutrophil infiltration and pulmonary edema, and decreased neutrophil extracellular trap (NET) secretion. The highly improved biocompatibility and efficiency of the multifunctional Siv‐PMB@G4@MM presents a promising strategy for the clinical treatment of antibiotic‐resistant bacterial pneumonia.

Targeted Delivery of Macrophage Membrane Biomimetic Liposomes Through Intranasal Administration for Treatment of Ischemic Stroke.

Ginsenoside Rg3 (Rg3) and Panax notoginseng saponins (PNS) can be used for ischemic stroke treatment, however, the lack of targeting to the ischemic region limits the therapeutic effect. To address this, we leveraged the affinity of macrophage membrane proteins for inflamed brain microvascular endothelial cells to develop a macrophage membrane-cloaked liposome loaded with Rg3 and PNS (MM-Lip-Rg3/PNS), which can precisely target brain lesion region through intranasal administration. MM-Lip-Rg3/PNS was prepared by co-extrusion method and was performed by characterization, stability, surface protein, and morphology. The cellular uptake, immune escape ability, and blood-brain barrier crossing ability of MM-Lip-Rg3/PNS were studied in vitro. The in vivo brain targeting, biodistribution and anti-ischemic efficacy of MM-Lip-Rg3/PNS were evaluated in MACO rats, and we determined the diversity of the nasal brain pathway through the olfactory nerve blockade model in rats. Finally, the pharmacokinetics and brain targeting index of MM-Lip-Rg3/PNS were investigated. Our results indicated that MM-Lip-Rg3/PNS was spherical with a shell-core structure. MM-Lip-Rg3/PNS can avoid mononuclear phagocytosis, actively bind to inflammatory endothelial cells, and have the ability to cross the blood-brain barrier. Moreover, MM-Lip-Rg3/PNS could specifically target ischemic sites, even microglia, increase the cumulative number of drugs in the brain, improve the inflammatory environment of the brain, and reduce the infarct size. By comparing olfactory nerve-blocking rats with normal rats, it was found that there are direct and indirect pathways for nasal entry into the brain. Pharmacokinetics demonstrated that MM-Lip-Rg3/PNS exhibited stronger brain targeting and prolonged drug half-life. MM-Lip-Rg3/PNS might contribute to the accumulation of Rg3 and PNS in the ischemic brain area to improve treatment efficacy. This biomimetic nano-drug delivery system provides a new and promising strategy for the treatment of ischemic stroke.

In Situ Colonization of Trojan‐Yeast for Targeted Glucose Starvation and Reconstruction of Tumor Immune Environment

AbstractGlucose is an important energy source for living cells. Particularly, most tumor cells use glycolysis to harness energy for their fast growth, invasion and metastasis even under aerobic conditions. Thus, reduction of the glucose level in cancer can lead to suppression of tumor growth. Here, macrophage membrane dressed yeast, Trojan M‐yeast, is developed, via coating the surface of yeast with macrophage membrane, for targeted accumulation and suppression of tumor by glucose starvation. Due to the inflammatory homing effects of macrophage membrane, M‐yeast efficiently target and colonize in the inflammatory tumor site, where they compete with tumor cells for glucose consumption, thereby disrupting glycolysis of cancer cells, resulting in the reduction of lactate accumulation and reversal of the acidosis of tumor microenvironment. Subsequently, the apoptotic tumor cells and yeast promote dendritic cell maturation, increase tumor‐infiltrating cytotoxic T lymphocytes. Meanwhile, ethanol and acetaldehyde produced by yeast metabolism of glucose can re‐polarize tumor associated macrophages (TAMs) to the anti‐tumor phenotype (M1), thus reprogramming the tumor immunosuppressive microenvironment, leading to synergistic tumor suppression together with glucose starvation, which is different from traditional chemotherapy and immunotherapy. M‐yeast exhibits promising targeted cancer therapy with a decent safety profile. This work may provide new insights as well as a new paradigm for yeast‐based cancer therapy.

IL-33/NF-κB/ST2L/Rab37 positive-feedback loop promotes M2 macrophage to limit chemotherapeutic efficacy in lung cancer

IL-33 is a danger signal that binds to its receptor ST2L to promote tumor progression. This study identifies the IL-33/ST2L positive-feedback loop and the trafficking of ST2L membrane presentation in macrophages that contribute to lung tumor progression. Mechanistically, IL-33 induces ST2L upregulation by activating NF-κB, which binds to the promoter region of the ST2L gene. Moreover, Rab37, a small GTPase involved in membrane trafficking, mediates ST2L trafficking to the plasma membrane of M2 macrophages. This IL-33/NF-κB/ST2L/Rab37 axis promotes positive-feedback loops that enhance ST2L expression and membrane trafficking in M2 macrophages. Notably, neutralizing antibodies against IL-33 or ST2L block NF-κB activity, suppress M2 macrophage polarization, and synergistically inhibit tumor growth when combined with cisplatin treatment in vitro/vivo. Clinically, Rab37+/ST2L+/CD206+ tumor-infiltrating M2 macrophages correlate with advanced-stage lung cancer patients with poor response to chemotherapy. These findings unveil a positive-feedback mechanism and provide a basis for IL-33/ST2L-targeting therapy for cancer.

Liver Fibrosis Amelioration by Macrophage-Biomimetic Polydopamine Nanoparticles via Synergistically Alleviating Inflammation and Scavenging ROS.

The progression of liver fibrosis is determined by the interaction of damaged hepatocytes, active hepatic stellate cells, and macrophages, contributing to the development of oxidative stress and inflammatory environments within the liver. Unfortunately, the current pharmacological treatment for liver fibrosis is limited by its inability to regulate inflammation and oxidative stress concurrently. In this study, we developed a cell membrane biomaterial for the treatment of liver fibrosis, which we designated as PM. PM is a biomimetic nanomaterial constructed by encapsulating polydopamine (PDA) with a macrophage membrane (MM). It is hypothesized that PM nanoparticles (NPs) can successfully target the site of inflammation, simultaneously inhibit inflammation, and scavenge reactive oxygen species (ROS). In vitro experiments demonstrated that PM NPs exhibited strong antioxidant properties and the ability to neutralize pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β). Moreover, the capacity of PM NPs to safeguard cells from oxidative stress and their anti-inflammatory efficacy in an inflammatory model were validated in subsequent cellular experiments. Additionally, PM NPs exhibited a high biocompatibility. In a mouse model of hepatic fibrosis, PM NPs were observed to aggregate efficiently in the fibrotic liver, displaying excellent antioxidant and anti-inflammatory properties. Notably, PM NPs exhibited superior targeting, anti-inflammatory, and ROS scavenging abilities in inflamed tissues compared to MM, PDA, or erythrocyte membrane-encapsulated PDA. Under the synergistic effect of anti-inflammation and antioxidant, PM NPs produced significant therapeutic effects on liver fibrosis in mice. In conclusion, the synergistic alleviation of inflammation and ROS scavenging by this specially designed nanomaterial, PM NPs, provides valuable insights for the treatment of liver fibrosis and other inflammatory- or oxidative stress-related diseases.

Effective glioblastoma immune sonodynamic treatment mediated by macrophage cell membrane cloaked biomimetic nanomedicines

Glioblastoma (GBM) as one of the most lethal brain tumours, remains poor therapeutic index due to its typical characters including heterogeneous, severe immune suppression as well as the existence of blood brain barrier (BBB). Immune sonodynamic (ISD) therapy combines noninvasive sonodynamic therapy with immunotherapy, which has great prospects for the combinational treatment of GBM. Herein, we develop macrophage cell membrane cloaked reactive oxygen species (ROS) responsive biomimetic nanoparticles, co-delivering of sonosensitizer Ce6 and JQ1 (a bromo-domain protein 4 (BRD4) inhibitor which can down-regulate PD-L1) and realizing potent GBM ISD therapy. The ApoE peptide decorated macrophage membrane coating endows these biomimetic nanoparticles with low immunogenicity, efficient BBB permeability, prolonged blood circulation half-live and good biocompatibility. The ROS responsive polymeric inner core could be readily degraded as triggered by excessive ROS under the ultrasound once they accumulated in tumour cells, fast release encapsulated drugs. The generation of ROS not only killed tumour cells via sonodynamic therapy, but also induced immunogenic cell death (ICD) and further activated the anti-tumour immune response. The released JQ1 inhibited tumour cell proliferation and augmented the immune activities by inhibiting the PD-L1 expression on the surface of tumour cells. The cascade sonodynamic and immune therapy resulted in significantly improved median survival time in both orthotopic GL261 and PTEN deficient immunosuppressive CT2A GBM mice models. Therefore, our developed biomimetic nanoparticle platform provides a promising combinational therapy strategy to treat immune suppressive GBM.

NF-κB-Signaling-Targeted Immunomodulatory Nanoparticle with Photothermal and Quorum-Sensing Inhibition Effects for Efficient Healing of Biofilm-Infected Wounds.

The development of therapeutics with high antimicrobial activity and immunomodulatory effects is urgently needed for the treatment of infected wounds due to the increasing danger posed by recalcitrant-infected wounds. In this study, we developed light-controlled antibacterial, photothermal, and immunomodulatory biomimetic N/hPDA@M nanoparticles (NPs). This nanoplatform was developed by loading flavonoid naringenin onto hollow mesoporous polydopamine NPs in a π-π-stacked configuration and encasing them with macrophage membranes. First, our N/hPDA@M NPs efficiently neutralized inflammatory factors present within the wound microenvironment by the integration of macrophage membranes. Afterward, the N/hPDA@M NPs effectively dismantled bacterial biofilms through a combination of the photothermal properties of PDA and the quorum sensing inhibitory effects of naringenin. It is worth noting that N/hPDA@M NPs near-infrared-enhanced release of naringenin exhibited specificity toward the NF-κB-signaling pathway, effectively mitigating the inflammatory response. This innovative design not only conferred remarkable antibacterial properties upon the N/hPDA@M NPs but also endowed them with the capacity to modulate inflammatory responses, curbing excessive inflammation and steering macrophage polarization toward the M2 phenotype. As a result, this multifaceted approach significantly contributes to expediting the healing process of infected skin wounds.

Inhaled NIR‐II Nanocatalysts for Real‐Time Monitoring and Immunomodulatory Therapy of Acute Lung Injury

AbstractAcute lung injury (ALI) poses a significant and escalating medical challenge, where precise diagnosis and timely intervention hold utmost importance in halting its deterioration. Nevertheless, persistent obstacles arise from the lack of agents proficient in both real‐time diagnosis and efficient mitigation of ALI. Here, a biocatalytic and second near‐infrared (NIR‐II) fluorescence‐illuminating nanoplatform is designed to simultaneously facilitate real‐time monitoring and robust inflammation alleviation in ALI. The study first develops a new aggregation‐induced emission luminogen with trifluoromethyl substitutions, which simultaneously increase NIR‐II emission wavelength and fluorescence brightness. The molecular probe is further integrated into biocatalytic hollow ceria nanostructures, and cloaked with pre‐activated macrophage membranes for targeted inflammation intervention. Upon inhalation administration in ALI mice, the theranostic nanoagents leverage the bright NIR‐II emission and active inflammation‐tropic properties for in vivo sensitive NIR‐II imaging of ALI, which also facilitates real‐time tracking of the nanoagents’ distribution and dynamic fate within pneumonia milieu. Concurrently, the catalytic prowess of the nanoplatforms efficaciously scavenges excess reactive oxygen species, dampens proinflammatory cytokines, and promotes macrophage repolarization, substantially alleviating acute lung damage. The multifaceted nanoplatform integrates NIR‐II bioimaging with nanocatalysis‐mediated immunoregulation, offering a versatile and promising approach for addressing the intricate challenges posed by acute inflammation diseases.

Decitabine-based nanoparticles for enhanced immunotherapy of hepatocellular carcinoma via DNA hypermethylation reversal

DNA methyltransferase (DNMT) inhibitor represents the first clinical breakthrough via targeting aberrant cancer epigenomes. Demethylation drugs such as decitabine can restore tumor suppressor gene (TSG) expression and function to achieve anti-tumor effect. Despite DNMT inhibitors have shown significant efficacy for treating leukemia, their application in solid tumor such as HCC is limited due to short in vivo half-lives. In this study, the DNMT1 inhibitor decitabine was first loaded into the Polylactic-co-glycolic acid (PLGA) spherical nanoparticles (Dec@PLGA). The vesicle of PD-L1 antibody and macrophage membrane (aMM) was further coated onto the surface of Dec@PLGA to finally synthesize Dec@PLGA@aMM. Dec@PLGA@aMM was in uniformed spherical structure with hydrodynamic particle size of 95.7 ± 9.1 nm and surface zeta potential of −15.1 ± 3.3 mV. Dec@PLGA@aMM significantly increased the expression of both p14 and p16 in a concentration-dependent manner. Dec@PLGA@aMM could enhance the tumor suppression through restoration of TSGs, which were epigenetically silenced by DNA hypermethylation. The Dec@PLGA@aMM group showed significantly (P < 0.05) less tumor volume than PBS group, PLGA@MM group, aPD-L1 group, PLGA@aMM group, decitabine group, Dec + aPD-L1 group, and Dec@PLGA@MM group. The decitabine could enhance aPD-L1-mediated immunotherapy of HCC via epigenetic alteration. This novel targeted PLGA NPs are aimed to treat HCC by decreasing DNA methylation and blocking PD-L1, thus providing new ideas for effective treatments via epigenetic alteration for HCC patients clinically.

Extracellular histones promote TWIK2-dependent potassium efflux and associated NLRP3 activation in alveolar macrophages during sepsis-induced lung injury.

Sepsis-induced acute lung injury (ALI) is a complex and life-threatening condition lacking specific and efficient clinical treatments. Extracellular histones, identified as a novel type of damage-associated molecular patterns, have been implicated in the inflammatory process of ALI. However, further elucidation is needed regarding the precise mechanism through which extracellular histones induce inflammation. The aim of this study was to investigate whether extracellular histones can activate NLRP3 inflammasome-mediated inflammation in alveolar macrophages (AMs) by affecting TWIK2-dependent potassium efflux. We conducted experiments using cecal ligation and puncture (CLP) C57BL/6 mice and extracellular histone-stimulated LPS-primed MH-Scells. The results demonstrated a significant increase in the levels of extracellular histones in the plasma and bronchoalveolar lavage fluid (BALF) of CLP mice. Furthermore, neutralizing extracellular histone mitigated lung injury and inflammation in CLP-induced ALI mice. In vitro studies confirmed that extracellular histones upregulated the expression of NLRP3 inflammasome activation-related proteins in MH-S cells, and this effect was dependent on increased potassium efflux mediated by the TWIK2 channel on the plasma membrane. Moreover, extracellular histones directly triggered a substantial influx of calcium, leading to increased Rab11 activity and facilitating the trafficking and location of TWIK2 to the plasma membrane. These findings underscore the critical role of extracellular histone-induced upregulation of TWIK2 expression on the plasma membrane of alveolar macrophages (AMs). This upregulation leads to potassium efflux and subsequent activation of the NLRP3 inflammasome, ultimately exacerbating lung inflammation and injury during sepsis.

Multifunctional Composite Scaffold with Nanosilver, Graphene Oxide, and Macrophage Membrane Vesicles for Sequential Treatment of Infected Bone Defects.

The management of infected bone defects poses a significant clinical challenge, and current treatment modalities exhibit various limitations. This study focuses on the development of a multifunctional composite scaffold comprising nanohydroxyapatite/polyethyleneglycol diacrylate matrix, silver nanoparticles, graphene oxide (GO), sodium alginate, and M2-type macrophage membrane vesicles (MVs) to enhance the healing of infected bone defects. The composite scaffold demonstrates several key features: first, it releases sufficient quantities of silver ions to effectively eliminate bacteria; second, the controlled release of MVs leads to a notable increase in M2-type macrophages, thereby significantly mitigating the inflammatory response. Additionally, GO acts synergistically with nanohydroxyapatite to enhance osteoinductive activity, thereby fostering bone regeneration. Through meticulous in vitro and in vivo investigations, the composite scaffold exhibits broad-spectrum antimicrobial effects, robust immunomodulatory capabilities, and enhanced osteoinductive activity. This multifaceted composite scaffold presents a promising approach for the sequential treatment of infected bone defects, addressing the antimicrobial, immunomodulatory, and osteogenic aspects. This study introduces innovative perspectives and offers new and effective treatment alternatives for managing infected bone defects.

Seeking Cells, Targeting Bacteria: A Cascade-Targeting Bacteria-Responsive Nanosystem for Combating Intracellular Bacterial Infections.

Intracellular bacteria pose a great challenge to antimicrobial therapy due to various physiological barriers at both cellular and bacterial levels, which impede drug penetration and intracellular targeting, thereby fostering antibiotic resistance and yielding suboptimal treatment outcomes. Herein, a cascade-target bacterial-responsive drug delivery nanosystem, MM@SPE NPs, comprising a macrophage membrane (MM) shell and a core of SPE NPs. SPE NPs consist of phenylboronic acid-grafted dendritic mesoporous silica nanoparticles (SP NPs) encapsulated with epigallocatechin-3-gallate (EGCG), a non-antibiotic antibacterial component, via pH-sensitive boronic ester bonds are introduced. Upon administration, MM@SPE NPs actively home in on infected macrophages due to the homologous targeting properties of the MM shell, which is subsequently disrupted during cellular endocytosis. Within the cellular environment, SPE NPs expose and spontaneously accumulate around intracellular bacteria through their bacteria-targeting phenylboronic acid groups. The acidic bacterial microenvironment further triggers the breakage of boronic ester bonds between SP NPs and EGCG, allowing the bacterial-responsive release of EGCG for localized intracellular antibacterial effects. The efficacy of MM@SPE NPs in precisely eliminating intracellular bacteria is validated in two rat models of intracellular bacterial infections. This cascade-targeting responsive system offers new solutions for treating intracellular bacterial infections while minimizing the risk of drug resistance.

Abstract 117: AIBP Deficiency Affects Inflammarafts Formation And Macrophage Reprogramming In Atherosclerosis

Background: Excessive accumulation of cholesterol in plasma membrane of vascular macrophages leads to formation of inflammarafts - large, cholesterol-rich lipid rafts hosting inflammatory receptors assemblies - and reprograms macrophages to facilitate hyperinflammatory responses. Removal of cholesterol from membrane and storage in intracellular lipid droplets reduces macrophage inflammatory status. Apolipoprotein A-I binding protein (AIBP) has been found to mediate selective cholesterol efflux and lipid raft dynamics regulation via binding to toll-like receptor-4 (TLR4) thus reducing inflammarafts in activated macrophages. However, the underlying mechanisms driving lipid raft dynamics changes of reprogrammed macrophages remain unclear. The objective of this study was to evaluate the effect of AIBP deficiency on inflammaraft formation and macrophage reprogramming, separately in macrophage foam cells and non-foamy macrophages. Methods: Single-cell suspensions from the aortae of 16-week high-fat diet-fed Apoa1bp -/- Ldlr -/- and Ldlr -/- mice were gated for BODIPY-high foamy and BODIPY-low non-foamy CD45 + F4/80 + macrophages by flow cytometry. Lipid droplets were assessed by BODIPY fluorescence and inflammarafts were characterized by increased levels of lipid rafts and TLR4 dimers. Transcriptome and chromatin accessibility were measured by RNA-seq and ATAC-seq. Plasma lipid levels and size of atherosclerotic lesions and necrotic cores at the aortic origin were measured using standard methods. Results: We found a larger number of foamy macrophages in Apoa1bp -/- Ldlr -/- mice, expressing significantly higher levels of lipid rafts and TLR4 dimers than those in Ldlr -/- mice. However, there were no inflammarafts differences between non-foamy macrophages in Apoa1bp -/- Ldlr -/- and Ldlr -/- mice. The inflammarafts measures were associated with plasma cholesterol levels and size of atherosclerotic lesions and necrotic cores. Inflammatory pathways were up-regulated in Apoa1bp -/- Ldlr -/- foamy macrophages, compared to Ldlr -/- mice. Conclusions: Our results suggest that AIBP helps reduce inflammarafts specifically in macrophage foam cells, rendering them less inflammatory as shown by transcriptomic and open chromatin analyses.