Neutrophil Membrane Research Articles

Stages of NETosis Development upon Stimulation of Neutrophils with Activators of Different Types.

Before NETs are released, the neutrophil undergoes structural changes. First, it flattens, accompanied by a change in cell shape and rearrangement of the cytoskeleton. Then, nuclear swelling begins, which ends with the ejection of NETs into the extracellular space. We used widefield and confocal fluorescence microscopy to register morphological and structural changes in neutrophils during activation and NETosis. Different types of activators were used, such as NOX-dependent PMA and calcium ionophore A23187. The measurements were performed in a series of sequential stages. In the first stage (30 s after addition of activators and immediately after stimulation of neutrophils), the response of neutrophils to A23187 and PMA exposure was studied. Subsequently, the characteristics of neutrophils in different phases of activation were examined over a longer period of time (30, 60, 120, 180, and 240 min). The specific features of NETosis development were analyzed separately. During the first 30 s, neutrophils appeared to be heterogeneous in shape and structure of the actin cytoskeleton. Characteristic cell shapes included 30″ type 1 cells, similar in shape to the control, with F-actin concentrated in the center of the cytoplasm, and 30″ type 2 cells, which had flattened (spread) shapes with increased frontal dimensions and F-actin distributed throughout the cell. Later, the development of nuclear swelling, the corresponding changes in neutrophil membranes, and NET release into the extracellular space were evaluated. The conditions determining the initiation of chromatin ejection and two characteristic types of decondensed chromatin ejection were revealed. The results obtained contribute to a better understanding of the biophysical mechanisms of neutrophil activation and NETosis development.

New-generation cytopharmaceuticals with powerfully boosted extravasation for enhanced cancer therapy.

Effective extravasation of therapeutic agents into solid tumors still faces huge challenges. Since the doubted effectiveness of enhanced penetration and retention effect, first-generation neutrophil cytopharmaceuticals with encapsulated drugs have been developed to improve the drug accumulation in tumors based on the active chemotaxis and extravasation of neutrophils. Herein, a new generation of neutrophil cytopharmaceuticals with enhanced tumor-specific extravasation is reported to satisfy more complex clinical demands. This neutrophil cytopharmaceutical is obtained by anchoring vascular endothelial growth factor receptor 2 (VEGFR2)-targeting peptide K237 on neutrophil membrane after endocytosis of chemotherapeutics by neutrophils. Leveraging the cytokine-mediated active migration of neutrophils, the specific-recognition of K237 peptide to tumor vascular endothelium expedites the migration and enhances tight adhesion of neutrophils to vascular endothelium, thus improving the extravasation of therapeutic agents to target sites. Moreover, anti-angiogenesis effect from VEGFR2-blocking by K237 peptide achieves a cooperative tumor destruction with cytotoxic effects from released chemotherapeutics. This study demonstrates the great potential of enhanced proactive extravasation of cytopharmaceuticals via a cell-anchoring technology, leading to expedited drug infiltration and boosted therapeutic effects, which can be applied in other cell therapies to improve efficacy.

Sfxn5 Regulation of Actin Polymerization for Neutrophil Spreading Depends on a Citrate-Cholesterol-PI(4,5)P2 Pathway.

Cell spreading is an initial and critical step in neutrophil adhesion and migration, leading to neutrophil recruitment to inflammatory tissues. Sideroflexin (Sfxn) family proteins are metabolite transporters located in the mitochondrial membrane. Recombinant SFXN5 protein is a citrate transporter invitro; however, whether Sfxn5 regulates any cellular behavior or function remains unknown. In this study, we found that small interfering RNA transfection or morpholino injection achieving Sfxn5 deficiency in neutrophils significantly decreased neutrophil recruitment in mice and zebrafish, respectively. Sfxn5 deficiency impaired neutrophil spreading and spreading-associated cellular phenotypes, such as cell adhesion, chemotaxis, and ROS production. Actin polymerization is critical for neutrophil spreading, and we found that actin polymerization in spreading neutrophils was partially inhibited by Sfxn5 deficiency. Mechanistically, we observed that the levels of cytosolic citrate and its downstream metabolic products, acetyl-CoA and cholesterol, were decreased in Sfxn5-deficient neutrophils. The levels of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), a mediator for the regulation of actin polymerization by cholesterol, were reduced in the plasma membrane of Sfxn5-deficient neutrophils. Exogenous supplementation with citrate or cholesterol partially reversed the reduction in PI(4,5)P2 levels, defective neutrophil actin polymerization, and cell spreading. Altogether, we demonstrated that Sfxn5 maintains cytosolic citrate levels and ensures the synthesis of sufficient cholesterol to promote actin polymerization in a PI(4,5)P2-dependent manner during neutrophil spreading, which is essential for the eventual inflammatory recruitment of neutrophils. Our study revealed the importance of Sfxn5 in neutrophil spreading and migration, thus identifying, to our knowledge, for the first time, the physiological cellular functions of the Sfxn5 gene.

The effect of acute phase proteins on the activity of peripheral blood neutrophils

Neutrophils are the leading cells of the innate immune system and the main population of leukocytes responsible for the primary reaction of the organism to various infectious agents. The latter are destroyed by neutrophils during the processes of phagocytosis and a cascade of reactions, including the respiratory burst. As a result of the respiratory burst, neutrophils produce reactive oxygen and halogen species, which are powerful cytotoxic agents which destroy foreign particles in the phagolysosome. All of these processes require strict regulation, since excessive activation of neutrophils may lead to higher production of reactive oxygen species thereby causing tissue damage in the focus of inflammation. Acute phase proteins may play a role as regulators of inflammatory processes. Our previous works have shown that ceruloplasmin is involved in the inhibition of the respiratory burst of neutrophils in whole blood samples. Fibrinogen, on the contrary, increased the intensity of respiratory burst. A detailed characterization of the effects acute phase proteins exert on peripheral blood neutrophils’ functions has been studied not for all acute phase proteins and especially their combinations. In this paper, for the first time, the flow cytometer and registration of reactive oxygen species production in peripheral blood cells have been used to study the effects of several acute phase reactants (C-reactive protein, serum amyloid A, alpha-1-acid glycoprotein and fibrinogen) on the ability of peripheral blood neutrophils to activate respiratory burst. The results showed that significant changes in the capacity of reactive oxygen species production by neutrophils were seen for a set of combinations of the studied acute phase proteins. The study of the interaction of ceruloplasmin and fibrinogen with peripheral blood neutrophils revealed that they were localized to the membrane. It seems promising to identify receptors for acute phase proteins at the neutrophil membrane.

Neutrophil membrane fusogenic nanoliposomal leonurine for targeted ischemic stroke therapy via remodeling cerebral niche and restoring blood-brain barrier integrity.

Ischemic stroke (IS) constitutes the leading cause of global morbidity and mortality. Neuroprotectants are essential to ameliorate the clinical prognosis, but their therapeutic outcomes are tremendously compromised by insufficient delivery to the ischemic lesion and intricate pathogenesis associated with neuronal damage, oxidative stress, inflammation responses, blood-brain barrier (BBB) dysfunction, etc. Herein, a biomimetic nanosystem (Leo@NM-Lipo) composed of neutrophil membrane-fused nanoliposomal leonurine (Leo) is constructed, which can not only efficiently penetrate and repair the disrupted BBB but also robustly remodel the harsh cerebral microenvironment to reverse ischemia-reperfusion (I/R) injury. More specifically, the neutrophil membrane inherits the BBB penetrating, infarct core targeting, inflammation neutralization, and immune evasion properties of neutrophils, while Leo, a naturally occurring neuroprotectant, exerts pleiotropic effects to attenuate brain damage. Remarkably, comprehensive investigations disclose the critical factors influencing the targetability and therapeutic performances of biomimetic nanosystems. Leo@NM-Lipo with a low membrane protein-to-lipid ratio of 1:10 efficiently targets the ischemic lesion and rescues the injured brain by alleviating neuronal apoptosis, oxidative stress, neuroinflammation, and restoring BBB integrity in transient middle cerebral artery occlusion (tMCAO) rats. Taken together, our study provides a neutrophil-mimetic nanoplatform for targeted IS therapy and sheds light on the rational design of biomimetic nanosystems favoring wide medical applications.

HRG inhibits liver cancer lung metastasis by suppressing neutrophil extracellular trap formation.

Distant metastasis is a sign of poor prognosis for cancer patients. Extrahepatic liver cancer metastases commonly spread to the lung. Remodelling of the metastatic microenvironment is essential for tumour metastasis. Neutrophil-associated metastatic microenvironment contributes to the early metastatic colonisation of cancer cells in the lung. The lung metastasis models were constructed via treated cancer cells by tail vein injection into mice. And samples of lung were harvested at the indicated time to analyze tumor growth and immune cells in the microenvironment. Tumors and lung metastasis specimens were obtained via surgical operations for research purposes. Neutrophils were obtained from peripheral blood of patients with liver cancer or healthy donors (HD). Hepatocellular carcinoma cells reduce the secretion of histidine-rich glycoprotein (HRG), regulate the recruitment and activation of neutrophils in the metastatic microenvironment and promote the production of neutrophil extracellular traps (NETs), thereby promoting liver cancer lung metastasis. HRG binds to FCγR1 on the neutrophil membrane while inhibiting PI3K and NF-κB activation, thereby reducing IL-8 secretion to reduce neutrophil recruitment. Meanwhile, HRG inhibited IL8-MAPK and NF-κB pathway activation and ROS production, resulting in reduced NETs formation. Our study reveals that liver cancer regulates neutrophil recruitment and NETs formation in the metastatic microenvironment by reducing HRG secretion, thereby promoting tumour lung metastasis. The results of this study will contribute to the development of possible strategies for treating metastases.

Role of the phospholipid binding sites, PX of p47phox and PB region of Rac1, in the formation of the phagocyte NADPH oxidase complex NOX2

In phagocytes, superoxide anion (O2−), the precursor of reactive oxygen species, is produced by the NADPH oxidase complex to kill pathogens. Phagocyte NADPH oxidase consists of the transmembrane cytochrome b558 (cyt b558) and four cytosolic components: p40phox, p47phox, p67phox, and Rac1/2. The phagocyte activation by stimuli leads to activation of signal transduction pathways. This is followed by the translocation of cytosolic components to the membrane and their association with cyt b558 to form the active enzyme.To investigate the roles of membrane-interacting domains of the cytosolic proteins in the NADPH oxidase complex assembly and activity, we used giant unilamellar phospholipid vesicles (GUV). We also used the neutrophil-like cell line PLB-985 to investigate these roles under physiological conditions. We confirmed that the isolated proteins must be activated to bind to the membrane. We showed that their membrane binding was strengthened by the presence of the other cytosolic partners, with a key role for p47phox. We also used a fused chimera consisting of p47phox(aa 1–286), p67phox(aa 1–212) and Rac1Q61L, as well as mutated versions in the p47phox PX domain and the Rac polybasic region (PB). We showed that these two domains have a crucial role in the trimera membrane-binding and in the trimera assembly to cyt b558. They also have an impact on O2.- production in vitro and in cellulo: the PX domain strongly binding to GUV made of a mix of polar lipids; and the PB region strongly binding to the plasma membrane of neutrophils and resting PLB-985 cells.

CD301b+ macrophage: the new booster for activating bone regeneration in periodontitis treatment

Periodontal bone regeneration is a major challenge in the treatment of periodontitis. Currently the main obstacle is the difficulty of restoring the regenerative vitality of periodontal osteoblast lineages suppressed by inflammation, via conventional treatment. CD301b+ macrophages were recently identified as a subpopulation that is characteristic of a regenerative environment, but their role in periodontal bone repair has not been reported. The current study indicates that CD301b+ macrophages may be a constituent component of periodontal bone repair, and that they are devoted to bone formation in the resolving phase of periodontitis. Transcriptome sequencing suggested that CD301b+ macrophages could positively regulate osteogenesis-related processes. In vitro, CD301b+ macrophages could be induced by interleukin 4 (IL-4) unless proinflammatory cytokines such as interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) were present. Mechanistically, CD301b+ macrophages promoted osteoblast differentiation via insulin-like growth factor 1 (IGF-1)/thymoma viral proto-oncogene 1 (Akt)/mammalian target of rapamycin (mTOR) signaling. An osteogenic inducible nano-capsule (OINC) consisting of a gold nanocage loaded with IL-4 as the “core” and mouse neutrophil membrane as the “shell” was designed. When injected into periodontal tissue, OINCs first absorbed proinflammatory cytokines in inflamed periodontal tissue, then released IL-4 controlled by far-red irradiation. These events collectively promoted CD301b+ macrophage enrichment, which further boosted periodontal bone regeneration. The current study highlights the osteoinductive role of CD301b+ macrophages, and suggests a CD301b+ macrophage-targeted induction strategy based on biomimetic nano-capsules for improved therapeutic efficacy, which may also provide a potential therapeutic target and strategy for other inflammatory bone diseases.

Neutrophil membrane biomimetic delivery system (Ptdser-NM-Lipo/Fer-1) designed for targeting atherosclerosis therapy.

Atherosclerosis is a progressive inflammatory disease characterised by excessive lipid accumulation and inflammatory cell infiltration and is the basis of most cardiovascular diseases and peripheral arterial diseases. Therefore, an effectively targeted delivery system is urgently needed to deliver ferroptosis-specific inhibitors to the site of arterial plaque and the inflammatory microenvironment. Inspired by the fact that neutrophils can be recruited to arterial plaques under the action of adhesion molecules and chemokines, the authors developed a neutrophil membrane hybrid liposome nano-mimetic system (Ptdser-NM-Lipo/Fer-1) that delivers Ferrostatin-1 (Fer-1) to the atherosclerotic plaque effectively, which is composed of Fer-1-loaded Ptdser-modified liposomes core and neutrophils shell. Fer-1 was released at the AS plaque site to remove reactive oxygen species (ROS) and improve the inflammatory microenvironment. In vitro ROS clearance experiments have shown that 50μmol/ml Fer-1 can significantly remove ROS produced by H2 O2 -induced MOVAS cells and Ptdser-NM-Lipo/Fer-1 revealed a 3-fold increase in the inhibition rate of ROS than free Fer-1 in induced-RAW264.7, demonstrating its superior ROS-cleaning effect. Based on the interaction of adhesion molecules, such as vascular cell adhesion molecule 1, ICAM-1, P-selectin, E-selectin, and chemokines released in the inflamed site, the aorta in NM-Lipo-treated mice displayed 1.3-fold greater radiant efficiency than platelet membrane-Lipo-treated mice. Meanwhile, due to the modification of the Ptdser, the aorta in Ptdser-NM-Lipo/Fer-1-treated mice exhibited the highest fluorescence intensity, demonstrating its excellent targeting ability for atherosclerosis. Therefore, we present a specific formulation for the treatment of atherosclerosis with the potential for novel therapeutic uses.

The Diagnostic Value of Triggering Receptor Expressed on Myeloid Cells-1 in Post-Traumatic Bacterial Endophthalmitis.

To determine whether soluble-triggering receptor expressed on myeloid cells-1 (sTREM-1) could serve as a reliable diagnostic biomarker of post-traumatic bacterial endophthalmitis (PTBE). Thirty-two patients (32 eyes) clinically diagnosed having PTBE were further divided into a culture-positive (CP) group and a culture-negative (CN) group. Sixty-two patients (62 eyes) without traumatic endophthalmic infection were also enrolled. Twenty-one eyes from 11 donors without globe ocular injuries were included as control group. Vitreous sTREM-1 levels were detected by ELISA. The expression and tissue distribution of TREM-1 were revealed by immunohistochemistry. The diagnostic value of sTREM-1 was determined by receiver operating characteristic curve (ROC). The correlation between sTREM-1 concentration and final best-corrected visual acuity (FBCVA) and Peyman endophthalmitis score (PES) were also assessed. The vitreous sTREM-1 level in the PTBE group was higher than that in noninfected group and control group (P < 0.05). No remarkable difference was found between the CP group and the CN group in vitreous sTREM-1 levels (P > 0.05). No remarkable difference was found between the noninfected group and the control group (P > 0.05). No remarkable difference in TREM-1 level was found before and after intravitreal antibiotics (P > 0.05). TREM-1 was selectively highly expressed on the surface of cell membrane of neutrophils and monocytes/macrophages infiltrated in vitreous and uveal of the PTBE group. The area under the ROC curve (AUC) was 0.79 (>0.75), with a medium diagnostic efficiency. The sensitivity and specificity of sTREM-1 to differentiate PTBE from the noninfected intraocular condition were 62.50% and 86.25% separately. A cutoff value >524.50 pg/mL for sTREM-1 was predicted to be PTBE. Vitreous sTREM-1 levels in PTBE group were positively correlated with PES (r = 0.428, P < 0.05). However, sTREM-1 levels and FBCVA did not significantly correlate with one another (P > 0.05). The sTREM-1 was a promising diagnostic biomarker of PTBE, especially CN-PTBE. Vitreous sTREM-1 levels were linked with intraocular inflammation levels and severity of PTBE.

Neutrophil membrane-camouflaged nanoparticles alleviate inflammation and promote angiogenesis in ischemic myocardial injury.

Acute myocardial infarction (AMI) induces a sterile inflammatory response, leading to cardiomyocyte damage and adverse cardiac remodeling. Interleukin-5 (IL-5) plays an essential role in developing eosinophils (EOS), which are beneficial for the resolution of inflammation. Furthermore, the proangiogenic properties of IL-5 also contribute to tissue healing following injury. Therefore, targeted delivery of IL-5 is an innovative therapeutic approach for treating AMI. It has been shown that conventional IL-5 delivery can result in undesirable adverse effects and potential drug overdose. In this study, we successfully synthesized a biomimetic IL-5 nanoparticle by camouflaging the IL-5 nanoparticle in a neutrophilic membrane. The administration of neutrophil membrane-camouflaged nanoparticles (NM-NPIL-5) in the in vivo model showed that these nanoparticles promoted EOS accumulation and angiogenesis in the infarcted myocardium, thereby limiting adverse cardiac remodeling after AMI. Our results also demonstrated that the NM-NPIL-5 could serve as neutrophil "decoys" to adsorb and neutralize the elevated neutrophil-related cytokines in the injured heart by inheriting multiple receptors from their "parent" neutrophils. Finally, the targeted delivery of NM-NPIL-5 protected the cardiomyocytes from excessive inflammatory-induced apoptosis and maintained cardiac function. Our findings provided a promising cardiac detoxification agent for acute cardiac injury.

Neutrophil membrane-derived nanoparticle loading TLR7 agonists augments radiotherapy efficacy and boosts abscopal effect via regulating tumor microenvironment

BackgroundIncreasing evidence indicates that radiotherapy (RT) has synergistic inhibitory efficiency with immunotherapy agents in multiple cancers and enhances abscopal effects by regulating the innate immune response, which was further investigated in this study. Neutrophils are recruited in radiated tumors. Therefore, neutrophil membrane-coated nanoparticles potentially deliver R837 (Toll-like receptor 7 agonist) to radiated tumors.MethodsA novel nanoparticle R837@PLGA@Neu was prepared by initially assembling PLGA (poly (lactic-co-glycolic acid)) with R837 (TLR7 agonist) into R837@PLGA followed by coating with neutrophil membrane. Characterizations of R837@PLGA@Neu were performed. Tumor targeting efficiency was evaluated by in vivo fluorescent imaging of CT26-bearing mice. Treatments of R837@PLGA@Neu combined with RT were carried out in unilateral and bilateral CRC tumor-bearing mice, followed by validations of immune cells in tumors by flow cytometry.ResultsThe characteristics of R837@PLGA@Neu were well identified, and it was confirmed to have high uptake ability and low cytotoxicity in colorectal cancer (CRC) cells in vitro, as well as its strong tumor-targeting efficiency in vivo in CRC tumor-bearing mice. The exciting findings were that R837@PLGA@Neu combined with RT exerted prominent tumor inhibition not only in radiated tumors, but also in distant tumors without RT, suggesting its enhancement of the efficacy and abscopal effect of RT. The possible underlying mechanisms were remodeling of the tumor microenvironment by triggering mature dendritic cells and CD8+ T cells.ConclusionIn summary, our findings suggested that neutrophil membrane-derived nanoparticle R837@PLGA@Neu with high uptake ability and low cytotoxicity showed strong tumor-targeting efficiency, and combination with RT had a promising effect in CT26-bearing mice via immune cell regulation. Our results provide a probable combination strategy for CRC treatment.

Neutrophil membrane-coated taurine nanoparticles protect against hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion (I/R) injury is a multifactorial process caused by transient tissue hypoxia and the following reoxygenation, commonly occurring in liver transplantation and hepatectomy. Hepatic I/R can induce a systemic inflammatory response, liver dysfunction, or even multiple organ failure. Although we have previously reported that taurine could attenuate acute liver injury after hepatic I/R, only a tiny proportion of the systemically injected taurine could reach the targeted organ and tissues. In this present study, we prepared taurine nanoparticles (Nano-taurine) by coating taurine with neutrophil membranes and investigated the protective effects of Nano-taurine against I/R-induced injury and the underlying mechanisms. Our results showed that Nano-taurine restored liver function by declining AST and ALT levels and reducing histology damage. Nano-taurine decreased inflammatory cytokines, including interleukin (IL)-6, tumor necrosis factor (TNF)-α, intercellular adhesion molecule (ICAM)-1, NLR pyrin domain containing 3 (NLRP3) and apoptosis-associated speck-like protein containing CARD (ASC) and oxidants including superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), catalase (CAT) and reactive oxygen species (ROS), exhibiting anti-inflammatory and antioxidant properties. The expression of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) was increased, while prostaglandin-endoperoxide synthase 2 (Ptgs2) was decreased upon administration of Nano-taurine, suggesting that inhibiting ferroptosis may be involved in the mechanism during hepatic I/R injury. These results suggest that Nano-taurine have a targeted therapeutic effect on hepatic I/R injury by inhibiting inflammation, oxidative stress, and ferroptosis.

A neutrophil mimicking metal-porphyrin-based nanodevice loaded with porcine pancreatic elastase for cancer therapy

Precise discrimination and eradication of cancer cells by immune cells independent of antigen recognition is promising for solid tumor therapeutics, yet remains a tremendous challenge. Inspired by neutrophils, here we design and construct a tumor discrimination nanodevice based on the differential histone H1 isoform expression. In this nanodevice, neutrophil membrane camouflage and glutathione (GSH)-unlocking effect on Fe-porphyrin metal−organic framework structure ensures selectivity to cancer cells. The released porcine pancreatic elastase (PPE) simulates neutrophils’ action to induce histone H1 release-dependent selective cancer cell killing. Meanwhile, nuclear localization signal (NLS) peptide-tagged porphyrin (porphyrin-NLS) acts as in-situ singlet oxygen (1O2) generator to amplify histone H1 nucleo-cytoplasmic translocation by inducing DNA double-strand breaks (DSBs) under laser irradiation, further promoting elimination of cancer cells. The overexpressed histone H1 isoform in cancer cells improves selectivity of our nanodevice to cancer cells. In vivo studies demonstrate that our design can not only inhibit primary tumor growth, but also induce adaptive T-cell response-mediated abscopal effect to against distal tumors.

Neutrophil-Membrane-Coated Biomineralized Metal-Organic Framework Nanoparticles for Atherosclerosis Treatment by Targeting Gene Silencing.

Antisense oligonucleotides (ASOs) are promising tools for gene silencing and have been exploited as therapeutics for human disease. However, delivery of therapeutic ASOs to diseased tissues or cells and subsequent escape from the endosomes and release of ASO in the cytosol remain a challenge. Here, we reported a neutrophil-membrane-coated zeolitic imidazolate framework-8 (ZIF-8) nanodelivery platform (AM@ZIF@NM) for the targeted transportation of ASOs against microRNA-155 (anti-miRNA-155) to the endothelial cells in atherosclerotic lesions. Neutrophil membrane could improve plaque endothelial cells targeting through the interaction between neutrophil membrane protein CD18 and endothelial cell membrane protein intercellular adhesion molecule-1 (ICAM-1). The ZIF-8 "core" provided high loading capacity and efficient endolysosomal escaping ability. Delivery of anti-miR-155 effectively downregulated miR-155 expression and also saved the expression of its target gene BCL6. Moreover, RELA expression and the expression of its downstream target genes CCL2 and ICAM-1 were correspondingly reduced. Consequently, this anti-miR-155 nanotherapy can inhibit the inflammation of atherosclerotic lesions and alleviate atherosclerosis. Our study shows that the designed biomimetic nanodelivery system has great application prospects in the treatment of other chronic diseases.

Neutrophil-like Biomimic AIE Nanoparticles with High-Efficiency Inflammatory Cytokine Targeting Enable Precise Photothermal Therapy and Alleviation of Inflammation.

Although photothermal therapy (PTT) has thrived as a promising treatment for drug-resistant bacterial infections by avoiding the abuse of antibiotics, the remaining challenges that limit the treatment efficiency are the poor targeting properties of infected lesions and low penetration to the cell membrane of Gram-negative bacteria. Herein, we developed a biomimetic neutrophil-like aggregation-induced emission (AIE) nanorobot (CM@AIE NPs) for precise inflammatory site homing and efficient PTT effects. Due to their surface-loaded neutrophil membranes, CM@AIE NPs can mimic the source cell and thus interact with immunomodulatory molecules that would otherwise target endogenous neutrophils. Coupled with the secondary near-infrared region absorption and excellent photothermal properties of AIE luminogens (AIEgens), precise localization, and treatment in inflammatory sites can be achieved, thereby minimizing damage to surrounding normal tissues. Moreover, CM@AIE NP-mediated PTT was stimulated in vivo by a 980 nm laser irradiation, which contributed to the extent of the therapeutic depth and limited the damage to skin tissues. The good biocompatibility and excellent in vitro and in vivo antibacterial effects prove that CM@AIE NPs can provide a strategy for broad-spectrum antibacterial applications.

Delivery of neutrophil membrane encapsulated non-steroidal anti-inflammatory drugs by degradable biopolymer microneedle patch for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a common chronic autoimmune disease and eventually ends in severe disability and death. RA has no cure, but there are some treatments for decreasing the severity of various symptoms. For example, pain management of RA by non-steroidal anti-inflammatory drugs (NSAIDs), neutralization of the inflammatory cytokines (or block their functions) of RA by specific biologics. However, the clinical benefit is limited due to their low permeability and poor bioavailability. Meanwhile, the system toxicity for long-term use of NSAIDs is another focal issue. Herein, degradable biopolymer microneedle patch was designed and synthesized. In this dual drug delivery patch, NSAIDs were encapsulated by polymeric nanoparticles, which were coated by the neutrophil membrane, followed by loaded into the microneedle patch for local transdermal delivery. When applied to the murine models, the microneedle patch gradually dissolves and releases the contained nanoparticles. Coating of neutrophil membrane provides the nanosized NSAIDs with the capability of cytokine binding and inflammatory joint tropism. Based on inflammatory microenvironment regulation by cytokine absorption and cyclooxygenase-2 inhibition, the microneedle shows a significant local anti-inflammatory therapeutic effect on mouse model of collagen-induced arthritis and rat model of adjuvant-induced arthritis. Further development based on this advanced strategy may provide additional therapeutic options for RA treatment.

Fucoidan-loaded, neutrophil membrane-coated nanoparticles facilitate MRSA-accompanied wound healing

Treatment of methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds remains an important clinical challenge. Current treatments using vancomycin usually result in high side effects with low treatment efficacy because of strong drug toxicity and weak targeting specificity. It is emergently needed to develop a novel antimicrobial agent and target drug delivery system. Herein, we developed anti-infection nanoparticles (LMM NPs) with autonomous targeting ability, loading low-molecular-weight fucoidan (LMWF) and coated by neutrophil membranes, and used for the therapy of MRSA-infected wounds. The LMWF molecules possess similar anti-MRSA effects as vancomycin but lower nephrotoxicity. Nanoparticles coated with the neutrophil membrane can escape immune recognition due to the retained cell membrane components and accumulate in the infection site. Furthermore, the MRSA-infected wound model confirms that the LMM NPs accumulate efficiently in MRSA-infected tissues and have good biocompatibility and excellent antibacterial ability in MRSA-infected wounds, which promote MRSA-accompanied wound healing. These novel infection-targeted LMWF-loaded NPs could be applied as a useful strategy for the targeted treatment of infection therapy. This will provide a meaningful reference to extend clinical treatment in MRSA infection of deep tissues.

Neutrophil-inspired photothermo-responsive drug delivery system for targeted treatment of bacterial infection and endotoxins neutralization

BackgroundP. aeruginosa, a highly virulent Gram-negative bacterium, can cause severe nosocomial infections, and it has developed resistance against most antibiotics. New therapeutic strategies are urgently needed to treat such bacterial infection and reduce its toxicity caused by endotoxin (lipopolysaccharide, LPS). Neutrophils have been proven to be able to target inflammation site and neutrophil membrane receptors such as Toll-like receptor-4 (TLR4) and CD14, and exhibit specific affinity to LPS. However, antibacterial delivery system based on the unique properties of neutrophils has not been reported.MethodsA neutrophil-inspired antibacterial delivery system for targeted photothermal treatment, stimuli-responsive antibiotic release and endotoxin neutralization is reported in this study. Specifically, the photothermal reagent indocyanine green (ICG) and antibiotic rifampicin (RIF) are co-loaded into poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NP-ICG/RIF), followed by coating with neutrophil membrane to obtain antibacterial delivery system (NM-NP-ICG/RIF). The inflammation targeting properties, synergistic antibacterial activity of photothermal therapy and antibiotic treatment, and endotoxin neutralization have been studied in vitro. A P. aeruginosa-induced murine skin abscess infection model has been used to evaluate the therapeutic efficacy of the NM-NP-ICG/RIF.ResultsOnce irradiated by near-infrared lasers, the heat generated by NP-ICG/RIF triggers the release of RIF and ICG, resulting in a synergistic chemo-photothermal antibacterial effect against P. aeruginosa (~ 99.99% killing efficiency in 5 min). After coating with neutrophil-like cell membrane vesicles (NMVs), the nanoparticles (NM-NP-ICG/RIF) specifically bind to inflammatory vascular endothelial cells in infectious site, endowing the nanoparticles with an infection microenvironment targeting function to enhance retention time. Importantly, it is discovered for the first time that NMVs-coated nanoparticles are able to neutralize endotoxins. The P. aeruginosa murine skin abscess infection model further demonstrates the in vivo therapeutic efficacy of NM-NP-ICG/RIF.ConclusionThe neutrophil-inspired antibacterial delivery system (NM-NP-ICG/RIF) is capable of targeting infection microenvironment, neutralizing endotoxin, and eradicating bacteria through a synergistic effect of photothermal therapy and antibiotic treatment. This drug delivery system made from FDA-approved compounds provides a promising approach to fighting against hard-to-treat bacterial infections.

A Nanotherapy of Octanoic Acid Ameliorates Cardiac Arrest/Cardiopulmonary Resuscitation-Induced Brain Injury via RVG29- and Neutrophil Membrane-Mediated Injury Relay Targeting.

Treatment of cardiac arrest/cardiopulmonary resuscitation (CA/CPR)-induced brain injury remains a challenging issue without viable therapeutic options. Octanoic acid (OA), a lipid oil that is mainly metabolized in the astrocytes of the brain, is a promising treatment for this type of injury owing to its potential functions against oxidative stress, apoptosis, inflammation, and ability to stabilize mitochondria. However, the application of OA is strictly limited by its short half-life and low available concentration in the target organ. Herein, based on our previous research, an OA-based nanotherapy coated with a neutrophil membrane highly expressing RVG29, RVG29-H-NPOA, was successfully constructed by computer simulation-guided supramolecular assembly of polyethylenimine and OA. The in vitro and in vivo experiments showed that RVG29-H-NPOA could target and be distributed in the injured brain focus via the relay-targeted delivery mediated by RVG29-induced blood-brain barrier (BBB) penetration and neutrophil membrane protein-induced BBB binding and injury targeting. This results in enhancements of the antioxidant, antiapoptotic, mitochondrial stability-promoting and anti-inflammatory effects of OA and exhibited systematic alleviation of astrocyte injury, neuronal damage, and inflammatory response in the brain. Due to their systematic intervention in multiple pathological processes, RVG29-H-NPOA significantly increased the 24 h survival rate of CA/CPR model rats from 40% to 100% and significantly improved their neurological functions. Thus, RVG29-H-NPOA are expected to be a promising therapeutic for the treatment of CA/CPR-induced brain injury.