Virus-mimetic nanovesicles as a versatile antigen-delivery system

Recent Advances of Engineered Cell Membrane-Based Nanotherapeutics to Combat Inflammatory Diseases

An immune reaction known as inflammation serves as a shield from external danger signals, but an overactive immune system may additionally lead to tissue damage and even a variety of inflammatory disorders. By inheriting biological functionalities and serving as both a therapeutic medication and a drug carrier, cell membrane-based nanotherapeutics offer the potential to treat inflammatory disorders. To further strengthen the anti-inflammatory benefits of natural cell membranes, researchers alter and optimize the membranes using engineering methods. This review focuses on engineered cell membrane-based nanotherapeutics (ECMNs) and their application in treating inflammation-related diseases. Specifically, this article discusses the methods of engineering cell membranes for inflammatory diseases and examines the progress of ECMNs in inflammation-targeted therapy, inflammation-neutralizing therapy, and inflammation-immunomodulatory therapy. Additionally, the article looks into the perspectives and challenges of ECMNs in inflammatory treatment and offers suggestions as well as guidance to encourage further investigations and implementations in this area.

Genetically Edited Cascade Nanozymes for Cancer Immunotherapy

Immune checkpoint blockade (ICB) has brought tremendous clinical progress, but its therapeutic outcome can be limited due to insufficient activation of dendritic cells (DCs) and insufficient infiltration of cytotoxic T lymphocytes (CTLs). Evoking immunogenic cell death (ICD) is one promising strategy to promote DC maturation and elicit T-cell immunity, whereas low levels of ICD induction of solid tumors restrict durable antitumor efficacy. Herein, we report a genetically edited cell membrane-coated cascade nanozyme (gCM@MnAu) for enhanced cancer immunotherapy by inducing ICD and activating the stimulator of the interferon genes (STING) pathway. In the tumor microenvironment (TME), the gCM@MnAu initiates a cascade reaction and generates abundant cytotoxic hydroxyl (•OH), resulting in improved chemodynamic therapy (CDT) and boosted ICD activation. In addition, released Mn2+ during the cascade reaction activates the STING pathway and further promotes the DC maturation. More importantly, activated immunogenicity in the TME significantly improves gCM-mediated PD-1/PD-L1 checkpoint blockade therapy by eliciting systemic antitumor responses. In breast cancer subcutaneous and lung metastasis models, the gCM@MnAu showed synergistically enhanced therapeutic effects and significantly prolonged the survival of mice. This work develops a genetically edited nanozyme-based therapeutic strategy to improve DC-mediated cross-priming of T cells against poorly immunogenic solid tumors.

Greatly isolated heterogeneous circulating tumor cells using hybrid engineered cell membrane-camouflaged magnetic nanoparticles

BACKGROUND

Circulating tumor cells (CTCs) are considered as a useful biomarker for early cancer diagnosis, which play a crucial role in metastatic process. Unfortunately, the tumor heterogeneity and extremely rare occurrence rate of CTCs among billions of interfering leukocytes seriously hamper the sensitivity and purity of CTCs isolation.

METHODS

To address these, we firstly used microfluidic chips to detect the broad-spectrum of triple target combination biomarkers in CTCs of 10 types of cancer patients, including EpCAM, EGFR and Her2. Then, we constructed hybrid engineered cell membrane-camouflaged magnetic nanoparticles (HE-CM-MNs) for efficient capture of heterogeneous CTCs with high-purity, which was enabled by inheriting the recognition ability of HE-CM for various CTCs and reducing homologous cell interaction with leukocytes. Compared with single E-CM-MNs, HE-CM-MNs showed a significant improvement in the capture efficiency for a cell mixture, with an efficiency of 90%. And the capture efficiency of HE-CM-MNs toward 12 subpopulations of tumor cells was ranged from 70 to 85%. Furthermore, by using HE-CM-MNs, we successfully isolated heterogeneous CTCs with high purity from clinical blood samples. Finally, the captured CTCs by HE-CM-MNs could be used for gene mutation analysis.

CONCLUSIONS

This study demonstrated the promising potential of HE-CM-MNs for heterogeneous CTCs detection and downstream analysis.

Bladder Cancer in Exosomal Perspective: Unraveling New Regulatory Mechanisms

Bladder cancer, a prevalent malignant neoplasm of the urinary tract, exhibits escalating morbidity and mortality rates. Current diagnosis standards rely on invasive and costly cystoscopy and histopathology, underscoring the urgency for non-invasive, high-throughput, and cost-effective novel diagnostic techniques to ensure timely detection and standardized treatment. Recent years have witnessed the rise of exosome research in bladder cancer studies. Exosomes contain abundant bioactive molecules that can help elucidate the intricate mechanisms underlying bladder cancer pathogenesis and metastasis. Exosomes hold potential as biomarkers for early bladder cancer diagnosis while also serving as targeted drug delivery vehicles to enhance treatment efficacy and mitigate adverse effects. Furthermore, exosome analyses offer insights into the complex molecular signaling networks implicated in bladder cancer progression, revealing novel therapeutic targets. This review provides a comprehensive overview of prevalent exosome isolation techniques and highlights the promising clinical utility of exosomes in both diagnostic and therapeutic applications in bladder cancer management.

Engineered and Mimicked Extracellular Nanovesicles for Therapeutic Delivery

Exosomes are spherical extracellular nanovesicles with an endosomal origin and unilamellar lipid-bilayer structure with sizes ranging from 30 to 100 nm. They contain a large range of proteins, lipids, and nucleic acid species, depending on the state and origin of the extracellular vesicle (EV)-secreting cell. EVs' function is to encapsulate part of the EV-producing cell content, to transport it through biological fluids to a targeted recipient, and to deliver their cargos specifically within the aimed recipient cells. Therefore, exosomes are considered to be potential biological drug-delivery systems that can stably deliver their cargo into targeted cells. Various cell-derived exosomes are produced for medical issues, but their use for therapeutic purposes still faces several problems. Some of these difficulties can be avoided by resorting to hemisynthetic approaches. We highlight here the uses of alternative exosome-mimes involving cell-membrane coatings on artificial nanocarriers or the hybridization between exosomes and liposomes. We also detail the drug-loading strategies deployed to make them drug-carrier systems and summarize the ongoing clinical trials involving exosomes or exosome-like structures. Finally, we summarize the open questions before considering exosome-like disposals for confident therapeutic delivery.

Dual-Antigen-Displaying Nanovaccines Elicit Synergistic Immunoactivation for Treating Cancer and Preventing Infectious Complications

As one of the most common complications, infection causes the majority of mortality in cancer patients. However, therapeutic strategies that can simultaneously suppress tumors and protect patients from infection have been rarely reported. Here, the use of dual-antigen-displaying nanovaccines (DADNs) is described to elicit synergistic immunoactivation for treating cancer and preventing infectious complications. DADNs are prepared by wrapping immunoadjuvant-loaded nanoparticles with a hybrid coating, which is fused from cell membranes that are separately genetically engineered to express tumor and infectious pathogenic antigens. Due to the presence of a dual-antigen combination, DADNs are able to promote the maturation of dendritic cells and more importantly to trigger cross-presentation of both combined antigens. During in vivo investigations, we find that DADNs can reverse immunosuppression by stimulating tumor-associated antigen-specific T-cell responses, resulting in significantly delayed tumor growth in mice. These nanovaccines also elicit effective protective immunity against tumor challenges and induce robust production of pathogenic antigen-specific immunoglobulin G antibody in a prophylactic study. This work offers a unique approach to develop dual-mode vaccines, which are promising for synchronously treating cancer and preventing infection.

A Bioengineered Nanovesicle Vaccine Boosts T-B cell Interaction for Immunotherapy of Echinococcus multilocularis

Alveolar echinococcosis (AE) is a zoonotic parasitic disease, resulting from being infected with the metacestode larvae of the tapeworm Echinococcus multilocularis (E. multilocularis). Novel prophylactic and therapeutic interventions are urgently needed since the current chemotherapy displays limited efficiency in AE treatment. Bioengineered nano cellular membrane vesicles are widely used for displaying the native conformational epitope peptides because of their unique structure and biocompatibility. In this study, four T-cells and four B-cells dominant epitope peptides of E. multilocularis with high immunogenicity were engineered into the Vero cell surface to construct a membrane vesicle nanovaccine for the treatment of AE. The results showed that the nanovesicle vaccine can efficiently activate dendritic cells, induce specific T/B cells to form a mutually activated circuit, and inhibit E. multilocularis infection. This study presents for the first time a nanovaccine strategy that can completely eliminate the burden of E. multilocularis.

In vivo production of CAR-T cells using virus-mimetic fusogenic nanovesicles

Engineered T cells expressing chimeric antigen receptor (CAR) exhibit high response rates in B-cell malignancy treatments and possess therapeutic potentials against various diseases. However, the complicated ex vivo production process of CAR-T cells limits their application. Herein, we use virus-mimetic fusogenic nanovesicles (FuNVs) to produce CAR-T cells in vivo via membrane fusion-mediated CAR protein delivery. Briefly, the FuNVs are modified using T-cell fusogen, adapted from measles virus or reovirus fusogens via displaying anti-CD3 single-chain variable fragment. The FuNVs can efficiently fuse with the T-cell membrane in vivo, thereby delivering the loaded anti-CD19 (αCD19) CAR protein onto T-cells to produce αCD19 CAR-T cells. These αCD19 CAR-T cells alone or in combination with anti-OX40 antibodies can treat B-cell lymphoma without inducing cytokine release syndrome. Thus, our strategy provides a novel method for engineering T cells into CAR-T cells in vivo and can further be employed to deliver other therapeutic membrane proteins.

Nanovaccines: A game changing approach in the fight against infectious diseases

The field of nanotechnology has revolutionised global attempts to prevent, treat, and eradicate infectious diseases in the foreseen future. Nanovaccines have proven to be a valuable pawn in this novel technology. Nanovaccines are made up of nanoparticles that are associated with or prepared with components that can stimulate the host's immune system. In addition to their delivery capabilities, the nanocarriers have been demonstrated to possess intrinsic adjuvant properties, working as immune cell stimulators. Thus, nanovaccines have the potential to promote rapid as well as long-lasting humoral and cellular immunity. The nanovaccines have several possible benefits, including site-specific antigen delivery, increased antigen bioavailability, and a diminished adverse effect profile. To avail these benefits, several nanoparticle-based vaccines are being developed, including virus-like particles, liposomes, polymeric nanoparticles, nanogels, lipid nanoparticles, emulsion vaccines, exomes, and inorganic nanoparticles. Inspired by their distinctive properties, researchers are working on the development of nanovaccines for a variety of applications, such as cancer immunotherapy and infectious diseases. Although a few challenges still need to be overcome, such as modulation of the nanoparticle pharmacokinetics to avoid rapid elimination from the bloodstream by the reticuloendothelial system, The future prospects of this technology are also assuring, with multiple options such as personalised vaccines, needle-free formulations, and combination nanovaccines with several promising candidates.

Genetically engineered nano-melittin vesicles for multimodal synergetic cancer therapy

Melittin, the principal constituent in bee venom, is an attractive candidate for cancer therapy. However, its clinical applications are limited by hemolysis, nonspecific cytotoxicity, and rapid metabolism. Herein, a novel genetically engineered vesicular antibody-melittin (VAM) drug delivery platform was proposed and validated for targeted cancer combination therapy. VAM generated from the cellular plasma membrane was bio-synthetically fabricated, with the recombinant protein (hGC33 scFv-melittin) being harbored and displayed on the cell membrane. The bioactive and targetable nanomelittin conjugated by hGC33 scFv could be released in an MMP14-responsive manner at tumor sites, which reduced off-target toxicity, especially the hemolytic activity of melittin. Importantly, VAM could be loaded with small-molecule drugs or nanoparticles for combination therapy. Nanomelittin formed pores in membranes and disturbed phospholipid bilayers, which allowed the anticancer agents (i.e., chemotherapeutic drug doxorubicin and sonosensitizer purpurin 18 nanoparticles) co-delivered by VAM to penetrate deeper tumor sites, leading to synergistic therapeutic effects. In particular, the punching effect generated by sonodynamic therapy further improved the immunomodulatory effect of nanomelittin to activate the immune response. Taken together, our findings indicate that clinically translatable VAM-based strategies represent a universal, promising approach to multimodal synergetic cancer therapy.

Biomimetic nanovaccine-mediated multivalent IL-15 self-transpresentation (MIST) for potent and safe cancer immunotherapy

Cytokine therapy, involving interleukin-15 (IL-15), is a promising strategy for cancer immunotherapy. However, clinical application has been limited due to severe toxicity and the relatively low immune response rate, caused by wide distribution of cytokine receptors, systemic immune activation and short half-life of IL-15. Here we show that a biomimetic nanovaccine, developed to co-deliver IL-15 and an antigen/major histocompatibility complex (MHC) selectively targets IL-15 to antigen-specific cytotoxic T lymphocytes (CTL), thereby reducing off-target toxicity. The biomimetic nanovaccine is composed of cytomembrane vesicles, derived from genetically engineered dendritic cells (DC), onto which IL-15/IL-15 receptor α (IL-15Rα), tumor-associated antigenic (TAA) peptide/MHC-I, and relevant costimulatory molecules are simultaneously anchored. We demonstrate that, in contrast to conventional IL-15 therapy, the biomimetic nanovaccine with multivalent IL-15 self-transpresentation (biNV-IL-15) prolonged blood circulation of the cytokine with an 8.2-fold longer half-life than free IL-15 and improved the therapeutic window. This dual targeting strategy allows for spatiotemporal manipulation of therapeutic T cells, elicits broad spectrum antigen-specific T cell responses, and promotes cures in multiple syngeneic tumor models with minimal systemic side effects.

Inhalation delivery of dexamethasone with iSEND nanoparticles attenuates the COVID-19 cytokine storm in mice and nonhuman primates

Dexamethasone (DEX) is the first drug to show life-saving efficacy in patients with severe coronavirus disease 2019 (COVID-19), while DEX is associated with serious adverse effects. Here, we report an inhaled, Self-immunoregulatory, Extracellular Nanovesicle-based Delivery (iSEND) system by engineering neutrophil nanovesicles with cholesterols to deliver DEX for enhanced treatment of COVID-19. Relying on surface chemokine and cytokine receptors, the iSEND showed improved targeting to macrophages and neutralized broad-spectrum cytokines. The nanoDEX, made by encapsulating DEX with the iSEND, efficiently promoted the anti-inflammation effect of DEX in an acute pneumonia mouse model and suppressed DEX-induced bone density reduction in an osteoporosis rat model. Relative to an intravenous administration of DEX at 0.1 milligram per kilogram, a 10-fold lower dose of nanoDEX administered by inhalation produced even better effects against lung inflammation and injury in severe acute respiratory syndrome coronavirus 2-challenged nonhuman primates. Our work presents a safe and robust inhalation delivery platform for COVID-19 and other respiratory diseases.

Organic-Inorganic Hybrid Nanocomposites for Nanotheranostics: Special Focus on Preventing Emerging Variants of SARS-COV-2

The worldwide emerging cases of various respiratory viral diseases and the current escalation of novel coronavirus disease (COVID-19) make people considerably attentive to controlling these viruses through innovative methods. Most re-emerging respiratory diseases envelop RNA viruses that employ attachment between the virus and host cell to get an entry form using the host cell machinery. Emerging variants of COVD-19 also bring about a constant threat to public health as it has wide infectivity and can quickly spread to infect humans. This review focuses on insights into the current investigations to prevent the progression of incipient variants of Severe Acute Respiratory Syndrome Coronavirus (SARS-COV-2) along with similar enveloped RNA viruses that cause respiratory illness in humans and animals. Nanotheranostics is a trailblazing arena of nanomedicine that simultaneously helps prevent or treat diseases and diagnoses. Nanoparticle coating and nanofibers were extensively explored, preventing viral contaminations. Several studies have proven the virucidal activities of metal nanoparticles like copper, silver, and titanium against respiratory viral pathogens. Worldwide many researchers have shown surfaces coated with ionic nanoparticles like zinc or titanium act as potent antiviral agents against RNA viruses. Carbon nanotubes, quantum dots, silica nanoparticles (NPs), polymeric and metallic nanoparticles have also been explored in the field of nanotheranostics in viral detection. In this review, we have comprehensively discussed different types of metallic, ionic, organic nanoparticles and their hybrids showing substantial antiviral properties to stop the progression of the novel coronavirus disease focused on three key classes: prevention, diagnostics, and treatment.

Vesicular Antibodies: Shedding Light on Antibody Therapeutics with Cell Membrane Nanotechnology

The high stability of antibodies and their ability to precisely bind to antigens and endogenous immune receptors, as well as their susceptibility to protein engineering, enable antibody-based therapeutics to be widely applied in cancer, inflammation, infection, and other disorders. Nevertheless, the application of traditional antibody-based therapeutics has certain limitations, such as high price, limited permeability, and protein engineering complexity. Recent breakthroughs in cell membrane nanotechnology have deepened the understanding of the critical role of membrane protein receptors in disease treatment, enabling vesicular-antibody-based therapeutics. Here, the concept of vesicular antibodies that are obtained by modifying target antibodies onto cell membranes for biomedical applications is proposed. Given that an antibody is basically a protein, as an extension of this concept, vesicles or membrane-coated nanoparticles that use surface antibodies and protein receptors on cell membranes for biomedical applications as vesicular antibodies are defined. Furthermore, several engineering strategies for vesicular antibodies are summarized and how vesicular antibodies can be used in a variety of situations is highlighted. In addition, current challenges and future prospects of vesicular antibodies are also discussed. It is anticipated this perspective will provide new insights on the development of next-generation antibodies for enhanced therapeutics.

Dendritic cell-mimicking scaffolds for ex vivo T cell expansion

We propose an ex vivo T cell expansion system that mimics natural antigen-presenting cells (APCs) for adoptive cell therapy (ACT). Microfiber scaffolds coated with dendritic cell (DC) membrane replicate physicochemical properties of dendritic cells specific for T cell activation such as rapid recognition by T cells, long duration of T cell tethering, and DC-specific co-stimulatory cues. The DC membrane-coated scaffold is first surface-immobilized with T cell stimulatory ligands, anti-CD3 (αCD3) and anti-CD28 (αCD28) antibodies, followed by adsorption of releasable interleukin-2 (IL-2). The scaffolds present both surface and soluble cues to T cells ex vivo in the same way that these cues are presented by natural APCs in vivo. We demonstrate that the DC-mimicking scaffold promotes greater polyclonal expansion of primary human T cells as compared to αCD3/αCD28-functionalized Dynabead. More importantly, major histocompatibility complex molecules derived from the DC membrane of the scaffold allow antigen-specific T cell expansion with target cell-specific killing ability. In addition, most of the expanded T cells (∼97%) can be harvested from the scaffold by density gradient centrifugation. Overall, the DC-mimicking scaffold offers a scalable, modular, and customizable platform for rapid expansion of highly functional T cells for ACT.

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The scaffold mimics physicochemical properties of natural antigen-presenting cells.

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The scaffold presents T cell stimulatory cues as antigen-presenting cell does.

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This platform supports both polyclonal and antigen-specific T cell expansion.

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This platform offers a large-scale manufacturing system for adoptive cell therapy.

Aspects of Nanotechnology for COVID-19 Vaccine Development and Its Delivery Applications

Coronavirus, a causative agent of the common cold to a much more complicated disease such as "severe acute respiratory syndrome (SARS-CoV-2), Middle East Respiratory Syndrome (MERS-CoV-2), and Coronavirus Disease 2019 (COVID-19)", is a member of the coronaviridae family and contains a positive-sense single-stranded RNA of 26-32 kilobase pairs. COVID-19 has shown very high mortality and morbidity and imparted a significantly impacted socioeconomic status. There are many variants of SARS-CoV-2 that have originated from the mutation of the genetic material of the original coronavirus. This has raised the demand for efficient treatment/therapy to manage newly emerged SARS-CoV-2 infections successfully. However, different types of vaccines have been developed and administered to patients but need more attention because COVID-19 is not under complete control. In this article, currently developed nanotechnology-based vaccines are explored, such as inactivated virus vaccines, mRNA-based vaccines, DNA-based vaccines, S-protein-based vaccines, virus-vectored vaccines, etc. One of the important aspects of vaccines is their administration inside the host body wherein nanotechnology can play a very crucial role. Currently, more than 26 nanotechnology-based COVID-19 vaccine candidates are in various phases of clinical trials. Nanotechnology is one of the growing fields in drug discovery and drug delivery that can also be used for the tackling of coronavirus. Nanotechnology can be used in various ways to design and develop tools and strategies for detection, diagnosis, and therapeutic and vaccine development to protect against COVID-19. The design of instruments for speedy, precise, and sensitive diagnosis, the fabrication of potent sanitizers, the delivery of extracellular antigenic components or mRNA-based vaccines into human tissues, and the administration of antiretroviral medicines into the organism are nanotechnology-based strategies for COVID-19 management. Herein, we discuss the application of nanotechnology in COVID-19 vaccine development and the challenges and opportunities in this approach.

Nanoimmunoengineering strategies in cancer diagnosis and therapy

Cancer immunotherapy strategies in combination with engineered nanosystems have yielded beneficial results in the treatment of cancer and their application is increasing day by day. The pivotal role of stimuli-responsive nanosystems and nanomedicine-based cancer immunotherapy, as a subsidiary discipline in the field of immunology, cannot be ignored. Today, rapid advances in nanomedicine are used as a platform for exploring new therapeutic applications and modern smart healthcare management strategies. The progress of nanomedicine in cancer treatment has confirmed the findings of immunotherapy in the medical research phase. This study concentrates on approaches connected to the efficacy of nanoimmunoengineering strategies for cancer immunotherapies and their applications. By assessing improved approaches, different aspects of the nanoimmunoengineering strategies for cancer therapies are discussed in this study.

A decoy microrobot that removes SARS-CoV-2 and its variants in wastewater

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can persist in wastewater for several days, has a risk of waterborne-human transmission. The emergence of SARS-CoV-2 variants with increased infection capacity further highlights the need to remove the virus and restrict its spread in wastewater. Here, we report a decoy microrobot created by camouflaging algae with cell membranes displaying angiotensin-converting enzyme 2 (ACE2) for effective elimination of SARS-CoV-2 and its variants. The decoy microrobots show fast self-propulsion (>85 μm/s), allowing for successful "on-the-fly" elimination of SARS-CoV-2 spike proteins and pseudovirus in wastewater. Moreover, relying on the robust binding between ACE2 and SARS-CoV-2 variants, the decoy microrobots exhibit a broad-spectrum elimination of virus with a high efficiency of 95% for the wild-type strain, 92% for the Delta variant, and 93% for the Omicron variant, respectively. Our work presents a simple and safe decoy microrobot aimed toward eliminating viruses and other environmental hazards from wastewater.

Cell membrane-coated nanoparticles for the treatment of bacterial infection

Despite the enormous success of antibiotics in antimicrobial therapy, the rapid emergence of antibiotic resistance and the complexity of the bacterial infection microenvironment make traditional antibiotic therapy face critical challenges against resistant bacteria, antitoxin, and intracellular infections. Consequently, there is a critical need to design antimicrobial agents that target infection microenvironment and alleviate antibiotic resistance. Cell membrane-coated nanoparticles (CMCNPs) are biomimetic materials that can be obtained by wrapping the cell membrane vesicles directly onto the surface of the nanoparticles (NPs) through physical means. Incorporating the biological functions of cell membrane vesicles and the superior physicochemical properties of NPs, CMCNPs have shown great promise in recent years for targeting infections, neutralizing bacterial toxins, and designing bacterial infection vaccines. This review highlights topics where CMCNPs present great value in advancing the treatment of bacterial infections, including drug delivery, detoxification, and vaccination. Lastly, we discuss the future hurdles and prospects of translating this technique into clinical practice, providing a comprehensive review of the technological developments of CMCNPs in the treatment of bacterial infections. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Envelope virus-mimetic nanovaccines by hybridizing bioengineered cell membranes with bacterial vesicles

Emerging threats of rapid spread highly lethal infectious diseases highlight the urgent need of vaccine development. Here, we describe the preparation of envelope virus-mimetic nanovaccines by hybridizing bioengineered cell membranes with bacterial vesicles. Membranes acquired from bioengineered cells overexpressing viral antigens are fused with bacterial outer membrane vesicles to develop hybrid nanovesicles. Because of the presence of intact viral antigenic proteins with natural conformation bound to lipid bilayer and pathogen-associated molecular patterns, hybrid nanovesicles can strikingly promote antigen uptake, processing and presentation by dendritic cells. Immunization with envelope virus-mimetic nanovaccines shows significantly enhanced maturation and activation of dendritic cells, which elicit robust humoral and cellular immune responses in mice. By virtue of their artificial characteristic and absence of loaded adjuvants, these biomimetic nanovaccines exhibit favorable biosafety. Our work demonstrates the effectiveness of envelope virus-mimetic nanovaccines to boost antigen-specific immunity and proposes a simple yet versatile platform to prepare antiviral vaccines.

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Nanovaccines were hybridized by bioengineered cell membranes and bacterial vesicles

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Nanovaccines possessed intact viral antigens with natural conformation

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Nanovaccines promoted antigen uptake, processing, and presentation by dendritic cells

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Nanovaccines elicited robust humoral and cellular immune responses in mice

A nanovaccine for antigen self-presentation and immunosuppression reversal as a personalized cancer immunotherapy strategy

The strategy of combining a vaccine with immune checkpoint inhibitors has been widely investigated in cancer management, but the complete response rate for this strategy is still unresolved. We describe a genetically engineered cell membrane nanovesicle that integrates antigen self-presentation and immunosuppression reversal (ASPIRE) for cancer immunotherapy. The ASPIRE nanovaccine is derived from recombinant adenovirus-infected dendritic cells in which specific peptide-major histocompatibility complex class I (pMHC-I), anti-PD1 antibody and B7 co-stimulatory molecules are simultaneously anchored by a programmed process. ASPIRE can markedly improve antigen delivery to lymphoid organs and generate broad-spectrum T-cell responses that eliminate established tumours. This work presents a powerful vaccine formula that can directly activate both native T cells and exhausted T cells, and suggests a general strategy for personalized cancer immunotherapy.

Bioinspired membrane-based nanomodulators for immunotherapy of autoimmune and infectious diseases

Autoimmune or infectious diseases often instigate the undesirable damages to tissues or organs to trigger immune-related diseases, which involve plenty of immune cells, pathogens and autoantibodies. Nanomedicine has a great potential in modulating immune system. Particularly, biomimetic nanomodulators can be designed for prevention, diagnosis and therapy to achieve a better targeted immunotherapy. With the development of materials science and bioengineering, a wide range of membrane-coated nanomodulators are available. Herein, we summarize recent advancements of bioinspired membrane-coated nanoplatform for systemic protection against immune-related diseases including autoimmune and infectious diseases. We also rethink the challenges or limitations in the progress of the therapeutic nanoplatform, and discuss the further application of the nanomodulators in the view of translational medicine for combating immune-related diseases.

Bio-engineered nano-vesicles for IR820 delivery: a therapy platform for cancer by surgery and photothermal therapy

Long-term unsolved health problems from pre-/intra-/postoperative complications and thermal ablation complications pose threats to liver-cancer patients. To reduce the threats, we propose a multimodal-imaging guided surgical navigation system and photothermal therapy strategy to improve specific labeling, real-time monitoring and effective treatment of hepatocellular carcinoma. Using a bioengineering approach, G-Nvs@IR820, a kind of human-cell-membrane nano-vesicle, was generated with growth arrest-specific 6 (Gas6) expressed on the membrane and with near-infrared absorbing dye (IR820) loaded into it, which is proven to be an effective nanoparticle-drug-delivery system for Axl-overexpressing hepatocellular carcinoma. G-Nvs@IR820 shows excellent features in vitro and in vivo. As Gas6 binds to Axl specifically, G-Nvs@IR820 has good targeting ability to the tumor site and also has a good ability to guide the further accurate obliteration of carcinoma from adjacent normal tissue in surgery with its highly resolved fluorescence/photoacoustic/surgical-navigation signals. Moreover, the G-Nvs@IR820 represented a new perspective for photothermal therapy. Briefly, Nvs@IR820 was synthesized at a gram scale with high affinity, specificity, and safety. It has promising potential in clinical application for IGS and PTT in Axl-overexpressing hepatoma carcinoma.

Bioinspired Membrane-Coated Nanoplatform for Targeted Tumor Immunotherapy

Immunotherapy can effectively activate the immune system and reshape the tumor immune microenvironment, which has been an alternative method in cancer therapy besides surgery, radiotherapy, and chemotherapy. However, the current clinical outcomes are not satisfied due to the lack of targeting of the treatment with some unexpected damages to the human body. Recently, cell membrane-based bioinspired nanoparticles for tumor immunotherapy have attracted much attention because of their superior immune regulating, drug delivery, excellent tumor targeting, and biocompatibility. Together, the article reviews the recent progress of cell membrane-based bioinspired nanoparticles for immunotherapy in cancer treatment. We also evaluate the prospect of bioinspired nanoparticles in immunotherapy for cancer. This strategy may open up new research directions for cancer therapy.

Exosomes in cancer immunoediting and immunotherapy

As an important means of communication among cells, exosomes are being studied more and more widely, especially in the context of cancer immunotherapy. In the phase of tumor immunoediting, exosomes derived from tumor cells and different immune cells have complex and changeable physiological functions, because they carry different proteins and nucleic acid from the source cells. Based on the role of exosomes in the communication between different cells, cancer treatment methods are also under continuous research. This review briefly introduces the molecular composition of exosomes, which is closely related to their secretion mechanism. Subsequently, the role of exosomes encapsulating different information molecules is summarized. The role of exosomes in the three phases of tumor immunoediting is introduced in detail, and the relevant literature of exosomes in the tumor immune microenvironment is summarized by using a novel framework for extracting relevant documents. Finally, it summarizes the various exosome-based immunotherapies currently proposed, as well as the challenges and future prospects of exosomes in tumor immunotherapy.

Genetically Programmable Fusion Cellular Vesicles for Cancer Immunotherapy

Herein, we report that genetically programmable fusion cellular vesicles (Fus-CVs) displaying high-affinity SIRPα variants and PD-1 can activate potent antitumor immunity through both innate and adaptive immune effectors. Dual-blockade of CD47 and PD-L1 with Fus-CVs significantly increases the phagocytosis of cancer cells by macrophages, promotes antigen presentation, and activates antitumor T-cell immunity. Moreover, the bispecific targeting design of Fus-CVs ensures better targeting on tumor cells, but less on other cells, which reduces systemic side effects and enhances therapeutic efficacies. In malignant melanoma and mammary carcinoma models, we demonstrate that Fus-CVs significantly improve overall survival of model animals by inhibiting post-surgery tumor recurrence and metastasis. The Fus-CVs are suitable for protein display by genetic engineering. These advantages, integrated with other unique properties inherited from source cells, make Fus-CVs an attractive platform for multi-targeting immune checkpoint blockade therapy.

Engineered Cell Membrane-Derived Nanoparticles in Immune Modulation

Immune modulation is one of the most effective approaches in the therapy of complex diseases, including public health emergency. However, most immune therapeutics such as drugs, vaccines, and cellular therapy suffer from the limitations of poor efficacy and adverse side effects. Fortunately, cell membrane-derived nanoparticles (CMDNs) have superior compatibility with other therapeutics and offer new opportunities to push the limits of current treatments in immune modulation. As the interface between cells and outer surroundings, cell membrane contains components which instruct intercellular communication and the plasticity of cytomembrane has significantly potentiated CMDNs to leverage our immune system. Therefore, cell membranes employed in immunomodulatory CMDNs have gradually shifted from natural to engineered. In this review, unique properties of immunomodulatory CMDNs and engineering strategies of emerging CMDNs for immune modulation, with an emphasis on the design logic are summarized. Further, this review points out some pressing problems to be solved during clinical translation and put forward some suggestions on the prospect of immunoregulatory CMDNs. It is anticipated that this review can provide new insights on the design of immunoregulatory CMDNs and expand their potentiation in the precise control of the dysregulated immune system.

Virus-inspired nanosystems for drug delivery

With over millions of years of evolution, viruses can infect cells efficiently by utilizing their unique structures. Similarly, the drug delivery process is designed to imitate the viral infection stages for maximizing the therapeutic effect. From drug administration to therapeutic effect, nanocarriers must evade the host's immune system, break through multiple barriers, enter the cell, and release their payload by endosomal escape or nuclear targeting. Inspired by the virus infection process, a number of virus-like nanosystems have been designed and constructed for drug delivery. This review aims to present a comprehensive summary of the current understanding of the drug delivery process inspired by the viral infection stages. The most recent construction of virus-inspired nanosystems (VINs) for drug delivery is sorted, emphasizing their novelty and design principles, as well as highlighting the mechanism of these nanosystems for overcoming each biological barrier during drug delivery. A perspective on the VINs for therapeutic applications is provided in the end.

Toward the next-generation phyto-nanomedicines: cell-derived nanovesicles (CDNs) for natural product delivery

Phytochemicals are plant-derived bioactive compounds, which have been widely used for therapeutic purposes. Due to the poor water-solubility, low bioavailability and non-specific targeting characteristic, diverse classes of nanocarriers are utilized for encapsulation and delivery of bio-effective agents. Cell-derived nanovesicles (CDNs), known for exosomes or extracellular vesicles (EVs), are biological nanoparticles with multiple functions. Compared to the artificial counterpart, CDNs hold great potential in drug delivery given the higher stability, superior biocompatibility and the lager capability of encapsulating bioactive molecules. Here, we provide a bench-to-bedside review of CDNs-based nanoplatform, including the bio-origin, preparation, characterization and functionalization. Beyond that, the focus is laid on the therapeutic effect of CDNs-mediated drug delivery for natural products. The state-of-art development as well as some pre-clinical applications of using CDNs for disease treatment is also summarized. It is highly expected that the continuing development of CDNs-based delivery systems will further promote the clinical utilization and translation of phyto-nanomedicines.

Genetically Engineered Cellular Membrane Vesicles as Tailorable Shells for Therapeutics

Benefiting from the blooming interaction of nanotechnology and biotechnology, biosynthetic cellular membrane vesicles (Bio-MVs) have shown superior characteristics for therapeutic transportation because of their hydrophilic cavity and hydrophobic bilayer structure, as well as their inherent biocompatibility and negligible immunogenicity. These excellent cell-like features with specific functional protein expression on the surface can invoke their remarkable ability for Bio-MVs based recombinant protein therapy to facilitate the advanced synergy in poly-therapy. To date, various tactics have been developed for Bio-MVs surface modification with functional proteins through hydrophobic insertion or multivalent electrostatic interactions. While the Bio-MVs grow through genetically engineering strategies can maintain binding specificity, sort orders, and lead to strict information about artificial proteins in a facile and sustainable way. In this progress report, the most current technology of Bio-MVs is discussed, with an emphasis on their multi-functionalities as "tailorable shells" for delivering bio-functional moieties and therapeutic entities. The most notable success and challenges via genetically engineered tactics to achieve the new generation of Bio-MVs are highlighted. Besides, future perspectives of Bio-MVs in novel bio-nanotherapy are provided.

Recent Advances in Engineered Materials for Immunotherapy-Involved Combination Cancer Therapy

Immunotherapy that can activate immunity or enhance the immunogenicity of tumors has emerged as one of the most effective methods for cancer therapy. Nevertheless, single-mode immunotherapy is still confronted with several critical challenges, such as the low immune response, the low tumor infiltration, and the complex immunosuppression tumor microenvironment. Recently, the combination of immunotherapy with other therapeutic modalities has emerged as a powerful strategy to augment the therapeutic outcome in fighting against cancer. In this review, recent research advances of the combination of immunotherapy with chemotherapy, phototherapy, radiotherapy, sonodynamic therapy, metabolic therapy, and microwave thermotherapy are summarized. Critical challenges and future research direction of immunotherapy-based cancer therapeutic strategy are also discussed.

Immunobiology and nanotherapeutics of severe acute respiratory syndrome 2 (SARS-CoV-2): a current update

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) constitutes the most significant global public health challenge in a century. It has reignited research interest in coronavirus. While little information is available, research is currently in progress to comprehensively understand the general biology and immune response mechanism against SARS-CoV-2. The spike proteins (S protein) of SARS-CoV-2 perform a crucial function in viral infection establishment. ACE2 and TMPRSS2 play a pivotal role in viral entry. Upon viral entry, the released pro-inflammatory proteins (cytokines and chemokines) cause the migration of the T cells, monocytes, and macrophages to the infection site. IFNϒ released by T cells initiates a loop of pro-inflammatory feedback. The inflammatory state may further enhance with an increase in immune dysfunction responsible for the infection's progression. A treatment approach that prevents ACE2-mediated viral entry and reduces inflammatory response is a crucial therapeutic intervention strategy, and nanomaterials and their conjugates are promising candidates. Nanoparticles can inhibit viral entry and replication. Nanomaterials have also found application in targeted drug delivery and also in developing a vaccine against SARS-CoV-2. Here, we briefly summarize the origin, transmission, and clinical features of SARS-CoV-2. We then discussed the immune response mechanisms of SARS-CoV-2. Finally, we further discussed nanotechnology's potentials as an intervention strategy against SARS-CoV-2 infection. All these understandings will be crucial in developing therapeutic strategies against SARS-CoV-2.

Nanotechnology Integration for SARS-CoV-2 Diagnosis and Treatment: An Approach to Preventing Pandemic

The SARS-CoV-2 outbreak is the COVID-19 disease, which has caused massive health devastation, prompting the World Health Organization to declare a worldwide health emergency. The corona virus infected millions of people worldwide, and many died as a result of a lack of particular medications. The current emergency necessitates extensive therapy in order to stop the spread of the coronavirus. There are various vaccinations available, but no validated COVID-19 treatments. Since its outbreak, many therapeutics have been tested, including the use of repurposed medications, nucleoside inhibitors, protease inhibitors, broad spectrum antivirals, convalescence plasma therapies, immune-modulators, and monoclonal antibodies. However, these approaches have not yielded any outcomes and are mostly used to alleviate symptoms associated with potentially fatal adverse drug reactions. Nanoparticles, on the other hand, may prove to be an effective treatment for COVID-19. They can be designed to boost the efficacy of currently available antiviral medications or to trigger a rapid immune response against COVID-19. In the last decade, there has been significant progress in nanotechnology. This review focuses on the virus's basic structure, pathogenesis, and current treatment options for COVID-19. This study addresses nanotechnology and its applications in diagnosis, prevention, treatment, and targeted vaccine delivery, laying the groundwork for a successful pandemic fight.

Biomimetic Nanoemulsion for Synergistic Photodynamic-Immunotherapy Against Hypoxic Breast Tumor

Photodynamic therapy (PDT) is commonly used as an "in situ vaccine" to enhance the response rate of PD-1/PD-L1 antibodies. Unfortunately, the high cost and adverse effects of these antibodies, and the hypoxic state of solid tumors limits the efficacy of synergistic photodynamic-immunotherapy. Here, we developed a biomimetic nanoemulsion camouflaged with a PD-1-expressing cell membrane for synergistic photodynamic-immunotherapy against hypoxic breast tumors. The perfluorocarbon of the nanoemulsion could provide oxygen as the source of PDT against hypoxic tumors. Moreover, co-delivering a photosensitizer and the PD-1 protein (substituting for a PD-L1 antibody) achieves the synergy effect of PDT and immunotherapy. Synergistic photodynamic-immunotherapy completely inhibited primary and distant subcutaneous 4T1 tumors, mechanistically by boosting the maturation of dendritic cells and tumor infiltration of cytotoxic T lymphocytes.

Emerging Approaches to Functionalizing Cell Membrane-Coated Nanoparticles

There has been significant interest in developing cell membrane-coated nanoparticles due to their unique abilities of biomimicry and biointerfacing. As the technology progresses, it becomes clear that the application of these nanoparticles can be drastically broadened if additional functions beyond those derived from the natural cell membranes can be integrated. Herein, we summarize the most recent advances in the functionalization of cell membrane-coated nanoparticles. In particular, we focus on emerging methods, including (1) lipid insertion, (2) membrane hybridization, (3) metabolic engineering, and (4) genetic modification. These approaches contribute diverse functions in a nondisruptive fashion while preserving the natural function of the cell membranes. They also improve on the multifunctional and multitasking ability of cell membrane-coated nanoparticles, making them more adaptive to the complexity of biological systems. We hope that these approaches will serve as inspiration for more strategies and innovations to advance cell membrane coating technology.

Recent Progress on Biomaterials Fighting against Viruses

Viruses not only pose severe threats to public health, but also influence the development of society. Over the past decade, rapid advances have been seen in the application of nanomaterials to virus research. As an interdisciplinary field, nanotechnology offers powerful functions because the structures of nanomaterials are unique, with remarkable physicochemical properties and excellent biocompatibility. Nanomaterials have been developed for virus detection and tracking and for antiviral strategies, to better understand viruses and reduce viral infections, implying a bright future for this field. Herein, the recent advances are systematically summarized regarding the nanomaterials used in viral studies. Representative applications of nanomaterials to viral detection and tracking are described. The antiviral effects achieved with nanomaterials based on different mechanisms are also described, including entry inhibition, inhibition of viral replication, and immunological enhancement. The current challenges and future opportunities in this promising field are also discussed.

Nanotechnology advances in pathogen- and host-targeted antiviral delivery: multipronged therapeutic intervention for pandemic control

The COVID-19 pandemic's high mortality rate and severe socioeconomic impact serve as a reminder of the urgent need for effective countermeasures against viral pandemic threats. In particular, effective antiviral therapeutics capable of stopping infections in its tracks is critical to reducing infection fatality rate and healthcare burden. With the field of drug delivery witnessing tremendous advancement in the last two decades owing to a panoply of nanotechnology advances, the present review summarizes and expounds on the research and development of therapeutic nanoformulations against various infectious viral pathogens, including HIV, influenza, and coronaviruses. Specifically, nanotechnology advances towards improving pathogen- and host-targeted antiviral drug delivery are reviewed, and the prospect of achieving effective viral eradication, broad-spectrum antiviral effect, and resisting viral mutations are discussed. As several COVID-19 antiviral clinical trials are met with lackluster treatment efficacy, nanocarrier strategies aimed at improving drug pharmacokinetics, biodistributions, and synergism are expected to not only contribute to the current disease treatment efforts but also expand the antiviral arsenal against other emerging viral diseases.

Engineering Nanoparticles toward the Modulation of Emerging Cancer Immunotherapy

Cancer immunotherapy is a new therapeutic strategy to fight cancer by activating the patients' own immune system. At present, immunotherapy approaches such as cancer vaccines, immune checkpoint blockade (ICB), adoptive cell transfer (ACT), monoclonal antibodies (mAbs) therapy, and cytokines therapy have therapeutic potential in preclinical and clinical applications. However, the intrinsic limitations of conventional immunotherapy are difficulty of precise dosage control, insufficient enrichment in tumor tissues, partial immune response silencing or hyperactivity, and high cost. Engineering nanoparticles (NPs) have been emerging as a promising multifunctional platform to enhance conventional immunotherapy due to their intrinsic immunogenicity, convenient delivery function, controlled surface chemistry activity, multifunctional modifying potential, and intelligent targeting. This review presents the recent progress reflected by engineering NPs, including the diversified selection of functionalized NPs, the superiority of engineering NPs for enhancing conventional immunotherapy, and NP-mediated multiscale strategies for synergistic therapy consisting of compositions and their mechanism. Finally, the perspective on multifunctional NP-based cancer immunotherapy for boosting immunomodulation is discussed, which reveals the expanding landscape of engineering NPs in clinical translation.

Cell-derived vesicles for delivery of cancer immunotherapy

In recent years, cancer immunotherapy has received unprecedented attention due to the clinical achievements. The applications of biomedical engineering and materials science to cancer immunotherapy have solved the challenges caused by immunotherapy to a certain extent. Among them, cell-derived vesicles are natural biomaterials chosen as carriers or immune-engineering in view of their many unique advantages. This review will briefly introduce the recent applications of cell-derived vesicles for cancer immunotherapy.

Cell-derived vesicles for delivery of cancer immunotherapy

In recent years, cancer immunotherapy has received unprecedented attention due to the clinical achievements. The applications of biomedical engineering and materials science to cancer immunotherapy have solved the challenges caused by immunotherapy to a certain extent. Among them, cell-derived vesicles are natural biomaterials chosen as carriers or immune-engineering in view of their many unique advantages. This review will briefly introduce the recent applications of cell-derived vesicles for cancer immunotherapy.

Application of Nanotechnology in the COVID-19 Pandemic

COVID-19, caused by SARS-CoV-2 infection, has been prevalent worldwide for almost a year. In early 2000, there was an outbreak of SARS-CoV, and in early 2010, a similar dissemination of infection by MERS-CoV occurred. However, no clear explanation for the spread of SARS-CoV-2 and a massive increase in the number of infections has yet been proposed. The best solution to overcome this pandemic is the development of suitable and effective vaccines and therapeutics. Fortunately, for SARS-CoV-2, the genome sequence and protein structure have been published in a short period, making research and development for prevention and treatment relatively easy. In addition, intranasal drug delivery has proven to be an effective method of administration for treating viral lung diseases. In recent years, nanotechnology-based drug delivery systems have been applied to intranasal drug delivery to overcome various limitations that occur during mucosal administration, and advances have been made to the stage where effective drug delivery is possible. This review describes the accumulated knowledge of the previous SARS-CoV and MERS-CoV infections and aims to help understand the newly emerged SARS-CoV-2 infection. Furthermore, it elucidates the achievements in developing COVID-19 vaccines and therapeutics to date through existing approaches. Finally, the applicable nanotechnology approach is described in detail, and vaccines and therapeutic drugs developed based on nanomedicine, which are currently undergoing clinical trials, have presented the potential to become innovative alternatives for overcoming COVID-19.

Recent advances in materials science: a reinforced approach toward challenges against COVID-19

With the recent COVID-19 pandemic, medical professionals and scientists have encountered an unprecedented trouble to make the latest technological solutions to work. Despite of abundant tools available as well as initiated for diagnosis and treatment, researchers in the healthcare systems were in backfoot to provide concrete answers to the demanding challenge of SARS-CoV-2. It has incited global collaborative efforts in every field from economic, social, and political to dedicated science to confront the growing demand toward solution to this outbreak. Field of materials science has been in the frontline to the current scenario to provide major diagnostic tools, antiviral materials, safety materials, and various therapeutic means such as, antiviral drug design, drug delivery, and vaccination. In the present article, we emphasized the role of materials science to the development of PPE kits such as protecting suits, gloves, and masks as well as disinfection of the surfaces/surroundings. In addition, contribution of materials science towards manufacturing diagnostic devices such as microfluidics, immunosensors as well as biomaterials with a point of care analysis has also been discussed. Further, the efficacy of nanoparticles and scaffolds for antiviral drug delivery and micro-physiological systems as well as materials derived from human tissues for extracorporeal membrane oxygenation (ECMO) devices have been elaborated towards therapeutic applications.

Biomimetic bacterial and viral-based nanovesicles for drug delivery, theranostics, and vaccine applications

Smart nanocarriers obtained from bacteria and viruses offer excellent biomimetic properties which has led to significant research into the creation of advanced biomimetic materials. Their versatile biomimicry has application as biosensors, biomedical scaffolds, immobilization, diagnostics, and targeted or personalized treatments. The inherent natural traits of biomimetic and bioinspired bacteria- and virus-derived nanovesicles show potential for their use in clinical vaccines and novel therapeutic drug delivery systems. The past few decades have seen significant progress in the bioengineering of bacteria and viruses to manipulate and enhance their therapeutic benefits. From a pharmaceutical perspective, biomimetics enable the safe integration of naturally occurring bacteria and virus particles to achieve high, stable rates of cellular transfection/infection and prolonged circulation times. In addition, biomimetic technologies can overcome safety concerns associated with live-attenuated and inactivated whole bacteria or viruses. In this review, we provide an update on the utilization of bacterial and viral particles as drug delivery systems, theranostic carriers, and vaccine/immunomodulation modalities.

Nano-Biomimetic Drug Delivery Vehicles: Potential Approaches for COVID-19 Treatment

The current COVID-19 pandemic has tested the resolve of the global community with more than 35 million infections worldwide and numbers increasing with no cure or vaccine available to date. Nanomedicines have an advantage of providing enhanced permeability and retention and have been extensively studied as targeted drug delivery strategies for the treatment of different disease. The role of monocytes, erythrocytes, thrombocytes, and macrophages in diseases, including infectious and inflammatory diseases, cancer, and atherosclerosis, are better understood and have resulted in improved strategies for targeting and in some instances mimicking these cell types to improve therapeutic outcomes. Consequently, these primary cell types can be exploited for the purposes of serving as a "Trojan horse" for targeted delivery to identified organs and sites of inflammation. State of the art and potential utilization of nanocarriers such as nanospheres/nanocapsules, nanocrystals, liposomes, solid lipid nanoparticles/nano-structured lipid carriers, dendrimers, and nanosponges for biomimicry and/or targeted delivery of bioactives to cells are reported herein and their potential use in the treatment of COVID-19 infections discussed. Physicochemical properties, viz., hydrophilicity, particle shape, surface charge, composition, concentration, the use of different target-specific ligands on the surface of carriers, and the impact on carrier efficacy and specificity are also discussed.

Decoy nanoparticles protect against COVID-19 by concurrently adsorbing viruses and inflammatory cytokines

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has highlighted the urgent need to rapidly develop therapeutic strategies for such emerging viruses without effective vaccines or drugs. Here, we report a decoy nanoparticle against COVID-19 through a powerful two-step neutralization approach: virus neutralization in the first step followed by cytokine neutralization in the second step. The nanodecoy, made by fusing cellular membrane nanovesicles derived from human monocytes and genetically engineered cells stably expressing angiotensin converting enzyme II (ACE2) receptors, possesses an antigenic exterior the same as source cells. By competing with host cells for virus binding, these nanodecoys effectively protect host cells from the infection of pseudoviruses and authentic SARS-CoV-2. Moreover, relying on abundant cytokine receptors on the surface, the nanodecoys efficiently bind and neutralize inflammatory cytokines including interleukin 6 (IL-6) and granulocyte-macrophage colony-stimulating factor (GM-CSF), and significantly suppress immune disorder and lung injury in an acute pneumonia mouse model. Our work presents a simple, safe, and robust antiviral nanotechnology for ongoing COVID-19 and future potential epidemics.