Engineering red-blood-cell-membrane-coated nanoparticles for broad biomedical applications

Cell-membrane engineering strategies for clinic-guided design of nanomedicine

Cells are the fundamental units of life. The cell membrane primarily composed of two layers of phospholipids (a bilayer) structurally defines the boundary of a cell, which can protect its interior from external disturbances and also selectively exchange substances and conduct signals from the extracellular environment. The complexity and particularity of transmembrane proteins provide the foundation for versatile cellular functions. Nanomedicine as an emerging therapeutic strategy holds tremendous potential in the healthcare field. However, it is susceptible to recognition and clearance by the immune system. To overcome this bottleneck, the technology of cell membrane coating has been extensively used in nanomedicines for their enhanced therapeutic efficacy, attributed to the favorable fluidity and biocompatibility of cell membranes with various membrane-anchored proteins. Meanwhile, some engineering strategies of cell membranes through various chemical, physical and biological ways have been progressively developed to enable their versatile therapeutic functions against complex diseases. In this review, we summarized the potential clinical applications of four typical cell membranes, elucidated their underlying therapeutic mechanisms, and outlined their current engineering approaches. In addition, we further discussed the limitation of this technology of cell membrane coating in clinical applications, and possible solutions to address these challenges.

Multifunctional cell membranes-based nano-carriers for targeted therapies: a review of recent trends and future perspective

Nanotechnology has ignited a transformative revolution in disease detection, prevention, management, and treatment. Central to this paradigm shift is the innovative realm of cell membrane-based nanocarriers, a burgeoning class of biomimetic nanoparticles (NPs) that redefine the boundaries of biomedical applications. These remarkable nanocarriers, designed through a top-down approach, harness the intrinsic properties of cell-derived materials as their fundamental building blocks. Through shrouding themselves in natural cell membranes, these nanocarriers extend their circulation longevity and empower themselves to intricately navigate and modulate the multifaceted microenvironments associated with various diseases. This comprehensive review provides a panoramic view of recent breakthroughs in biomimetic nanomaterials, emphasizing their diverse applications in cancer treatment, cardiovascular therapy, viral infections, COVID-19 management, and autoimmune diseases. In this exposition, we deliver a concise yet illuminating overview of the distinctive properties underpinning biomimetic nanomaterials, elucidating their pivotal role in biomedical innovation. We subsequently delve into the exceptional advantages these nanomaterials offer, shedding light on the unique attributes that position them at the forefront of cutting-edge research. Moreover, we briefly explore the intricate synthesis processes employed in creating these biomimetic nanocarriers, shedding light on the methodologies that drive their development.

Exploring the Microfluidic Production of Biomimetic Hybrid Nanoparticles and Their Pharmaceutical Applications

Nanomedicines have made remarkable advances in recent years, addressing the limitations of traditional therapy and treatment methods. Due to their improved drug solubility, stability, precise delivery, and ability to target specific sites, nanoparticle-based drug delivery systems have emerged as highly promising solutions. The successful interaction of nanoparticles with biological systems, on the other hand, is dependent on their intentional surface engineering. As a result, biomimetic nanoparticles have been developed as novel drug carriers. In-depth knowledge of various biomimetic nanoparticles, their applications, and the methods used for their formulation, with emphasis on the microfluidic production technique, is provided in this review. Microfluidics has emerged as one of the most promising approaches for precise control, high reproducibility, scalability, waste reduction, and faster production times in the preparation of biomimetic nanoparticles. Significant advancements in personalized medicine can be achieved by harnessing the benefits of biomimetic nanoparticles and leveraging microfluidic technology, offering enhanced functionality and biocompatibility.

Development and evaluation of cell membrane-based biomimetic nanoparticles loaded by Clostridium perfringens epsilon toxin: a novel vaccine delivery platform for Clostridial-associated diseases

As Clostridium perfringens (C. perfringens) epsilon toxin (ETX) ranks as the third most potent clostridial toxin after botulinum and tetanus toxins, vaccination is necessary for creatures that can be affected by it to be safe from the effects of this toxin. Nowadays, nanostructures are good choices for carriers for biological environments. We aimed to synthesize biomimetic biodegradable nanodevices to enhance the efficiency of the ETX vaccine. For this purpose, poly(lactic-co-glycolic acid) (PLGA) copolymer loaded with purified epsilon protoxin (proETX) to create nanoparticles called nanotoxins (NTs) and then coated by RBC membrane-derived vesicles (RVs) to form epsilon nanotoxoids (RV-NTs). The resulting RV-NTs shaped smooth spherical surfaces with double-layer core/shell structure with an average particle size of 105.9 ± 35.1 nm and encapsulation efficiency of 97.5% ± 0.13%. Compared with NTs, the RV-NTs were more stable for 15 consecutive days. In addition, although both structures showed a long-term cumulative release, the release rates from RV-NTs were slower than NTs during 144 hours. According to the results of cell viability, ETX loading in PLGA and entrapment in the RBC membrane decreased the toxicity of the toxin. The presence of PLGA enhances the uptake of proETX, and the synthesized structures showed no significant lesion after injection. These results demonstrate that NTs and RV-NTs could serve as an effective vaccine platform to deliver ETX for future in vivo assays.

Boosting Ferroptosis Therapy with Iridium Single-Atom Nanocatalyst in Ultralow Metal Content

Nanocatalysts are promising tumor therapeutics due to their ability to induce reactive oxygen species in the tumor microenvironment. Although increasing metal loading can improve catalytic activity, the quandary of high metal content versus potential systemic biotoxicity remains challenging. Here, a fully exposed active site strategy by site-specific anchoring of single iridium (Ir) atoms on the outer surface of a nitrogen-doped carbon composite (Ir single-atom catalyst (SAC)) is reported to achieve remarkable catalytic performance at ultralow metal content (≈0.11%). The Ir SAC exhibits prominent dual enzymatic activities to mimic peroxidase and glutathione peroxidase, which catalyzes the conversion of endogenous H2 O2 into •OH in the acidic TME and depletes glutathione (GSH) simultaneously. With an advanced support of GSH-trapping platinum(IV) and encapsulation with a red-blood-cell membrane, this nanocatalytic agent (Pt@IrSAC/RBC) causes intense lipid peroxidation that boosts tumor cell ferroptosis. The Pt@IrSAC/RBC demonstrates superior therapeutic efficacy in a mouse triple-negative mammary carcinoma model, resulting in complete tumor ablation in a single treatment session with negligible side effects. These outcomes may provide valuable insights into the design of nanocatalysts with high performance and biosafety for biomedical applications.

Cell membrane-coated nanoparticles: a novel multifunctional biomimetic drug delivery system

Recently, nanoparticle-based drug delivery systems have been widely used for the treatment, prevention, and detection of diseases. Improving the targeted delivery ability of nanoparticles has emerged as a critical issue that must be addressed as soon as possible. The bionic cell membrane coating technology has become a novel concept for the design of nanoparticles. The diverse biological roles of cell membrane surface proteins endow nanoparticles with several functions, such as immune escape, long circulation time, and targeted delivery; therefore, these proteins are being extensively studied in the fields of drug delivery, detoxification, and cancer treatment. Furthermore, hybrid cell membrane-coated nanoparticles enhance the beneficial effects of monotypic cell membranes, resulting in multifunctional and efficient delivery carriers. This review focuses on the synthesis, development, and application of the cell membrane coating technology and discusses the function and mechanism of monotypic/hybrid cell membrane-modified nanoparticles in detail. Moreover, it summarizes the applications of cell membranes from different sources and discusses the challenges that may be faced during the clinical application of bionic carriers, including their production, mechanism, and quality control. We hope this review will attract more scholars toward bionic cell membrane carriers and provide certain ideas and directions for solving the existing problems.

Macrophage membrane biomimetic drug delivery system: for inflammation targeted therapy

In recent years, there have been many exciting developments in the biomedical applications of the macrophage membrane bionic drug delivery system (MM-Bio-DDS). Macrophages, as an important immune cell, are involved in initiating and regulating the specific immune response of the body. Therefore, the inflammatory process related to macrophages is an important goal in the diagnosis and treatment of many diseases. In this review, we first summarise the different methods of preparation, characterisation, release profiles and natural advantages of using macrophages as a drug delivery system (DDS). Second, we introduce the processes of various chronic inflammatory diseases and the role of macrophages in them, specifically clarifying how the MM-Bio-DDS provides a wide and effective treatment for the targeted inflammatory site. Finally, based on the existing research, we propose the application prospect and existing challenges of the MM-Bio-DDS, especially the problems in clinical transformation, to provide new ideas for the development and utilisation of the MM-Bio-DDS in targeted drug delivery for inflammation and the treatment of diseases.

Red Blood Cell Inspired Strategies for Drug Delivery: Emerging Concepts and New Advances

In the past five decades, red blood cells (RBCs) have been extensively explored as drug delivery systems due to their distinguishing potential in modulating the pharmacokinetic, pharmacodynamics, and biological activity of carried payloads. The extensive interests in RBC-mediated drug delivery technologies are in part derived from RBCs' unique biological features such as long circulation time, wide access to many tissues in the body, and low immunogenicity. Owing to these outstanding properties, a large body of efforts have led to the development of various RBC-inspired strategies to enable precise drug delivery with enhanced therapeutic efficacy and reduced off-target toxicity. In this review, we discuss emerging concepts and new advances in such RBC-inspired strategies, including native RBCs, ghost RBCs, RBC-mimetic nanoparticles, and RBC-derived extracellular vesicles, for drug delivery.

Transformation of Amphiphilic Antiviral Drugs into New Dimensional Nanovesicles Structures

Improved techniques were applied to formulate drugs into dimensional nanostructures, doped "nanovesicles". These nanovesicles are solely composed of self-assembled amphiphilic antiviral agents used for the treatment of viral infections caused by flaviviruses, such as Zika virus. Studies were done to evaluate the effectiveness of the syntheses, formation, and performance under different experimental conditions, and behavior of the drug nanovesicles in vitro and in vivo. These studies demonstrated that assembling the hydrophobic antiviral drug molecules into nanodrugs is a successful technique for the delivery of the therapeutic agents, otherwise difficult to be supplied. Our studies confirmed that this nanodrug preserved and, in many cases, enhanced the embedded cellular activity of the parental free drug molecules, both in vitro and in vivo. This proposed formulation is highly important as it addresses the issue of insolubility and low bioavailabiity of a wide range of highly potent pharmaceutical drugs-not limited to a specific class of antiviral drugs-that are of high demand for the treatment of medical conditions and emerging pathogens.

Enhancing cancer chemo-immunotherapy by biomimetic nanogel with tumor targeting capacity and rapid drug-releasing in tumor microenvironment

In the development of chemo-immunotherapy, many efforts have been focusing on designing suitable carriers to realize the co-delivery of chemotherapeutic and immunotherapeutic with different physicochemical properties and mechanisms of action. Besides, rapid drug release at the tumor site with minimal drug degradation is also essential to facilitate the antitumor effect in a short time. Here, we reported a cancer cell membrane-coated pH-responsive nanogel (NG@M) to co-deliver chemotherapeutic paclitaxel (PTX) and immunotherapeutic agent interleukin-2 (IL-2) under mild conditions for combinational treatment of triple-negative breast cancer. In the designed nanogels, the synthetic copolymer PDEA-co-HP-β-cyclodextrin-co-Pluronic F127 and charge reversible polymer dimethylmaleic anhydride-modified polyethyleneimine endowed nanogels with excellent drug-loading capacity and rapid responsive drug-releasing behavior under acidic tumor microenvironment. Benefited from tumor homologous targeting capacity, NG@M exhibited 4.59-fold higher accumulation at the homologous tumor site than heterologous cancer cell membrane-coated NG. Rapidly released PTX and IL-2 enhanced the maturation of dendritic cells and quickly activated the antitumor immune response in situ, followed by prompted infiltration of immune effector cells. By the combined chemo-immunotherapy, enhanced antitumor effect and efficient pulmonary metastasis inhibition were achieved with a prolonged median survival rate (39 days).

Surface functionalized biomimetic bioreactors enable the targeted starvation-chemotherapy to glioma

Altering the glucose supply and the metabolic pathways would be an intriguing strategy in starvation therapy toward cancers. Nevertheless, starvation therapy alone could be inadequate to eliminate tumor cells completely. Herein, a multifunctional bioreactor was fabricated for synergistic starvation-chemotherapy through embedding glucose oxidase (GOx) and doxorubicin (DOX) in the tumor targeting ligands (RGD) modified red blood cell membrane camouflaged metal-organic framework (MOF) nanoparticle (denoted as RGD-mGZD). Owing to the remarkable biointerfacing property, the designed RGD-mGZD could not only possess enhanced blood retention time inherited from red blood cells, but also preferentially target the tumor site after the modification with RGD peptide. Once the bioreactor reached the desired region, GOx promptly consumed the intratumoral glucose and oxygen to starve cancer cells for robust starvation therapy. More importantly, the aggravated acidic microenvironment at the tumor region was found to induce the decomposition of the MOF structure, thus triggering the release of DOX for reinforced chemotherapy. This bioreactor would further prompt the development of synergistic patterns toward cancer treatment in a spatiotemporally controlled manner.

"Cluster Bomb" Based on Redox-Responsive Carbon Dot Nanoclusters Coated with Cell Membranes for Enhanced Tumor Theranostics

Designing intelligent stimuli-responsive nanoplatforms that are integrated with a biological membrane system and nanomaterials to realize efficient imaging and therapy of tumors still remains to be challenging. Herein, we report a unique strategy to prepare redox-responsive yellow fluorescent carbon dot nanoclusters (y-CDCs) loaded with anticancer drug doxorubicin (DOX) and coated with the cancer cell membrane (CCM) for precision fluorescence imaging and homologous targeting chemotherapy of tumors. The y-CDs with a size of 7.2 nm were first synthesized via a hydrothermal method and crosslinked to obtain redox-responsive y-CDCs with a size of 150.0 nm. The formulated y-CDCs were physically loaded with DOX with an efficiency of up to 81.0% and coated with CCM to endow them with antifouling properties, immune escape ability to escape from macrophage uptake, and homologous targeting capability to cancer cells. Within the reductive tumor microenvironment, the y-CDCs with quenched fluorescence can dissociate to form single y-CDs with recovered fluorescence and improved tumor penetration ability and simultaneously release DOX from the "cluster bomb", thus realizing efficient targeted tumor fluorescence imaging and chemotherapy. The designed y-CDCs/DOX@CCM may represent an updated nanomedicine formulation based on CDs for improved theranostics of different types of tumors.

Surface modification of nano-drug delivery systems for enhancing antibiotic delivery and activity

Rampant antimicrobial resistance calls for innovative strategies to effectively control bacterial infections, enhance antibacterial efficacy, minimize side effects, and protect existing antibiotics in the market. Therefore, to enhance the delivery of antibiotics and increase their bioavailability and accumulation at the site of infection, the surfaces of nano-drug delivery systems have been diversely modified. This strategy applies various covalent and non-covalent techniques to introduce specific coating materials that have been found to be effective against various sensitive and resistant microorganisms. In this review, we discuss the techniques of surface modification of nanocarriers loaded with antibacterial agents. Furthermore, saccharides, polymers, peptides, antibiotics, enzymes and cell membranes coatings that have been used for surface functionalization of nano-drug delivery systems are described, emphasizing current approaches for enhancing delivery, bioavailability, and efficacy of surface-modified antibacterial nanocarriers at infection sites. This article offers a critical overview of the potential of surface-modified antibacterial nanocarriers to overcome the limitations of conventional antibiotics in the treatment of bacterial infections. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Surface loading of nanoparticles on engineered or natural erythrocytes for prolonged circulation time: strategies and applications

Nano drug-delivery systems (DDS) may significantly improve efficiency and reduce toxicity of loaded drugs, but a few nano-DDS are highly successful in clinical use. Unprotected nanoparticles in blood flow are often quickly cleared, which could limit their circulation time and drug delivery efficiency. Elongating their blood circulation time may improve their delivery efficiency or grant them new therapeutic possibilities. Erythrocytes are abundant endogenous cells in blood and are continuously renewed, with a long life span of 100-120 days. Hence, loading nanoparticles on the surface of erythrocytes to protect the nanoparticles could be highly effective for enhancing their in vivo circulation time. One of the key questions here is how to properly attach nanoparticles on erythrocytes for different purposes and different types of nanoparticles to achieve ideal results. In this review, we describe various methods to attach nanoparticles and drugs to the erythrocyte surface, and discuss the key factors that influence the stability and circulation properties of the erythrocytes-based delivery system in vivo. These data show that using erythrocytes as a host for nanoparticles possesses great potential for further development.

Erythrocyte-Camouflaged Mesoporous Titanium Dioxide Nanoplatform for an Ultrasound-Mediated Sequential Therapies of Breast Cancer

BACKGROUND

The hypoxic microenvironment promotes tumor resistance to most treatments, especially highly oxygen-dependent sonodynamic therapy (SDT).

METHOD AND RESULTS

In view of the aggravation of hypoxia by oxygen consumption during SDT, a biomimetic drug delivery system was tailored to integrate SDT with hypoxia-specific chemotherapy. In this system, mesoporous titanium dioxide nanoparticles (mTNPs) were developed to deliver the hypoxia-activated prodrug AQ4N with high loading efficiency. Subsequently, a red blood cell (RBC) membrane was coated onto the surface of mTNP@AQ4N. RBC-mTNPs@AQ4N inherited the immune escape ability from RBC membranes, thus efficiently reducing the immunological clearance and improving the work concentration. Upon activation by ultrasound (US), mTNPs as sonosensitizers generate reactive oxide species (ROS), which not only induce apoptosis and necrosis but also disrupt RBC membranes to achieve the US-mediated on-demand release of AQ4N. The released AQ4N was activated by hypoxia to convert into toxic products, which effectively supplemented the inefficiency of SDT in hypoxic tissues. Importantly, SDT-aggravated hypoxia further potentiated this hypoxia-specific chemotherapy of AQ4N.

CONCLUSION

Based on the sequential strategy, RBC-mTNPs@AQ4N exhibited an excellent synergistic therapeutic effect, thus potentially advancing the development of SDT in cancer treatments.

Artemisinin co-delivery system based on manganese oxide for precise diagnosis and treatment of breast cancer

Tumor microenvironment (TME) responsive intelligent system can realize the specific release and uniform distribution of chemotherapy drugs in tumor tissues, to achieve high-efficiency and low-toxic treatment of tumors. In this paper, drug delivery system TKD@RBCm-Mn₂O₃-ART with the above characteristics was constructed. We synthesized hollow mesoporous manganese trioxide (Mn₂O₃) nanoparticles and firstly found that they owned time-dependent size transformation feature in simulated TME. The particle size decreased from 318 nm to 50 nm and 6 nm at 1 h and 4 h in simulated TME, respectively. Then artemisinin (ART) was loaded into Mn₂O₃to realize the co-delivery of Mn²⁺and ART. The modification of homologous red cell membrane (RBCm) and TKD peptide was aimed at long circulation and tumor targeting in the body.In vitroresults demonstrated that in the presence of GSH, the cumulative drug release percentage could achieve 97.5%. Meanwhile, Mn₂O₃exhibited a good imaging capability in tumor, with the relaxation rate of 6.3113 mM^-1s^-1. After entering into MCF-7 cells, TKD@RBCm-Mn₂O₃/ART synchronously released Mn²⁺and ART to generate large amount of ROS and induce DNA damage.In vivoresults proved TKD@RBCm-Mn₂O₃/ART could arrive the deep area of solid tumors and achieve accurate diagnosis and treatment of breast cancer.

Biomimetic nanoreactor for targeted cancer starvation therapy and cascade amplificated chemotherapy

Consuming glucose by glucose oxidase (GOx) has attracted great interest in cancer starvation therapy, but the therapeutic effect is severely limited by the tumor hypoxia environment. Herein, to overcome such limitation, cancer cell membranes disguised biomimetic nanoreactors were elaborately established for synergetic cancer starvation therapy and cascade amplificated hypoxia activated chemotherapy. Via a metallothionein-like self-assembly and infiltration approach, GOx and hypoxia activated prodrug banoxantrone (AQ4N) were efficiently loaded into metal-organic framework ZIF-8 nanocarriers to yield nanoreactor AQ4N/GOx@ZIF-8. Subsequently, the biomimetic nanoreactor (AQ4N/GOx@ZIF-8@CM) was obtained by camouflaging the nanoreactor with cancer cell membrane, which endowed the biomimetic nanoreactor homotypic targeting, immune escape and prolonged blood circulation features. Once targeted accumulating into tumor sites, the acid environment triggered the decomposition of ZIF-8, then encapsulated GOx and AQ4N were released. GOx would rapidly exhaust endogenous glucose and O₂ to shut off the energy supply of tumor cells for starvation treatment. Furthermore, the aggravated tumor intracellular hypoxia environment would activate the cytotoxicity of AQ4N for chemotherapy. In vitro and in vivo results demonstrated that the designed biomimetic nanoreactor exhibited negligible systemic toxicity, besides, the combination of starvation therapy and cascade amplified hypoxia activated chemotherapy significantly inhibited the tumor growth and improved the therapeutic efficacy.

De Novo Nano-Erythrocyte Structurally Braced by Biomimetic Au(I)-peptide Skeleton for MDM2/MDMX Predation toward Augmented Pulmonary Adenocarcinoma Immunotherapy

In nature, cells rely on a structural framework called the "cytoskeleton" to maintain their shape and polarity. Based on this, herein a new class of cell-mimicking nanomedicine using bionic skeletons constituted by the oligomeric Au(I)-peptide complex is developed. The peptide function of degrading pathological MDM2 and MDMX is used to synthesize an oligomeric Au(I)-PMIV precursor capable of self-assembling into a clustered spherical bionic skeleton. Through coating by erythrocyte membrane, an erythrocyte-mimicking nano-cell (Nery-PMIV) is developed with depressed macrophage uptakes, increased colloidal stability, and prolonged blood circulation. Nery-PMIV potently restores p53 and p73 in vitro and in vivo by degrading MDM2/MDMX. More importantly, Nery-PMIV effectively augments antitumor immunity elicited by anti-PD1 therapy in a murine orthotopic allograft model for LUAD and a humanized patient-derived xenograft (PDX) mouse model for LUAD, while maintaining a favorable safety profile. Taken together, this work not only presents evidence showing that MDM2/MDMX degradation is a potentially viable therapeutic paradigm to synergize anti-PD1 immunotherapy toward LUAD carrying wild-type p53; it also suggests that cell-mimicking nanoparticles with applicable bionic skeletons hold tremendous promise in offering new therapies to revolutionize nanomedicine in the treatment of a myriad of human diseases.

Advances on erythrocyte-mimicking nanovehicles to overcome barriers in biological microenvironments

Although nanocarriers offer many advantages as drug delivery systems, their poor stability in circulation, premature drug release and nonspecific uptake in non-target organs have prompted biomimetic approaches using natural cell membranes to camouflage nanovehicles. Among them, erythrocytes, representing the most abundant blood circulating cells, have been extensively investigated for biomimetic coating on artificial nanocarriers due to their upgraded biocompatibility, biodegradability, non-immunogenicity and long-term blood circulation. Due to the cell surface mimetic properties combined with customized core material, erythrocyte-mimicking nanovehicles (EM-NVs) have a wide variety of applications, including drug delivery, imaging, phototherapy, immunomodulation, sensing and detection, that foresee a huge potential for therapeutic and diagnostic applications in several diseases. In this review, we summarize the recent advances in the biomedical applications of EM-NVs in cancer, infection, heart-, autoimmune- and CNS-related disorders and discuss the major challenges and opportunities in this research area.

Cell primitive-based biomimetic functional materials for enhanced cancer therapy

Cell primitive-based functional materials that combine the advantages of natural substances and nanotechnology have emerged as attractive therapeutic agents for cancer therapy. Cell primitives are characterized by distinctive biological functions, such as long-term circulation, tumor specific targeting, immune modulation etc. Moreover, synthetic nanomaterials featuring unique physical/chemical properties have been widely used as effective drug delivery vehicles or anticancer agents to treat cancer. The combination of these two kinds of materials will catalyze the generation of innovative biomaterials with multiple functions, high biocompatibility and negligible immunogenicity for precise cancer therapy. In this review, we summarize the most recent advances in the development of cell primitive-based functional materials for cancer therapy. Different cell primitives, including bacteria, phages, cells, cell membranes, and other bioactive substances are introduced with their unique bioactive functions, and strategies in combining with synthetic materials, especially nanoparticulate systems, for the construction of function-enhanced biomaterials are also summarized. Furthermore, foreseeable challenges and future perspectives are also included for the future research direction in this field.

Recent advances in functionalized nanomaterials for the diagnosis and treatment of bacterial infections

The growing problem of resistant infections due to antibiotic misuse is a worldwide concern that poses a grave threat to healthcare systems. Thus, it is necessary to discover new strategies to combat infectious diseases. In this review, we provide a selective overview of recent advances in the use of nanocomposites as alternatives to antibiotics in antimicrobial treatments. Metals and metal oxide nanoparticles (NPs) have been associated with inorganic and organic supports to improve their antibacterial activity and stability as well as other properties. For successful antibiotic treatment, it is critical to achieve a high drug concentration at the infection site. In recent years, the development of stimuli-responsive systems has allowed the vectorization of antibiotics to the site of infection. These nanomaterials can be triggered by various mechanisms (such as changes in pH, light, magnetic fields, and the presence of bacterial enzymes); additionally, they can improve antibacterial efficacy and reduce side effects and microbial resistance. To this end, various types of modified polymers, lipids, and inorganic components (such as metals, silica, and graphene) have been developed. Applications of these nanocomposites in diverse fields ranging from food packaging, environment, and biomedical antimicrobial treatments to diagnosis and theranosis are discussed.

Novel Chinese Angelica Polysaccharide Biomimetic Nanomedicine to Curcumin Delivery for Hepatocellular Carcinoma Treatment and Immunomodulatory Effect

BACKGROUND

Using natural polysaccharides from Traditional Chinese Medicine as nanodrug delivery systems have considerable potential for tumor diagnostics and therapeutics.

PURPOSE

On the basis of targeted therapy and combining the advantages of natural polysaccharides (angelica polysaccharide, APS) and natural Chinese medicine (curcumin, Cur) to design functionalized nanoparticles to improve the therapeutic through cell membrane encapsulation and immunotherapy.

STUDY DESIGN AND METHODS

Cur-loaded, glycyrrhetic acid (GA)-APS-disulfide bond (DTA)-Cur nanomicelle (GACS-Cur), which were prepared by the dialysis method. GACS-Cur was encapsulated with the membranes from red blood cells (RBCm) termed GACS-Cur@RBCm, which were prepared by the principle of extrusion using a miniature extruder. The developed formulations were subjected to various in vitro and in vivo evaluation tests.

RESULTS

The resulting APS nanocarriers supported a favorable drug-loading capacity, biocompatibility, and enhanced synergistic anti-hepatoma effects both in vitro and in vivo. After administration in mice, in vivo imaging results showed that the GACS-Cur and RBCm-coated groups had an obvious stronger tumor tissue targeting ability than the control treatment groups. Additionally, the immunomodulatory effect increased IL-12, TNF-α and IFN-γ expression and CD8+ T cell infiltration (1.9-fold) than that of the saline group. Notably, in comparison with hyaluronic acid (HA) nanocarriers, APS nanocarriers possess higher anti-hepatoma efficiency and targeting capabilities and, thus, should be further studied for a wide range of anti-cancer applications.

CONCLUSION

Our data demonstrated that APS nanocarriers encapsulated with erythrocyte membrane mighty be a promising clinical method in the development of efficacy, safety and targeting of liver cancer therapy.

Recent advances in mesenchymal stem cell membrane-coated nanoparticles for enhanced drug delivery

Studies of nanomedicine have achieved dramatic progress in recent decades. However, the main challenges that traditional nanomedicine has to overcome include low accumulation at target sites and rapid clearance from the blood circulation. An interesting approach using cell membrane coating technology has emerged as a possible way to overcome these limitations, owing to the enhanced targeted delivery and reduced immunogenicity of cell membrane moieties. Mesenchymal stem cell (MSC) therapy has been investigated for treating various diseases, ranging from inflammatory diseases to tissue damage. Recent studies with engineered modified MSCs or MSC membranes have focused on enhancing cell therapeutic efficacy. Therefore, bioengineering strategies that couple synthetic nanoparticles with MSC membranes have recently received much attention due to their homing ability and tumor tropism. Given the various membrane receptors on their surfaces, MSC membrane-coated nanoparticles are an effective method with selective targeting properties, allowing entry into specific cells. Here, we review recent progress on the use of MSC membrane-coated nanoparticles for biomedical applications, particularly in the two main antitumor and anti-inflammatory fields. The combination of a bioengineered cell membrane and synthesized nanoparticles presents a wide range of possibilities for the further development of targeted drug delivery, showing the potential to enhance the therapeutic efficacy for treating various diseases.

Engineered algae: A novel oxygen-generating system for effective treatment of hypoxic cancer

Microalgae, a naturally present unicellular microorganism, can undergo light photosynthesis and have been used in biofuels, nutrition, etc. Here, we report that engineered live microalgae can be delivered to hypoxic tumor regions to increase local oxygen levels and resensitize resistant cancer cells to both radio- and phototherapies. We demonstrate that the hypoxic environment in tumors is markedly improved by in situ-generated oxygen through microalgae-mediated photosynthesis, resulting in notably radiotherapeutic efficacy. Furthermore, the chlorophyll from microalgae produces reactive oxygen species during laser irradiation, further augmenting the photosensitizing effect and enhancing tumor cell apoptosis. Thus, the sequential combination of oxygen-generating algae system with radio- and phototherapies has the potential to create an innovative treatment strategy to improve the outcome of cancer management. Together, our findings demonstrate a novel approach that leverages the products of photosynthesis for treatment of tumors and provide proof-of-concept evidence for future development of algae-enhanced radio- and photodynamic therapy.

512-Channel Geometric Droplet-Splitting Microfluidic Device by Injection of Premixed Emulsion for Microsphere Production

We present a 512-channel geometric droplet-splitting microfluidic device that involves the injection of a premixed emulsion for microsphere production. The presented microfluidic device was fabricated using conventional photolithography and polydimethylsiloxane casting. The fabricated microfluidic device consisted of 512 channels with 256 T-junctions in the last branch. Five hundred and twelve microdroplets with a narrow size distribution were produced from a single liquid droplet. The diameter and size distribution of prepared micro water droplets were 35.29 µm and 8.8% at 10 mL/h, respectively. Moreover, we attempted to prepare biocompatible microspheres for demonstrating the presented approach. The diameter and size distribution of the prepared poly (lactic-co-glycolic acid) microspheres were 6.56 µm and 8.66% at 10 mL/h, respectively. To improve the monodispersity of the microspheres, we designed an additional post array part in the 512-channel geometric droplet-splitting microfluidic device. The monodispersity of the microdroplets prepared with the microfluidic device combined with the post array part exhibited a significant improvement.

Intrinsic Biotaxi Solution Based on Blood Cell Membrane Cloaking Enables Fullerenol Thrombolysis In Vivo

We report the construction of blood cell membrane cloaked mesoporous silica nanoparticles for delivery of nanoparticles [fullerenols (Fols)] with fibrinolysis activity which endows the active Fol with successful thrombolysis effect in vivo. In vitro, Fols present excellent fibrinolysis activity, and the Fol with the best fibrinolysis activity is screened based on the correlation between Fols' structure and their fibrinolysis activity. However, the thrombolytic effect in vivo is not satisfactory. To rectify the unsatisfactory situation and avoid the exogenous stimuli, a natural blood cell membrane cloaking strategy with loading the active Fol is chosen to explore as a novel thrombolysis drug. After cloaking, the therapeutic platform prolongs blood circulation time and enhances the targeting effect. Interestingly, compared with platelet membrane cloaking, red blood cell (RBC) membrane cloaking demonstrates stronger affinity with fibrin and more enrichment at the thrombus site. The Fol with RBC cloaking shows quick and efficient thrombolysis efficacy in vivo with less bleeding risk, more excellent blood compatibility, and better biosafety when compared with the clinical drug urokinase (UK). These findings not only validate the blood cell membrane cloaking strategy as an effective platform for Fol delivery on thrombolysis treatment, but also hold a great promising solution for other active nanoparticle deliveries in vivo.

A Hybrid Eukaryotic-Prokaryotic Nanoplatform with Photothermal Modality for Enhanced Antitumor Vaccination

Cytomembrane-derived nanoplatforms are an effective biomimetic strategy in cancer therapy. To improve their functionality and expandability for enhanced vaccination, a eukaryotic-prokaryotic vesicle (EPV) nanoplatform is designed and constructed by fusing melanoma cytomembrane vesicles (CMVs) and attenuated Salmonella outer membrane vesicles (OMVs). Inheriting the virtues of the parent components, the EPV integrates melanoma antigens with natural adjuvants for robust immunotherapy and can be readily functionalized with complementary therapeutics. In vivo prophylactic testing reveals that the EPV nanoformulation can be utilized as a prevention vaccine to stimulate the immune system and trigger the antitumor immune response, combating tumorigenesis. In the melanoma model, the poly(lactic-co-glycolic acid)-indocyanine green (ICG) moiety (PI)-implanted EPV (PI@EPV) in conjunction with localized photothermal therapy with durable immune inhibition shows synergetic antitumor effects as a therapeutic vaccine. The eukaryotic-prokaryotic fusion strategy provides new perspectives for the design of tumor-immunogenic, self-adjuvanting, and expandable vaccine platforms.

Development of a nanodrug-delivery system camouflaged by erythrocyte membranes for the chemo/phototherapy of cancer

Aim: Development of a new drug-delivery system using a compound derived from Pronephrium penangianum (J5) for the treatment of cervical cancer. Materials & methods: The delivery system was developed using Prussian blue nanoparticles, camouflaged by red blood cell membrane and with folic acid surface modifications. Results: Our results showed the successful development of a nanodrug-delivery system, which increases the half-life and immune evasion ability of the drug. The mechanism of this system was through suppressing B-cell lymphoma 2 and increasing B-cell lymphoma 2-associated X protein and the cleaved caspase level. An in vivo study also confirmed good antitumor activity without any side effects to normal tissue. Conclusion: This drug-delivery system provides a good alternative for the treatment of cervical cancer using J5.

Eradication of Helicobacter pylori: the power of nanosized formulations

Helicobacter pylori is a pathogen that is considered to cause several gastric disorders such as chronic gastritis, peptic ulcer and even gastric carcinoma. The current therapeutic regimens mainly constitute of a combination of several antimicrobial agents and proton pump inhibitors. However, the prevalence of antibiotic resistance has been significantly lowering the cure rates over the years. Nanocarriers possess unique strengths in this regard owing to the fact that they can protect the drugs (such as antibiotics) from the harsh environment in the stomach, penetrate the mucosal barrier and deliver drugs to the desired site. In this review we summarized recent studies of different antibacterial agents orally delivered by nanosized carriers for the eradication of H. pylori.

Bacteria-Responsive Biomimetic Selenium Nanosystem for Multidrug-Resistant Bacterial Infection Detection and Inhibition

Multidrug-resistant (MDR) bacterial infections are a severe threat to public health owing to their high risk of fatality. Noticeably, the premature degradation and undeveloped imaging ability of antibiotics still remain challenging. Herein, a selenium nanosystem in response to a bacteria-infected microenvironment is proposed as an antibiotic substitute to detect and inhibit methicillin-resistant Staphylococcus aureus (MRSA) with a combined strategy. Using natural red blood cell membrane (RBCM) and bacteria-responsive gelatin nanoparticles (GNPs), the Ru-Se@GNP-RBCM nanosystem was constructed for effective delivery of Ru-complex-modified selenium nanoparticles (Ru-Se NPs). Taking advantage of natural RBCM, the immune system clearance was reduced and exotoxins were neutralized efficiently. GNPs could be degraded by gelatinase in pathogen-infected areas in situ; therefore, Ru-Se NPs were released to destroy the bacteria cells. Ru-Se NPs with intense fluorescence imaging capability could accurately monitor the infection treatment process. Moreover, excellent in vivo bacteria elimination and a facilitated wound healing process were confirmed by two kinds of MRSA-infected mice models. Overall, the above advantages proved that the prepared nanosystem is a promising antibiotic alternative to combat the ever-threatening multidrug-resistant bacteria.

Neutrophil-mimicking therapeutic nanoparticles for targeted chemotherapy of pancreatic carcinoma

Due to the critical correlation between inflammation and carcinogenesis, a therapeutic candidate with anti-inflammatory activity may find application in cancer therapy. Here, we report the therapeutic efficacy of celastrol as a promising candidate compound for treatment of pancreatic carcinoma via naïve neutrophil membrane-coated poly(ethylene glycol) methyl ether-block-poly(lactic-co-glycolic acid) (PEG-PLGA) nanoparticles. Neutrophil membrane-coated nanoparticles (NNPs) are well demonstrated to overcome the blood pancreas barrier to achieve pancreas-specific drug delivery in vivo. Using tumor-bearing mice xenograft model, NNPs showed selective accumulations at the tumor site following systemic administration as compared to nanoparticles without neutrophil membrane coating. In both orthotopic and ectopic tumor models, celastrol-loaded NNPs demonstrated greatly enhanced tumor inhibition which significantly prolonged the survival of tumor bearing mice and minimizing liver metastases. Overall, these results suggest that celastrol-loaded NNPs represent a viable and effective treatment option for pancreatic carcinoma.

Biconcave Carbon Nanodisks for Enhanced Drug Accumulation and Chemo-Photothermal Tumor Therapy

It is considered a significant challenge to construct nanocarriers that have high drug loading capacity and can overcome physiological barriers to deliver efficacious amounts of drugs to solid tumors. Here, the development of a safe, biconcave carbon nanodisk to address this challenge for treating breast cancer is reported. The nanodisk demonstrates fluorescent imaging capability, an exceedingly high loading capacity (947.8 mg g-1 , 94.78 wt%) for doxorubicin (DOX), and pH-responsive drug release. It exhibits a higher uptake rate by tumor cells and greater accumulation in tumors in a mouse model than its carbon nanosphere counterpart. In addition, the nanodisk absorbs and transforms near-infrared (NIR) light to heat, which enables simultaneous NIR-responsive drug release for chemotherapy and generation of thermal energy for tumor cell destruction. Notably, this NIR-activated dual therapy demonstrates a near complete suppression of tumor growth in a mouse model of triple-negative breast cancer when DOX-loaded nanodisks are administered systemically.

Cell membrane protein functionalization of nanoparticles as a new tumor-targeting strategy

Nanoparticles have seen considerable popularity as effective tools for drug delivery. However, non-specific targeting continues to remain a challenge. Recently, biomimetic nanoparticles have emerged as an innovative solution that exploits biologically-derived components to improve therapeutic potential. Specifically, cell membrane proteins extracted from various cells (i.e., leukocytes, erythrocytes, platelets, mesenchymal stem cells, cancer) have shown considerable promise in bestowing nanoparticles with increased circulation and targeting efficacy. Traditional nanoparticles can be detected and removed by the immune system which significantly hinders their clinical success. Biomimicry has been proposed as a promising approach to overcome these limitations. In this review, we highlight the current trends in biomimetic nanoparticles and describe how they are being used to increase their chemotherapeutic effect in cancer treatment.

Biomorphic Engineering of Multifunctional Polylactide Stomatocytes toward Therapeutic Nano-Red Blood Cells

Morphologically discrete nanoarchitectures, which mimic the structural complexity of biological systems, are an increasingly popular design paradigm in the development of new nanomedical technologies. Herein, engineered polymeric stomatocytes are presented as a structural and functional mimic of red blood cells (RBCs) with multifunctional therapeutic features. Stomatocytes, comprising biodegradable poly(ethylene glycol)-block-poly(D,L-lactide), possess an oblate-like morphology reminiscent of RBCs. This unique dual-compartmentalized structure is augmented via encapsulation of multifunctional cargo (oxygen-binding hemoglobin and the photosensitizer chlorin e6). Furthermore, stomatocytes are decorated with a cell membrane isolated from erythrocytes to ensure that the surface characteristics matched those of RBCs. In vivo biodistribution data reveal that both the uncoated and coated nano-RBCs have long circulation times in mice, with the membrane-coated ones outperforming the uncoated stomatoctyes. The capacity of nano-RBCs to transport oxygen and create oxygen radicals upon exposure to light is effectively explored toward photodynamic therapy, using 2D and 3D tumor models; addressing the challenge presented by cancer-induced hypoxia. The morphological and functional control demonstrated by this synthetic nanosystem, coupled with indications of therapeutic efficacy, constitutes a highly promising platform for future clinical application.

Erythrocyte-Coated Nanoparticles Block Cytotoxic Effects of Group B Streptococcus β-Hemolysin/Cytolysin

Group B Streptococcus (GBS) emerged as a leading cause of invasive infectious disease in neonates in the 1970s, but has recently been identified as an escalating public health threat in non-pregnant adults, particularly those of advanced aged or underlying medical conditions. GBS infection can rapidly develop into life-threatening disease despite prompt administration of effective antibiotics and initiation of state-of-the-art intensive care protocols and technologies due to deleterious bacterial virulence factors, such as the GBS pore-forming toxin β-hemolysin/cytolysin (β-H/C). β-H/C is known to have noxious effects on a wide range of host cells and tissues, including lung epithelial cell injury, blood brain barrier weakening, and immune cell apoptosis. Neonatal and adult survivors of GBS infection are at a high risk for substantial long-term health issues and neurologic disabilities due to perturbations in organ systems caused by bacterial- and host- mediated inflammatory stressors. Previously engineered anti-virulence inhibitors, such as monoclonal antibodies and small molecular inhibitors, generally require customized design for each different pathogenic toxin and do not target deleterious host pro-inflammatory responses that may cause organ injury, septic shock, or death. By simply wrapping donor red blood cells (RBCs) around polymeric cores, we have created biomimetic "nanosponges." Because nanoparticles retain the same repertoire of cell membrane receptors as their host cell, they offer non-specific and all-purpose toxin decoy strategies with a broad ability to sequester and neutralize various bacterial toxins and host pro-inflammatory chemokines and cytokines to attenuate the course of infectious disease. This proof-of-concept study successfully demonstrated that intervention with nanosponges reduced the hemolytic activity of live GBS and stabilized β-H/C in a dose-dependent manner. Nanosponge treatment also decreased lung epithelial and macrophage cell death following exposure to live GBS bacteria and stabilized β-H/C, improved neutrophil killing of GBS, and diminished GBS-induced macrophage IL-1β production. Our results, therefore, suggest biomimetic nanosponges provide a titratable detoxification therapy that may provide a first-in-class treatment option for GBS infection by sequestering and inhibiting β-H/C activity.

Erythrocyte Membrane Cloaked Metal-Organic Framework Nanoparticle as Biomimetic Nanoreactor for Starvation-Activated Colon Cancer Therapy

Shutting down glucose supply by glucose oxidase (GOx) to starve tumors has been considered to be an attractive strategy in cancerous starvation therapy. Nevertheless, the in vivo applications of GOx-based starvation therapy are severely restricted by the poor GOx delivery efficiency and the self-limiting therapeutic effect. Herein, a biomimetic nanoreactor has been fabricated for starvation-activated cancer therapy by encapsulating GOx and prodrug tirapazamine (TPZ) in an erythrocyte membrane cloaked metal-organic framework (MOF) nanoparticle (TGZ@eM). The fabricated TGZ@eM nanoreactor can assist the delivery of GOx to tumor cells and then exhaust endogenous glucose and O₂ to starve tumors efficiently. Importantly, the resulting tumor hypoxia by GOx-based starvation therapy further initiates the activation of TPZ, which is released from the nanoreactor in the acid lyso/endosome environment, for enhanced colon cancer therapy. More importantly, by integrating the biomimetic surface modification, the immunity-escaping and prolonged blood circulation characteristics endow our nanoreactor dramatically improved cancer targeting ability. The in vitro and in vivo outcomes indicate our biomimetic nanoreactor exhibits a strong synergistic cascade effect for colon cancer therapy in an accurate and facile manner.

A highly hemocompatible erythrocyte membrane-coated ultrasmall selenium nanosystem for simultaneous cancer radiosensitization and precise antiangiogenesis

Radiotherapy is a vitally important strategy for clinical treatment of malignant cancers. Therefore, rational design and development of radiosensitizers that could enhance radiotherapeutic efficacy has attracted tremendous attention. Antiangiogenesis therapy could be a potentially effective strategy to regulate tumor growth and metastasis due to angiogenesis plays a pivotal role for tumor growth, invasion and metastasis to other organs. Herein, we have rationally designed a smart and effective nanosystem by combining ultrasmall selenium nanoparticles and bevacizumab (Avastin™, Av), for simultaneous radiotherapy and antiangiogenic therapy of cancer. The nanosystem was further coated with red blood cell (RBC) membranes to develop the final construct, RBCs@Se/Av. The RBC membrane coating effectively prolongs the blood circulation time and reduces the elimination of the nanosystem by autoimmune responses. As expected, RBCs@Se/Av, when irradiated with X-ray demonstrated potent anticancer and antiangiogenesis response in vitro and in vivo, as evidenced by strong inhibition of A375 tumor growth in nude mice, without causing any obvious histological damage to the non-target major organs. Taken together, this study demonstrates an effective strategy for design of smart Se-based nanosystem decorated with RBC membrane for simultaneous cancer radiosensitization and precise antiangiogenesis.

Biomimetic O2-Evolving metal-organic framework nanoplatform for highly efficient photodynamic therapy against hypoxic tumor

Improving the supply of O₂ and the circulation lifetime of photosensitizers for photodynamic therapy (PDT) in vivo would be a promising approach to eliminate hypoxic tumors. Herein, by taking advantage of the significant gas-adsorption capability of metal-organic frameworks (MOFs), a biomimetic O₂-evolving photodynamic therapy (PDT) nanoplatform with long circulating properties was fabricated. Zirconium (IV)-based MOF (UiO-66) was used as a vehicle for O₂ storing, then conjugated with indocyanine green (ICG) by coordination reaction, and further coated with red blood cell (RBC) membranes. Upon 808 nm laser irradiation, the initial singlet oxygen (¹O₂) generated by ICG would decompose RBC membranes. At the same time, The photothermal property of ICG could facilitate the burst release of O₂ from UiO-66. Subsequently, the generated O₂ could significantly improve the PDT effects on hypoxic tumor. Owing to the advantages of long circulation and O₂ self-sufficient, the designed nanotherapeutic agent can improve the efficiency of treatment against hypoxia tumor via PDT. Hence, this study presents a new paradigm for co-delivery of O₂ and photosensitizers, and provides a new avenue to eliminate hypoxic tumors.

Erythrocyte Membrane Modified Janus Polymeric Motors for Thrombus Therapy

We report the construction of erythrocyte membrane-cloaked Janus polymeric motors (EM-JPMs) which are propelled by near-infrared (NIR) laser irradiation and are successfully applied in thrombus ablation. Chitosan (a natural polysaccharide with positive charge, CHI) and heparin (glycosaminoglycan with negative charge, Hep) were selected as wall materials to construct biodegradable and biocompatible capsules through the layer-by-layer self-assembly technique. By partially coating the capsule with a gold (Au) layer through sputter coating, a NIR-responsive Janus structure was obtained. Due to the asymmetric distribution of Au, a local thermal gradient was generated upon NIR irradiation, resulting in the movement of the JPMs through the self-thermophoresis effect. The reversible "on/off" motion of the JPMs and their motile behavior were easily tuned by the incident NIR laser intensity. After biointerfacing the Janus capsules with an erythrocyte membrane, the EM-JPMs displayed red blood cell related properties, which enabled them to move efficiently in relevant biological environments (cell culture, serum, and blood). Furthermore, this therapeutic platform exhibited excellent performance in ablation of thrombus through photothermal therapy. As man-made micromotors, these biohybrid EM-JPMs hold great promise of navigating in vivo for active delivery while overcoming the drawbacks of existing synthetic therapeutic platforms. We expect that this biohybrid motor has considerable potential to be widely used in the biomedical field.

Lipoyl Ester Terminated Star PLGA as a Simple and Smart Material for Controlled Drug Delivery Application

PLGA, a copolymer of lactide and glycolide, is one of the most used biodegradable polymers that find a wide range of biomedical applications including drug delivery and tissue engineering. However, in spite of remarkable advancement, nanotherapeutics based on PLGA might have drawbacks of inadequate stability, drug leakage, and slow drug release at the tumor site, which reduces its targeting ability and therapeutic efficacy. Here, we report that direct modification of star PLGA ends with lipoic acid, a natural antioxidant present in our human body, affords a smart material (sPLGA-LA) that forms reversibly crosslinked and bioresponsive multifunctional nanoparticles (sPLGA XNPs). Interestingly, sPLGA XNPs obtained in the presence of 23.0 wt % PEG-PDLLA displayed a small hydrodynamic size of 73 ± 1.2 nm, high stability against dilution and 10% serum, while fast destabilization under a reductive environment. Moreover, sPLGA XNPs achieved efficient loading of lipophilic anticancer drug model, doxorubicin (DOX), at a theoretical drug loading content of 13.3 wt %, giving DOX-loaded sPLGA XNPs with reduced drug leakage under physiological conditions as well as significantly accelerated drug release under 10 mM glutathione condition compared with both linear and star PLGA controls (denoted as lPLGA NPs and sPLGA NPs, respectively). Confocal microscopy and flow cytometry displayed obviously stronger DOX fluorescence in B16F10 melanoma cells treated with DOX-loaded sPLGA XNPs than with lPLGA and sPLGA counterparts. MTT assays revealed that DOX-sPLGA XNPs caused 2.4- and 4.2-fold higher antitumor activity toward B16F10 cells than DOX-sPLGA NPs and DOX-lPLGA NPs, respectively. Notably, in vivo pharmacokinetics studies showed prolonged circulation time and significantly improved AUC for DOX-sPLGA XNPs over lPLGA NPs control. Hence, lipoyl ester terminated star PLGA emerges as a simple and smart material for better-controlled anticancer drug delivery.

Biomimetic Nanosponges for Treating Antibody-Mediated Autoimmune Diseases

Autoimmune diseases are characterized by overactive immunity, where the body's defense system launches an attack against itself. If left unchecked, this can result in the destruction of healthy tissue and significantly affect patient well-being. In the case of type II autoimmune hypersensitivities, autoreactive antibodies attack the host's own cells or extracellular matrix. Current clinical treatment modalities for managing this class of disease are generally nonspecific and face considerable limitations. In this Topical Review, we cover emerging therapeutic strategies, with an emphasis on novel nanomedicine platforms. Specifically, the use of biomimetic cell membrane-coated nanosponges that are capable of specifically binding and neutralizing pathological antibodies will be explored. There is significant untapped potential in the application of nanotechnology for the treatment of autoimmune diseases, and continued development along this line may help to eventually change the clinical landscape.

Ultrasound induced phase-transition and invisible nanobomb for imaging-guided tumor sonodynamic therapy

This ‘nanobomb’ can mechanically destroy tumor vessels, significantly relieve hypoxia within the tumor and reduce the microvessel density.

Biomimetic Virulomics for Capture and Identification of Cell-Type Specific Effector Proteins

An unmet challenge in the study of disease is to accurately streamline the identification of important virulence factors. Traditional, genetically driven approaches miss biologically relevant markers due to discordance between the genome and proteome. Here, we developed a nanotechnology-enabled affinity enrichment strategy coupled with multiplexed quantitative proteomics, namely Biomimetic Virulomics, for successful identification of cell-type specific effector proteins of both prokaryotic and eukaryotic pathogens. We highlight the power of Biomimetic Virulomics by capturing known virulence factors in a high-throughput, cell-type guided fashion. Additionally, a comprehensive characterization of the membrane protein component of biomimetics utilized in this strategy is provided. Interfacing cell-derived nanomaterials with multiplexed quantitative proteomics allow for a specific targeting strategy of virulence factors that can be utilized for drug discovery against prominent human diseases.

Self-Assembled Colloidal Gel Using Cell Membrane-Coated Nanosponges as Building Blocks

Colloidal gels consisting of oppositely charged nanoparticles are increasingly utilized for drug delivery and tissue engineering. Meanwhile, cell membrane-coated nanoparticles are becoming a compelling biomimetic system for innovative therapeutics. Here, we demonstrate the successful use of cell membrane-coated nanoparticles as building blocks to formulate a colloidal gel that gelates entirely based on material self-assembly without chemical cross-linking. Specifically, we prepare red blood cell membrane-coated nanosponges and mix them with an appropriate amount of cationic nanoparticles, resulting in a spontaneously formed gel-like complex. Rheological test shows that the nanosponge colloidal gel has pronounced shear-thinning property, which makes it an injectable formulation. The gel formulation not only preserves the nanosponges' toxin neutralization capability but also greatly prolongs their retention time after subcutaneous injection into mouse tissue. When tested in a mouse model of subcutaneous group A Streptococcus infection, the nanosponge colloidal gel shows significant antibacterial efficacy by markedly reducing skin lesion development. Overall, the nanosponge colloidal gel system is promising as an injectable formulation for therapeutic applications such as antivirulence treatment for local bacterial infections.