Preparation and Application of Cell Membrane-Camouflaged Nanoparticles for Cancer Therapy

Liposomes for Tumor Targeted Therapy: A Review

Liposomes, the most widely studied nano-drug carriers in drug delivery, are sphere-shaped vesicles consisting of one or more phospholipid bilayers. Compared with traditional drug delivery systems, liposomes exhibit prominent properties that include targeted delivery, high biocompatibility, biodegradability, easy functionalization, low toxicity, improvements in the sustained release of the drug it carries and improved therapeutic indices. In the wake of the rapid development of nanotechnology, the studies of liposome composition have become increasingly extensive. The molecular diversity of liposome composition, which includes long-circulating PEGylated liposomes, ligand-functionalized liposomes, stimuli-responsive liposomes, and advanced cell membrane-coated biomimetic nanocarriers, endows their drug delivery with unique physiological functions. This review describes the composition, types and preparation methods of liposomes, and discusses their targeting strategies in cancer therapy.

Metabolic glycoengineering - exploring glycosylation with bioorthogonal chemistry

Glycans are involved in numerous biological recognition events. Being secondary gene products, their labeling by genetic methods - comparable to GFP labeling of proteins - is not possible. To overcome this limitation, metabolic glycoengineering (MGE, also known as metabolic oligosaccharide engineering, MOE) has been developed. In this approach, cells or organisms are treated with synthetic carbohydrate derivatives that are modified with a chemical reporter group. In the cytosol, the compounds are metabolized and incorporated into newly synthesized glycoconjugates. Subsequently, the reporter groups can be further derivatized in a bioorthogonal ligation reaction. In this way, glycans can be visualized or isolated. Furthermore, diverse targeting strategies have been developed to direct drugs, nanoparticles, or whole cells to a desired location. This review summarizes research in the field of MGE carried out in recent years. After an introduction to the bioorthogonal ligation reactions that have been used in in connection with MGE, an overview on carbohydrate derivatives for MGE is given. The last part of the review focuses on the many applications of MGE starting from mammalian cells to experiments with animals and other organisms.

Biologically inspired stealth - Camouflaged strategies in nanotechnology for the improved therapies in various diseases

Nanotechnology has received increasing attention in the past decade and it's being used as a model for developing better treatments for a variety of diseases. Despite the fact that nanotechnology-based therapy has greatly improved treatment regimens, it still faces challenges such as inadequate circulation, insufficient accumulation at the target region, and undesired toxicity. In this regard, scientists are working on producing cell-membrane camouflaged nanoparticles as a biomimetic technique for modifying the surface of existing nanoparticles to produce significant therapeutic benefits following imparting myriad of desired functionalities. Membranes originating from erythrocytes, white blood cells, cancer cells, stem cells, platelets, or bacterial cells have been used to coat nanoparticle surfaces and create biologically inspired camouflaged nanoparticles. These biomemitic delivery systems have been proven to have potential applications in diagnosing and treating vaiorus diseases, including drug administration, immunisation, immunological regulation, and detoxification. From its inception to the present, we provide a complete description of this advanced technique for functionalizing nanoparticle surfaces. The method of making these membrane coated nanoparticles as well as their characterisation have been thoroughly discussed. Following that, we focused on the diversity of cell membranes derived from distinct cells in the evolution of nanoparticles, emphasising how these biologically inspired stealth - camouflaged techniques have led to increased therapeutic efficacy in a variety of disease states.

Exosomes and ultrasound: The future of theranostic applications

Biomaterials and pertaining formulations have been very successful in various diagnostic and therapeutic applications because of its ability to overcome pharmacological limitations. Some of them have gained significant focus in the recent decade for their theranostic properties. Exosomes can be grouped as biomaterials, since they consist of various biological micro/macromolecules and possess all the properties of a stable biomaterial with size in nano range. Significant research has gone into isolation and exploitation of exosomes as potential theranostic agent. However, the limitations in terms of yield, efficacy, and target specificity are continuously being addressed. On the other hand, several nano/microformulations are responsive to physical or chemical alterations and were successfully stimulated by tweaking the physical characteristics of the surrounding environment they are in. Some of them are termed as photodynamic, sonodynamic or thermodynamic therapeutic systems. In this regard, ultrasound and acoustic systems were extensively studied for its ability towards altering the properties of the systems to which they were applied on. In this review, we have detailed about the diagnostic and therapeutic applications of exosomes and ultrasound separately, consisting of their conventional applications, drawbacks, and developments for addressing the challenges. The information were categorized into various sections that provide complete overview of the isolation strategies and theranostic applications of exosomes in various diseases. Then the ultrasound-based disease diagnosis and therapy were elaborated, with special interest towards the use of ultrasound in enhancing the efficacy of nanomedicines and nanodrug delivery systems, Finally, we discussed about the ability of ultrasound in enhancing the diagnostic and therapeutic properties of exosomes, which could be the future of theranostics.

The role of cell membrane-coated nanoparticles as a novel treatment approach in glioblastoma

Glioblastoma multiform (GBM) is the most prevalent and deadliest primary brain malignancy in adults, whose median survival rate does not exceed 15 months after diagnosis. The conventional treatment of GBM, including maximal safe surgery followed by chemotherapy and radiotherapy, usually cannot lead to notable improvements in the disease prognosis and the tumor always recurs. Many GBM characteristics make its treatment challenging. The most important ones are the impermeability of the blood-brain barrier (BBB), preventing chemotherapeutic drugs from reaching in adequate amounts to the tumor site, intratumoral heterogeneity, and roles of glioblastoma stem cells (GSCs). To overcome these barriers, the recently-developed drug-carrying approach using nanoparticles (NPs) may play a significant role. NPs are tiny particles, usually less than 100 nm showing various diagnostic and therapeutic medical applications. In this regard, cell membrane (CM)-coated NPs demonstrated several promising effects in GBM in pre-clinical studies. They benefit from fewer adverse effects due to their specific targeting of tumor cells, biocompatibility because of their CM surfaces, prolonged half-life, easy penetrating of the BBB, and escaping from the immune reaction, making them an attractive option for GBM treatment. To date, CM-coated NPs have been applied to enhance the effectiveness of major therapeutic approaches in GBM treatment, including chemotherapy, immunotherapy, gene therapy, and photo-based therapies. Despite the promising results in pre-clinical studies regarding the effectiveness of CM-coated NPs in GBM, significant barriers like high expenses, complex preparation processes, and unknown long-term effects still hinder its mass production for the clinic. In this regard, the current study aims to provide an overview of different characteristics of CM-coated NPs and comprehensively investigate their application as a novel treatment approach in GBM.

Nanotechnology-based cell-mediated delivery systems for cancer therapy and diagnosis

The global prevalence of cancer is increasing, necessitating new additions to traditional treatments and diagnoses to address shortcomings such as ineffectiveness, complications, and high cost. In this context, nano and microparticulate carriers stand out due to their unique properties such as controlled release, higher bioavailability, and lower toxicity. Despite their popularity, they face several challenges including rapid liver uptake, low chemical stability in blood circulation, immunogenicity concerns, and acute adverse effects. Cell-mediated delivery systems are important topics to research because of their biocompatibility, biodegradability, prolonged delivery, high loading capacity, and targeted drug delivery capabilities. To date, a variety of cells including blood, immune, cancer, and stem cells, sperm, and bacteria have been combined with nanoparticles to develop efficient targeted cancer delivery or diagnosis systems. The review paper aimed to provide an overview of the potential applications of cell-based delivery systems in cancer therapy and diagnosis.

Advances in cell membrane-coated nanoparticles and their applications for bone therapy

Due to the specific structure of natural bone, most of the therapeutics are incapable to be delivered into the targeted site with effective concentrations. Nanotechnology has provided a good way to improve this issue, cell membrane mimetic nanoparticles (NPs) have been emerging as an ideal nanomaterial which integrates the advantages of natural cell membranes with synthetic NPs to significantly improve the biocompatibility as well as achieving long-lasting circulation and targeted delivery. In addition, functionalized modifications of the cell membrane facilitate more precise targeting and therapy. Here, an overview of the preparation of cell membrane-coated NPs and the properties of cell membranes from different cell sources has been given to expatiate their function and potential applications. Strategies for functionalized modification of cell membranes are also briefly described. The application of cell membrane-coated NPs for bone therapy is then presented according to the function of cell membranes. Moreover, the prospects and challenges of cell membrane-coated NPs for translational medicine have also been discussed.

Engineered biomembrane-derived nanoparticles for nanoscale theranostics

Currently, biological membrane-derived nanoparticles (NPs) have shown enormous potential as drug delivery vehicles due to their outstanding biomimetic properties. To make these NPs more adaptive to complex biological systems, some methods have been developed to modify biomembranes and endow them with more functions while preserving their inherent natures. In this review, we introduce five common approaches used for biomembrane decoration: membrane hybridization, the postinsertion method, chemical methods, metabolism engineering and gene engineering. These methods can functionalize a series of biomembranes derived from red blood cells, white blood cells, tumor cells, platelets, exosomes and so on. Biomembrane engineering could markedly facilitate the targeted drug delivery, treatment and diagnosis of cancer, inflammation, immunological diseases, bone diseases and Alzheimer's disease. It is anticipated that these membrane modification techniques will advance biomembrane-derived NPs into broader applications in the future.

Immune cell-camouflaged surface-engineered nanotherapeutics for cancer management

Nanocarriers (NCs) have shown potential in delivering hydrophobic cytotoxic drugs and tumor-specific targeting. However, the inability to penetrate the tumor microenvironment and entrapment by macrophages has limited their clinical translation. Various cell-based drug delivery systems have been explored for their ability to improve circulation half-life and tumor accumulation capabilities. Tumors are characterized by high inflammation, which aids in tumor progression and metastasis. Immune cells show natural tumor tropism and penetration inside the tumor microenvironment (TME) and are a topic of great interest in cancer drug delivery. However, the TME is immunosuppressive and can polarize immune cells to pro-tumor. Thus, the use of immune cell membrane-coated NCs has gained popularity. Such carriers display immune cell-specific surface receptors for tumor-specific accumulation but lack cell machinery. The lack of immune cell machinery makes them unaffected by the immunosuppressive TME, meanwhile maintaining the inherent tumor tropism. In this review, we discuss the molecular mechanism behind the movement of various immune cells toward TME, the preparation and characterization of membrane-coated NCs, and the efficacy of immune cell-mimicking NCs in tumor therapy. Regulatory guidelines and the bottlenecks in clinical translation are also highlighted. STATEMENT OF SIGNIFICANCE: Nanocarriers have been explored for the site-specific delivery of chemotherapeutics. However, low systemic circulation half-life, extensive entrapment by macrophages, and poor accumulation inside the tumor microenvironment prevent the clinical translation of conventional nanotherapeutics. Immune cells possess the natural tropism towards the tumor along the chemokine gradient. Hence, coating the nanocarriers with immune cell-derived membranes can improve the accumulation of nanocarriers inside the tumor. Moreover, coating with membranes derived autologous immune cells will prevent engulfment by the macrophages.

Macrophage cell membrane-based nanoparticles: a new promising biomimetic platform for targeted delivery and treatment

Synthetic nanoparticles with surface bioconjugation are promising platforms for targeted therapy, but their simple biological functionalization is still a challenging task against the complex intercellular environment. Once synthetic nanoparticles enter the body, they are phagocytosed by immune cells by the immune system. Recently, the cell membrane camouflage strategy has emerged as a novel therapeutic tactic to overcome these issues by utilizing the fundamental properties of natural cells. Macrophage, a type of immune system cells, plays critical roles in various diseases, including cancer, atherosclerosis, rheumatoid arthritis, infection and inflammation, due to the recognition and engulfment function of removing substances and pathogens. Macrophage membranes inherit the surface protein profiles and biointerfacing properties of source cells. Therefore, the macrophage membrane cloaking can protect synthetic nanoparticles from phagocytosis by the immune cells. Meanwhile, the macrophage membrane can make use of the natural correspondence to accurately recognize antigens and target inflamed tissue or tumor sites. In this review, we have summarized the advances in the fabrication, characterization and homing capacity of macrophage membrane cloaking nanoparticles in various diseases, including cancers, immune diseases, cardiovascular diseases, central nervous system diseases, and microbial infections. Although macrophage membrane-camouflaged nanoparticles are currently in the fetal stage of development, there is huge potential and challenge to explore the conversion mode in the clinic.

Biomimetic cell-derived nanocarriers in cancer research

Nanoparticles have now long demonstrated capabilities that make them attractive to use in biology and medicine. Some of them, such as lipid nanoparticles (SARS-CoV-2 vaccines) or metallic nanoparticles (contrast agents) are already approved for their use in the clinic. However, considering the constantly growing body of different formulations and the huge research around nanomaterials the number of candidates reaching clinical trials or being commercialized is minimal. The reasons behind being related to the "synthetic" and "foreign" character of their surface. Typically, nanomaterials aiming to develop a function or deliver a cargo locally, fail by showing strong off-target accumulation and generation of adverse responses, which is connected to their strong recognition by immune phagocytes primarily. Therefore, rendering in negligible numbers of nanoparticles developing their intended function. While a wide range of coatings has been applied to avoid certain interactions with the surrounding milieu, the issues remained. Taking advantage of the natural cell membranes, in an approach that resembles a cell transfer, the use of cell-derived surfaces has risen as an alternative to artificial coatings or encapsulation methods. Biomimetic technologies are based on the use of isolated natural components to provide autologous properties to the nanoparticle or cargo being encapsulated, thus, improving their therapeutic behavior. The main goal is to replicate the (bio)-physical properties and functionalities of the source cell and tissue, not only providing a stealthy character to the core but also taking advantage of homotypic properties, that could prove relevant for targeted strategies. Such biomimetic formulations have the potential to overcome the main issues of approaches to provide specific features and identities synthetically. In this review, we provide insight into the challenges of nano-biointerfaces for drug delivery; and the main applications of biomimetic materials derived from specific cell types, focusing on the unique strengths of the fabrication of novel nanotherapeutics in cancer therapy.

Erythrocyte Membrane-Camouflaged Aggregation-Induced Emission Nanoparticles for Fetal Intestinal Maturation Assessment

Assessment of fetal maturity is essential for timely termination of pregnancy, especially in pregnant women with pregnancy complications. However, there is a lack of methods to assess the maturity of fetal intestinal function. Here, we constructed erythrocyte membrane-camouflaged aggregation-induced emission (AIE) nanoparticles. Nanocore is formed using a hollow mesoporous silicon nanobox (HMSN) of different particle sizes loaded with AIE luminogens -PyTPA (P), which are then co-extruded with erythrocyte membranes (M) to construct M@HMSN@P. The 100 nm M@HMSN@P has a more effective cellular uptake efficiency in vitro and in vivo. Swallowing and intestinal function in fetal mice mature with the increase in gestational age. After intrauterine injection of M@HMSN@P, they were swallowed and absorbed by fetal mice, and their swallowed and absorbed amount was positively correlated with the gestational age with a correlation coefficient of 0.9625. Using the M@HMSN@P (fluorescence intensity) in fetal mice, the gestational age can be imputed, and the difference between this imputed gestational age and the actual gestational age is less than 1 day. Importantly, M@HMSN@P has no side effect on the health status of pregnant and fetal mice, showing good biocompatibility. In conclusion, we constructed M@HMSN@P nanoparticles with different particle sizes and confirmed that the smaller size M@HMSN@P has more efficient absorption efficiency and it can assess fetal intestinal maturity by the intensity of the fluorescence signal.

Recent advances in developing active targeting and multi-functional drug delivery systems via bioorthogonal chemistry

Bioorthogonal chemistry reactions occur in physiological conditions without interfering with normal physiological processes. Through metabolic engineering, bioorthogonal groups can be tagged onto cell membranes, which selectively attach to cargos with paired groups via bioorthogonal reactions. Due to its simplicity, high efficiency, and specificity, bioorthogonal chemistry has demonstrated great application potential in drug delivery. On the one hand, bioorthogonal reactions improve therapeutic agent delivery to target sites, overcoming off-target distribution. On the other hand, nanoparticles and biomolecules can be linked to cell membranes by bioorthogonal reactions, providing approaches to developing multi-functional drug delivery systems (DDSs). In this review, we first describe the principle of labeling cells or pathogenic microorganisms with bioorthogonal groups. We then highlight recent breakthroughs in developing active targeting DDSs to tumors, immune systems, or bacteria by bioorthogonal chemistry, as well as applications of bioorthogonal chemistry in developing functional bio-inspired DDSs (biomimetic DDSs, cell-based DDSs, bacteria-based and phage-based DDSs) and hydrogels. Finally, we discuss the difficulties and prospective direction of bioorthogonal chemistry in drug delivery. We expect this review will help us understand the latest advances in the development of active targeting and multi-functional DDSs using bioorthogonal chemistry and inspire innovative applications of bioorthogonal chemistry in developing smart DDSs for disease treatment.

A ferroptosis-inducing biomimetic nanocomposite for the treatment of drug-resistant prostate cancer

Second-generation androgen receptor (AR) inhibitors such as enzalutamide are the first-line treatments for castration-resistant prostate cancer (CRPC). Resistance to enzalutamide will greatly increase the difficulty of prostate cancer treatment and reduce the survival time of patients. However, drug-resistant cancer cells seem to be more sensitive to ferroptosis. Therefore, we constructed a biomimetic tumor-targeting magnetic lipid nanoparticle (t-ML) to codeliver dihomo-γ-linolenic acid (DGLA) and 2,4-dienoyl-CoA reductase 1 (DECR1) siRNA (t-ML@DGLA/siDECR1). DGLA is a dietary polyunsaturated fatty acid (PUFA), while DECR1 is overexpressed in prostate cancer and can inhibit the generation of PUFAs. The combination of DGLA and siDECR1 can efficiently induce ferroptosis by peroxidation of PUFAs, which has been verified both in vitro and in vivo. With the assistance of an external magnet, t-ML showed good tumor targeting ability and biocompatibility, and t-ML@DGLA/siDECR1 exhibited significant ferroptosis induction and tumor suppression capabilities. Moreover, in a nude mouse model of prostate cancer fed on a high-fat diet (HFD), there was no distant organ metastasis when the tumor-bearing mice were treated with t-ML@DGLA/siDECR1 and an external magnet, with upregulated PUFAs and downregulated monounsaturated fatty acids (MUFAs). Hence, this study has broadened the way of treating drug-resistant prostate cancer based on ferroptosis induction.

Biomimetic fabrication of nanotherapeutics by leukocyte membrane cloaking for targeted therapy

Cell membrane cloaking is an important biomimetic approach for improving drug residence time in the body due to its distinctive concealment ability, making it highly biocompatible and efficient for targeted drug delivery. Leukocytes are considered a fundamental part of the immune system. Leukocyte membrane cloaked nanoparticles offer site-specificity and can escape the opsonization process besides enhanced systemic circulation time. This review emphasizes the anatomical and physiological features of different leukocytes in addition to the preparation and characterization of leukocyte membrane cloaked nanoparticles. It also covers the recent advancements of this biointerfacing platform in cancer therapy, inflammatory disorders, multifunctional targeted therapy and hybrid membrane-coated nanoparticles. However, leukocytes are complex, nucleated cell structures and isolating their membranes poses a greater difficulty. Leukocyte membrane cloaking is an upcoming strategy in the infancy stage; nevertheless, there is immense scope to explore this biomimetic delivery system in terms of clinical transition, particularly for inflammatory diseases and cancer.

Bacterial outer membrane vesicle-based cancer nanovaccines

Tumor vaccines, a type of personalized tumor immunotherapy, have developed rapidly in recent decades. These vaccines evoke tumor antigen-specific T cells to achieve immune recognition and killing of tumor cells. Because the immunogenicity of tumor antigens alone is insufficient, immune adjuvants and nanocarriers are often required to enhance anti-tumor immune responses. At present, vaccine carrier development often integrates nanocarriers and immune adjuvants. Among them, outer membrane vesicles (OMVs) are receiving increasing attention as a delivery platform for tumor vaccines. OMVs are natural nanovesicles derived from Gram-negative bacteria, which have adjuvant function because they contain pathogen associated molecular patterns. Importantly, OMVs can be functionally modified by genetic engineering of bacteria, thus laying a foundation for applications as a delivery platform for tumor nanovaccines. This review summarizes 5 aspects of recent progress in, and future development of, OMV-based tumor nanovaccines: strain selection, heterogeneity, tumor antigen loading, immunogenicity and safety, and mass production of OMVs.

Overview of Nanoparticle-Based Approaches for the Combination of Photodynamic Therapy (PDT) and Chemotherapy at the Preclinical Stage

Simple Summary

The present review represents the outstanding and promising recent literature reports (2017–2022) on nanoparticle-based formulations developed for anticancer therapy with photodynamic therapy (PDT), photosensitizers, and chemotherapeutics. Besides brief descriptions of chemotherapeutics’ classification and of PDT mechanisms and limitations, several examples of nanosystems endowed with different responsiveness (e.g., acidic pH and reactive oxygen species) and peculiarity (e.g., tumor oxygenation capacity, active tumor targeting, and biomimetic features) are described, and for each drug combination, in vitro and in vivo results on preclinical cancer models are reported.

Abstract

The widespread diffusion of photodynamic therapy (PDT) as a clinical treatment for solid tumors is mainly limited by the patient’s adverse reaction (skin photosensivity), insufficient light penetration in deeply seated neoplastic lesions, unfavorable photosensitizers (PSs) biodistribution, and photokilling efficiency due to PS aggregation in biological environments. Despite this, recent preclinical studies reported on successful combinatorial regimes of PSs with chemotherapeutics obtained through the drugs encapsulation in multifunctional nanometric delivery systems. The aim of the present review deals with the punctual description of several nanosystems designed not only with the objective of co-transporting a PS and a chemodrug for combination therapy, but also with the goal of improving the therapeutic efficacy by facing the main critical issues of both therapies (side effects, scarce tumor oxygenation and light penetration, premature drug clearance, unspecific biodistribution, etc.). Therefore, particular attention is paid to the description of bio-responsive drugs and nanoparticles (NPs), targeted nanosystems, biomimetic approaches, and upconverting NPs, including analyzing the therapeutic efficacy of the proposed photo-chemotherapeutic regimens in in vitro and in vivo cancer models.

Nanomaterials: A powerful tool for tumor immunotherapy

Cancer represents the leading global driver of death and is recognized as a critical obstacle to increasing life expectancy. In recent years, with the development of precision medicine, significant progress has been made in cancer treatment. Among them, various therapies developed with the help of the immune system have succeeded in clinical treatment, recognizing and killing cancer cells by stimulating or enhancing the body’s intrinsic immune system. However, low response rates and serious adverse effects, among others, have limited the use of immunotherapy. It also poses problems such as drug resistance and hyper-progression. Fortunately, thanks to the rapid development of nanotechnology, engineered multifunctional nanomaterials and biomaterials have brought breakthroughs in cancer immunotherapy. Unlike conventional cancer immunotherapy, nanomaterials can be rationally designed to trigger specific tumor-killing effects. Simultaneously, improved infiltration of immune cells into metastatic lesions enhances the efficiency of antigen submission and induces a sustained immune reaction. Such a strategy directly reverses the immunological condition of the primary tumor, arrests metastasis and inhibits tumor recurrence through postoperative immunotherapy. This paper discusses several types of nanoscale biomaterials for cancer immunotherapy, and they activate the immune system through material-specific advantages to provide novel therapeutic strategies. In summary, this article will review the latest advances in tumor immunotherapy based on self-assembled, mesoporous, cell membrane modified, metallic, and hydrogel nanomaterials to explore diverse tumor therapies.

Membrane-wrapped nanoparticles for photothermal cancer therapy

Cancer is a global health problem that needs effective treatment strategies. Conventional treatments for solid-tumor cancers are unsatisfactory because they cause unintended harm to healthy tissues and are susceptible to cancer cell resistance. Nanoparticle-mediated photothermal therapy is a minimally invasive treatment for solid-tumor cancers that has immense promise as a standalone therapy or adjuvant to other treatments like chemotherapy, immunotherapy, or radiotherapy. To maximize the success of photothermal therapy, light-responsive nanoparticles can be camouflaged with cell membranes to endow them with unique biointerfacing capabilities that reduce opsonization, prolong systemic circulation, and improve tumor delivery through enhanced passive accumulation or homotypic targeting. This ensures a sufficient dose of photoresponsive nanoparticles arrives at tumor sites to enable their complete thermal ablation. This review summarizes the state-of-the-art in cell membrane camouflaged nanoparticles for photothermal cancer therapy and provides insights to the path forward for clinical translation.

A stable DNA Tetrahedra-AuNCs nanohybrid: On-site programmed disassembly for tumor imaging and combination therapy

Despite DNA nanotechnology has spawned a broad variety and taken a giant leap toward cancer theranostic applications over the last decade, the homogeneous DNA nanostructures often suffer from fatal degradation due to their limited stability and specificity. Herein, for the first time, we report a stable DNA tetrahedra-gold nanoclusters (DT/AuNCs) nanohybrid with a self-assembly/programmed disassembly manner for stimuli-responsive tumor imaging and gene-chemo therapy. By utilizing the multifunctional peptides with positive and legumain-specific domains as bioligands, AuNCs were synthesized as signal generators and gate guard attached on the dual-responsive DT, forming the DT/AuNCs with sequential response to legumain-TK1 mRNA & glutathione. The tumorous biomarker of legumain initiated the signal generation relying on the nanosurface energy transfer effect of AuNCs and denudation of DT-Dox (preliminary disassembly). Successively, the dual-responsive DT-Dox administrated a sequential fragmentation along with Dox release in response to the up-regulated glutathione and TK1 mRNA (secondary disassembly), thereby leading to combined gene silencing and chemo-therapy. The results revealed that the DT/AuNCs nanohybrids significantly improved the stability and enhanced the therapeutic efficiency compared to naked DT. Endowing with remarkable stability against biological milieu and site specificity for drug release, our work exhibits a new prospect of fabricating DNA-based nanohybrids for precise tumor theranostics.

Macrophage Cell Membrane-Cloaked Nanoplatforms for Biomedical Applications

Biomimetic approaches utilize natural cell membrane-derived nanovesicles to camouflage nanoparticles to circumvent some limitations of nanoscale materials. This emergent cell membrane-coating technology is inspired by naturally occurring intercellular interactions, to efficiently guide nanostructures to the desired locations, thereby increasing both therapeutic efficacy and safety. In addition, the intrinsic biocompatibility of cell membranes allows the crossing of biological barriers and avoids elimination by the immune system. This results in enhanced blood circulation time and lower toxicity in vivo. Macrophages are the major phagocytic cells of the innate immune system. They are equipped with a complex repertoire of surface receptors, enabling them to respond to biological signals, and to exhibit a natural tropism to inflammatory sites and tumorous tissues. Macrophage cell membrane-functionalized nanosystems are designed to combine the advantages of both macrophages and nanomaterials, improving the ability of those nanosystems to reach target sites. Recent studies have demonstrated the potential of these biomimetic nanosystems for targeted delivery of drugs and imaging agents to tumors, inflammatory, and infected sites. The present review covers the preparation and biomedical applications of macrophage cell membrane-coated nanosystems. Challenges and future perspectives in the development of these membrane-coated nanosystems are addressed.

Cancer cell membrane targeting and red light-triggered carbon monoxide (CO) release for enhanced chemotherapy

Chemotherapy assisted by carbon monoxide (CO) gas therapy is an emerging powerful cancer therapeutic modality. However, the effective delivery and controlled release of CO in tumor cells remain a challenge. Herein, a cell membrane bionic nano delivery system (RBC-H@DOX/3-HF@MSN, termed as RHM) was designed to selectively accumulate in tumors and generate CO in situ upon red light irradiation for the combination of chemotherapy and gas therapy. CO significantly improves the therapeutic effect of DOX from 29.0% to 82.4%.

Immunomodulation and delivery of macrophages using nano-smooth drug-loaded magnetic microrobots for dual targeting cancer therapy

To realize the potential to use micro/nanorobots for targeted cancer therapy, it is important to improve their biocompatibility and targeting ability. Here, we report on drug-loaded magnetic microrobots capable of polarizing macrophages into the antitumor phenotype to target and inhibit cancer cells. In vitro tests demonstrated that the microrobots have good biocompatibility with normal cells and immune cells. Positively charged DOX was loaded onto the surface of microrobots via electrostatic interactions and exhibited pH-responsive release behavior. The nano-smooth surfaces of the microrobots activated M1 polarization of macrophages, thus activating their intrinsic targeting and antitumor abilities toward cancer cells. Through dual targeting from magnetic guidance and M1 macrophages, the microrobots were able to target and kill cancer cells in a 3D tumor spheroid culture assay. These findings demonstrate a way to improve the tumor-targeting and antitumor abilities of microrobots through the combined use of magnetic control, macrophages, and pH-responsive drug release.

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Drug-loaded achiral magnetic microrobots developed with scalability and mass fabrication

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Magnetic microrobot with nano-smooth surface can activate antitumor phenotype macrophage

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The magnetic targeting and targeted therapy of polarized macrophages were combined

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The magnetic microrobots exhibit enhanced tumor-targeting and antitumor capabilities

Biomimetic Nanotherapeutics: Employing Nanoghosts to fight Melanoma

Melanoma is a cancer of melanocytes present at the basal layer of the skin. Nanomedicine has armed us with competent platform to manage such fatal neoplastic diseases. Nevertheless, it suffers from numerous pitfalls such as rapid clearance and opsonization of surface-functionalized carriers, biocompatibility and idiopathic reactions which could be difficult to predict in the patient. Biomimetic approach, a novel step towards personalized medicine bridges these drawbacks by employing endogenous cell membranes to traverse physiological barriers. Camouflaged carriers coated with natural cell membranes possess unique characteristics such as high circulatory periods, and the absence of allogenic and xenogenic responses. Proteins residing on the cell membranes render a diverse range of utilities to the coated nanoparticles including natural efficiency to identify cellular targets, homologous targeting, reticuloendothelial system evasion, biocompatibility and reduced adverse and idiopathic effects. In the present article, we have focused on cell membrane camouflaged nanocarriers for melanoma management. We have discussed various types of biomimetic systems, their processing and coating approaches, and their characterization. We have also enumerated novel avenues in melanoma treatment and the combination of biomimetic systems with smart nanoparticulate systems with the potential to bring breakthroughs in the near future. Additionally, immunotherapy-based biomimetic systems to combat melanoma have been highlighted. Hurdles towards clinical translation and ways to overcome them have been explained in detail.

Cell membrane-based biomimetic nanosystems for advanced drug delivery in cancer therapy: A comprehensive review

Natural types of cells display distinct characteristics with homotypic targeting and extended circulation in the blood, which are worthy of being explored as promising drug delivery systems (DDSs) for cancer therapy. To enhance their delivery efficiency, these cells can be combined with therapeutic agents and artificial nanocarriers to construct the next generation of DDSs in the form of biomimetic nanomedicines. In this review, we present the recent advances in cell membrane-based DDSs (CDDSs) and their applications for efficient cancer therapy. Different sources of cell membranes are discussed, mainly including red blood cells (RBC), leukocytes, cancer cells, stem cells and hybrid cells. Moreover, the extraction methods used for obtaining such cells and the mechanism contributing to the functional action of these biomimetic CDDSs are explained. Finally, a future perspective is proposed to highlight the limitations of CDDSs and the possible resolutions toward clinical transformation of currently developed biomimetic chemotherapies.

Anti-EpCAM Functionalized I-131 Radiolabeled Biomimetic Nanocarrier Sodium/Iodide-Symporter-Mediated Breast-Cancer Treatment

Currently, breast-cancer treatment has a number of adverse side effects and is associated with poor rates of progression-free survival. Therefore, a radiolabeled anti-EpCAM targeted biomimetic coated nanocarrier (EINP) was developed in this study to overcome some of the treatment challenges. The double emulsion method synthesized the poly(lactic-co-glycolic acid) (PLGA) nanoparticle with Na131I entrapped in the core. The PLGA nanoparticle was coated in human red blood cell membranes and labeled with epithelial cell adhesion molecule (EpCAM) antibody to enable it to target EpCAM overexpression by breast-cancer cells. Characterization determined the EINP size as 295 nm, zeta potential as −35.9 mV, and polydispersity as 0.297. EINP radiochemical purity was >95%. Results determined the EINP efficacy against EpCAM positive MCF-7 breast cancer at 24, 48, and 72 h were 69.11%, 77.84%, and 74.6%, respectively, demonstrating that the EINPs achieved greater cytotoxic efficacy supported by NIS-mediated Na131I uptake than the non-targeted 131INPs and Na131I. In comparison, fibroblast (EpCAM negative) treated with EINPs had significantly lower cytotoxicity than Na131I and 131INPs (p < 0.05). Flow cytometry fluorescence imaging visually signified delivery by EINPs specifically to breast-cancer cells as a result of anti-EpCAM targeting. Additionally, the EINP had a favorable safety profile, as determined by hemolysis.

Loading Drugs in Natural Phospholipid Bilayers of Cell Membrane Shells to Construct Biomimetic Nanocomposites for Enhanced Tumor Therapy

Drug-based oncotherapy is seriously challenged by insufficient drug accumulation at tumor sites, mainly resulting from low drug loading efficiency and poor tumor-targeting ability of drug carriers. We herein proposed a "one-stone, two-bird" strategy to circumvent both obstacles, utilizing the source cancer cell membrane (CM) as a dual-function carrier to simultaneously achieve sufficient drug loading and homologous tumor targeting. Combining the use of TPGS (d-α-tocopherol polyethylene glycol 1000 succinate) to inhibit the drug efflux process of drug-resistant tumor, we constructed core-shell-structured nanocomposites CMGNPs consisting of ICG (indocyanine green)/DOX (doxorubicin)-loaded, TPGS/OA (oleic acid)-stabilized upconversion nanoparticles as the core and ICG-loaded MCF7/ADR CMs as the shell, for combined chemo/phototherapy of MCF7/ADR tumor. The employment of phospholipid bilayers of CMs as natural pockets for extra drug loading while preserving the homologous targeting ability greatly enhanced drug concentration at tumor sites, endowing CMGNPs with excellent therapeutic efficacy. Our effort provides a versatile approach for facilitating drug delivery in diverse therapeutic systems.

Cell membrane-camouflaged inorganic nanoparticles for cancer therapy

Inorganic nanoparticles (INPs) have been paid great attention in the field of oncology in recent past years since they have enormous potential in drug delivery, gene delivery, photodynamic therapy (PDT), photothermal therapy (PTT), bio-imaging, driven motion, etc. To overcome the innate limitations of the conventional INPs, such as fast elimination by the immune system, low accumulation in tumor sites, and severe toxicity to the organism, great efforts have recently been made to modify naked INPs, facilitating their clinical application. Taking inspiration from nature, considerable researchers have exploited cell membrane-camouflaged INPs (CMCINPs) by coating various cell membranes onto INPs. CMCINPs naturally inherit the surface adhesive molecules, receptors, and functional proteins from the original cell membrane, making them versatile as the natural cells. In order to give a timely and representative review on this rapidly developing research subject, we highlighted recent advances in CMCINPs with superior unique merits of various INPs and natural cell membranes for cancer therapy applications. The opportunity and obstacles of CMCINPs for clinical translation were also discussed. The review is expected to assist researchers in better eliciting the effect of CMCINPs for the management of tumors and may catalyze breakthroughs in this area.

Biomimetic nanobubbles for triple-negative breast cancer targeted ultrasound molecular imaging

Triple-negative breast cancer (TNBC) is a highly heterogeneous breast cancer subtype with poor prognosis. Although anatomical imaging figures prominently for breast lesion screening, TNBC is often misdiagnosed, thus hindering early medical care. Ultrasound (US) molecular imaging using nanobubbles (NBs) capable of targeting tumor cells holds great promise for improved diagnosis and therapy. However, the lack of conventional biomarkers in TNBC impairs the development of current targeted agents. Here, we exploited the homotypic recognition of cancer cells to synthesize the first NBs based on TNBC cancer cell membrane (i.e., NB_CCM) as a targeted diagnostic agent. We developed a microfluidic technology to synthesize NB_CCM based on the self-assembly property of cell membranes in aqueous solutions. In vitro, optimal NB_CCM had a hydrodynamic diameter of 683 ± 162 nm, showed long-lasting US contrast enhancements and homotypic affinity. In vivo, we demonstrated that NB_CCM showed increased extravasation and retention in a TNBC mouse model compared to non-targeted NBs by US molecular imaging. Peak intensities and areas under the curves from time-intensity plots showed a significantly enhanced signal from NB_CCM compared to non-targeted NBs (2.1-fold, P = 0.004, and, 3.6-fold, P = 0.0009, respectively). Immunofluorescence analysis further validated the presence of NB_CCM in the tumor microenvironment. Circumventing the challenge for universal cancer biomarker identification, our approach could enable TNBC targeting regardless of tumor tissue heterogeneity, thus improving diagnosis and potentially gene/drug targeted delivery. Ultimately, our approach could be used to image many cancer types using biomimetic NBs prepared from their respective cancer cell membranes.

Cell Membrane Camouflaged Metal Oxide-Black Phosphorus Biomimetic Nanocomplex Enhances Photo-chemo-dynamic Ferroptosis

Despite the availability of various treatment options, the inherent complexity of tumors significantly impairs therapeutic efficacy. Recently, combination treatments exhibited great anticancer potential due to low cross-resistance and good therapeutic additivity. Herein, a photoactive metal oxide-black phosphorus biomimetic nanocomplex (photophage) is developed for improving the antitumor combination of ferroptosis and photodynamic therapy (PDT). The photophage is composed of M1 macrophage membrane camouflaged MnO2 and Fe3O4 nanoparticles anchored black phosphorus nanosheets (BPNs), which together trigger a synergistic antitumor action. Fe3O4 acts as an iron source to activate Fenton-reaction-dependent ferroptosis, which can be further strengthened by BPN-mediated PDT. Besides the original antitumor effects, PDT also generates reactive oxygen species to enhance lipid peroxidation and glutathione depletion, which in turn reinforce ferroptosis and PDT efficacy. Importantly, MnO2 can in situ generate oxygen to relieve tumor hypoxia and consequently leverage cell behaviors to improve therapeutic responses. Particularly, M1 macrophage membrane modification endows the photophage with good tumor targeting capability and tumor penetration, which promote synergistic ferroptosis and PDT to destroy tumors while reducing systemic side effects, resulting in the prolonged survival of tumor-bearing mice. Therefore, we present a biomimetic nanoplatform for overcoming tumor barriers and advancing tumor-targeted treatment.

Study on biomimetic nano tumor targeted delivery system for chemotherapy-laser immunotherapy

To explore the immune adjuvant effect of nano mesoporous materials and laser immune effect of cancer therapy combined with chemotherapy, we designed a bionic nano tumor targeting delivery system with homologous cancer cell membrane as the outermost layer. Inorganic mesoporous silica (mSiO₂) and hydroxyapatite (HAP) are used as the intermediate immune adjuvant layer and drug carrier layer, and gold nanorods(GNR) are used as the core. It degrade to release drug under the condition of low pH value, and the gold nanorods are wrapped for near-infrared laser response. Homologous cancer cell membrane wrapping is expected to greatly improve the efficiency of targeted delivery. Laser immunotherapy is more widely applied than antibody and vaccine, and has no serious side effects. Combined with controlled release drug targeted chemotherapy and encapsulated with tumor cell membrane, it is expected to further achieve low toxicity and high efficiency cancer treatment.

Advancements in cell membrane camouflaged nanoparticles: A bioinspired platform for cancer therapy

The idea of employing natural cell membranes as a coating medium for nanoparticles (NPs) endows man-made vectors with natural capabilities and benefits. In addition to retaining the physicochemical characteristics of the NPs, the biomimetic NPs also have the functionality of source cell membranes. It has emerged as a promising approach to enhancing the properties of NPs for drug delivery, immune evasion, imaging, cancer-targeting, and phototherapy sensitivity. Several studies have been reported with a multitude of approaches to reengineering the surface of NPs using biological membranes. Owing to their low immunogenicity and intriguing biomimetic properties, cell-membrane-based biohybrid delivery systems have recently gained a lot of interest as therapeutic delivery systems. This review summarises different kinds of biomimetic NPs reported so far, their fabrication aspects, and their application in the biomedical field. Finally, it briefs on the latest advances available in this biohybrid concept.

Challenges in the Development of Drug Delivery Systems Based on Small Extracellular Vesicles for Therapy of Brain Diseases

Small extracellular vesicles (sEVs) have ∼30–200 nm diameter size and may act as carriers of different cargoes, depending on the cell of origin or on the physiological/pathological condition. As endogenous nanovesicles, sEVs are important in intercellular communication and have many of the desirable features of an ideal drug delivery system. sEVs are naturally biocompatible, with superior targeting capability, safety profile, nanometric size, and can be loaded with both lipophilic and hydrophilic agents. Because of their biochemical and physical properties, sEVs are considered a promising strategy over other delivery vehicles in the central nervous system (CNS) since they freely cross the blood-brain barrier and they can be directed to specific nerve cells, potentiating a more precise targeting of their cargo. In addition, sEVs remain stable in the peripheral circulation, making them attractive nanocarrier systems to promote neuroregeneration. This review focuses on the recent progress in methods for manufacturing, isolating, and engineering sEVs that can be used as a therapeutic strategy to overcome neurodegeneration associated with pathologies of the CNS, with particular emphasis on Alzheimer’s, Parkinson’s, and amyotrophic lateral sclerosis diseases, as well as on brain tumors.

Plasma Membrane-Derived Liposomes Exhibit Robust Antiviral Activity against HSV-1

Plasma membranes host a plethora of proteins and glycans on their outer surface that are exploited by viruses to enter the cells. In this study, we have utilized this property to limit a viral infection using plasma membrane-derived vesicles. We show that plasma membrane-derived liposomes are prophylactically and therapeutically competent at preventing herpes simplex virus type-1 (HSV-1) infection. Plasma membrane liposomes derived from human corneal epithelial (HCE) cells, which are natural targets of HSV-1 infection, as well as Vero and Chinese hamster ovary (CHO) cells were used in this study. Our study clearly demonstrates that HCE and Vero-derived cellular liposomes, which express the viral entry-specific cell surface protein receptors, exhibit robust antiviral activity especially when compared to CHO-derived liposomes, which lack the relevant HSV-1 entry receptors. Further experimentation of the plasma membrane-derived liposomes with HSV type-2 (HSV-2) and pseudorabies virus yielded similar results, indicating strong potential for the employment of these liposomes to study viral entry mechanisms in a cell free-environment.

Hybrid-Membrane-Decorated Prussian Blue for Effective Cancer Immunotherapy via Tumor-Associated Macrophages Polarization and Hypoxia Relief

Both tumor-associated macrophages (TAMs) and hypoxia condition severely restrict the antitumor potency during cancer immunotherapy. It is essential to overcome the two issues for improving therapeutic efficacy. In this study, a hollow mesoporous Prussian blue (HMPB) nanosystem with mannose decoration and hydroxychloroquine (HCQ) adsorption is built, to form Man-HMPB/HCQ. It can facilitate cellular internalization via mannose-receptor mediated endocytosis and induce TAM polarization via iron ion/HCQ release with HMPB degradation. The hybrid macrophage and thylakoid (TK) membrane is camouflaged on the Man-HMPB/HCQ surface, denoted as TK-M@Man-HMPB/HCQ, to reduce in vivo reticuloendothelial system uptake, enhance tumor accumulation, and mitigate hypoxia. The in vivo results indicate that TK-M@Man-HMPB/HCQ notably inhibits tumor growth, induces TAM polarization, facilitates cytotoxic T lymphocytes infiltration, and alleviates hypoxia microenvironment. The rational design may provide a new pathway to modulate the tumor microenvironment for promoting cancer immunotherapy effects.

Research Progress of Cell Membrane Biomimetic Nanoparticles for Tumor Therapy

Nanoparticles have unique properties and high design flexibility, which are thought to be safe, site-specific, and efficient drug delivery systems. However, nanoparticles as exogenous materials can provide recognition and be eliminated by the body's immune system, which considerably restricts their applications. To overcome these drawbacks, natural cell membrane coating method has attracted great attention in the field of drug delivery systems, which can prolong nanoparticles blood circulation time and avoiding the capture as well as elimination by the body immune system. Biomimetic nanoparticles via a top-down approach can avoid the laborious group modified engineering and keep the integrity of cell membrane structure and membrane antigens, which can be endowed with unique properties, such as immune escape, longer blood circulation time, targeting delivery and controlling drugs sustain-release. At the present research, erythrocyte membrane, cancer cell membrane, platelet membrane, lymphocyte membrane and hybrid membrane have been successfully coated into the surface of nanoparticles to achieve biological camouflage. Thus, integrating various kinds of cell membranes and nanoparticles into one system, the biomimetic nanoparticles can inherit unique biofunction and drug delivery properties to exhibit tumor targeting-delivery and antitumor outcomes. In this article, we will discuss the prospects and challenges of some basic cell membrane cloaking nanoparticles as a drug delivery system for cancer therapy.

Homologous targeting nanoparticles for enhanced PDT against osteosarcoma HOS cells and the related molecular mechanisms

BACKGROUND

No prominent advancements in osteosarcoma (OS) treatment have been made in the past 20 years. Although photodynamic therapy (PDT) is an emerging technique for cancer therapy, the lack of targeted photosensitizers for OS treatment severely limits its applications.

RESULTS

In this study, we constructed a potential theranostic nanoplatform by using (poly (lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) encapsulating IR780 into the shell (PLGA-IR780 NPs), which were further camouflaged with human OS cell membranes from the HOS cell line (MH-PLGA-IR780 NPs). These constructed NPs showed the capacity for homologous targeting with excellent photoacoustic (PA)/fluorescence (FL) imaging ability. Benefitting from their homologous targeting capacity, MH-PLGA-IR780 NPs obviously promoted cell endocytosis in vitro and tumor accumulation in vivo, which could further improve PDT performance under near-infrared (NIR) irradiation. In addition, to their homologous targeting and PA/FL dual-mode imaging ability, MH-PLGA-IR780 NPs had advantages in penetrating deeper into tumor tissues and in real-time dynamic distribution monitoring in vivo, which laid a foundation for further clinical applications in OS. Moreover, we demonstrated that PDT guided by the constructed NPs could significantly induce HOS cells apoptosis and ferroptosis via excessive accumulation of reactive oxygen species (ROS), and further determined that the potential anticancer molecular mechanism of apoptosis was triggered by the release of cytochrome c-activated mitochondrial apoptosis (endogenous apoptosis), and that ferroptosis caused the activation of nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy and the inactivation of glutathione peroxidase 4 (GPX4), synergistically leading to excessive accumulation of Lipid-ROS and Lipid peroxides (LPOs). Concurrently, MH-PLGA-IR780 NPs-guided PDT also showed an obvious inhibitory effect on tumor growth in vivo.

CONCLUSION

These results suggest that this homologous targeting-based theranostic nanoplatform provides an effective method to improve PDT performance in OS and contributes a new and promising approach for OS therapy.

Near-Infrared-II Quantum Dots for In Vivo Imaging and Cancer Therapy

In vivo fluorescence imaging can perform real-time, noninvasive, and high spatiotemporal resolution imaging to accurately obtain the dynamic biological information in vivo, which plays significant roles in the early diagnosis and treatment of cancer. However, traditional in vivo fluorescence imaging usually operates in the visible and near-infrared (NIR)-I windows, which are severely interfered by the strong tissue absorption, tissue scattering, and autofluorescence. The emergence of NIR-II imaging at 1000-1700 nm significantly breaks through the imaging limitations in deep tissues, due to less tissue scattering and absorption. Benefiting from the outstanding optical properties of NIR-II quantum dots (QDs), such as high brightness and good photostability, in vivo fluorescence imaging exhibits excellent temporal-spatial resolution and large penetration depth, and QDs have become a kind of promising fluorescent biomarkers in the field of in vivo fluorescence imaging. Herein, the authors review NIR-II QDs from preparation to modification, and summarize recent applications of NIR-II QDs, including in vivo imaging and imaging-guided therapies. Finally, they discuss the special concerns when NIR-II QDs are shifted from in vivo imaging applications to further in-depth applications.

Cell membrane coated-nanoparticles for cancer immunotherapy

Cancer immunotherapy can effectively inhibit cancer progression by activating the autoimmune system, with low toxicity and high effectiveness. Some of cancer immunotherapy had positive effects on clinical cancer treatment. However, cancer immunotherapy is still restricted by cancer heterogeneity, immune cell disability, tumor immunosuppressive microenvironment and systemic immune toxicity. Cell membrane-coated nanoparticles (CMCNs) inherit abundant source cell-relevant functions, including “self” markers, cross-talking with the immune system, biological targeting, and homing to specific regions. These enable them to possess preferred characteristics, including better biological compatibility, weak immunogenicity, immune escaping, a prolonged circulation, and tumor targeting. Therefore, they are applied to precisely deliver drugs and promote the effect of cancer immunotherapy. In the review, we summarize the latest researches of biomimetic CMCNs for cancer immunotherapy, outline the existing specific cancer immune therapies, explore the unique functions and molecular mechanisms of various cell membrane-coated nanoparticles, and analyze the challenges which CMCNs face in clinical translation.

Mitochondria-targeting multifunctional nanoplatform for cascade phototherapy and hypoxia-activated chemotherapy

Despite considerable progress has been achieved in hypoxia-associated anti-tumor therapy, the efficacy of utilizing hypoxia-activated prodrugs alone is not satisfied owing to the inadequate hypoxia within the tumor regions. In this work, a mitochondrial targeted nanoplatform integrating photodynamic therapy, photothermal therapy and hypoxia-activated chemotherapy has been developed to synergistically treat cancer and maximize the therapeutic window. Polydopamine coated hollow copper sulfide nanoparticles were used as the photothermal nanoagents and thermosensitive drug carriers for loading the hypoxia-activated prodrug, TH302, in our study. Chlorin e6 (Ce6) and triphenyl phosphonium (TPP) were conjugated onto the surface of the nanoplatform. Under the action of TPP, the obtained nanoplatform preferentially accumulated in mitochondria to restore the drug activity and avoid drug resistance. Using 660 nm laser to excite Ce6 can generate ROS and simultaneously exacerbate the cellular hypoxia. While under the irradiation of 808 nm laser, the nanoplatform produced local heat which can increase the release of TH302 in tumor cells, ablate cancer cells as well as intensify the tumor hypoxia levels. The aggravated tumor hypoxia then significantly boosted the anti-tumor efficiency of TH302. Both in vitro and in vivo studies demonstrated the greatly improved anti-cancer activity compared to conventional hypoxia-associated chemotherapy. This work highlights the potential of using a combination of hypoxia-activated prodrugs plus phototherapy for synergistic cancer treatment.

Stem Cell Mimicking Nanoencapsulation for Targeting Arthritis

Mesenchymal stem cells (MSCs) are considered a promising regenerative therapy due to their ability to migrate toward damaged tissues. The homing ability of MSCs is unique compared with that of non-migrating cells and MSCs are considered promising therapeutic vectors for targeting major cells in many pathophysiological sites. MSCs have many advantages in the treatment of malignant diseases, particularly rheumatoid arthritis (RA). RA is a representative autoimmune disease that primarily affects joints, and secreted chemokines in the joints are well recognized by MSCs following their migration to the joints. Furthermore, MSCs can regulate the inflammatory process and repair damaged cells in the joints. However, the functionality and migration ability of MSCs injected in vivo still show insufficient. The targeting ability and migration efficiency of MSCs can be enhanced by genetic engineering or modification, eg, overexpressing chemokine receptors or migration-related genes, thus maximizing their therapeutic effect. However, there are concerns about genetic changes due to the increased probability of oncogenesis resulting from genome integration of the viral vector, and thus, clinical application is limited. Furthermore, it is suspected that administering MSCs can promote tumor growth and metastasis in xenograft and orthotopic models. For this reason, MSC mimicking nanoencapsulations are an alternative strategy that does not involve using MSCs or bioengineered MSCs. MSC mimicking nanoencapsulations consist of MSC membrane-coated nanoparticles, MSC-derived exosomes and artificial ectosomes, and MSC membrane-fused liposomes with natural or genetically engineered MSC membranes. MSC mimicking nanoencapsulations not only retain the targeting ability of MSCs but also have many advantages in terms of targeted drug delivery. Specifically, MSC mimicking nanoencapsulations are capable of encapsulating drugs with various components, including chemotherapeutic agents, nucleic acids, and proteins. Furthermore, there are fewer concerns over safety issues on MSC mimicking nanoencapsulations associated with mutagenesis even when using genetically engineered MSCs, because MSC mimicking nanoencapsulations use only the membrane fraction of MSCs. Genetic engineering is a promising route in clinical settings, where nano-encapsulated technology strategies are combined. In this review, the mechanism underlying MSC homing and the advantages of MSC mimicking nanoencapsulations are discussed. In addition, genetic engineering of MSCs and MSC mimicking nanoencapsulation is described as a promising strategy for the treatment of immune-related diseases.

Biomimetic nanoparticles: U937 cell membranes based core-shell nanosystems for targeted atherosclerosis therapy

Atherosclerosis (AS), with its intricate pathogenesis, is primarily responsible for the development and progression of cardiovascular diseases. Although drug development has made some achievements in AS therapy, limited targeting ability and rapid blood clearance remain great challenges for achieving superior clinical outcomes. Herein, ginsenoside (Re)- and catalase (CAT)-coloaded porous poly(lactic-coglycolic acid) (PLGA) nanoparticles (NPs) were prepared and then surface modified with U937 cell membranes (UCMs) to yield a dual targeted model and multimechanism treatment biomimetic nanosystem (Cat/Re@PLGA@UCM). The nanoparticles consisted of a core-shell spherical morphology with a favorable size of 112.7 ± 0.4 nm. Furthermore, UCM assisted the nanosystem in escaping macrophage phagocytosis and targeting atherosclerotic plaques. Meanwhile, loading with catalase might not only exhibit favorable antioxidant effects but also enable H₂O₂-responsive drug release ability. The Cat/Re@PLGA@UCM NPs also exhibited outstanding ROS scavenging properties, downregulating ICAM-1, TNF-α and IL-1β, while preventing angiogenesis to attenuate the progression of AS. Moreover, the nanodrugs displayed 2.7-fold greater efficiency in reducing the atherosclerotic area in ApoE^-/- mouse models compared to free Re. Our nanoformulation also displayed excellent biosafety in response to long-term administration. Overall, our study demonstrated the superiority of UCM-coated stimuli-responsive nanodrugs for effective and safe AS therapy.

Autophagy-inhibiting biomimetic nanodrugs enhance photothermal therapy and boost antitumor immunity

The instinctive protective stress responses of tumor cells hamper the low-temperature photothermal therapy (LTPTT), resulting in tumor recurrence and metastasis. The rapid blood clearance and low-efficiency tumor enrichment of nanomedicines...

Cell membrane-engineered nanoparticles for cancer therapy

Cell-membrane-coated nanotechnology involves dressing the synthetic nanoparticles (NPs) with membrane derived from different types of cells to endow the NPs with the properties of a specific cell type and to further...