Cell Membrane-Camouflaged Nanocarriers for Cancer Diagnostic and Therapeutic

Biohybrid nano-platforms manifesting effective cancer therapy: Fabrication, characterization, challenges and clinical perspective

Nanotechnology-based delivery systems have brought a paradigm shift in the management of cancer. However, the main obstacles to nanocarrier-based delivery are their limited circulation duration, excessive immune clearance, inefficiency in interacting effectively in a biological context and overcoming biological barriers. This demands effective engineering of nanocarriers to achieve maximum efficacy. Nanocarriers can be maneuvered with biological components to acquire biological identity for further regulating their biodistribution and cell-to-cell cross-talk. Thus, the integration of synthetic and biological components to deliver therapeutic cargo is called a biohybrid delivery system. These delivery systems possess the advantage of synthetic nanocarriers, such as high drug loading, engineerable surface, reproducibility, adequate communication and immune evasion ability of biological constituents. The biohybrid delivery vectors offer an excellent opportunity to harness the synergistic properties of the best entities of the two worlds for improved therapeutic outputs. The major spotlights of this review are different biological components, synthetic counterparts of biohybrid nanocarriers, recent advances in hybridization techniques, and the design of biohybrid delivery systems for cancer therapy. Moreover, this review provides an overview of biohybrid systems with therapeutic and diagnostic applications. In a nutshell, this article summarizes the advantages and limitations of various biohybrid nano-platforms, their clinical potential and future directions for successful translation in cancer management.

On the design of cell membrane-coated nanoparticles to treat inflammatory conditions

Biomimetic-based drug delivery systems (DDS) attempt to recreate the complex interactions that occur naturally between cells. Cell membrane-coated nanoparticles (CMCNPs) have been one of the main strategies in this area to prevent opsonization and clearance. Moreover, coating nanoparticles with cell membranes allows them to acquire functions and properties inherent to the mother cells. In particular, cells from bloodstream show to have specific advantages depending on the cell type to be used for that application, specifically in cases of chronic inflammation. Thus, this review focuses on the biomimetic strategies that use membranes from blood cells to target and treat inflammatory conditions.

A Review of the Efficacy of Nanomaterial-Based Natural Photosensitizers to Overcome Multidrug Resistance in Cancer

Natural photosensitizers (PS) are compounds derived from nature, with photodynamic properties. Natural PSs have a similar action to that of commercial PSs, where cancer cell death occurs by necrosis, apoptosis, and autophagy through ROS generation. Natural PSs have garnered great interest over the last few decades because of their high biocompatibility and good photoactivity. Specific wavelengths could cause phytochemicals to produce harmful ROS for photodynamic therapy (PDT). However, natural PSs have some shortcomings, such as reduced solubility and lower uptake, making them less appropriate for PDT. Nanotechnology offers an opportunity to develop suitable carriers for various natural PSs for PDT applications. Various nanoparticles have been developed to improve the outcome with enhanced solubility, optical adsorption, and tumor targeting. Multidrug resistance (MDR) is a phenomenon in which tumor cells develop resistance to a wide range of structurally and functionally unrelated drugs. Over the last decade, several researchers have extensively studied the effect of natural PS-based photodynamic treatment (PDT) on MDR cells. Though the outcomes of clinical trials for natural PSs were inconclusive, significant advancement is still required before PSs can be used as a PDT agent for treating MDR tumors. This review addresses the increasing literature on MDR tumor progression and the efficacy of PDT, emphasizing the importance of developing new nano-based natural PSs in the fight against MDR that have the required features for an MDR tumor photosensitizing regimen.

Advances in Composite Biofilm Biomimetic Nanodrug Delivery Systems for Cancer Treatment

Single biofilm biomimetic nanodrug delivery systems based on single cell membranes, such as erythrocytes and cancer cells, have immune evasion ability, good biocompatibility, prolonged blood circulation, and high tumor targeting. Because of the different characteristics and functions of each single cell membrane, more researchers are using various hybrid cell membranes according to their specific needs. This review focuses on several different types of biomimetic nanodrug-delivery systems based on composite biofilms and looks forward to the challenges and possible development directions of biomimetic nanodrug-delivery systems based on composite biofilms to provide reference and ideas for future research.

Cell Membrane Biomimetic Nano-Delivery Systems for Cancer Therapy

Nano-delivery systems have demonstrated great promise in the therapy of cancer. However, the therapeutic efficacy of conventional nanomedicines is hindered by the clearance of the blood circulation system and the physiological barriers surrounding the tumor. Inspired by the unique capabilities of cells within the body, such as immune evasion, prolonged circulation, and tumor-targeting, there has been a growing interest in developing cell membrane biomimetic nanomedicine delivery systems. Cell membrane modification on nanoparticle surfaces can prolong circulation time, activate tumor-targeting, and ultimately improve the efficacy of cancer treatment. It shows excellent development potential. This review will focus on the advancements in various cell membrane nano-drug delivery systems for cancer therapy and the obstacles encountered during clinical implementation. It is hoped that such discussions will inspire the development of cell membrane biomimetic nanomedical systems.

Cell or cell derivative-laden hydrogels for myocardial infarction therapy: from the perspective of cell types

Myocardial infarction (MI) is a global cardiovascular disease with high mortality and morbidity. To treat acute MI, various therapeutic approaches have been developed, including cells, extracellular vesicles, and biomimetic nanoparticles. However, the clinical application of these therapies is limited due to low cell viability, inadequate targetability, and rapid elimination from cardiac sites. Injectable hydrogels, with their three-dimensional porous structure, can maintain the biomechanical stabilization of hearts and the transplantation activity of cells. However, they cannot regenerate cardiomyocytes or repair broken hearts. A better understanding of the collaborative relationship between hydrogel delivery systems and cell or cell-inspired therapy will facilitate advancing innovative therapeutic strategies against MI. Following that, from the perspective of cell types, MI progression and recent studies on using hydrogel to deliver cell or cell-derived preparations for MI treatment are discussed. Finally, current challenges and future prospects of cell or cell derivative-laden hydrogels for MI therapy are proposed.

Dual-Targeting Biomimetic Nanomaterials for Photo-/Chemo-/Antiangiogenic Synergistic Therapy

Avoiding the low specificity of phototheranostic reagents at the tumor site is a major challenge in cancer phototherapy. Meanwhile, angiogenesis in the tumor is not only the premise of tumor occurrence but also the basis of tumor growth, invasion, and metastasis, making it an ideal strategy for tumor therapy. Herein, biomimetic cancer cell membrane-coated nanodrugs (mBPP NPs) have been prepared by integrating (i) homotypic cancer cell membranes for evading immune cell phagocytosis to increase drug accumulation, (ii) protocatechuic acid for tumor vascular targeting along with chemotherapy effect, and (iii) near-infrared phototherapeutic agent diketopyrrolopyrrole derivative for photodynamic/photothermal synergetic therapy. The mBPP NPs exhibit high biocompatibility, superb phototoxicity, excellent antiangiogenic ability, and double-trigging cancer cell apoptosis in vitro. More significantly, mBPP NPs could specifically bind to tumor cells and vasculature after intravenous injection, inducing fluorescence and photothermal imaging-guided tumor ablation without recurrence and side effects in vivo. The biomimetic mBPP NPs could cause drug accumulation at the tumor site, inhibit tumor neovascularization, and improve phototherapy efficiency, providing a novel avenue for cancer treatment.

Cell membrane-coated nanomaterials for cancer therapy

With the development of nanotechnology, nanoparticles have emerged as a delivery carrier for tumor drug therapy, which can improve the therapeutic effect by increasing the stability and solubility and prolonging the half-life of drugs. However, nanoparticles are foreign substances for humans, are easily cleared by the immune system, are less targeted to tumors, and may even be toxic to the body. As a natural biological material, cell membranes have unique biological properties, such as good biocompatibility, strong targeting ability, the ability to evade immune surveillance, and high drug-carrying capacity. In this article, we review cell membrane-coated nanoparticles (CMNPs) and their applications to tumor therapy. First, we briefly describe CMNP characteristics and applications. Second, we present the characteristics and advantages of different cell membranes as well as nanoparticles, provide a brief description of the process of CMNPs, discuss the current status of their application to tumor therapy, summarize their shortcomings for use in cancer therapy, and propose future research directions. This review summarizes the research progress on CMNPs in cancer therapy in recent years and assesses remaining problems, providing scholars with new ideas for future research on CMNPs in tumor therapy.

Toll-like Receptor Signaling-deficient Cells Enhance Antitumor Activity of Cell-based Immunotherapy by Increasing Tumor Homing

Cancer immunotherapy aims to activate the immune system. Some immunotherapeutic agents can be loaded in carrier cells for delivering to the tumors. However, a challenge with cell-based therapies is the selection of the appropriate cells to produce effective clinical outcomes. We hypothesize that therapies based on cells presenting a natural low proinflammatory profile ("silent cells") in the peripheral blood would result in better antitumor responses by increasing their homing to the tumor site. We studied our hypothesis in an immunotherapy model consisting of mesenchymal stromal cells (MSCs) carrying oncolytic adenoviruses for the treatment of immunocompetent mice. Toll-like receptor signaling-deficient cells (TLR4, TLR9, or MyD88 knockout) were used as "silent cells," while regular MSCs were used as control. Although in vitro migration was similar in regular and knockout carrier cells, in vivo tumor homing of silent cells was significantly higher after systemic administration. This better homing to the tumor site was highly related to the mild immune response triggered by these silent cells in peripheral blood. As a result, the use of silent cells significantly improved the antitumor efficacy of the treatment in comparison with the use of regular MSCs. While cancer immunotherapies generally aim to boost local immune responses in the tumor microenvironment, low systemic inflammation after systemic administration of the treatment may indeed enhance their tumor homing and improve the overall antitumor effect. These findings highlight the importance of selecting appropriate donor cells as therapeutic carriers in cell-based therapies for cancer treatment.

Significance

Cells carrying drugs, virus, or other antitumor agents are commonly used for the treatment of cancer. This research shows that silent cells are excellent carriers for immunotherapies, improving tumor homing and enhancing the antitumor effect.

Immune-regulating camouflaged nanoplatforms: A promising strategy to improve cancer nano-immunotherapy

Although nano-immunotherapy has advanced dramatically in recent times, there remain two significant hurdles related to immune systems in cancer treatment, such as (namely) inevitable immune elimination of nanoplatforms and severely immunosuppressive microenvironment with low immunogenicity, hampering the performance of nanomedicines. To address these issues, several immune-regulating camouflaged nanocomposites have emerged as prevailing strategies due to their unique characteristics and specific functionalities. In this review, we emphasize the composition, performances, and mechanisms of various immune-regulating camouflaged nanoplatforms, including polymer-coated, cell membrane-camouflaged, and exosome-based nanoplatforms to evade the immune clearance of nanoplatforms or upregulate the immune function against the tumor. Further, we discuss the applications of these immune-regulating camouflaged nanoplatforms in directly boosting cancer immunotherapy and some immunogenic cell death-inducing immunotherapeutic modalities, such as chemotherapy, photothermal therapy, and reactive oxygen species-mediated immunotherapies, highlighting the current progress and recent advancements. Finally, we conclude the article with interesting perspectives, suggesting future tendencies of these innovative camouflaged constructs towards their translation pipeline.

Liver fibrosis therapy based on biomimetic nanoparticles which deplete activated hepatic stellate cells

Liver fibrosis is one of the most common liver diseases with substantial morbidity and mortality. However, effective therapy for liver fibrosis is still lacking. Considering the key fibrogenic role of activated hepatic stellate cells (aHSCs), here we reported a strategy to deplete aHSCs by inducing apoptosis as well as quiescence. Therefore, we engineered biomimetic all-trans retinoic acid (ATRA) loaded PLGA nanoparticles (NPs). HSC (LX2 cells) membranes, presenting the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), were coated on the surface of the nanoparticles, while the clinically approved agent ATRA with anti-fibrosis ability was encapsulated in the inner core. The biomimetic coating of TRAIL-expressing HSC membranes does not only provide homologous targeting to HSCs, but also effectively triggers apoptosis of aHSCs. ATRA could induce quiescence of activated fibroblasts. While TM-NPs (i.e. membrane coated NPs without ATRA) and ATRA/NPs (i.e. non-coated NPs loaded with ATRA) only showed the ability to induce apoptosis and decrease the α-SMA expression in aHSCs, respectively, TM-ATRA/NPs induced both apoptosis and quiescence in aHSCs, ultimately leading to improved fibrosis amelioration in both carbon tetrachloride-induced and methionine and choline deficient L-amino acid diet induced liver fibrosis mouse models. We conclude that biomimetic TM-ATRA/NPs may provide a novel strategy for effective antifibrosis therapy.

Surgically Derived Cancer Cell Membrane-Coated R837-Loaded Poly(2-Oxazoline) Nanoparticles for Prostate Cancer Immunotherapy

Cancer cell membranes (CCMs) are widely used as sources of tumor-associated antigens (TAAs) for the development of cancer vaccines. To improve the CCM-associated cancer vaccine efficiency, personalized cancer vaccines and effective delivery systems are required. In this study, we employed surgically harvested cancer tissues to prepare personalized CCMs for use as TAAs. Thioglycolic-acid-grafted poly(2-methyl-2-oxazoline)-block-poly(2-butyl-2-oxazoline-co-2-butenyl-2-oxazoline) (PMBEOx-COOH) was synthesized to load imiquimod (R837) efficiently. The personalized CCMs were then coated onto R837-loaded PMBEOx-COOH nanoparticles (POxTA NPs/R837) to obtain surgically derived CCM-coated POxTA NPs (SCNPs/R837). SCNPs/R837 efficiently travelled to the draining lymph nodes and were taken up and presented by plasmacytoid dendritic cells to elicit enhanced antitumor immune responses. When combined with programmed cell death-1 antibodies, SCNPs/R837 exhibited high efficiency corresponding to antitumor progression. Therefore, SCNP/R837 might represent a promising personalized cancer vaccine with significant potential for cancer immunotherapy.

Tumor-Targeted Erythrocyte Membrane Nanoparticles for Theranostics of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) cells do not contain various receptors for targeted treatment, a reason behind the poor prognosis of this disease. In this study, biocompatible theranostic erythrocyte-derived nanoparticles (EDNs) were developed and evaluated for effective early diagnosis and treatment of TNBC. The anti-cancer drug, doxorubicin (DOX), was encapsulated into the EDNs and diagnostic quantum dots (QDs) were incorporated into the lipid bilayers of EDNs for tumor bio-imaging. Then, anti-epidermal growth factor receptor (EGFR) antibody molecules were conjugated to the surface of EDNs for TNBC targeting (iEDNs). According to the confocal microscopic analyses and biodistribution assay, iEDNs showed a higher accumulation in EGFR-positive MDA-MB-231 cancers in vitro as well as in vivo, compared to untargeted EDNs. iEDNs containing doxorubicin (iEDNs-DOX) showed a stronger inhibition of target tumor growth than untargeted ones. The resulting anti-EGFR iEDNs exhibited strong biocompatibility, prolonged blood circulation, and efficient targeting of TNBC in mice. Therefore, iEDNs may be used as potential TNBC-targeted co-delivery systems for therapeutics and diagnostics.

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.

A Perspective on EGFR and Proteasome-based Targeted Therapy for Cancer

BACKGROUND

Cancer is known to be the most leading cause of death worldwide. It is understood that the sources causing cancer mainly include the activity of endogenous oncogenes, nonviral compounds and the fundamental portion of these oncogenes; the tyrosine kinase activity and proteasome activity are the main biomarkers responsible for cell proliferation. These biomarkers can be used as main targets and are believed to be the 'prime switches' for the signal communication activity to regulate cell death and cell cycle. Thus, signal transduction inhibitors (ligandreceptor tyrosine kinase inhibitors) and proteasome inhibitors can be used as a therapeutic modality to block the action of signaling between the cells as well as protein breakdown in order to induce cell apoptosis.

AIMS

This article highlights the key points and provides an overview of the recent patents on EGFR and proteosome-based inhibitors having therapeutic efficacy. This review focuses on the patents related to therapeutic agents, their preparation process and the final outcome.

OBJECTIVE

The main objective of this study is to facilitate the advancement and current perspectives in the treatment of cancer.

CONCLUSION

There are numerous strategies discussed in these patents to improve the pharmacokinetics and pharmacodynamics of EGFR and proteasome inhibitors. Further, the resistance to targeted therapy after long-term treatment can be overcome by using various excipients that can be used as a strategy to carry the drug. However, there is a need and scope for improving targeted therapeutics for cancer treatment with better fundamentals and characteristics. The widespread research on cancer therapy can create the path for future advancements in therapy with more prominent outcomes.

Platelets for cancer treatment and drug delivery

Extensive research is currently being conducted into a variety of bio-inspired biomimetic nanoparticles (NPs) with new cell simulation functions across the fields of materials science, chemistry, biology, physics, and engineering. Cells such as erythrocytes, platelets, and stem cells have been engineered as new drug carriers. The platelet-derived drug delivery system, which is a new targeted drug delivery system (TDDS), can effectively navigate the blood circulatory system and interact with the complex tumor microenvironment; it appears to outperform traditional anticancer drugs; hence, it has attracted considerable research interest. In this review, we describe innovative studies and outline the latest progress regarding the use of platelets as tumor targeting and drug delivery vehicles; we also highlight opportunities and challenges relevant to the manufacture of tumor-related platelet TDDSs.

Engineered extracellular vesicles as intelligent nanosystems for next-generation nanomedicine

Extracellular vesicles (EVs), as natural carriers of bioactive cargo, have a unique micro/nanostructure, bioactive composition, and characteristic morphology, as well as fascinating physical, chemical and biochemical features, which have shown promising application in the treatment of a wide range of diseases. However, native EVs have limitations such as lack of or inefficient cell targeting, on-demand delivery, and therapeutic feedback. Recently, EVs have been engineered to contain an intelligent core, enabling them to (i) actively target sites of disease, (ii) respond to endogenous and/or exogenous signals, and (iii) provide treatment feedback for optimal function in the host. These advances pave the way for next-generation nanomedicine and offer promise for a revolution in drug delivery. Here, we summarise recent research on intelligent EVs and discuss the use of "intelligent core" based EV systems for the treatment of disease. We provide a critique about the construction and properties of intelligent EVs, and challenges in their commercialization. We compare the therapeutic potential of intelligent EVs to traditional nanomedicine and highlight key advantages for their clinical application. Collectively, this review aims to provide a new insight into the design of next-generation EV-based theranostic platforms for disease treatment.

Cell membrane camouflaged biomimetic nanoparticles: Focusing on tumor theranostics

Nanoparticles (NPs) modified by cell membranes represent an emerging biomimetic platform that can mimic the innate biological functions resulting from the various cell membranes in biological systems. researchers focus on constructing the cell membrane camouflaged NPs using a wide variety of cells, such as red blood cell membranes (RBC), macrophages and cancer cells. Cell membrane camouflaged NPs (CMNPs) inherit the composition of cell membranes, including specific receptors, antigens, proteins, for target delivering to the tumor, escaping immune from clearance, and prolonging the blood circulation time, etc. Combining cell membrane-derived biological functions and the NP cores acted cargo carriers to encapsulate the imaging agents, CMNPs are widely developed to apply in tumor imaging techniques, including computed tomography (CT), magnetic resonance imaging (MRI), fluorescence imaging (FL) and photoacoustic imaging (PA). Herein, in this review, we systematically summarize the superior functions of various CMNPs in tumor imaging, especially highlighting the advanced applications in different imaging techniques, which is to provide the theoretical supports for the development of precise guided imaging and tumor treatment.

Enzyme Catalysis Biomotor Engineering of Neutrophils for Nanodrug Delivery and Cell-Based Thrombolytic Therapy

Utilizing neutrophils (NEs) to target and deliver nanodrugs to inflammation sites has received considerable attention. NEs are involved in the formation and development of thrombosis by transforming into neutrophil extracellular traps (NETs); this indicates that NEs may be a natural thrombolytic drug delivery carrier. However, NEs lack an effective power system to overcome blood flow resistance and enhance targeting efficiency. Herein, we report the application of a urease catalysis micromotor powered NEs nanodrug delivery system to promote thrombolysis and suppress rethrombosis. The urease micromotor powered Janus NEs (UM-NEs) were prepared by immobilizing the enzyme asymmetrically onto the surface of natural NEs and then loading urokinase (UK) coupled silver (Ag) nanoparticles (Ag-UK) to obtain the UM-NEs (Ag-UK) system. Urease catalytic endogenous urea is used to generate thrust by producing ammonia and carbon dioxide, which propels NEs actively targeting the thrombus. The UM-NEs (Ag-UK) can be activated by enriched inflammatory cytokines to release NETs at the thrombosis site, resulting in a concomitant release of Ag-UK. Ag-UK induces thrombolysis to restore vascular recanalization. This urease micromotor-driven NEs drug delivery system can significantly reduce the hemorrhagic side effects, promote thrombolysis, and inhibit rethrombosis with high bioavailability and biosafety, which can be used for the treatment of thrombotic diseases.

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.

Recent advances of engineered and artificial drug delivery system towards solid tumor based on immune cells

Precise drug delivery in cancer treatment is a long-standing concern of modern medicine. Compared with traditional molecular medicines and nano-medicines, emerging cell-based biomimetic delivery strategies display numerous merits, including successive biological functions, innate biocompatibility and superior security since they originate from living organisms, providing a very promising approach. Among them, immune cells receive increasing attention because of their inherent ability in tumor resistance, pathogen elimination, and other significant physiological functions. Herein, we investigated the recent advances on immune cell-based high efficient delivery and therapeutic strategies in solid tumor treatment, mainly focus on T cells, NK cells and macrophages, which have been used as drug cargos directly or provided membrane/exosomes as nanoscale drug delivery systems. We also discuss the further potential applications and perspective of this innovative strategy, as well as the predictable challenges in forward exploration in this emerging area.

Effective Triple-Negative Breast Cancer Targeted Treatment Using iRGD-Modified RBC Membrane-Camouflaged Nanoparticles

Introduction

Triple-negative breast cancer (TNBC) has the high degree of malignancy and aggressiveness. There is no targeted therapy drug. Many studies have shown that RBC membrane-coated nanoparticles achieve biological camouflage. In addition, the RGD module in the iRGD mediates the penetration of the vector across the tumor blood vessels to the tumor tissue space. Therefore, we developed iRGD-RM-(DOX/MSNs) by preparing MSNs loaded with doxorubicin as the core, and coating the surface of the MSNs with iRGD-modified RBC membranes.

Methods

iRGD-RM-(DOX/MSNs) were fabricated using physical extrusion. In addition, their physical and chemical characterization, hemolytic properties, in vivo acute toxicity and inflammatory response, in vitro and in vivo safety, and qualitative and quantitative cellular uptake by RAW 264.7 cells and MDA-MB-231 cells were evaluated and compared. Furthermore, we examined the antitumor efficacy of iRGD-RM-(DOX/MSN) nanoparticles in vitro and in vivo.

Results

iRGD-RM-(DOX/MSNs) have reasonable physical and chemical properties. iRGD-RM-(DOX/MSNs) escaped the phagocytosis of immune cells and achieved efficient targeting of nanoparticles at the tumor site. The nanoparticles showed excellent antitumor effects in vivo and in vitro.

Conclusion

In this study, we successfully developed biomimetic iRGD-RM-(DOX/MSNs) that could effectively target tumors and provide a promising strategy for the effective treatment of TNBC.

Biomimetic cell membrane-coated DNA nanoparticles for gene delivery to glioblastoma

Gene therapy has been introduced as an alternative to radiation and chemical therapy for glioblastoma. Biomimetic nanoparticles coated with cell membranes (CM) have advantages such as high biocompatibility and prolong half-life. To apply CM coated nanoparticles to gene delivery, the polyethylenimine (PEI25k)/plasmid DNA (pDNA) complexes were coated with CM from C6 rat glioblastoma cells. With the CM covering, the PEI25k/pDNA complexes formed stable nanoparticles with negative surface charge. The PEI25k/pDNA/CM nanoparticles had high colloidal stability and could be stored for approximately 20 days without aggregation. The transfection efficiency of the PEI25k/pDNA/CM nanoparticles was higher than that of the PEI25k/pDNA complex in serum-containing medium. This suggests that serum does not interfere with transfection efficiency of the nanoparticles. Moreover, the PEI25k/pDNA/CM nanoparticles had lower toxicity than the PEI25k/DNA complex in vitro and in vivo. The PEI25k/pDNA/CM nanoparticles prepared with CMs of different types of cells were transfected into cells. The results showed that the PEI25k/pDNA/CM nanoparticles with the C6 CM had the highest transfection efficiency to C6 cells, suggesting the homotypic targeting effect. The therapeutic effects of the nanoparticles were evaluated in intracranial C6 transplanted glioblastoma animal models. The PEI25k/pDNA/CM nanoparticles were prepared with herpes simplex virus thymidine kinase plasmid (pHSVtk) and injected into the tumor locally. The results showed that the PEI25k/pHSVtk/CM nanoparticles induced higher HSVtk expression compared with the PEI25k/pHSVtk complex. Furthermore, tumor size was reduced more efficiently by the PEI25k/pHSVtk/CM nanoparticles than by the PEI25k/pHSVtk complex. Overall results indicate that PEI25k/pDNA/CM nanoparticles are suitable for pDNA delivery to glioblastoma.

Integrin αvβ6-targeted MR molecular imaging of breast cancer in a xenograft mouse model

BACKGROUND

The motif RXDLXXL-based nanoprobes allow specific imaging of integrin αvβ6, a protein overexpressed during tumorigenesis and tumor progression of various tumors. We applied a novel RXDLXXL-coupled cyclic arginine-glycine-aspartate (RGD) nonapeptide conjugated with ultrasmall superparamagnetic iron oxide nanoparticles (referred to as cFK-9-USPIO) for the application of integrin αvβ6-targeted magnetic resonance (MR) molecular imaging for breast cancer.

METHODS

A novel MR-targeted nanoprobe, cFK-9-USPIO, was synthesized by conjugating integrin αvβ6-targeted peptide cFK-9 to N-amino (-NH2)-modified USPIO nanoparticles via a dehydration esterification reaction. Integrin αvβ6-positive mouse breast cancer (4 T1) and integrin αvβ6 negative human embryonic kidney 293 (HEK293) cell lines were incubated with cFK-9-AbFlour 647 (blocking group) or cFK-9-USPIO (experimental group), and subsequently imaged using laser scanning confocal microscopy (LSCM) and 3.0 Tesla magnetic resonance imaging (MRI) system. The affinity of cFK-9 targeting αvβ6 was analyzed by calculating the mean fluorescent intensity in cells, and the nanoparticle targeting effect was measured by the reduction of T2 values in an in vitro MRI. The in vivo MRI capability of cFK-9-USPIO was investigated in 4 T1 xenograft mouse models. Binding of the targeted nanoparticles to αvβ6-positive 4 T1 tumors was determined by ex vivo histopathology.

RESULTS

In vitro laser scanning confocal microscopy (LSCM) imaging showed that the difference in fluorescence intensity between the targeting and blocking groups of 4 T1 cells was significantly greater than that in HEK293 cells (P < 0.05). The in vitro MRI demonstrated a more remarkable T2 reduction in 4 T1 cells than in HEK293 cells (P < 0.001). The in vivo MRI of 4 T1 xenograft tumor-bearing nude mice showed significant T2 reduction in tumors compared to controls. Prussian blue staining further confirmed that αvβ6 integrin-targeted nanoparticles were specifically accumulated in 4 T1 tumors and notably fewer nanoparticles were detected in 4 T1 tumors of mice injected with control USPIO and HEK293 tumors of mice administered cFK-9-USPIO.

CONCLUSIONS

Integrin αvβ6-targeted nanoparticles have great potential for use in the detection of αvβ6-overexpressed breast cancer with MR molecular imaging.

Membrane engineering of cell membrane biomimetic nanoparticles for nanoscale therapeutics

In recent years, cell membrane camouflaging technology has emerged as an important strategy of nanomedicine, and the modification on the membranes is also a promising approach to enhance the properties of the nanoparticles, such as cancer targeting, immune evasion, and phototherapy sensitivity. Indeed, diversified approaches have been exploited to re-engineer the membranes of nanoparticles in several studies. In this review, first we discuss direct modification strategy of cell membrane camouflaged nanoparticles (CM-NP) via noncovalent, covalent, and enzyme-involved methods. Second, we explore how the membranes of CM-NPs can be re-engineered at the cellular level using strategies such as genetic engineering and membranes fusion. Due to the innate biological properties and excellent biocompatibility, the functionalized cell membrane-camouflaged nanoparticles have been widely applied in the fields of drug delivery, imaging, detoxification, detection, and photoactivatable therapy.

Dendritic Cells and Immunogenic Cancer Cell Death: A Combination for Improving Antitumor Immunity

The safety and feasibility of dendritic cell (DC)-based immunotherapies in cancer management have been well documented after more than twenty-five years of experimentation, and, by now, undeniably accepted. On the other hand, it is equally evident that DC-based vaccination as monotherapy did not achieve the clinical benefits that were predicted in a number of promising preclinical studies. The current availability of several immune modulatory and targeting approaches opens the way to many potential therapeutic combinations. In particular, the evidence that the immune-related effects that are elicited by immunogenic cell death (ICD)-inducing therapies are strictly associated with DC engagement and activation strongly support the combination of ICD-inducing and DC-based immunotherapies. In this review, we examine the data in recent studies employing tumor cells, killed through ICD induction, in the formulation of anticancer DC-based vaccines. In addition, we discuss the opportunity to combine pharmacologic or physical therapeutic approaches that can promote ICD in vivo with in situ DC vaccination.