A platelet-mimicking theranostic platform for cancer interstitial brachytherapy

Biomimetic copper-doped polypyrrole nanoparticles induce glutamine metabolism inhibition to enhance breast cancer cuproptosis and immunotherapy

Cuproptosis, a newly discovered mechanism of inducing tumor cell death, primarily relies on the intracellular accumulation of copper ions. The utilization of Cu-based nanomaterials to induce cuproptosis holds promising prospects in future biomedical applications. However, the presence of high levels of glutathione (GSH) within tumor cells hinders the efficacy of cuproptosis. In this study, we have developed a BPTES-loaded biomimetic Cu-doped polypyrrole nanoparticles (CuP) nanosystem (PCB) for enhanced cuproptosis and immune modulation. PCB comprises an internal BPTES and CuP core and an external platelet membrane (PM) that facilitates active targeting to tumor sites following intravenous administration. Subsequently, PCB effectively suppresses glutaminase (GLS1) activity, thereby reducing GSH content. Moreover, CuP catalyze intracellular H2O2, amplifying oxidative stress while simultaneously inducing dihydrolipoyl transacetylase (DLAT) oligomerization through released Cu2+, resulting in cuproptosis. PCB not only inhibits primary tumors but also exhibits inhibitory effects on abscopal tumors. This work represents the first instance where GLS inhibition has been employed to enhance cuproptosis and immunotherapy. It also provides valuable insights into further investigations on cuproptosis.

Harnessing PD-1 cell membrane-coated paclitaxel dimer nanoparticles for potentiated chemoimmunotherapy

Chemoimmunotherapy has emerged as a promising strategy for improving the efficacy of cancer treatment. Herein, we present PD-1 receptor-presenting membrane-coated paclitaxel dimers nanoparticles (PD-1@PTX2 NPs) for enhanced treatment efficacy. PD-1 cell membrane-cloaked PTX dimer exhibited effective cellular uptake and increased cytotoxicity against cancer cells. PD-1@PTX2 NPs could selectively bind with PD-L1 ligands expressed on breast cancer cells. Our nanoparticles exhibit a remarkable tumor growth inhibition rate of 71.3% in mice bearing 4T1 xenografts and significantly prolong survival in mouse models of breast cancer. Additionally, our nanoparticles promoted a significant 3.2-fold increase in CD8+ T cell infiltration and 73.7% regulatory T cell (Treg) depletion within tumors, boosting a robust antitumor immune response. These findings underscore the potential of utilizing immune checkpoint receptor-presented PTX nanoparticles to enhance the efficacy of chemoimmunotherapy, providing an alternative approach for improving cancer treatment.

Two-dimensional multifunctional nanosheets as radiosensitizers for chemodynamic/radio-therapy

The hypoxia tumor microenvironment and low radiation attenuation coefficient of tumor tissue usually limit the efficiency of radiotherapy. In this study, a two-dimensional multifunctional nano-sensitizer, CuNS@Pt, was prepared to function as a radiosensitizer, enhancing radiotherapy through multiple mechanisms. Numerous active sites were provided for the deposition of X-ray radiation energy by the in-situ chemical reduction of Pt to create functional hybrids on Cu-based nanosheets. CuNS@Pt catalyzed high concentration of endogenous hydrogen peroxide to generate oxygen in tumor microenvironment, alleviating the physiological environment of hypoxic tumors. Additionally, CuNS could reduce the content of intrinsic glutathione (GSH) and catalyze hydrogen peroxide to form hydroxyl radicals (·OH). The generated ·OH could damage mitochondria and destroy redox homeostasis due to the functional inclusion of Cu species, thereby achieving chemodynamic therapy and further improving the radiation effect. Both in vivo and in vitro experiments showed that the nano sensitizer effectively improved the therapeutic efficiency of radiotherapy and had good biological safety. All in all, this study provides a pragmatic and doable platform for maximizing the efficacy of RT in cancer. This study also highlights the future research value of two-dimensional nanomaterials.

Copper-Based Single-Atom Nanozyme System Mimicking Platelet Cells for Enhancing the Outcome of Radioimmunotherapy

Background

Radiotherapy is an indispensable part of the multidisciplinary treatment of breast cancer (BC). Due to the potential for serious side effects from ionizing radiation in the treatment of breast cancer, which can adversely affect the patient's quality of life, the radiation dose is often limited. This limitation can result in an incomplete eradication of tumors.

Methods

In this study, biomimetic copper single-atom catalysts (platelet cell membrane camouflaging, PC) were synthesized with the aim of improving the therapeutic outcomes of radiotherapy for BC. Following guidance to the tumor site facilitated by the platelet cell membrane coating, PC releases a copper single-atom nanozyme (SAzyme). This SAzyme enhances therapeutic effects by generating reactive oxygen species from H2O2 and concurrently inhibiting the self-repair mechanisms of cancer cells through the consumption of intracellular glutathione (GSH) within the tumor microenvironment. PC-augmented radiotherapy induces immunogenic cell death, which triggers an immune response to eradicate tumors.

Results

With the excellent biocompatibility, PC exhibited precise tumor-targeting capabilities. Furthermore, when employed in conjunction with radiotherapy, PC showed impressive tumor elimination results through immunological activation. Remarkably, the tumor suppression rate achieved with PC-enhanced radiotherapy reached an impressive 93.6%.

Conclusion

Therefore, PC presents an innovative approach for designing radiosensitizers with tumor-specific targeting capabilities, aiming to enhance the therapeutic impact of radiotherapy on BC.

Biomimetic Copper-Doped Polypyrrole Nanoparticles for Enhanced Cancer Low-Temperature Photothermal Therapy

Introduction

Photothermal therapy (PTT) has a significant potential for its application in precision tumour therapy. However, PTT-induced hyperthermia may damage healthy tissues and trigger the expression of heat shock proteins (HSPs), thereby compromising the long-term therapeutic efficacy of PTT.

Methods

In this study, a biomimetic drug delivery system comprising CuP nanozymes as the inner core and platelet membrane (PM) as the outer shell was successfully developed for administering synergistic chemodynamic therapy and mild PTT. PM is encapsulated on CuP to form this biomimetic nanoparticle (PM-coated CuP nanoparticles, PC). PC possesses peroxidase (POD) activity, can facilitate the conversion of hydrogen peroxide into ·OH, thereby inhibiting the expression of HSPs.

Results

Upon exposure to low-power laser irradiation (0.5 W/cm2, 1064 nm), PC can convert near-infrared II laser energy into heat energy, thereby enabling the administration of enhanced mild PTT. In vitro and in vivo experiments have demonstrated that this synergistic approach can induce over 90% tumour eradication with favourable biocompatibility.

Discussion

PC exhibits high efficacy and biocompatibility, making it a promising candidate for future applications.

Reactive oxidative species (ROS)-based nanomedicine for BBB crossing and glioma treatment: current status and future directions

Glioma is the most common primary intracranial tumor in adults with poor prognosis. Current clinical treatment for glioma includes surgical resection along with chemoradiotherapy. However, the therapeutic efficacy is still unsatisfactory. The invasive nature of the glioma makes it impossible to completely resect it. The presence of blood-brain barrier (BBB) blocks chemotherapeutic drugs access to brain parenchyma for glioma treatment. Besides, tumor heterogeneity and hypoxic tumor microenvironment remarkably limit the efficacy of radiotherapy. With rapid advances of nanotechnology, the emergence of a new treatment approach, namely, reactive oxygen species (ROS)-based nanotherapy, provides an effective approach for eliminating glioma via generating large amounts of ROS in glioma cells. In addition, the emerging nanotechnology also provides BBB-crossing strategies, which allows effective ROS-based nanotherapy of glioma. In this review, we summarized ROS-based nanomedicine and their application in glioma treatment, including photodynamic therapy (PDT), photothermal therapy (PTT), chemodynamic therapy (CDT), sonodynamic therapy (SDT), radiation therapy, etc. Moreover, the current challenges and future prospects of ROS-based nanomedicine are also elucidated with the intention to accelerate its clinical translation.

Cu-doped polypyrrole hydrogel with tumor catalyst activity for NIR-II thermo-radiotherapy

Introduction: Radiotherapy (RT) is one of the key methods for treating breast cancer. However, the effect of single RT is often poor because of insufficient deposition of X-rays in tumor sites and radiation resistance induced by the abnormal tumor microenvironment (overexpression of glutathione (GSH)). The development of multifunctional RT sensitizers and synergetic therapeutic strategies is, therefore, a promising area for enhancing the anticancer effect of RT. Methods: In this study, a multifunctional nanozyme hydrogel based on Cu-doped polypyrrole (CuP) was designed to work concertedly with a second near-infrared thermal RT. The CuP-based hydrogel (CH) reached the tumor site when injected in-situ and achieved long-term storage. Results: Once stimulated with 1064-nm laser irradiation, the heated and softened hydrogel system released CuP nanozyme to provide photothermal therapy, thereby inhibiting the repair of DNA damage caused by RT. In addition, CuP with dual nanozyme activity depleted the intracellular GSH to reduce the antioxidant capacity of the tumor. Moreover, CuP converted H₂O₂ to produce ·OH to directly kill the tumor cells, thus enhancing the capability of low-dose RT to inhibit tumor growth. In vivo experiments showed that the CH system used in combination with a low-power 1064-nm laser and low-dose RT (4 Gy) exhibited good synergistic anticancer effects and biological safety. Discussion: As a new light-responsive hydrogel system, CH holds immense potential for radio-sensitization.

Type-I AIE Photosensitizer Loaded Biomimetic System Boosting Cuproptosis to Inhibit Breast Cancer Metastasis and Rechallenge

Cuproptosis shows good application prospects in tumor therapy. However, the copper efflux mechanism and highly expressed intracellular reducing substances can inhibit the cuproptosis effects. In this study, a platelet vesicle (PV) coated cuprous oxide nanoparticle (Cu₂O)/TBP-2 cuproptosis sensitization system (PTC) was constructed for multiple induction of tumor cuproptosis. PTC was prepared by physical extrusion of AIE photosensitizer (TBP-2), Cu₂O, and PV. After the biomimetic modification, PTC can enhance its long-term blood circulation and tumor targeting ability. Subsequently, PTC was rapidly degraded to release copper ions under acid conditions and hydrogen peroxides in tumor cells. Then, under light irradiation, TBP-2 quickly enters the cell membrane and generates hydroxyl radicals to consume glutathione and inhibit copper efflux. Accumulated copper can cause lipoylated protein aggregation and iron-sulfur protein loss, which result in proteotoxic stress and ultimately cuproptosis. PTC treatment can target and induce cuproptosis in tumor cells in vitro and in vivo, significantly inhibit lung metastasis of breast cancer, increase the number of central memory T cells in peripheral blood, and prevent tumor rechallenge. It provides an idea for the design of nanomedicine based on cuproptosis.

Self-cascade catalytic single-atom nanozyme for enhanced breast cancer low-dose radiotherapy

Radiotherapy (RT) efficacy can be promoted with the help of nanoenzyme that can "re-programing" the tumour's micro-environment by changing the expression level of special bio-molecules. However, problems such as low reaction efficiency, limited endogenous H₂O₂, and/or unsatisfactory results of a single catalysis mode in treatment limit the application in the RT field. Herein, a novel Au nanoparticles (AuNPs) decorated iron SAE (FeSAE@Au) was formulated for self-cascade catalytic RT. In this dual-nanozyme system, embedded AuNPs can sever as GOx and endow FeSAE@Au with self-H₂O₂ supplying ability, which can elevate the H₂O₂ level in tumors by catalyzing cellular glucose in situ, further improving the catalytic performance of FeSAE with peroxidase-like activity. The self-cascade catalytic reaction can significantly increase cellular hydroxyl radicals (•OH) level, further promoting RT's effect. Furthermore, in vivo findings demonstrated that FeSAE can effectively limit tumor growth while causing low damage in important organs. According to our understanding, FeSAE@Au is the first description of a hybrid SAE-based nanomaterial employed in cascade catalytic RT. The research yields new and interesting insights for developing various SAE systems for anticancer therapy.

Boosting Checkpoint Immunotherapy with Biomaterials

The immune checkpoint blockade (ICB) therapy has revolutionized the field of cancer treatment, while low response rates and systemic toxicity limit its clinical outcomes. With the rapid advances in nanotechnology and materials science, various types of biomaterials have been developed to maximize therapeutic efficacy while minimizing side effects by increasing tumor antigenicity, reversing immunosuppressive microenvironment, amplifying antitumor immune response, and reducing extratumoral distribution of checkpoint inhibitors as well as enhancing their retention within target sites. In this review, we reviewed current design strategies for different types of biomaterials to augment ICB therapy effectively and then discussed present representative biomaterial-assisted immune modulation and targeted delivery of checkpoint inhibitors to boost ICB therapy. Current challenges and future development prospects for expanding the ICB with biomaterials were also summarized. We anticipate this review will be helpful for developing emerging biomaterials for ICB therapy and promoting the clinical application of ICB therapy.

Novel strategies for tumor radiosensitization mediated by multifunctional gold-based nanomaterials

Radiotherapy (RT) is one of the most effective and commonly used cancer treatments for malignant tumors. However, the existing radiosensitizers have a lot of side effects and poor efficacy, which limits the curative effect and further application of radiotherapy. In recent years, emerging nanomaterials have shown unique advantages in enhancing radiosensitization. In particular, gold-based nanomaterials, with high X-ray attenuation capacity, good biocompatibility, and promising chemical, electronic and optical properties, have become a new type of radiotherapy sensitizer. In addition, gold-based nanomaterials can be used as a carrier to load a variety of drugs and immunosuppressants; in particular, its photothermal therapy, photodynamic therapy and multi-mode imaging functions aid in providing excellent therapeutic effect in coordination with RT. Recently, many novel strategies of radiosensitization mediated by multifunctional gold-based nanomaterials have been reported, which provides a new idea for improving the efficacy and reducing the side effects of RT. In this review, we systematically summarize the recent progress of various new gold-based nanomaterials that mediate radiosensitization and describe the mechanism. We further discuss the challenges and prospects in the field. It is hoped that this review will help researchers understand the latest progress of gold-based nanomaterials for radiosensitization, and encourage people to optimize the existing methods or explore novel approaches for radiotherapy.

Research Progress of Nanomedicine-Based Mild Photothermal Therapy in Tumor

With the booming development of nanomedicine, mild photothermal therapy (mPTT, 42-45°C) has exhibited promising potential in tumor therapy. Compared with traditional PTT (>50°C), mPTT has less side effects and better biological effects conducive to tumor treatment, such as loosening the dense structure in tumor tissues, enhancing blood perfusion, and improving the immunosuppressive microenvironment. However, such a relatively low temperature cannot allow mPTT to completely eradicate tumors, and therefore, substantial efforts have been conducted to optimize the application of mPTT in tumor therapy. This review extensively summarizes the latest advances of mPTT, including two sections: (1) taking mPTT as a leading role to maximize its effect by blocking the cell defense mechanisms, and (2) regarding mPTT as a supporting role to assist other therapies to achieve synergistic antitumor curative effect. Meanwhile, the special characteristics and imaging capabilities of nanoplatforms applied in various therapies are discussed. At last, this paper puts forward the bottlenecks and challenges in the current research path of mPTT, and possible solutions and research directions in future are proposed correspondingly.

[Preparation and Tumor Targeting Analysis of Cell Membrane Nanovesicles Derived from Breast Cancer Cells]

Objective

To prepare cell membrane nanovesicles (NVs) derived from breast cancer cells, to explore their basic characteristics, tumor cell endocytosis, and in vivo distribution in a tumor-bearing mouse model, and to investigate their tumor targeting properties.

Methods

4T1 breast cancer cells were cultured in vitro. The cell membrane of 4T1 cells was isolated through ultracentrifugation and NVs were formulated with a liposome extruder. The size distribution of NVs was determined by way of dynamic light scattering, and the morphology properties of the NVs were examined with transmission electron microscope. The stability of NVs was analyzed by measuring the diameter changes of NVs submerged in phosphate-buffered saline (PBS). The biocompatibility of NVs was investigated by measuring the viability of dendritic cells treated with NVs at different concentrations (5, 10, 20, 50, and 100 mg·L -1) by CCK-8 assay. Fluorescence microscopy was used to analyze the cellular uptake of NVs by breast cancer cells. A mice model of breast cancer model was established with mice bearing subcutaneous xenograft of 4T1 cells. The mice were treated with Cy5.5-labeled NVs injected via the tail vein and the in vivo distribution of NVs was analyzed with an imaging system for small live animals.

Results

The results showed that NVs derived from 4T1 breast cancer cells were successfully prepared. The NVs had a mean diameter of 123.2 nm and exhibited a hollow spherical structure under transmission electron microscope. No obvious change in the size of the NVs was observed after 7 days of incubation in PBS solution. CCK-8 assay results showed that the viability of dendritic cells treated with NVs at different concentrations was always higher than 90%. Fluorescence microscopic imaging showed that NVs could be efficiently internalized into breast cancer cells. in vivo biodistribution analysis revealed that breast cancer cell-derived NVs showed higher distribution in tumor tissue than the NVs prepared with normal cells did.

Conclusion

We successfully prepared cell membrane NVs derived from 4T1 breast cancer cells. These NVs had efficient cellular uptake by breast cancer cells and sound tumor targeting properties.

Biomimetic CuS nanoparticles for radiosensitization with mild photothermal therapy and GSH-depletion

Due to its non-invasive and highly effective characteristics, radiotherapy has attracted significant interest in cancer treatment. However, radioresistance of solid tumors caused by a unique tumor microenvironment diminishes the therapeutic effect of cancer radiotherapy. To address this issue, we developed a nanoplatform for tumor-specific targeting to improve radiotherapy. Specifically, hollow CuS nanoparticles were decorated with the platelet cell membrane (PC), endowing this nanoplatform with the therapeutic property of navigating to the tumor region for glutathione (GSH)-depletion photothermal therapy. It was discovered that mild photothermal therapy mediated by PC ameliorated hypoxia in the tumor microenvironment. Meanwhile, GSH, which contributes to repairing radiotherapy-induced DNA double-strand breaks, was depleted by PC in an acidic microenvironment. Therefore, radioresistance could be diminished while cancer cell self-repair was prevented. At therapeutic doses, PC nanoparticles have negligible toxic effects on normal tissues. PC demonstrates promise for both in vivo and in vitro radiosensitization due to its GSH-depletion, photothermal efficiency, and tumor-specific properties.

Injectable agarose hydrogels and doxorubicin-encapsulated iron-gallic acid nanoparticles for chemodynamic-photothermal synergistic therapy against osteosarcoma

Osteosarcoma is a malignant bone cancer that usually occurs in children and adolescents. Although chemotherapy, radiotherapy and other methods have been used to treat osteosarcoma, these therapeutic regimens fail to cure this disease completely. Herein, doxorubicin-encapsulated iron–gallic acid (FeGA-DOX) nanoparticles (NPs) were fused with agarose hydrogels (AG) for synergistic therapy of osteosarcoma. Under near-infrared laser irradiation, the local temperature of FeGA-DOX NPs was increased. Therefore, tumour cells were killed using photothermal therapy, and AG dissolved to release FeGA-DOX into the cells. Doxorubicin generates hydrogen peroxide, which is then converted to reactive oxygen species (ROS) via FeGA-DOX by the Fenton reaction, inducing tumour cell apoptosis. ROS induced by chemodynamic therapy compensates for the incomplete cure of osteosarcoma cells. The AG-encapsulated NPs could mediate synergistic chemodynamic and photothermal therapy with self-sufficient H₂O₂, providing a novel therapeutic strategy for osteosarcoma.

Red Phosphorus/P25 Nanophotosensitizers Coated with Platelet Membrane for Enhancing Cancer Cells Photodynamic Therapy

Photodynamic therapy (PDT), which uses targeted photosensitizing drugs, has been regarded as a promising method for cancer therapy. In the present study, photosensitizer red phosphorus modified P25 nanophotosensitizers (P25-RP) were generated, which were coated with platelet membrane (P25-RP@PLT) extracted from platelet rich plasma. The biocompatibility of P25-RP was demonstrated by cell counting kit-8 (CCK-8) and optical microscope assay, more than 93 % cells in the concentration of 100 μg/ml of P25-RP suspension after co-incubation for 24 h were still kept alive. The antitumor performance of P25-RP@PLT was evaluated via CCK-8 assay, flow cytometry and fluorescence staining of live/dead cells. The experiment results showed that P25-RP@PLT could ablate 55 % malignant tumor cells upon laser irradiation within 5 min, which was 10 % higher than P25-RP alone against cancer cells. Mechanistically, the cancer cell toxicity of P25-RP@PLT nanophotosensitizers was attributed to its heterojunction structure that broadens the absorption spectra, whereas PLT membrane coating technology allows for immune escape and selective adhesion capacity to cancer cells. This work provided a novel pathway on the design of novel visible-light-driven photosensitizer for cancer therapy.

Biomimetic nanomaterial-facilitated oxygen generation strategies for enhancing tumour treatment outcomes

Hypoxia, as a typical hallmark of the tumour microenvironment (TME), has been verified to exist in most malignancies and greatly hinders the outcome of tumour treatments, including chemotherapy, photodynamic therapy, radiotherapy, and immunotherapy. Various approaches to alleviate tumour hypoxia have been reported. Among them, biomimetic nanomaterial-facilitated tumour oxygenation strategies, based on the engagement of human endogenous proteins, red blood cells, the cell membrane, and catalase, are the most impressive due to their excellent tumour active-targeting ability and superior tumour-selective capability, which, however, have not yet been systematically reviewed. Herein, we are ready to describe the current progress in biomimetic nanomaterial-facilitated tumour oxygenation strategies and corresponding improvements in tumour treatment outputs. In this review, the underlying mechanism behind the superior effect of these biomimetic nanomaterials, compared with other materials, on alleviating the hypoxic TME is highlighted. Additionally, the ongoing problems and potential solutions are also discussed.

Hsa_circ_0000098 is a novel therapeutic target that promotes hepatocellular carcinoma development and resistance to doxorubicin

Background

Circular RNA (circRNA) is crucial to the progression of hepatocellular cancer (HCC). In addition, Mitochondrial calcium uniporter regulatory factor 1 (MCUR1) is commonly overexpressed in HCC to increase cellular ATP levels. Due to the highly aggressive characteristics of HCC, it is essential to identify new diagnostic biomarkers and therapeutic targets that may facilitate the diagnosis of HCC and the development of effective anti-HCC treatments.

Methods

A series of in vitro and in vivo experiments were undertaken to investigate the biological importance and underlying mechanisms of circ_0000098 in HCC.

Results

The expression of circ_0000098 was higher in HCC tissues compared to paired adjacent tissues. According to the receiver-operating characteristic curves, circ_0000098 functioned as a potential diagnostic tumor marker in HCC. Our experiments indicated that circ_0000098 served as a key oncogenic circRNA to increase HCC cell proliferation and invasion in vitro and HCC progression in vivo. Furthermore, mechanistic investigation demonstrated that by sequestering miR-383 from the 3′-UTR of MCUR1, circ_0000098 positively regulated MCUR1 expression in HCC cells and finally promoted HCC progression. On the other hand, inhibiting circ_0000098 in HCC cells could diminish doxorubicin (DOX) resistance by decreasing P-glycoprotein (P-gp, MDR1) expression and intracellular ATP levels. Either downregulation of MCUR1 or overexpression of miR-383 improved DOX sensitivity in HCC cells. Subsequently, a short hairpin RNA targeting circ_0000098 (referred to as sh-1) and doxorubicin (DOX) were encapsulated into platelets (PLTs), referred to as DOX/sh-1@PLT. Activated DOX/sh-1@PLT through HCC cells resulted in the creation of platelet-derived particles that were capable of delivering the DOX/sh-1 combination into HCC cells and promoting intracellular DOX accumulation. Furthermore, our in vivo experiments showed that DOX/sh-1@PLT can effectively reduce P-gp expression, promote DOX accumulation, and reverse DOX resistance.

Conclusions

Our results demonstrated that circ_0000098 is an oncogenic circRNA that promotes HCC development through the miR-383/MCUR1 axis and targeting circ_0000098 with DOX/sh-1@PLT may be a promising and practical therapeutic strategy for preventing DOX resistance in HCC.

Research update on cell membrane camouflaged nanoparticles for cancer therapy

Cell membrane-camouflaged biomimetic functionalization of nanoparticles has emerged as a promising strategy for cancer theranostics. These cell membranes used for camouflaging are generally isolated from natural or engineered erythrocytes, neutrophils, macrophages, T lymphatic cells, stem cells, and cancer cells. The camouflaging strategy of coating nanoparticles with cell membranes allows for tumor homotypic targeting through self-recognition as source cells, immune evasion, and a prolonged blood circulation time, thereby improving the effective payload delivery and tumor therapy. More so, some engineered cell membranes with functionalized peptides, proteins and moieties on membrane surface can be transferred for therapy in the same time. In this review, we summarize the latest research on various types of cell membrane-camouflaged nanoparticles aimed at anti-cancer therapy, focusing on the biological advantages of different cell membranes, constitutions of nanoparticles, fabrication processes, key findings, potential therapies, and discuss the major challenges and future opportunities.

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.

Neutrophil membrane-coated immunomagnetic nanoparticles for efficient isolation and analysis of circulating tumor cells

The isolation and analysis of scarce circulating tumor cells (CTCs) with immunomagnetic nanoparticles (IMNs) have shown promising outcomes in noninvasive cancer diagnosis. However, the IMNs adsorb nonspecific proteins after entering into biofluids and the formed protein coronas cover surface targeting ligands, limiting the detection efficiency of IMNs. In addition, the interaction between surface targeting ligands and white blood cells (WBCs) significantly limits the purity of CTCs isolated by IMNs. Furthermore, the interfacial collision of nanoparticles and cells has negative effects on the viability of isolated CTCs. All of these limitations synthetically restrict the isolation and analysis of rare CTCs for early diagnosis and precision medicine. Here, we proposed that surface functionalization of IMNs with neutrophil membranes can simultaneously reduce nonspecific protein adsorption, enhance the interaction with CTCs, reduce the distraction from WBCs, and improve the viability of isolated CTCs. In spiked blood samples, our neutrophil membrane-coated IMNs (Neu-IMNs) exhibited a superior separation efficiency from 41.36% to 96.82% and an improved purity from 40.25% to 90.68% when compared to bare IMNs. Additionally, we successfully isolated CTCs in 19 out of total 20 blood samples from breast cancer patients using Neu-IMNs and further confirmed the feasibility of the isolated CTCs for downstream cell sequencing. Our work provides a new perspective on engineered IMNs for efficient isolation and analysis of CTCs, paving the way for early noninvasive diagnosis of cancer.

Synergistic Radiosensitization Mediated by Chemodynamic Therapy via a Novel Biodegradable Peroxidases Mimicking Nanohybrid

Purpose

Reactive oxygen species (ROS) are practically essential in radiotherapy to damage cancer cells; however, they are always inadequate for some malignant entities. Here, we designed a biodegradable mesoporous silica decorated with hemin and glucose oxidase (GOD@Hemin-MSN) to generate a chemodynamic therapy in order to enhance the killing capacity of radiotherapy.

Methods

Mesoporous silica, as an outstanding drug carrier, can deliver hemin and glucose oxidase to the tumor site. With high level of metabolism activity, cancer cells are abundant in glucose, which can be oxidized into H₂O₂ by glucose oxidase (GOD) on site. The generated H₂O₂ is subsequently converted into intracellular ROS, especially hydroxyl radical within the tumor microenvironment, by hemin, which has mimetic peroxidase properties. By this means, the ROS can be supplemented or enriched to facilitate the killing of tumor cells.

Results

The chemodynamic therapy induced by GOD@Hemin-MSN produced quantities of ROS, which compensated for their inadequacy as a result of radiotherapy, and exhibited remarkable antitumor efficacy, with a tumor inhibition rate of 91.5% in A549 tumor-bearing mice.

Conclusion

This work has validated GOD@Hemin-MSN as a radiosensitizer in chemodynamic therapy, which showed biocompatibility and potential for translational application.

Engineered extracellular vesicles and their mimics in cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Current pharmacological interventions for the CVDs suffer from low bioavailability, low retention rate, poor targeting, drug resistance complicated side effects. Extracellular vesicles (EVs), which are lipid vesicles secreted by cells, play key roles in pathological processes of CVDs. Engineered EVs and EV mimics with superior properties can overcome limitations of traditional medicine, thus emerging as alternative therapeutic options for the CVDs. In this Review, we summarized basic concepts of EVs and EV mimics, highlighted engineering strategies, and lastly discussed applications of engineered EVs and EV mimics against the CVDs. We believe this Review can provide some new insights on engineering EVs and EV mimics and facilitate their application in precise control of CVDs.

A Platelet-Mimicking Single-Atom Nanozyme for Mitochondrial Damage-Mediated Mild-Temperature Photothermal Therapy

Single-atom nanozyme (SAzyme) systems have shown great potential in tumor therapy. A multifunctional SAzyme not only possesses high catalytic activity but also can be used as photothermal agents in photothermal therapy (PTT). Furthermore, it is also imperative to overcome tumor thermal resistance in SAzyme-based PTT so that PTT under a mild temperature is achievable. Herein, a novel platelet membrane (PM)-coated mesoporous Fe single-atom nanozyme (Fe-SAzyme) was formulated to solve these issues. The PM-coated mesoporous Fe-SAzyme (PMS) showed a satisfactory NIR-II photothermal performance, high peroxidase (POD) activity, and good tumor-targeting ability. In addition, PMS may be used as a carrier for protein drugs owing to its inner mesoporous structure. In vitro experiments showed that PMS could inhibit the expression of heat shock protein (HSP) by damaging the mitochondria, thereby finally improving the effect of mild-temperature PTT. Moreover, in vivo results showed that PMS could efficiently accumulate in tumor sites and suppress tumor growth with minimal toxicity in major organs. To the best of our knowledge, this study is the first report of a biomimetic mesoporous Fe-SAzyme used to achieve mitochondrial damage-mediated mild-temperature PTT. The study provides new promising ideas for designing other SAzyme systems for cancer treatment.

Camptothecin Delivery via Tumor-Derived Exosome for Radiosensitization by Cell Cycle Regulation on Patient-Derived Xenograft Mice

Purpose: While radiotherapy remains the leading clinical treatment for many tumors, its efficacy can be significantly hampered by the insensitivity of cells in the S phase of the cell cycle to such irradiation.

Methods: Here, we designed a highly targeted drug delivery platform in which exosomes were loaded with the FDA-approved anti-tumor drug camptothecin (CPT) which is capable of regulating cell cycle. The utilized exosomes were isolated from patient tumors, enabling the personalized treatment of individuals to ensure better therapeutic outcomes.

Results: This exosome-mediated delivery strategy was exhibited robust targeted to patient-derived tumor cells in vitro and in established patient-derived xenograft models. By delivering CPT to tumor cells, this nanoplatform was able to decrease cell cycle arrest in the S phase, increasing the frequency of cells in the G1 and G2/M phases such that they were more radiosensitive.

Conclusion: This therapeutic approach was able to substantially enhance the sensitivity of patient-derived tumors to ionizing radiation, thereby improving the overall efficacy of radiotherapy without the need for a higher radiation dose.

Development of nanotechnology-mediated precision radiotherapy for anti-metastasis and radioprotection

Radiotherapy (RT), including external beam RT and internal radiation therapy, uses high-energy ionizing radiation to kill tumor cells.