Platelet-Membrane-Camouflaged Black Phosphorus Quantum Dots Enhance Anticancer Effect Mediated by Apoptosis and Autophagy

Advances in Black Phosphorus Quantum Dots for Cancer Research: Synthesis, Characterization, and Applications

In the past few years, there has been notable advancement in nanotechnology, leading to the development of new materials with potential uses in the medical field, especially in cancer diagnosis, imaging, and therapy. Black phosphorus quantum dots (BPQDs) are one of the emerging nanomaterials that have generated interest due to their unique properties and potential in biomedical applications. This review aims to give a detailed overview of how BPQDs are synthesized, characterized, and utilized. The synthesis methods of BPQDs are discussed, with a focus on obtaining size-controlled and high-quality BPQDs. Two main approaches, top-down exfoliation and bottom-up techniques, are described. Despite advancements in synthesis, there are challenges hindering the practical application of BPQDs, such as poor dispersion and short durability. To address these issues, techniques to enhance biocompatibility and reduce potential toxicity, such as surface modifications, are discussed. BPQDs have potential in bioimaging as they offer higher resolution and sensitivity compared with traditional imaging agents. Their small size and expansive surface area make them suitable for drug delivery systems, enabling the effective incorporation of therapeutic substances. By functionalizing BPQDs with targeting ligands, they can selectively bind to cancer cells or tissue, making them ideal for targeted therapies. Moreover, BPQDs can serve as biosensors to detect biomarkers in bodily fluids, further expanding their biomedical applications. However, before they can be successfully translated into clinical settings, further research is needed to optimize the synthesis methods of BPQDs and evaluate their long-term safety profiles. Nonetheless, with ongoing research and development, the medical uses of BPQDs are expected to expand.

Platelet Membrane-Camouflaged Silver Metal-Organic Framework Biomimetic Nanoparticles for the Treatment of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is characterized by high malignancy and limited treatment options. Given the pressing need for more effective treatments for TNBC, this study aimed to develop platelet membrane (PM)-camouflaged silver metal-organic framework nanoparticles (PM@MOF-Ag NPs), a biomimetic nanodrug. PM@MOF-Ag NP construction involved the utilization of 2-methylimidazole and silver nitrate to prepare silver metal-organic framework (MOF-Ag) NPs. The PM@MOF-Ag NPs, due to their camouflage, possess excellent blood compatibility, immune escape ability, and a strong affinity for 4T1 tumor cells. This enhances their circulation time in vivo and promotes the aggregation of PM@MOF-Ag NPs at the 4T1 tumor site. Importantly, PM@MOF-Ag NPs demonstrated promising antitumor activity in vitro and in vivo. We further revealed that PM@MOF-Ag NPs induced tumor cell death by overproducing reactive oxygen species and promoting cell apoptosis. Moreover, PM@MOF-Ag NPs enhanced apoptosis by upregulating the ratios of Bax/Bcl-2 and cleaved caspase3/pro-caspase3. Notably, PM@MOF-Ag NPs exhibited no significant organ toxicity, whereas the administration of MOF-Ag NPs resulted in liver inflammation compared to the control group.

An updated review of the pharmacological effects and potential mechanisms of hederagenin and its derivatives

Hederagenin (HG) is a natural pentacyclic triterpenoid that can be isolated from various medicinal herbs. By modifying the structure of HG, multiple derivatives with superior biological activities and safety profiles have been designed and synthesized. Accumulating evidence has demonstrated that HG and its derivatives display multiple pharmacological activities against cancers, inflammatory diseases, infectious diseases, metabolic diseases, fibrotic diseases, cerebrovascular and neurodegenerative diseases, and depression. Previous studies have confirmed that HG and its derivatives combat cancer by exerting cytotoxicity, inhibiting proliferation, inducing apoptosis, modulating autophagy, and reversing chemotherapy resistance in cancer cells, and the action targets involved mainly include STAT3, Aurora B, KIF7, PI3K/AKT, NF-κB, Nrf2/ARE, Drp1, and P-gp. In addition, HG and its derivatives antagonize inflammation through inhibiting the production and release of pro-inflammatory cytokines and inflammatory mediators by regulating inflammation-related pathways and targets, such as NF-κB, MAPK, JAK2/STAT3, Keap1-Nrf2/HO-1, and LncRNA A33/Axin2/β-catenin. Moreover, anti-pathogen, anti-metabolic disorder, anti-fibrosis, neuroprotection, and anti-depression mechanisms of HG and its derivatives have been partially elucidated. The diverse pharmacological properties of HG and its derivatives hold significant implications for future research and development of new drugs derived from HG, which can lead to improved effectiveness and safety profiles.

A Redox-Triggered Autophagy-Induced Nanoplatform with PD-L1 Inhibition for Enhancing Combined Chemo-Immunotherapy

Epirubicin (EPI) alone can trigger mildly protective autophagy in residual tumor cells, resulting in an immunosuppressive microenvironment. This accelerates the recurrence of residual tumors and leads to antiprogrammed death ligand 1 (anti-PD-1)/PD-L1 therapy resistance, posing a significant clinical challenge in tumor immunotherapy. The combination of checkpoint inhibitors targeting the PD-1/PD-L1 pathway and amplifying autophagy presents an innovative approach to tumor treatment, which can prevent tumor immune escape and enhance therapeutic recognition. Herein, we aimed to synthesize a redox-triggered autophagy-induced nanoplatform with SA&EA-induced PD-L1 inhibition. The hyaluronic acid (HA) skeleton and arginine segment promoted active nanoplatform targeting, cell uptake, and penetration. The PLGLAG peptide was cleaved by overexpressing matrix metalloproteinase-2 (MMP-2) in the tumor microenvironment, and the PD-L1 inhibitor D-PPA was released to inhibit tumor immune escape. The intense autophagy inducers, STF-62247 and EPI, were released owing to the cleavage of disulfide bonds influenced by the high glutathione (GSH) concentration in tumor cells. The combination of EPI and STF induced apoptosis and autophagic cell death, effectively eliminating a majority of tumor cells. This indicated that the SA&EA nanoplatform has better therapeutic efficacy than the single STF@AHMPP and EPI@AHMPTP groups. This research provided a way to set up a redox-triggered autophagy-induced nanoplatform with PD-L1 inhibition to enhance chemo-immunotherapy.

The impact of nanomaterials on autophagy across health and disease conditions

Autophagy, a catabolic process integral to cellular homeostasis, is constitutively active under physiological and stress conditions. The role of autophagy as a cellular defense response becomes particularly evident upon exposure to nanomaterials (NMs), especially environmental nanoparticles (NPs) and nanoplastics (nPs). This has positioned autophagy modulation at the forefront of nanotechnology-based therapeutic interventions. While NMs can exploit autophagy to enhance therapeutic outcomes, they can also trigger it as a pro-survival response against NP-induced toxicity. Conversely, a heightened autophagy response may also lead to regulated cell death (RCD), in particular autophagic cell death, upon NP exposure. Thus, the relationship between NMs and autophagy exhibits a dual nature with therapeutic and environmental interventions. Recognizing and decoding these intricate patterns are essential for pioneering next-generation autophagy-regulating NMs. This review delves into the present-day therapeutic potential of autophagy-modulating NMs, shedding light on their status in clinical trials, intervention of autophagy in the therapeutic applications of NMs, discusses the potency of autophagy for application as early indicator of NM toxicity.

All Roads Lead to Rome: Comparing Nanoparticle- and Small Molecule-Driven Cell Autophagy

Autophagy, vital for removing cellular waste, is triggered differently by small molecules and nanoparticles. Small molecules, like rapamycin, non-selectively activate autophagy by inhibiting the mTOR pathway, which is essential for cell regulation. This can clear damaged components but may cause cytotoxicity with prolonged use. Nanoparticles, however, induce autophagy, often causing oxidative stress, through broader cellular interactions and can lead to a targeted form known as "xenophagy." Their impact varies with their properties but can be harnessed therapeutically. In this review, the autophagy induced by nanoparticles is explored and small molecules across four dimensions: the mechanisms behind autophagy induction, the outcomes of such induction, the toxicological effects on cellular autophagy, and the therapeutic potential of employing autophagy triggered by nanoparticles or small molecules. Although small molecules and nanoparticles each induce autophagy through different pathways and lead to diverse effects, both represent invaluable tools in cell biology, nanomedicine, and drug discovery, offering unique insights and therapeutic opportunities.

Biomimetic MDSCs membrane coated black phosphorus nanosheets system for photothermal therapy/photodynamic therapy synergized chemotherapy of cancer

Photothermal therapy is favored by cancer researchers due to its advantages such as controllable initiation, direct killing and immune promotion. However, the low enrichment efficiency of photosensitizer in tumor site and the limited effect of single use limits the further development of photothermal therapy. Herein, a photo-responsive multifunctional nanosystem was designed for cancer therapy, in which myeloid-derived suppressor cell (MDSC) membrane vesicle encapsulated decitabine-loaded black phosphorous (BP) nanosheets (BP@ Decitabine @MDSCs, named BDM). The BDM demonstrated excellent biosafety and biochemical characteristics, providing a suitable microenvironment for cancer cell killing. First, the BDM achieves the ability to be highly enriched at tumor sites by inheriting the ability of MDSCs to actively target tumor microenvironment. And then, BP nanosheets achieves hyperthermia and induces mitochondrial damage by its photothermal and photodynamic properties, which enhancing anti-tumor immunity mediated by immunogenic cell death (ICD). Meanwhile, intra-tumoral release of decitabine induced G2/M cell cycle arrest, further promoting tumor cell apoptosis. In vivo, the BMD showed significant inhibition of tumor growth with down-regulation of PCNA expression and increased expression of high mobility group B1 (HMGB1), calreticulin (CRT) and caspase 3. Flow cytometry revealed significantly decreased infiltration of MDSCs and M2-macrophages along with an increased proportion of CD4+, CD8+ T cells as well as CD103+ DCs, suggesting a potentiated anti-tumor immune response. In summary, BDM realizes photothermal therapy/photodynamic therapy synergized chemotherapy for cancer.

Black phosphorus-based nanoparticles induce liver cancer cell mitochondrial apoptosis and immune cell tumor infiltration for enhancing dendritic cell therapy

Cellular immunotherapy is a crucial aspect of current tumor immunotherapy, though it presents several challenges such as immune cell dysfunction, limited recognition of neoantigens, and inadequate lymphocyte infiltration into the tumor microenvironment. This study proposes a novel approach utilizing a combination of dendritic cell (DC)-based cellular immunotherapy and a photothermal nanoadjuvant black phosphorus (BP) nanoparticles to overcome these challenges. A new platform called PLGA@BP-R848, which consists of modifying poly-(lactic-co-glycolic acid) (PLGA) onto BP nanosheets loading the immune adjuvant R848. The PLGA@BP-R848 nanoparticles demonstrated exceptional drug delivery and release capabilities, as well as a photothermal effect, biocompatibility, and the ability to activate the mitochondrial apoptotic pathway Blc-2-Bax-Cytochrome c-caspase-3 and inhibit the PI3K-AKT-mTOR signaling pathway. In a hepatocellular carcinoma mouse model, the binding of PLGA@BP-R848 nanoparticles and dendritic cells primed with GPC3 peptides, successfully induced a systemic anti-tumor immune response. PLGA@BP-R848 nanoparticles bolster immune cell infiltration into tumors and induce cancer cell apoptosis. The synergistic therapy involving dendritic cells and photothermal nanoadjuvant effectively suppressed tumor growth, and facilitated the formation of tertiary lymphatic structures (TLS) in tumors. This study presents a novel approach in using photothermal nanoadjuvants to advance antitumor effect of cellular immunotherapy, such as DCs therapy.

Autophagy-modulating biomembrane nanostructures: A robust anticancer weapon by modulating the inner and outer cancer environment

Recently, biomembrane nanostructures, such as liposomes, cell membrane-coated nanostructures, and exosomes, have demonstrated promising anticancer therapeutic effects. These nanostructures possess remarkable biocompatibility, multifunctionality, and low toxicity. However, their therapeutic efficacy is impeded by chemoresistance and radiotherapy resistance, which are closely associated with autophagy. Modulating autophagy could enhance the therapeutic sensitivity and effectiveness of these biomembrane nanostructures by influencing the immune system and the cancer microenvironment. For instance, autophagy can regulate the immunogenic cell death of cancer cells, antigen presentation of dendritic cells, and macrophage polarization, thereby activating the inflammatory response in the cancer microenvironment. Furthermore, combining autophagy-regulating drugs or genes with biomembrane nanostructures can exploit the targeting and long-term circulation properties of these nanostructures, leading to increased drug accumulation in cancer cells. This review explores the role of autophagy in carcinogenesis, cancer progression, metastasis, cancer immune responses, and resistance to treatment. Additionally, it highlights recent research advancements in the synergistic anticancer effects achieved through autophagy regulation by biomembrane nanostructures. The review also discusses the prospects and challenges associated with the future clinical translation of these innovative treatment strategies. In summary, these findings provide valuable insights into autophagy, autophagy-modulating biomembrane-based nanostructures, and the underlying molecular mechanisms, thereby facilitating the development of promising cancer therapeutics.

NIR light-facilitated bone tissue engineering

In the last decades, near-infrared (NIR) light has attracted considerable attention due to its unique properties and numerous potential applications in bioimaging and disease treatment. Bone tissue engineering for bone regeneration with the help of biomaterials is currently an effective means of treating bone defects. As a controlled light source with deeper tissue penetration, NIR light can provide real-time feedback of key information on bone regeneration in vivo utilizing fluorescence imaging and be used for bone disease treatment. This review provides a comprehensive overview of NIR light-facilitated bone tissue engineering, from the introduction of NIR probes as well as NIR light-responsive materials, and the visualization of bone regeneration to the treatment of bone-related diseases. Furthermore, the existing challenges and future development directions of NIR light-based bone tissue engineering are also discussed. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement.

Polyphenolic Carbon Quantum Dots with Intrinsic Reactive Oxygen Species Amplification for Two-Photon Bioimaging and In Vivo Tumor Therapy

Recent studies indicate that mitochondrial dysfunctions and DNA damage have a critical influence on cell survival, which is considered one of the therapeutic targets for cancer therapy. In this study, we demonstrated a comparative study of the effect of polyphenolic carbon quantum dots (CQDs) on in vitro and in vivo antitumor efficacy. Dual emissive (green and yellow) shape specific polyphenolic CQDs (G-CQDs and Y-CQDs) were synthesized from easily available nontoxic precursors (phloroglucinol), and the antitumor property of the as-synthesized probe was investigated as compared to round-shaped blue emissive CQDs (B-CQDs) derived from well-reported precursor citric acid and urea. The B-CQDs had a nuclei-targeting property, and G-CQDs and Y-CQDs had mitochondria-targeting properties. We have found that the polyphenol containing CQDs (at a dose of 100 μg mL-1) specifically attack mitochondria by excess accumulation, altering the metabolism, inhibiting branching pattern, imbalanced Bax/Bcl-2 homeostasis, and ultimately generating oxidative stress levels, leading to oxidative stress-induced cell death in cancer cells in vitro. We show that G-CQDs are the main cause of oxidative stress in cancer cells because of their ability to produce sufficient •OH- and 1O2 radicals, evidenced by electron paramagnetic resonance spectroscopy and a terephthalic acid test. Moreover, the near-infrared absorption properties of the CQDs were exhibited in two-photon (TP) emission, which was utilized for TP cellular imaging of cancer cells without photobleaching. The in vivo antitumor test further discloses that intratumoral injection of G-CQDs can significantly augment the treatment efficacy of subcutaneous tumors without any adverse effects on BalB/c nude mice. We believe that shape-specific polyphenolic CQD-based nanotheranostic agents have a potential role in tumor therapy, thus proving an insight on treatment of malignant cancers.

Tailor-Made Autophagy Cascade Amplification Polymeric Nanoparticles for Enhanced Tumor Immunotherapy

Chemotherapeutics can induce immunogenic cell death (ICD) by triggering autophagy and mediate antitumor immunotherapy. However, using chemotherapeutics alone can only cause mild cell-protective autophagy and be incapable of inducing sufficient ICD efficacy. The participation of autophagy inducer is competent to enhance autophagy, so the level of ICD is promoted and the effect of antitumor immunotherapy is highly increased. Herein, tailor-made autophagy cascade amplification polymeric nanoparticles STF@AHPPE are constructed to enhance tumor immunotherapy. Arginine (Arg), polyethyleneglycol-polycaprolactone, and epirubicin (EPI) are grafted onto hyaluronic acid (HA) via disulfide bond to form the AHPPE nanoparticles and autophagy inducer STF-62247 (STF) is loaded. When STF@AHPPE nanoparticles target to tumor tissues and efficiently enter into tumor cells with the help of HA and Arg, the high glutathione concentration leads to the cleavage of disulfide bond and the release of EPI and STF. Finally, STF@AHPPE induces violent cytotoxic autophagy and strong ICD efficacy. As compared to AHPPE nanoparticles, STF@AHPPE nanoparticles kill the most tumor cells and show the more obvious ICD efficacy and immune activation ability. This work provides a novel strategy for combining tumor chemo-immunotherapy with autophagy induction.

Black phosphorus quantum dots induce autophagy and apoptosis of human bronchial epithelial cells via endoplasmic reticulum stress

PURPOSE

The board application of black phosphorus quantum dots (BP-QDs) increases the risk of inhalation exposure in the manufacturing process. The aim of this study is to explore the toxic effect of BP-QDs on human bronchial epithelial cells (Beas-2B) and lung tissue of Balb/c mice.

METHODS

The BP-QDs were characterized using transmission electron microscopy (TEM) and a Malvern laser particle size analyzer. Cell Counting Kit-8 (CCK-8) and TEM were used to detect cytotoxicity and organelle injury. Damage to the endoplasmic reticulum (ER) was detected by using the ER-Tracker molecular probe. Rates of apoptosis were detected by AnnexinV/PI staining. Phagocytic acid vesicles were detected using AO staining. Western blotting and immunohistochemistry were used to examine the molecular mechanisms.

RESULTS

After treatment with different concentrations of BP-QDs for 24 h, the cell viability decreased, as well as activation of the ER stress and autophagy. Furthermore, the rate of apoptosis was increased. Inhibition of ER stress caused by 4-phenyl butyric acid (4-PBA) was shown to significantly inhibit both apoptosis and autophagy, suggesting that ER stress could be an upstream mediator of both autophagy and apoptosis. BP-QD-induced autophagy can also inhibit the occurrence of apoptosis using molecules related to autophagy including rapamycin (Rapa), 3-methyladenine (3-MA), and bafilomycin A1 (Bafi A1). In general, BP-QDs activate ER stress in Beas-2B cells, which further induces autophagy and apoptosis, and autophagy may be activated as a factor that protects against apoptosis. We also observed strong staining of related proteins of ER stress, autophagy, and apoptosis proteins in mouse lung tissue following intracheal instillation over the course of a week.

CONCLUSION

BP-QD-induced ER stress facilitates autophagy and apoptosis in Beas-2B cells and autophagy may be activated as a protective factor against apoptosis. Under conditions of ER stress induced by BP-QDs, The interplay between autophagy and apoptosis determines cell fate.

Recent Update and Drug Target in Molecular and Pharmacological Insights into Autophagy Modulation in Cancer Treatment and Future Progress

Recent evidence suggests that autophagy is a governed catabolic framework enabling the recycling of nutrients from injured organelles and other cellular constituents via a lysosomal breakdown. This mechanism has been associated with the development of various pathologic conditions, including cancer and neurological disorders; however, recently updated studies have indicated that autophagy plays a dual role in cancer, acting as a cytoprotective or cytotoxic mechanism. Numerous preclinical and clinical investigations have shown that inhibiting autophagy enhances an anticancer medicine's effectiveness in various malignancies. Autophagy antagonists, including chloroquine and hydroxychloroquine, have previously been authorized in clinical trials, encouraging the development of medication-combination therapies targeting the autophagic processes for cancer. In this review, we provide an update on the recent research examining the anticancer efficacy of combining drugs that activate cytoprotective autophagy with autophagy inhibitors. Additionally, we highlight the difficulties and progress toward using cytoprotective autophagy targeting as a cancer treatment strategy. Importantly, we must enable the use of suitable autophagy inhibitors and coadministration delivery systems in conjunction with anticancer agents. Therefore, this review briefly summarizes the general molecular process behind autophagy and its bifunctional role that is important in cancer suppression and in encouraging tumor growth and resistance to chemotherapy and metastasis regulation. We then emphasize how autophagy and cancer cells interacting with one another is a promising therapeutic target in cancer treatment.

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.

Boron- and phosphorus-containing molecular/nano platforms: exploiting pathological redox imbalance to fight cancer

Cancer is currently the second leading cause of death globally. Despite multidisciplinary efforts, therapies to fight various types of cancer still remain inefficient. Reducing high recurrence rates and mortality is thus a major challenge to tackle. In this context, redox imbalance is an undervalued characteristic of cancer. However, it may be targeted by boron- and phosphorus-containing materials to selectively or systemically fight cancer. In particular, boron and phosphorus derivatives are attractive building blocks for rational drug discovery due to their unique and wide regioselective chemistry, high degree of tuneability and chemical stability. Thus, they can be meticulously employed to access tunable molecular platforms to selectively exploit the redox imbalance of cancer cells towards necrosis/apoptosis. This field of research holds a remarkable potential; nevertheless, it is still in its infancy. In this mini-review, we underline recent advances in the development of boron- or phosphorus-derivatives as molecular/nano platforms for rational anticancer drug design. Our goal is to provide comprehensive information on different methodologies that bear an outstanding potential to further develop this very promising field of research.

2D Hetero-Nanoconstructs of Black Phosphorus for Breast Cancer Theragnosis: Technological Advancements

As per global cancer statistics of 2020, female breast cancer is the most commonly diagnosed cancer and also the foremost cause of cancer death in women. Traditional treatments include a number of negative effects, making it necessary to investigate novel smart drug delivery methods and identify new therapeutic approaches. Efforts for developing novel strategies for breast cancer therapy are being devised worldwide by various research groups. Currently, two-dimensional black phosphorus nanosheets (BPNSs) have attracted considerable attention and are best suited for theranostic nanomedicine. Particularly, their characteristics, including drug loading efficacy, biocompatibility, optical, thermal, electrical, and phototherapeutic characteristics, support their growing demand as a potential substitute for graphene-based nanomaterials in biomedical applications. In this review, we have explained different platforms of BP nanomaterials for breast cancer management, their structures, functionalization approaches, and general methods of synthesis. Various characteristics of BP nanomaterials that make them suitable for cancer therapy and diagnosis, such as large surface area, nontoxicity, solubility, biodegradability, and excellent near-infrared (NIR) absorption capability, are discussed in the later sections. Next, we summarize targeting approaches using various strategies for effective therapy with BP nanoplatforms. Then, we describe applications of BP nanomaterials for breast cancer treatment, which include drug delivery, codelivery of drugs, photodynamic therapy, photothermal therapy, combined therapy, gene therapy, immunotherapy, and multidrug resistance reversal strategy. Finally, the present challenges and future aspects of BP nanomaterials are discussed.

Design principles of bioinspired interfaces for biomedical applications in therapeutics and imaging

In the past two decades, we have witnessed rapid developments in nanotechnology, especially in biomedical applications such as drug delivery, biosensing, and bioimaging. The most commonly used nanomaterials in biomedical applications are nanoparticles, which serve as carriers for various therapeutic and contrast reagents. Since nanomaterials are in direct contact with biological samples, biocompatibility is one of the most important issues for the fabrication and synthesis of nanomaterials for biomedical applications. To achieve specific recognition of biomolecules for targeted delivery and biomolecular sensing, it is common practice to engineer the surfaces of nanomaterials with recognition moieties. This mini-review summarizes different approaches for engineering the interfaces of nanomaterials to improve their biocompatibility and specific recognition properties. We also focus on design strategies that mimic biological systems such as cell membranes of red blood cells, leukocytes, platelets, cancer cells, and bacteria.

Activated platelet membrane nanovesicles recruit neutrophils to exert the antitumor efficiency

Platelets play a crucial role in the recruitment of neutrophils, mediated by P-selectin, CCL5, and ICAM-2. In this study, we prepared platelet membrane nanovesicles from activated platelets. Whether activated platelet membrane nanovesicles can recruit neutrophils has not been reported, nor has their role in antitumor immunity. The results of SDS-PAGE showed that the platelet membrane nanovesicles retained almost all the proteins of platelets. Western blotting showed that both the activated platelets and the platelet membrane nanovesicles expressed P-selectin, ICAM-2, and CCL5. In vivo results of a mouse model of breast cancer-transplanted tumor showed that tumor volume reduced significantly, Ki-67-positive tumor cells decreased, and TUNEL-positive tumor cells increased in tumors after treatment with activated platelet membrane nanovesicles (aPNs). After treatment with aPNs, not only the number of neutrophils, CD8⁺, CD4⁺ T cells, and B cells increased, but also IL-12, TNF-α, and IFN-γ levels elevated significantly in tumor tissues.

Perturbation of autophagy: An intrinsic toxicity mechanism of nanoparticles

Nanoparticles (NPs) have been widely used for various purposes due to their unique physicochemical properties. Such widespread applications greatly increase the possibility of human exposure to NPs in various ways. Once entering the human body, NPs may interfere with cellular homeostasis and thus affect the physiological system. As a result, it is necessary to evaluate the potential disturbance of NPs to multiple cell functions, including autophagy. Autophagy is an important cell function to maintain cellular homeostasis, and minimizing the disturbance caused by NP exposures to autophagy is critical to nanosafety. Herein, we summarized the recent research progress in nanotoxicity with particular focuses on the perturbation of NPs to cell autophagy. The basic processes of autophagy and complex relationships between autophagy and major human diseases were further discussed to emphasize the importance of keeping autophagy under control. Moreover, the most recent advances on perturbation of different types of NPs to autophagy were also reviewed. Last but not least, we also discussed major research challenges and potential coping strategies and proposed a safe-by-design strategy towards safer applications of NPs.

Nanocarrier cancer therapeutics with functional stimuli-responsive mechanisms

Presently, nanocarriers (NCs) have gained huge attention for their structural ability, good biocompatibility, and biodegradability. The development of effective NCs with stimuli-responsive properties has acquired a huge interest among scientists. When developing drug delivery NCs, the fundamental goal is to tackle the delivery-related problems associated with standard chemotherapy and to carry medicines to the intended sites of action while avoiding undesirable side effects. These nanocarriers were able of delivering drugs to tumors through regulating their pH, temperature, enzyme responsiveness. With the use of nanocarriers, chemotherapeutic drugs could be supplied to tumors more accurately that can equally encapsulate and deliver them. Material carriers for chemotherapeutic medicines are discussed in this review keeping in viewpoint of the structural properties and targeting methods that make these carriers more therapeutically effective, in addition to metabolic pathways triggered by drug-loaded NCs. Largely, the development of NCs countering to endogenous and exogenous stimuli in tumor regions and understanding of mechanisms would encourage the progress for tumor therapy and precision diagnosis in future.

Nanocarriers surface engineered with cell membranes for cancer targeted chemotherapy

Background

Inspired by nature, the biomimetic approach has been incorporated into drug nanocarriers for cancer targeted chemotherapy. The nanocarriers are cloaked in cell membranes, which enables them to incorporate the functions of natural cells.

Key scientific concepts of review

Nanocarriers surface engineered with cell membranes have emerged as a fascinating source of materials for cancer targeted chemotherapy. A distinctive characteristic of cell membrane-coated nanocarriers (CMCNs) is that they include carbohydrates, proteins, and lipids, in addition to being biocompatible. CMCNs are capable of interacting with the complicated biological milieu of the tumor because they contain the signaling networks and intrinsic functions of their parent cells. Numerous cell membranes have been investigated for the purpose of masking nanocarriers with membranes, and various tumor-targeting methods have been devised to improve cancer targeted chemotherapy. Moreover, the diverse structure of the membrane from different cell sources broadens the spectrum of CMCNs and offers an entirely new class of drug-delivery systems.

Aim of review

This review will describe the manufacturing processes for CMCNs and the therapeutic uses for different kinds of cell membrane-coated nanocarrier-based drug delivery systems, as well as addressing obstacles and future prospects.

Graphical Abstract

Mesoporous Doxorubicin-Loaded Polydopamine Nanoparticles Coated with a Platelet Membrane Suppress Tumor Growth in a Murine Model of Human Breast Cancer

Bringing together photothermal therapy and chemotherapy (photothermal-chemotherapy, PT-CT) is a highly promising clinical approach but requires the development of intelligent multifunctional delivery vectors. In this work, we prepared mesoporous polydopamine nanoparticles (MPDA NPs) loaded with the chemotherapeutic drug doxorubicin (DOX). These NPs were then coated with the platelet membrane (PLTM). The coated MPDA NPs are spherical and clearly mesoporous in structure. They have a particle size of approximately 184 nm and pore size of ca. 45 nm. The NPs are potent photothermal agents and efficient DOX carriers, with increased rates of drug release observed in vitro in conditions representative of the tumor microenvironment. The NPs are preferentially taken up by cancer cells but not by macrophage cells, and while cytocompatible with healthy cells are highly toxic to cancer cells. An in vivo murine model of human breast cancer revealed that the NPs can markedly slow the growth of a tumor (ca. 9-fold smaller after 14 days' treatment), have extended pharmacokinetics compared to free DOX (with DOX still detectable in the bloodstream after 24 h when the NPs are applied), and are highly targeted with minimal off-site effects on the heart, liver, spleen, kidney, and lungs.

Black phosphorous quantum dots for signal-on cathodic photoelectrochemical aptasensor monoitoring amyloid β peptide

In this paper, a quantitative cathodic photoelectrochemical aptasensor is described by using black phosphorous quantum dots (BPQDs) as photoactive material and assisted by heme as electron acceptor for sensing of amyloid β peptide (Aβ). Specifically, BPQDs were synthesized by solvothermal method and characterized by various techniques. The as-prepared BPQDs were assembled on the transparent indium tin oxide electrode, and the positively charged poly-l-lysine (PLL) was then absorbed onto BPQDs via electronic interaction. Subsequently, the aptamer as the specific recognition element for Aβ oligomer was introduced on the BPQDs-PLL modified electrode. After bound with heme to form Aβ-heme complex, Aβ oligomer was simultaneously captured by the aptamer on the electrode, resulting in an enhanced photocurrent response. Under the optimized conditions, the present PEC sensor reveals a good linear response to Aβ peptide ranging from 1.0 fM to 100 nM with a detection limit of 0.87 fM. The present signal-on cathodic PEC bioassay possesses the potential to create a new paradigm in amplified PEC assays that could provide outstanding performance for bioanalysis.

Curcumin doped zeolitic imidazolate framework nanoplatform as a multifunctional nanocarrier for tumor chemo/immunotherapy

Curcumin as a hydrophobic polyphenol has great potential for tumor therapy, yet rapid degradation and hydrophobicity severely impair its therapeutic effect in the clinic. Herein, we report a novel strategy...

Combination of Nanomaterials in Cell-Based Drug Delivery Systems for Cancer Treatment

Cell-based drug delivery systems have shown tremendous advantages in cancer treatment due to their distinctive properties. For instance, delivery of therapeutics using tumor-tropic cells like neutrophils, lymphocytes and mesenchymal stem cells can achieve specific tumor targeting due to the "Trojan Horse" effect. Other circulatory cells like erythrocytes and platelets can greatly improve the circulation time of nanoparticles due to their innate long circulation property. Adipocytes, especially cancer-associated adipocytes, play key roles in tumor development and metabolism, therefore, adipocytes are regarded as promising bio-derived nanoplatforms for anticancer targeted drug delivery. Nanomaterials are important participants in cell-based drug delivery because of their unique physicochemical characteristics. Therefore, the integration of various nanomaterials with different cell types will endow the constructed delivery systems with many attractive properties due to the merits of both. In this review, a number of strategies based on nanomaterial-involved cell-mediated drug delivery systems for cancer treatment will be summarized. This review discusses how nanomaterials can be a benefit to cell-based therapies and how cell-derived carriers overcome the limitations of nanomaterials, which highlights recent advancements and specific biomedical applications based on nanomaterial-mediated, cell-based drug delivery systems.

Platelet-armored nanoplatform to harmonize janus-faced IFN-γ against tumor recurrence and metastasis

Interferon-γ (IFN-γ) plays contradictory roles in tumor immunology: (I) to activate positive host's immunity for eliminating tumor; (II) to induce negative adaptive immune resistance via up-regulating programmed death ligand-1 (PD-L1) expression for tumors to evade immune surveillance. The negative feedback loop between the IFN-γ recovery and the IFN-γ-induced PD-L1 up-regulation puts postoperative adjuvant chemotherapy into a dilemma. It is of great significance but challenging to manipulate the double-edge effects of IFN-γ against postoperative tumor progression. Herein, a platelet-engineered nanoplatform (PMF@DR NPs) capable of harmonizing janus-faced nature of IFN-γ was designed via uniquely co-assembling doxorubicin (Dox) and cyclin-dependent kinase 5 inhibitor roscovitine (Rosco) with platelet membrane fragment (PMF) as the particulate stabilizer. With PMF@DR NPs navigated by PMF to residual tumor, the Dox-activated immune response recovered IFN-γ secretion for positive host's immunity, while the IFN-γ-induced negative adaptive immune resistance was potently overcome by Rosco via disabling PD-L1 expression without dependence of IFN-γ stimulation. The negative feedback loop between IFN-γ recovery and PD-L1 up-regulation was thus potently disrupted in postoperative adjuvant chemotherapy. Our PMF@DR NPs not only harmonized janus-faced nature of IFN-γ to effectively regulate postoperative tumor progression, but also illustrated an innovative strategy for high-drug-loading biomimic nanoplatform.

2D Black Phosphorus-Based Cytomembrane Mimics with Stimuli-Responsive Antibacterial Action Inspired by Endotoxin-Associated Toxic Behavior

Biomimetic membrane materials have been widely explored and developed for drug loading and tissue engineering applications due to their excellent biocompatibility and abundant reaction sites. However, novel cytomembrane mimics have been lacking for a long time. In this study, black phosphorus (BP) was used as the foundation for a new generation of promising cytomembrane mimics due to its multiple similarities to cytomembranes. Inspired by the dual function of endotoxins on membranes, we prepared a BP-based cytomembrane mimic with controllable antibacterial ability via electrostatic interaction between BP and [1-pentyl-1-quaternary ammonium-3-vinyl-imidazole]Br ([PQVI]Br). The release of PQVI could be manipulated in different conditions by adjusting the electrostatic force, thereby achieving controllable antibacterial ability. This report confirms the possibility of using BP as a new material to mimic cytomembranes and provides a new concept of controllable antibacterial action based on endotoxins.

Black Phosphorus, an Emerging Versatile Nanoplatform for Cancer Immunotherapy

Black phosphorus (BP) is one of the emerging versatile nanomaterials with outstanding biocompatibility and biodegradability, exhibiting great potential as a promising inorganic nanomaterial in the biomedical field. BP nanomaterials possess excellent ability for valid bio-conjugation and molecular loading in anticancer therapy. Generally, BP nanomaterials can be classified into BP nanosheets (BPNSs) and BP quantum dots (BPQDs), both of which can be synthesized through various preparation routes. In addition, BP nanomaterials can be applied as photothermal agents (PTA) for the photothermal therapy (PTT) due to their high photothermal conversion efficiency and larger extinction coefficients. The generated local hyperpyrexia leads to thermal elimination of tumor. Besides, BP nanomaterials are capable of producing singlet oxygen, which enable its application as a photosensitizer for photodynamic therapy (PDT). Moreover, BP nanomaterials can be oxidized and degraded to nontoxic phosphonates and phosphate under physiological conditions, improving their safety as a nano drug carrier in cancer therapy. Recently, it has been reported that BP-based PTT is capable of activating immune responses and alleviating the immunosuppressive tumor microenvironment by detection of T lymphocytes and various immunocytokines, indicating that BP-based nanocomposites not only serve as effective PTAs to ablate large solid tumors but also function as an immunomodulation agent to eliminate discrete tumorlets. Therefore, BP-mediated immunotherapy would provide more possibilities for synergistic cancer treatment.

Recent advances in near infrared light responsive multi-functional nanostructures for phototheranostic applications

Light-based theranostics have become indispensable tools in the field of cancer nanomedicine. Specifically, near infrared (NIR) light mediated imaging and therapy of deeply seated tumors using a single multi-functional nanoplatform have gained significant attention. To this end, several multi-functional nanomaterials have been utilized to tackle cancer and thereby achieve significant outcomes. The present review mainly focuses on the recent advances in the development of NIR light activatable multi-functional materials such as small molecules, quantum dots, and metallic nanostructures for the diagnosis and treatment of deeply seated tumors. The need for improved disease detection and enhanced treatment options, together with realistic considerations for clinically translatable nanomaterials will be the key driving factors for theranostic agent research in the near future. NIR-light mediated cancer imaging and therapeutic approaches offer several advantages in terms of minimal invasiveness, deeper tissue penetration, spatiotemporal resolution, and molecular specificities. Herein, we have reviewed the recent developments in NIR light responsive multi-functional nanostructures for phototheranostic applications in cancer therapy.

Investigation on conformational variation and activity of trypsin affected by black phosphorus quantum dots via multi-spectroscopy and molecular modeling

Binding interaction between black phosphorus quantum dots (BPQDs) and trypsin was researched deeply to illustrate the variations on conformation and activity of trypsin affected by BPQDs via multi-spectroscopy and molecular modeling. Experimental results implied that inherent fluorescence of trypsin was quenched by BPQDs via static fluorescence quenching mode. BPQDs bound with trypsin to construct ground-state complex under the binding forces of van der Waal interaction and hydrophobic interaction, resulting in the conformational change of trypsin to be more hydrophilic and incompact. The result of molecular modeling indicated that BPQDs interacted with trypsin at its allosteric site and inhibited the activity of trypsin via non-competitive manner. Finally, BPQDs efficiently inhibited the digestion activity of trypsin on human serum albumin, human cervical carcinoma HeLa cells, and human lung adenocarcinoma A549 cells. This work not only explores the in-depth understanding on the influence of BPQDs on proteinases but also paves the way for further application of BPQDs on human beings for diseases treatments.

pH-responsive black phosphorus quantum dots for tumor-targeted photodynamic therapy

Black phosphorus quantum dots(BPQDs) have shown a good application prospect in the field of tumor therapy due to their photoelectric effect and good biodegradability. Due to the active endocytosis and fast metabolic efficiency of tumor cells, BPQDs are easy to be absorbed by tumor cells. However, this does not guarantee that BPQDs will be completely targeted to tumor cells, and normal cells will also absorb BPQDs. Because the cell membrane is negatively charged, BPQDs are also negatively charged and are not easily absorbed by cells under the action of electrostatic repulsion. Surface pegylation is the most common modification method of black phosphorus at present. However, surface pegylation can reduce the uptake of BPQDs by tumor cells. Positive PEG is also easy to be recognized and swallowed by the reticuloendothelial system. The inherent instability and poor tumor targeting of BPQDs under physiological conditions limit further research and clinical application. For this purpose, we selected cationic polymer polyethylenimine (PEI) to modify BPQDs and then added RGD peptides targeting tumor cells. An outer layer of negatively charged PEG+DMMA makes the nanosystem more stable . In the acidic environment of the tumor, the PEG layer has a charge reversal, and the positively charged PEI and the RGD polypeptide BPQDs targeted by the tumor cells are released into the tumor cells. It provides a new method for efficiently and accurately transporting BPQDs, a novel photosensitive nanomaterial, into tumor cells for photodynamic therapy.

Cell-derived biomimetic nanocarriers for targeted cancer therapy: cell membranes and extracellular vesicles

Nanotechnology provides synthetic carriers for cancer drug delivery that protect cargos from degradation, control drug release and increase local accumulation at tumors. However, these non-natural vehicles display poor tumor targeting and potential toxicity and are eliminated by the immune system. Recently, biomimetic nanocarriers have been widely developed based on the concept of ‘mimicking nature.’ Among them, cell-derived biomimetic vehicles have become the focus of bionics research because of their multiple natural functions, such as low immunogenicity, long circulation time and targeting ability. Cell membrane-coated carriers and extracellular vesicles are two widely used cell-based biomimetic materials. Here, this review summarizes the latest progress in the application of these two biomimetic carriers in targeted cancer therapy. Their properties and performance are compared, and their future challenges and development prospects are discussed.

Recent Advances of Cell Membrane Coated Nanoparticles in Treating Cardiovascular Disorders

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, causing approximately 17.9 million deaths annually, an estimated 31% of all deaths, according to the WHO. CVDs are essentially rooted in atherosclerosis and are clinically classified into coronary heart disease, stroke and peripheral vascular disorders. Current clinical interventions include early diagnosis, the insertion of stents, and long-term preventive therapy. However, clinical diagnostic and therapeutic tools are subject to a number of limitations including, but not limited to, potential toxicity induced by contrast agents and unexpected bleeding caused by anti-platelet drugs. Nanomedicine has achieved great advancements in biomedical area. Among them, cell membrane coated nanoparticles, denoted as CMCNPs, have acquired enormous expectations due to their biomimetic properties. Such membrane coating technology not only helps avoid immune clearance, but also endows nanoparticles with diverse cellular and functional mimicry. In this review, we will describe the superiorities of CMCNPs in treating cardiovascular diseases and their potentials in optimizing current clinical managements.

Biomimetic Ca2+ nanogenerator based on ions interference strategy for tumour-specific therapy

Intracellular Ca²⁺ ions as second messenger played key role in cell behaviour, which was often overlooked in traditional antitumor treatment. Disrupting Ca²⁺ ion homeostasis by Ca²⁺ overload might switch ions signal from 'regulating' to 'destroying'. Inspired by this, a biomimetic Ca²⁺ nanogenerator was constructed. Briefly, the curcumin (CUR) was loaded into mesoporous calcium carbonate nanoparticles (MCC NPs), and then coated with platelet (PLT) membrane. Upon reaching tumour cells by PLT membrane-mediated tumour targeting effect, PLT@MCC/CUR would instantaneously decompose in acidic lysosomes, concurrently accompanying with Ca²⁺ generation and CUR release. The CUR could further facilitate Ca²⁺ release from endoplasmic reticulum (ER) and inhibit Ca²⁺ efflux, aggravating Ca²⁺ overload to disrupt mitochondrial Ca²⁺ homeostasis for mitochondria apoptosis signalling pathway activation. Interestingly, such effect was ineffective in normal cells, realising the tumour-specific therapeutic therapy. Based on ions interference strategy, PLT@MCC/CUR herein offered synergistic combination of Ca²⁺ overload therapy and chemotherapy, which would pave the way towards more effective nanotherapeutics.

Recent advances in the biomedical applications of black phosphorus quantum dots

Zero-dimensional (0D) black phosphorus quantum dots (BPQDs), the new derivatives of black phosphorus (BP) nanomaterials, have attracted considerable attention since they were first prepared in 2015. Compared to traditional two-dimensional (2D) BP nanosheets, BPQDs exhibit some unique properties and demonstrate great potential for a broad range of applications, especially in the field of biomedicine. Due to the rapid development and substantial research interest in this area, it is urgent to review the current advances, challenges and near-future possibilities of BPQD-related biomedical research, which will benefit the further development of this field. This review is mainly focused on the latest progress of BPQD related applications in the biomedical field, including photothermal therapy (PTT), photodynamic therapy (PDT), drug delivery, biological imaging, etc. The challenges and future prospects are also discussed.

Current Advances in Black Phosphorus-Based Drug Delivery Systems for Cancer Therapy

Cancer has been one of the major threats to the lives of human beings for centuries. Traditional therapy is more or less faced with certain defects, such as poor targeting, easy degradation, high side effects, etc. Therefore, in order to improve the treatment efficiency of drugs, an intelligent drug delivery system (DDS) is considered as a promising solution strategy. Due to their special structure and large specific surface area, 2D materials are considered to be a good platform for drug delivery. Black phosphorus (BP), as a new star of the 2D family, is recommended to have the potential to construct DDS by virtue of its outstanding photothermal therapy (PTT), photodynamic therapy (PDT), and biodegradable properties. This tutorial review is intended to provide an introduction of the current advances in BP-based DDSs for cancer therapy, which covers topics from its construction, classified by the types of platforms, to the stimuli-responsive controlled drug release. Moreover, their cancer therapy applications including mono-, bi-, and multi-modal synergistic cancer therapy as well as the research of biocompatibility are also discussed. Finally, the current status and future prospects of BP-based DDSs for cancer therapy are summarized.

Cancer-associated-platelet-inspired nanomedicines for cancer therapy

Platelets, with hemostasis and thrombosis activities, are one of the key components in the blood circulation. As a guard, they rapidly respond to any abnormal blood vessel injury signal and release their granules' contents, which induce their adhesion and aggregation on wound site for hemostasis. Recently, increasing evidence has indicated that platelets are critically involved in the growth and metastasis of cancer cells by releasing a variety of cytokines and chemokines to stimulate cancer cell proliferation and various angiogenic regulators to accelerate tumor angiogenesis. Platelets also secrete active transforming growth factor beta (TGF-β) to promote the epithelial-mesenchymal transition of cancer cells and their extravasation from primary site, and form microthrombus on the surface of cancer cells to protect them from immune attack and high-speed shear force in the circulation. Therefore, blocking platelet-cancer cell interaction may be an attractive strategy to treat primary tumor and/or prevent cancer metastasis. However, systemic inhibition or depletion of platelets brings risk of severe bleeding complication. Cancer-associated-platelets-targeted nanomedicines and biomimetic nanomedicines coated with platelet membrane can be used for targeted anticancer drug delivery, due to their natural targeting ability to tumor cells and platelets. In the current review, we first summarized the platelet mechanisms of action in physiological condition and their multiple roles in cancer progression and conventional antiplatelet therapeutics. We then highlighted the recent progress on the design and fabrication of cancer-associated-platelet-targeted nanomedicines and platelet membrane coating nanomedicines for cancer therapy. Finally, we discussed opportunities and challenges and offered our thoughts for the future development. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Lipid-Based Structures.

Construction and characterization of folate-functionalized curdlan-trilysine siRNA delivery platform for in vivo hepatic carcinoma treatment

RNA interference technology is a powerful tool with substantially clinical prospects for carcinoma therapy, in which efficiency and specificity of delivery of dsRNA remains a critical issue. Herein, aiming at delivery of dsRNA in efficient and safe way, we constructed targeting delivery platform (CTL-PEG-FA) by grafting curdlan with trilysine through click reaction, then modifying with PEG linked folic acid. The CTL-PEG-FA vector exhibited excellent gene binding capacity to condense siRNA and dramatically reduced cytotoxicity. Increased cell uptake of CTL-PEG-FA/Bcl-2 siRNA was achieved by the synergism of folate mediated endocytosis and charge interaction, and further causing severe HepG2 cells injury through apoptosis mechanism after down-regulation of Bcl-2 protein. In vivo experiments, CTL-PEG-FA/Bcl-2 siRNA complex distinctly accumulated in tumor site and significantly inhibited the growth of tumor, while no obvious toxicity was observed. Therefore, well-performed CTL-PEG-FA with excellent biocompatibility, has the potential to be the candidate of gene therapy for clinical applications.

Immunogenic exosome-encapsulated black phosphorus nanoparticles as an effective anticancer photo-nanovaccine

Tumor vaccines are a promising form of cancer immunotherapy, but difficulties such as neo-antigen identification, activation of immune cells, and tumor infiltration prevent their clinical breakthrough. Interestingly, nanotechnology-based photothermal therapy (PTT) has great potential to overcome these barriers. Previous studies have shown that serum exosomes (hEX) from hyperthermia-treated tumor-bearing mice displayed an array of patient-specific tumor-associated antigens (TAAs), and strong immunoregulatory abilities in promoting dendritic cell (DC) differentiation and maturation. Here, we developed a tumor vaccine (hEX@BP) by encapsulating black phosphorus quantum dots (BPQDs) with exosomes (hEX) against a murine subcutaneous lung cancer model. In comparison with BPQDs alone (BP), hEX@BP demonstrated better long-term PTT performance, greater elevation of tumor temperature and tumor targeting efficacy in vivo. Vaccination with hEX@BP in combination with PTT further demonstrated an outstanding therapeutic efficacy against established lung cancer, and promoted the infiltration of T lymphocytes into the tumor tissue. Our findings demonstrated that hEX@BP might be an innovative cancer photo-nanovaccine that offers effective immuno-PTT against cancers.

Drug Targeting via Platelet Membrane-Coated Nanoparticles

Platelets possess distinct surface moieties responsible for modulating their adhesion to various disease-relevant substrates involving vascular damage, immune evasion, and pathogen interactions. Such broad biointerfacing capabilities of platelets have inspired the development of platelet-mimicking drug carriers that preferentially target drug payloads to disease sites for enhanced therapeutic efficacy. Among these carriers, platelet membrane-coated nanoparticles (denoted 'PNPs') made by cloaking synthetic substrates with the plasma membrane of platelets have emerged recently. Their 'top-down' design combines the functionalities of natural platelet membrane and the engineering flexibility of synthetic nanomaterials, which together create synergy for effective drug delivery and novel therapeutics. Herein, we review the recent progress of engineering PNPs with different structures for targeted drug delivery, focusing on three areas, including targeting injured blood vessels to treat vascular diseases, targeting cancer cells for cancer treatment and detection, and targeting drug-resistant bacteria to treat infectious diseases. Overall, current studies have established PNPs as versatile nanotherapeutics for drug targeting with strong potentials to improve the treatment of various diseases.

Ag+ -Coupled Black Phosphorus Vesicles with Emerging NIR-II Photoacoustic Imaging Performance for Cancer Immune-Dynamic Therapy and Fast Wound Healing

A silver-ion-coupled black phosphorus (BP) vesicle (BP Ve-Ag⁺ ) with a second near infrared (NIR-II) window photoacoustic (PA) imaging capability was firstly constructed to maximize the potential of BP quantum dot (QD) in deeper bioimaging and diversified therapy. The embedded Ag⁺ could improve the relatively large band gap of BP QD via intense charge coupling based on theoretical simulation results, subsequently leading to the enhanced optical absorption capability, accompanied with the occurrence of the strong NIR-II PA signal. Guiding by NIR-II PA bioimaging, the hidden Ag⁺ could be precisely released with the disassembly of Ve during photodynamic therapy process and captured by macrophages located in lesion region for arousing synergistic cancer photodynamic/Ag⁺ immunotherapy. BP Ve-Ag⁺ can contrapuntally kill pathogenic bacteria and accelerate wound healing monitored by NIR-II PA imaging.

Irradiation pretreatment enhances the therapeutic efficacy of platelet-membrane-camouflaged antitumor nanoparticles

BACKGROUND

Cell membrane-based nanocarriers are promising candidates for delivering antitumor agents. The employment of a simple and feasible method to improve the tumor-targeting abilities of these systems is appealing for further application. Herein, we prepared a platelet membrane (PM)-camouflaged antitumor nanoparticle. The effects of irradiation pretreatment on tumor targeting of the nanomaterial and on its antitumor action were evaluated.

RESULTS

The biomimetic nanomaterial constructed by indocyanine green, poly(d,l-lactide-co-glycolide), and PM is termed PINPs@PM. A 4-Gy X-ray irradiation increased the proportions of G2/M phase and Caveolin-1 content in 4T1 breast cancer cells, contributing to an endocytic enhancement of PINPs@PM. PINPs@PM produced hyperthermia and reactive oxygen species upon excitation by near-infrared irradiation, which were detrimental to the cytoplasmic lysosome and resulted in cell death. Irradiation pretreatment thus strengthened the antitumor activity of PINPs@PM in vitro. Mice experiments revealed that irradiation enhanced the tumor targeting capability of PINPs@PM in vivo. When the same dose of PINPs@PM was intravenously administered, irradiated mice had a better outcome than did mice without X-ray pretreatment.

CONCLUSION

The study demonstrates an effective strategy combining irradiation pretreatment and PM camouflage to deliver antitumor nanoparticles, which may be instrumental for targeted tumor therapy.

A Nano-Traditional Chinese Medicine Against Lymphoma That Regulates the Level of Reactive Oxygen Species

Jolkinolide B (JB) is a bioactive compound isolated from a Chinese herbal medicine that exerts antitumor activity. However, the anti-lymphoma effect of JB and its mechanism are yet to be revealed. Because free JB has poor pharmacokinetics and weak antitumor efficacy, we opted to use black phosphorus quantum dot (BPQD) nanomaterials as a drug loading platform to synthesize a nano-traditional Chinese medicine (nano-TCM) called BPQDs@JB. Compared with free JB, Raji cells administrated with BPQDs@JB exhibited the cell viability of 19.85 ± 1.02%, and the production of intracellular reactive oxygen species (ROS) was promoted. Likewise, BPQDs@JB was capable of rising the apoptosis rate of Raji cells to 34.98 ± 1.76%. In nude mice transplanted tumor model administrated with BPQDs@JB, the tumor tissue sections administrated with BPQDS@JB achieved a conspicuous red fluorescence, demonstrating the presence of most ROS production in the BPQDS@JB. TUNEL achieved a number of positive (brown) nuclei in vivo, revealing that BPQDS@JB could significantly induce tumor tissue apoptosis. As revealed from the mentioned results, BPQDs@JB can generate considerable ROS and interfere with the redox state to inhibit tumor. In brief, BPQDs@JB may be adopted as a treatment option for lymphoma.

Platelet-Membrane-Camouflaged Zirconia Nanoparticles Inhibit the Invasion and Metastasis of Hela Cells

Zirconia nanoparticles (ZrO2 NPs) are widely applied in the field of biomedicine. In this study, we constructed a nanoplatform of ZrO2 NPs coated with a platelet membrane (PLTm), named PLT@ZrO2. PLTm nanovesicles camouflage ZrO2 NPs, prevent nanoparticles from being cleared by macrophage, and target tumor sites. Compared to ZrO2 alone, PLT@ZrO2 is better at inhibiting the invasion and metastasis of Hela cells in vitro and in vivo. In vitro, PLT@ZrO2 inhibited the growth and proliferation of Hela cells. Scratch-wound healing recovery assay demonstrated that PLT@ZrO2 inhibited Hela cells migration. Transwell migration and invasion assays showed that PLT@ZrO2 inhibited Hela cells migration and invasion. In vivo, PLT@ZrO2 inhibited the tumor growth of Xenograft mice and inhibited the lung and liver metastasis of Hela cells. Immunofluorescence and Western blotting results showed that anti-metastasis protein (E-cadherin) was upregulated and pro-metastasis proteins (N-cadherin, Smad4, Vimentin, E-cadherin,β-catenin, Fibronectin, Snail, Slug, MMP2, Smad2) were down-regulated. Our study indicated that PLT@ZrO2 significantly inhibits tumor growth, invasion, and metastasis.