Platelet-Covered Nanocarriers for Targeted Delivery of Hirudin to Eliminate Thrombotic Complication in Tumor Therapy

Emerging advances in drug delivery systems (DDSs) for optimizing cancer complications

The management and treatment of tumor complications pose continuous challenges due to the inherent complexity. However, the advent of drug delivery systems (DDSs) brings promising opportunities to address the tumor complications using innovative technological approaches. This review focuses on common oncological complications, including cancer thrombosis, malignant serous effusion, tumor-associated infections, cancer pain, and treatment-related complications. Emphasis was placed on the application and potential of DDSs in mitigating and treating these tumor complications, and we delved into the underlying mechanisms of common cancer-associated complications, discussed the limitations of conventional treatments, and outlined the current status and potential development of DDSs for various complications in this review. Moreover, we have discussed the existing challenges in DDSs research, underscoring the need for addressing issues related to biocompatibility and targeting of DDSs, optimizing drug delivery routes, and enhancing delivery efficiency and precision. In conclusion, DDSs offer promising avenues for treating cancer complications, offering the potential for the development of more effective and safer drug delivery strategies, thereby improving the quality of life and survival rates of cancer patients.

Novel drug delivery systems for hirudin-based product development and clinical applications

Hirudin, a natural biological polypeptide macromolecule secreted by the salivary glands of medicinal leech, is a specific thrombin inhibitor with multiple favourable bioactivities, including anti-coagulation, anti-fibrotic, and anti-tumour. Despite several anticoagulants have been widely applied in clinic, hirudin shows advantages in reducing the incidence of bleeding side effects by virtue of its high specificity in binding to thrombin. As a result, hirudin has been tested in clinical practice to prevent and treat several complex diseases. However, the application of this polypeptide macromolecule is compromised by its low bioavailability and bioactivity due to poor serum stability and susceptibility to protease degradation in vivo. To overcome these drawbacks, several studies have proposed novel drug delivery systems (NDDSs) to prevent the degradation and increase the targeting efficiency of hirudin. This systematic review summarises the clinical research on hirudin, including its classification and bioactivities, and highlights the opportunities and challenges in the clinical use of hirudin. The NDDSs designed to enhance the bioavailability and bioactivity of hirudin are discussed to explore its application in the treatment of related diseases. This review may considerably contribute to the advancement of delivery science and technology, particularly in the context of polypeptide-based therapeutics.

Combined drug anti-deep vein thrombosis therapy based on platelet membrane biomimetic targeting nanotechnology

After orthopedic surgeries, such as hip replacement, many patients are prone to developing deep vein thrombosis (DVT), which in severe cases can lead to fatal pulmonary embolism or major bleeding. Clinical intervention with high-dose anticoagulant therapy inevitably carries the risk of bleeding. Therefore, a targeted drug delivery system that adjusts local DVT lesions and potentially reduces drug dosage and toxic side effects important. In this study, we developed a targeted drug delivery platelet-derived nanoplatform (AMSNP@PM-rH/A) for DVT treatment that can simultaneously deliver a direct thrombin inhibitor (DTI) Recombinant Hirudin (rH), and the Factor Xa inhibitor Apixaban (A) by utilizing Aminated mesoporous silica nanoparticles (AMSNP). This formulation exhibits improved biocompatibility and blood half-life and can effectively eliminate deep vein thrombosis lesions and achieve therapeutic effects at half the dosage. Furthermore, we employed various visualization techniques to capture the targeted accumulation and release of a platelet membrane (PM) coating in deep vein thrombosis and explored its potential targeting mechanism.

Innovative utilization of cell membrane-coated nanoparticles in precision cancer therapy

Cell membrane-coated nanoparticles (CMNPs) have recently emerged as a promising platform for cancer therapy. By encapsulating therapeutic agents within a cell membrane-derived coating, these nanoparticles combine the advantages of synthetic nanoparticles and natural cell membranes. This review provides a comprehensive overview of the recent advancements in utilizing CMNPs as effective drug delivery vehicles for cancer therapy. The synthesis and fabrication methods of CMNPs are comprehensively discussed. Various techniques, such as extrusion, sonication, and self-assembly, are employed to coat synthetic nanoparticles with cell membranes derived from different cell types. The cell membrane coating enables biocompatibility, reducing the risk of an immune response and enhancing the stability of the nanoparticles in the bloodstream. Moreover, functionalization strategies for CMNPs, primarily chemical modification, genetic engineering, and external stimuli, are highlighted. The presence of specific cell surface markers on the coated membrane allows targeted drug delivery to cancer cells and maximizes therapeutic efficacy. Preclinical studies utilizing CMNPs for cancer therapy demonstrated the successful delivery of various therapeutic agents, such as chemotherapeutic drugs, nucleic acids, and immunotherapeutic agents, using CMNPs. Furthermore, the article explores the future directions and challenges of this technology while offering insights into its clinical potential.

Toward the Integration of Machine Learning and Molecular Modeling for Designing Drug Delivery Nanocarriers

The pioneering work on liposomes in the 1960s and subsequent research in controlled drug release systems significantly advances the development of nanocarriers (NCs) for drug delivery. This field is evolved to include a diverse array of nanocarriers such as liposomes, polymeric nanoparticles, dendrimers, and more, each tailored to specific therapeutic applications. Despite significant achievements, the clinical translation of nanocarriers is limited, primarily due to the low efficiency of drug delivery and an incomplete understanding of nanocarrier interactions with biological systems. Addressing these challenges requires interdisciplinary collaboration and a deep understanding of the nano-bio interface. To enhance nanocarrier design, scientists employ both physics-based and data-driven models. Physics-based models provide detailed insights into chemical reactions and interactions at atomic and molecular scales, while data-driven models leverage machine learning to analyze large datasets and uncover hidden mechanisms. The integration of these models presents challenges such as harmonizing different modeling approaches and ensuring model validation and generalization across biological systems. However, this integration is crucial for developing effective and targeted nanocarrier systems. By integrating these approaches with enhanced data infrastructure, explainable AI, computational advances, and machine learning potentials, researchers can develop innovative nanomedicine solutions, ultimately improving therapeutic outcomes.

Delivering urokinase-type plasminogen activator using mulberry leaf exosomes enables thrombolysis and remodeling of venous microenvironments

In the treatment of thrombosis, conventional nanocarriers inevitably have problems, such as adverse reactions and difficulties in synthesis. Inspired by the concept of 'medicine food homology,' we extracted and purified natural exosomes from mulberry leaves as carriers for the delivery of urokinase-type plasminogen activator (uPA) for targeted therapy. The obtained mulberry leaf exosomes (MLE) possessed a desirable hydrodynamic particle size (119.4 nm), a uniform size distribution (polydispersity index = 0.174), and a negative surface charge (-23.3 mv). Before loading with uPA, MLE were grafted with cyclic RGD (cRGD) to selectively bind activated platelets for thrombus targeting. The cytometry studies revealed that MLE@cRGD has a high thrombus targeting ability about 74.3 %. Animal tests demonstrated that the delivered uPA could dissolve clots almost completely in femoral vein thrombosis models. In addition, MLE could remodel venous microenvironments by effectively eliminating reactive oxygen species (ROS) and promoting the phenotypic transformation of macrophages from M1 to M2 for venous tissue repair.

Therapeutic Potentials of Medicinal Leech in Chinese Medicine

The use of medicinal leeches in clinical therapy has been employed for a long time, as it was originally recognized for exerting antithrombin effects. These effects were due to the ability of the leech to continuously suck blood while attached to human skin. According to Chinese Pharmacopoei, leeches used in traditional Chinese medicine mainly consist of Whitmania pigra Whitman, Hirudo nipponia Whitman, and Whitmania acranulata, but the latter two species are relatively scarce. The main constituents of leeches are protein and peptide macromolecules. They can be categorized into two categories based on their pharmacological effects. One group consists of active ingredients that directly target the coagulation system, such as hirudin, heparin, and histamine, which are widely known. The other group comprises protease inhibitor components like Decorsin and Hementin. Among these, hirudin secreted by the salivary glands of the leech is the most potent thrombin inhibitor and served as the sole remedy for preventing blood clotting until the discovery of heparin. Additionally, leeches play a significant role in various traditional Chinese medicine formulations. In recent decades, medicinal leeches have been applied in fields including anti-inflammatory treatment, cardiovascular disease management, antitumor treatment, and many other medical conditions. In this review, we present a comprehensive overview of the historical journey and medicinal applications of leeches in various medical conditions, emphasizing their pharmaceutical significance within traditional Chinese medicine. This review offers valuable insights for exploring additional therapeutic opportunities involving the use of leeches in various diseases and elucidating their underlying mechanisms for future research.

Bio-inspired drug delivery systems: A new attempt from bioinspiration to biomedical applications

Natural organisms have evolved sophisticated and multiscale hierarchical structures over time to enable survival. Currently, bionic design is revolutionizing drug delivery systems (DDS), drawing inspiration from the structure and properties of natural organisms that offer new possibilities to overcome the challenges of traditional drug delivery systems. Bionic drug delivery has contributed to a significant improvement in therapeutic outcomes, providing personalized regimens for patients with various diseases and enhancing both their quality of life and drug efficacy. Therefore, it is important to summarize the progress made so far and to discuss the challenges and opportunities for future development. Herein, we review the recent advances in bio-inspired materials, bio-inspired drug vehicles, and drug-loading platforms of biomimetic structures and properties, emphasizing the importance of adapting the structure and function of organisms to meet the needs of drug delivery systems. Finally, we highlight the delivery strategies of bionics in DDS to provide new perspectives and insights into the research and exploration of bionics in DDS. Hopefully, this review will provide future insights into utilizing biologically active vehicles, bio-structures, and bio-functions, leading to better clinical outcomes.

Platelet-derived drug delivery systems: Pioneering treatment for cancer, cardiovascular diseases, infectious diseases, and beyond

Platelets play a critical role as circulating cells in the human body and contribute to essential physiological processes such as blood clotting, hemostasis, vascular repair, and thrombus formation. Currently, platelets are extensively employed in the development of innovative biomimetic drug delivery systems, offering significant enhancements in circulation time, biocompatibility, and targeted delivery efficiency compared to conventional drug delivery approaches. Leveraging the unique physiological functions of platelets, these platelet-derived drug delivery systems (DDSs) hold great promise for the treatment of diverse diseases, including cancer, cardiovascular diseases, infectious diseases, wound healing and other diseases. This review primarily focuses on the design and characteristics of existing platelet-derived DDSs, including their preparation and characterization methods. Furthermore, this review comprehensively outlines the applications of these materials across various diseases, offering a holistic understanding of their therapeutic potential. This study aimed to provide a comprehensive overview of the potential value of these materials in clinical treatment, serving as a valuable reference for the advancement of novel platelet-derived DDSs and their broader utilization in the field of disease treatment.

Bio-Responsive Sliver Peroxide-Nanocarrier Serves as Broad-Spectrum Metallo-β-lactamase Inhibitor for Combating Severe Pneumonia

Metallo-β-lactamases (MBLs) represent a prevalent resistance mechanism in Gram-negative bacteria, rendering last-line carbapenem-related antibiotics ineffective. Here, a bioresponsive sliver peroxide (Ag2 O2 )-based nanovesicle, named Ag2 O2 @BP-MT@MM, is developed as a broad-spectrum MBL inhibitor for combating MBL-producing bacterial pneumonia. Ag2 O2 nanoparticle is first orderly modified with bovine serum albumin and polydopamine to co-load meropenem (MER) and [5-(p-fluorophenyl)-2-ureido]-thiophene-3-carboxamide (TPCA-1) and then encapsulated with macrophage membrane (MM) aimed to target inflammatory lung tissue specifically. The resultant Ag2 O2 @BP-MT@MM effectively abrogates MBL activity by displacing the Zn2+ cofactor in MBLs with Ag+ and displays potent bactericidal and anti-inflammatory properties, specific targeting abilities, and great bioresponsive characteristics. After intravenous injection, the nanoparticles accumulate prominently at infection sites through MM-mediated targeting . Ag+ released from Ag2 O2 decomposition at the infection sites effectively inhibits MBL activity and overcomes the resistance of MBL-producing bacteria to MER, resulting in synergistic elimination of bacteria in conjunction with MER. In two murine infection models of NDM-1+ Klebsiella pneumoniae-induced severe pneumonia and NDM-1+ Escherichia coli-induced sepsis-related bacterial pneumonia, the nanoparticles significantly reduce bacterial loading, pro-inflammatory cytokine levels locally and systemically, and the recruitment and activation of neutrophils and macrophages. This innovative approach presents a promising new strategy for combating infections caused by MBL-producing carbapenem-resistant bacteria.

Biomimetic Nano-Drug Delivery System: An Emerging Platform for Promoting Tumor Treatment

With the development of nanotechnology, nanoparticles (NPs) have shown broad prospects as drug delivery vehicles. However, they exhibit certain limitations, including low biocompatibility, poor physiological stability, rapid clearance from the body, and nonspecific targeting, which have hampered their clinical application. Therefore, the development of novel drug delivery systems with improved biocompatibility and high target specificity remains a major challenge. In recent years, biofilm mediated biomimetic nano-drug delivery system (BNDDS) has become a research hotspot focus in the field of life sciences. This new biomimetic platform uses bio-nanotechnology to encapsulate synthetic NPswithin biomimetic membrane, organically integrating the low immunogenicity, low toxicity, high tumor targeting, good biocompatibility of the biofilm with the adjustability and versatility of the nanocarrier, and shows promising applications in the field of precision tumor therapy. In this review, we systematically summarize the new progress in BNDDS used for optimizing drug delivery, providing a theoretical reference for optimizing drug delivery and designing safe and efficient treatment strategies to improve tumor treatment outcomes.

Cell Membrane-Camouflaged Nanoparticles Mediated Nucleic Acids Delivery

Nucleic acids have emerged as promising therapeutic agents for many diseases because of their potential in modulating gene expression. However, the delivery of nucleic acids remains a significant challenge in gene therapy. Although viral vectors have shown high transfection efficiency, concerns regarding teratogenicity or carcinogenicity have been raised. Non-viral vehicles, including cationic polymers, liposomes, and inorganic materials possess advantages in terms of safety, ease of preparation, and low cost. Nevertheless, they also face limitations related to immunogenicity, quick clearance in vivo, and lack of targeting specificity. On the other hand, bioinspired strategies have shown increasing potential in the field of drug delivery, yet there is a lack of comprehensive reviews summarizing the rapid development of bioinspired nanoparticles based on the cell membrane camouflage to construct the nucleic acids vehicles. Herein, we enumerated the current difficulties in nucleic acid delivery with various non-viral vehicles and provided an overview of bioinspired strategies for nucleic acid delivery.

Platelets as delivery vehicles for targeted enrichment of NO· to cerebral glioma for magnetic resonance imaging

Using a magnetic resonance imaging (MRI) contrast agent, MRI has made substantial contributions to glioma diagnosis. Metal-free MRI agents, such as the nano free radical nitric oxide (NO·) micelle, can overcome the inherent toxicity of metal-based agents in certain patient populations. However, the low spatial resolution of nano NO· micelle in MRI limits its clinical development. In this study, we pretreated platelets (PLTs) and loaded them with nano NO· micelles to synthesize NO·@PLT, which can overcome the low contrast and poor in vivo stability of nitroxide-based MRI contrast agents. The PLTs can serve as potential drug carriers for targeting and delivering nano NO· micelles to gliomas and thus increase the contrast in T1-weighted imaging (T1WI) of MRI. This drug carrier system uses the unique tumor-targeting ability of PLTs and takes advantage of the high signal presentation of steady nano NO· micelles in T1WI, thereby ultimately achieving signal amplification of glioma in T1WI. With the effect of PLTs-tumor cell adhesion, NO·@PLT has per-nitroxide transverse relativities of approximately 2-fold greater than those of free NO· particles. These features allow a sufficient NO·@PLT concentration to accumulate in murine subcutaneous glioma tumors up from 5 min to 2.5 h (optimum at 1.5 h) after systemic administration. This results in MRI contrast comparable to that of metal-based agents. This study established a promising metal-free MRI contrast agent, NO·@PLT, for glioma diagnosis, because it has superior spatial resolution owing to its high glioma-targeting ability and has significant translational implications in the clinic.

Enhanced Antitumor Efficacy of Novel Biomimetic Platelet Membrane-Coated Tetrandrine Nanoparticles in Nonsmall Cell Lung Cancer

Nonsmall cell lung cancer (NSCLC) remains one of the leading causes of cancer-related death worldwide, posing a serious threat to global health. Tetrandrine (Tet) is a small molecule in traditional Chinese medicine with proven primary efficacy against multiple cancers. Although previous studies have demonstrated the potential anticancer effects of Tet on NSCLC, its poor water solubility has limited its further clinical application. Herein, a novel nanoparticle-based drug delivery system, platelet membrane (PLTM)-coated Tet-loaded polycaprolactone-b-poly(ethylene glycol)-b-polycaprolactone nanoparticles (PTeNPs), is proposed to increase the potency of Tet against NSCLC. First, tetrandrine nanoparticles (TeNPs) are created using an emulsion solvent evaporation method, and biomimetic nanoparticles (PTeNPs) are prepared by coating the nanoparticles with PLTMs. When coated with PLTMs, PTeNPs are considerably less phagocytized by macrophages than Tet and TeNPs. In addition, compared with Tet and TeNPs, PTeNPs can significantly inhibit the growth and invasion of NSCLC both in vitro and in vivo. With reliable biosafety, this drug delivery system provides a new method of sustained release and efficient anticancer effects against NSCLC, facilitating the incorporation of Tet in modern nanotechnology.

Inorganic Nanoparticles as Radiosensitizers for Cancer Treatment

Nanotechnology has expanded what can be achieved in our approach to cancer treatment. The ability to produce and engineer functional nanoparticle formulations to elicit higher incidences of tumor cell radiolysis has resulted in substantial improvements in cancer cell eradication while also permitting multi-modal biomedical functionalities. These radiosensitive nanomaterials utilize material characteristics, such as radio-blocking/absorbing high-Z atomic number elements, to mediate localized effects from therapeutic irradiation. These materials thereby allow subsequent scattered or emitted radiation to produce direct (e.g., damage to genetic materials) or indirect (e.g., protein oxidation, reactive oxygen species formation) damage to tumor cells. Using nanomaterials that activate under certain physiologic conditions, such as the tumor microenvironment, can selectively target tumor cells. These characteristics, combined with biological interactions that can target the tumor environment, allow for localized radio-sensitization while mitigating damage to healthy cells. This review explores the various nanomaterial formulations utilized in cancer radiosensitivity research. Emphasis on inorganic nanomaterials showcases the specific material characteristics that enable higher incidences of radiation while ensuring localized cancer targeting based on tumor microenvironment activation. The aim of this review is to guide future research in cancer radiosensitization using nanomaterial formulations and to detail common approaches to its treatment, as well as their relations to commonly implemented radiotherapy techniques.

Thermoplasmonic Controlled Optical Absorber Based on a Liquid Crystal Metasurface

Metasurfaces can be realized by organizing subwavelength elements (e.g., plasmonic nanoparticles) on a reflective surface covered with a dielectric layer. Such an array of resonators, acting collectively, can completely absorb the resulting resonant wavelength. Unfortunately, despite the excellent optical properties of metasurfaces, they lack the tunability to perform as adaptive optical components. To boost the utilization of metasurfaces and realize a new generation of dynamically controlled optical components, we report our recent finding based on the powerful combination of an innovative metasurface-optical absorber and nematic liquid crystals (NLCs). The metasurface consists of self-assembled silver nanocubes (AgNCs) immobilized on a 50 nm thick gold layer by using a polyelectrolyte multilayer as a dielectric spacer. The resulting optical absorbers show a well-defined reflection band centered in the near-infrared of the electromagnetic spectrum (750-770 nm), a very high absorption efficiency (∼60%) at the resonant wavelength, and an elevated photothermal efficiency estimated from the time constant value (34 s). Such a metasurface-based optical absorber, combined with an NLC layer, planarly aligned via a photoaligned top cover glass substrate, shows homogeneous NLC alignment and an absorption band photothermally tunable over approximately 46 nm. Detailed thermographic studies and spectroscopic investigations highlight the extraordinary capability of the active metasurface to be used as a light-controllable optical absorber.

Biomembrane‐inspired design of medical micro/nanorobots: From cytomembrane stealth cloaks to cellularized Trojan horses

Micro/nanorobots are promising for a wide range of biomedical applications (such as targeted tumor, thrombus, and infection therapies in hard‐to‐reach body sites) because of their tiny size and high maneuverability through the actuation of external fields (e.g., magnetic field, light, ultrasound, electric field, and/or heat). However, fully synthetic micro/nanorobots as foreign objects are susceptible to phagocytosis and clearance by diverse phagocytes. To address this issue, researchers have attempted to develop various cytomembrane‐camouflaged micro/nanorobots by two means: (1) direct coating of micro/nanorobots with cytomembranes derived from living cells and (2) the swallowing of micro/nanorobots by living immunocytes via phagocytosis. The camouflaging with cytomembranes or living immunocytes not only protects micro/nanorobots from phagocytosis, but also endows them with new characteristics or functionalities, such as prolonging propulsion in biofluids, targeting diseased areas, or neutralizing bacterial toxins. In this review, we comprehensively summarize the recent advances and developments of cytomembrane‐camouflaged medical micro/nanorobots. We first discuss how cytomembrane coating nanotechnology has been employed to engineer synthetic nanomaterials, and then we review in detail how cytomembrane camouflage tactic can be exploited to functionalize micro/nanorobots. We aim to bridge the gap between cytomembrane‐cloaked micro/nanorobots and nanomaterials and to provide design guidance for developing cytomembrane‐camouflaged micro/nanorobots.