Red blood cells: The metamorphosis of a neglected carrier into the natural mothership for artificial nanocarriers

MnO2-based nanoparticles remodeling tumor micro-environment to augment sonodynamic immunotherapy against breast cancer

The tumor microenvironment (TME) is characterized by a complex array of factors, including aerobic conditions, high glutathione (GSH) levels, acidic pH, and elevated hydrogen peroxide (H2O2) content, all of which promote cancer progression and contribute to poor prognosis. Fortunately, these challenges can be addressed using MnO2-based nanomaterials. In this study, we have designed and synthesized a Curcumin/MnO2@PLGA@4T1 cell membrane (CMP@4T1m) system aimed at remodelling the TME and enhancing sonodynamic immunotherapy for breast cancer. Through the homologous targeting ability of 4T1m, CMP@4T1m efficiently accumulates at the tumor site. Upon ultrasound irradiation, curcumin (Cur) acts as a sonosensitizer, generating cytotoxic reactive oxygen species (ROS) that induce immunogenic cell death (ICD), activate T-cell responses, and repolarize protumoral M2-like macrophages to antitumoral M1-like macrophages. In the TME, which is mildly acidic and enriched with GSH and H2O2, MnO2 not only oxidizes GSH to glutathione disulfide (GSSG) but also reacts with H2O2 and H+ to produce oxygen, alleviating hypoxia and significantly enhancing the sonodynamic immunotherapy effect. Additionally, Mn2+ generated during this process converts H2O2 into cytotoxic hydroxyl radicals (˙OH). This study thus lays the foundation for advancing cancer nanomedicine, offering a novel approach that integrates TME remodelling with sonodynamic immunotherapy.

Engineering of Erythrocytes as Drug Carriers for Therapeutic Applications

Erythrocytes, also known as red blood cells (RBCs), have garnered considerable attention as potential carriers for drug delivery, owing to their inherent properties such as biocompatibility, biodegradability, and prolonged circulation half-life. This paper presents a comprehensive overview of the role of erythrocytes in drug delivery, elucidating recent advancements in delivering a diverse array of therapeutic agents, including small molecules, nucleic acids, antibodies, protein enzymes, and nanoparticles. Two primary strategies for encapsulating drugs within erythrocytes are systematically discussed: internal loading and surface loading. Each strategy offers distinct advantages in terms of drug stability and release kinetics. Notably, the utilization of erythrocyte membrane camouflaged nanocarriers holds promise for enhancing the biocompatibility of conventional nanoparticles and facilitating targeted drug delivery. Furthermore, the broad spectrum of biomedical applications of erythrocyte-based drug delivery systems are examined, ranging from cancer treatment to diabetes management, thrombosis prevention, and immunotherapy. This review provides a comprehensive evaluation of current technologies in erythrocyte-loaded drug delivery, highlighting the strengths, weaknesses, and future directions for advancing therapeutic interventions in various disease contexts.

Red blood cells-derived components as biomimetic functional materials: Matching versatile delivery strategies based on structure and function

Red blood cells (RBCs), often referred to as "intelligent delivery systems", can serve as biological or hybrid drug carriers due to their inherent advantages and characteristics. This innovative approach has the potential to enhance biocompatibility, pharmacokinetics, and provide targeting properties for drugs. By leveraging the unique structure and contents of RBCs, drug-loading pathways can be meticulously designed to align with these distinctive features. This review article primarily discusses the drug delivery strategies and their applications that are informed by the structural and functional properties of the main components of RBCs, including living RBCs, membranes, hollow RBCs, and hemoglobin. Overall, this review article would assist efforts to make better decisions on optimization and rational utilization of RBCs derivatives-based drug delivery strategies for the future direction in clinical translation.

Bottom-up development of lipid-based synthetic cells for practical applications

Synthetic cells (SCs) can be engineered from the bottom up to recapitulate the functional properties of natural cells while performing specialized tasks such as drug delivery, biosensors, bioproduction, vaccine development, and even environmental remediation. Recent advances in synthetic biology, biomaterials, and microfluidics have enabled the development of increasingly sophisticated SCs. Transitioning from proof-of-concept demonstrations to practical applications requires a deep understanding of the design principles, materials, and fabrication techniques involved. This review provides a comprehensive overview of the current state of bottom-up SC technology and highlights the most promising approaches and applications. Challenges in the implementation of SCs and their prospects for future applications are also discussed.

Biomechanical and Functional Features of the Carrier Erythrocytes Prolonging Circulation Time of Biotherapeutic Targeted to Glycophorin A

Red blood cells (RBCs) serve as natural transporters and can be modified to enhance the pharmacokinetics and pharmacodynamics of a protein cargo. Affinity targeting of Factor IX (FIX) to the RBC membrane is a promising approach to improve the (pro)enzyme's pharmacokinetics. For RBC targeting, purified human FIX was conjugated to the anti-mouse glycophorin A monoclonal antibody Ter119. The goal of this study was to characterize the activity of the FIX-Ter119 conjugate and efficacy of its loading on RBCs, as well as to investigate the biodistribution, pharmacokinetics, and various biological properties of the loaded RBCs. Mouse RBCs were incubated with the Ter119-FIX conjugate, where adding 10,000 molecules per RBC resulted in 37% binding (4K/RBC), and 50,000 molecules per RBC resulted in 34% binding (17K/RBC). The pharmacokinetics (PK) profile showed that more than 90% of the Ter119-FIX conjugate was associated with RBCs and circulated stably bound to the RBCs for 24 h, increasing the area under the PK curve 7.6 times vs free FIX. Ter119-FIX loaded RBCs have specific procoagulant FIXa activity, including promotion of thrombin generation and acceleration of clotting in FIX-deficient plasma. Morphological characterization shows that Ter119-FIX-loaded RBCs undergo a shape change, with an increased fraction of echinocytes and spheroidal RBCs. Ektacytometry and electron microscopy assessment of RBC compressibility reveal a dose-dependent reduction in the deformability of RBCs loaded with Ter119-FIX. In conclusion, RBCs loaded with Ter119-FIX have the potential to serve as prohemostatic agents, but their reduced deformability warrants further engineering of Ter119-FIX to improve the safety profile.

One-step on-chip preparation of nanoparticle-conjugated red blood cell carriers

Red blood cell (RBC)-based carriers have emerged as promising vehicles for drug delivery due to their inherent biocompatibility and biodegradability. Traditional methods for loading nanoparticles (NPs) onto RBC surfaces often involve labor-intensive processes like incubation and multiple centrifugation steps, limiting their practicality and controllability. In this study, we introduce a fully integrated acoustofluidic platform that enables one-step preparation of NP-loaded RBC carriers with controlled modification and on-site purification. By incorporating a high-frequency bulk acoustic wave (BAW) resonator into a microfluidic chip, we utilize acoustic streaming effects to manipulate the movement and interaction of RBCs and NPs within the microchannel. This design allows for precise control over NP loading efficiency by adjusting the input power to the resonator. Experimental results using 200 nm positively charged fluorescent NPs demonstrate that our platform significantly enhances the interaction between RBCs and NPs, achieving efficient and controllable surface loading of NPs onto RBCs. Furthermore, the platform simplifies post-processing by directing excess NPs to waste outlets, eliminating the need for repetitive washing and centrifugation. This acoustofluidics approach not only automates the loading process but also offers high controllability, highlighting its potential for various applications in particle and cell surface modification.

Flexible Morphological Regulation of Photothermal Nanodrugs: Understanding the Relationship between the Structure, Photothermal Effect, and Tumoral Biodistribution

The morphology of nanodrugs is of utmost importance in photothermal therapy because it directly influences their physicochemical behavior and biological responses. However, clarifying the inherent relationship between morphology and the resultant properties remains challenging, mainly due to the limitations in the flexible morphological regulation of nanodrugs. Herein, we created a range of morphologically controlled nanoassemblies based on poly(ethylene glycol)-block-poly(d,l-lactide) (PEG-PLA) block copolymer building blocks, in which the model photosensitizer phthalocyanine was incorporated. Four different topologies were compared, namely, spherical vesicles, bowl-shaped vesicles, rodlike micelles, and vesicular tubes. The photothermal properties and in vivo tumoral biodistribution were investigated, revealing their relationship with the particle morphology. Finally, the tumor ablation capability of the optimized nanodrugs was demonstrated. This study represents a systematic study of the morphologically discrete regulation of nanodrugs, highlighting the importance of customization of supramolecular photothermal nanodrugs toward clinical antitumor therapy.

Nonviral targeted mRNA delivery: principles, progresses, and challenges

Messenger RNA (mRNA) therapeutics have garnered considerable attention due to their remarkable efficacy in the treatment of various diseases. The COVID-19 mRNA vaccine and RSV mRNA vaccine have been approved on the market. Due to the inherent nuclease-instability and negative charge of mRNA, delivery systems are developed to protect the mRNA from degradation and facilitate its crossing cell membrane to express functional proteins or peptides in the cytoplasm. However, the deficiency in transfection efficiency and targeted biological distribution are still the major challenges for the mRNA delivery systems. In this review, we first described the physiological barriers in the process of mRNA delivery and then discussed the design approach and recent advances in mRNA delivery systems with an emphasis on their tissue/cell-targeted abilities. Finally, we pointed out the existing challenges and future directions with deep insights into the design of efficient mRNA delivery systems. We believe that a high-precision targeted delivery system can greatly improve the therapeutic effects and bio-safety of mRNA therapeutics and accelerate their clinical transformations. This review may provide a new direction for the design of mRNA delivery systems and serve as a useful guide for researchers who are looking for a suitable mRNA delivery system.

Cell-derived biomimetic drug delivery system for inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is a chronic recurrent disease with an increasing incidence year by year. At present, no safe and effective treatment for IBD exists. Thus, there is an urgent need to create new therapeutic options that have decreased adverse effects and positive clinical efficacy. A range of nanomaterials have fueled the advancement of nanomedicine in recent years, which is establishing more appealing and prospective treatment approaches for IBD. However, traditional synthetic nanomaterials still have some problems in the IBD drug delivery process, such as weak targeting ability of vectors, difficulty escaping immune surveillance, and poor biosecurity. Natural sources of biological nanomaterials have been identified to solve the above problems. A drug delivery system based on bionic technology is expected to achieve a new breakthrough in the targeted therapy of IBD by nanotechnology due to its organic integration of low immunogenicity and natural targeting of biological materials and the controllability and versatility of synthetic nanocarrier design. We begin this review by outlining the fundamental traits of both inflammatory and healthy intestinal microenvironments. Subsequently, we review the latest application of a cell-derived bionic drug delivery system in IBD therapy. Finally, we discuss the development prospects of this delivery system and challenges to its clinical translation. Biomimetic nanotherapy is believed to offer a new strategy for the treatment of IBD.

Long-Circulating Nanoemulsion with Oxygen and Drug Co-Delivery for Potent Photodynamic/Antibiotic Therapy Against Multidrug-Resistant Gram-Negative Bacterial Infection

Purpose

Compared to conventional photodynamic therapy (PDT), oxygen-affording PDT represents a promising strategy for treating multidrug-resistant (MDR) gram-negative bacterial infections due to its enhanced sensitization ability towards bacteria and amplified therapeutic efficacy. Over the last decade, various nanoplatforms for the co-delivery of oxygen and photosensitizers have been developed. However, their application in the treatment of infectious diseases is hampered by their poor stability and easy clearance by the reticuloendothelial system (RES).

Methods

To address these obstacles, we reported an erythrocyte membrane (EM) camouflaged nanoemulsion containing chlorin e6 (Ce6) and perfluorocarbon (FDC), named ECF, showing good colloidal stability and long-circulating potential, making it suitable for fighting against MDR Gram-negative bacterial infections. The nanoemulsion was fabricated and characterized. The oxygen loading and release performance, photodynamic activity, and bactericidal performance of ECF against Acinetobacter baumannii (A. baumannii) were evaluated. Furthermore, the antiphagocytosis profile was tested in vitro using Raw 264.7 cells. In addition, the pharmacokinetic behavior and therapeutic efficiency of ECF were studied in vivo.

Results

ECF exhibited superior oxygen loading and release behavior, potent photodynamic activity, and negligible toxicity to mammalian cells. Upon light irradiation, the antibacterial rate of preoxygenated-ECF reached 98% at 40 μg mL-1 of Ce6 and the bactericidal activity of preoxygenated-ECF and Gen was 3.3 folds higher than that of Gen. Furthermore, ECF could effectively inhibit uptake by phagocytes and circulate in the blood 1.5-fold longer than that of nanoemulsion without EM modification (CF) following intravenous administration. In addition, preoxygenated-ECF combined with antibiotic plus light irradiation showed prominent therapeutic efficacy in treating A. baumannii-induced acute peritonitis, accompanied by good biocompatibility in vivo.

Conclusion

Our results provide a novel paradigm for evading immune clearance, prolonging retention time and improving synergetic bactericidal capacity in combination with PDT and antibiotic therapy against planktonic bacteria and gram-negative bacterial infections.

Biofilm-camouflaged Prussian blue synergistic mitochondrial mass enhancement for Alzheimer's disease based on Cu2+ chelation and photothermal therapy

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases characterized by cognitive and memory impairment. Metal ion imbalance and Mitochondrial dysfunction, leading to abnormal aggregation of β-amyloid protein (Aβ), are key factors in the pathogenesis of AD. Therefore, we designed a composite nanometer system of red blood cell (RBC) membranes-encapsulated Prussian blue nanoparticles (PB/RBC). Prussian blue nanoparticles (PBNPs) can chelate Cu2+ and reduce reactive oxygen species (ROS). The RBC membranes are a kind of natural long-lasting circulating carrier. At the same time, through NIR irradiation, the excellent photothermal ability of PBNPs can also temporarily open the blood-brain barrier (BBB), enhance the transmission efficiency of PB/RBC across the BBB, and depolymerize the formed Aβ deposits, thereby achieving the optimal therapeutic effect. In vitro and in vivo studies demonstrated that PB/RBC could inhibit Cu2+-induced Aβ monomers aggregation, eliminate the deposition of Aβ plaques, improve the quality of mitochondria, restore the phagocytic function of microglia, alleviate neuroinflammation in APP/PS1 mice, and repair memory damage. In conclusion, our biofilm-camouflaged nano-delivery system provides significant neuroprotection by inhibiting Cu2+-induced Aβ monomers aggregation, photothermally depolymerizing Aβ fibrils and reducing the level of ROS, thus effectively ameliorating and treating AD.

Harnessing cells to improve transport of nanomedicines

Efficient tumour treatment is hampered by the poor selectivity of anticancer drugs, resulting in scarce tumour accumulation and undesired off-target effects. Nano-sized drug-delivery systems in the form of nanoparticles (NPs) have been proposed to improve drug distribution to solid tumours, by virtue of their ability of passive and active tumour targeting. Despite these advantages, literature studies indicated that less than 1% of the administered NPs can successfully reach the tumour mass, highlighting the necessity for more efficient drug transporters in cancer treatment. Living cells, such as blood cells, circulating immune cells, platelets, and stem cells, are often found as an infiltrating component in most solid tumours, because of their ability to naturally circumvent immune recognition, bypass biological barriers, and reach inaccessible tissues through innate tropism and active motility. Therefore, the tumour-homing ability of these cells can be harnessed to design living cell carriers able to improve the transport of drugs and NPs to tumours. Albeit promising, this approach is still in its beginnings and suffers from difficult scalability, high cost, and poor reproducibility. In this review, we present an overview of the most common cell transporters of drugs and NPs, and we discuss how different cell types interact with biological barriers to deliver cargoes of various natures to tumours. Finally, we analyse the different techniques used to load drugs or NPs in living cells and discuss their advantages and disadvantages.

Red Blood Cell-Like Poly(ethylene glycol) Particles: Influence of Particle Stiffness on Biological Behaviors

Cell-like particles represent a category of synthetic particles designed to emulate the structures or functions of natural cells. Herein, we present the assembly of cell-like poly(ethylene glycol) (PEG) particles with different stiffnesses and shapes via replication of animal cells and investigate the impact of particle stiffness on their biological behaviors. As a proof of concept, we fabricate red blood cell-like and spherical PEG particles with varying cross-linking densities. A systematic exploration of their properties, encompassing morphology, stiffness, deformability, and biodistribution, reveal the vital influence of particle stiffness on in vivo fate, elucidating its role in governing the traversal of capillaries and the dynamic interactions with phagocytic cells.

Complex Emulsions as an Innovative Pharmaceutical Dosage form in Addressing the Issues of Multi-Drug Therapy and Polypharmacy Challenges

This review explores the intersection of microfluidic technology and complex emulsion development as a promising solution to the challenges of formulations in multi-drug therapy (MDT) and polypharmacy. The convergence of microfluidic technology and complex emulsion fabrication could herald a transformative era in multi-drug delivery systems, directly confronting the prevalent challenges of polypharmacy. Microfluidics, with its unparalleled precision in droplet formation, empowers the encapsulation of multiple drugs within singular emulsion particles. The ability to engineer emulsions with tailored properties-such as size, composition, and release kinetics-enables the creation of highly efficient drug delivery vehicles. Thus, this innovative approach not only simplifies medication regimens by significantly reducing the number of necessary doses but also minimizes the pill burden and associated treatment termination-issues associated with polypharmacy. It is important to bring forth the opportunities and challenges of this synergy between microfluidic-driven complex emulsions and multi-drug therapy poses. Together, they not only offer a sophisticated method for addressing the intricacies of delivering multiple drugs but also align with broader healthcare objectives of enhancing treatment outcomes, patient safety, and quality of life, underscoring the importance of dosage form innovations in tackling the multifaceted challenges of modern pharmacotherapy.

All-stage targeted red blood cell membrane-coated docetaxel nanocrystals for glioma treatment

Challenges for glioma treatment with nanomedicines include physio-anatomical barriers (the blood-brain barrier and blood-brain tumor barrier), low drug loading capacity, and limited circulation time. Here, a red blood cell membrane-coated docetaxel drug nanocrystal (pV-RBCm-NC(DTX)), modified with pHA-VAP (pV) for all-stage targeting of glioma, was designed. The NC(DTX) core exhibited a high drug loading capacity but low in vivo stability, and the RBCm coating significantly enhanced the stability and prolonged in vivo circulation. Moreover, the Y-shaped targeting ligand pV was modified by a mild avidin-biotin interaction, which endowed RBCm-NC(DTX) with superior barrier-crossing ability and therapeutic efficacy. The integration of nanocrystal technology, cell membrane coating, and the avidin-biotin insertion method into this active targeting biomimetic formulation represents a promising drug delivery strategy for glioma.

Advanced Nano-Drug Delivery Systems in the Treatment of Ischemic Stroke

In recent years, the frequency of strokes has been on the rise year by year and has become the second leading cause of death around the world, which is characterized by a high mortality rate, high recurrence rate, and high disability rate. Ischemic strokes account for a large percentage of strokes. A reperfusion injury in ischemic strokes is a complex cascade of oxidative stress, neuroinflammation, immune infiltration, and mitochondrial damage. Conventional treatments are ineffective, and the presence of the blood-brain barrier (BBB) leads to inefficient drug delivery utilization, so researchers are turning their attention to nano-drug delivery systems. Functionalized nano-drug delivery systems have been widely studied and applied to the study of cerebral ischemic diseases due to their favorable biocompatibility, high efficiency, strong specificity, and specific targeting ability. In this paper, we briefly describe the pathological process of reperfusion injuries in strokes and focus on the therapeutic research progress of nano-drug delivery systems in ischemic strokes, aiming to provide certain references to understand the progress of research on nano-drug delivery systems (NDDSs).

Cancer Cell-Mimicking Prussian Blue Nanoplatform for Synergistic Mild Photothermal/Chemotherapy via Heat Shock Protein Inhibition

Combined mild-temperature photothermal/chemotherapy has emerged as a highly promising modality for tumor therapy. However, its therapeutic efficacy is drastically compromised by the heat-induced overexpression of heat shock proteins (HSPs) by the cells, which resist heat stress and apoptosis. The purpose of this study was to downregulate HSPs and enhance the mild-temperature photothermal/chemotherapy effect. In detail, the colon cancer cell membrane (CT26M)-camouflaged HSP90 inhibitor ganetespib and the chemotherapeutic agent doxorubicin (DOX)-coloaded hollow mesoporous Prussian blue (HMPB) nanoplatform (named PGDM) were designed for synergistic mild photothermal/chemotherapy via HSP inhibition. In addition to being a photothermal agent with a high efficiency of photothermal conversion (24.13%), HMPB offers a hollow hole that can be filled with drugs. Concurrently, the cancer cell membrane camouflaging enhances tumor accumulation through a homologous targeting mechanism and gives the nanoplatform the potential to evade the immune system. When exposed to NIR radiation, HMPB's photothermal action (44 °C) not only causes tumor cells to undergo apoptosis but also causes ganetespib to be released on demand. This inhibits the formation of HSP90, which enhances the mild photothermal/chemotherapy effect. The results confirmed that the combined treatment regimen of mild photothermal therapy (PTT) and chemotherapy showed a better therapeutic efficacy than the individual treatment methods. Therefore, this multimodal nanoparticle can advance the development of drugs for the treatment of malignancies, such as colon cancer, and has prospects for clinical application.

Artificial cells for in vivo biomedical applications through red blood cell biomimicry

Recent research in artificial cell production holds promise for the development of delivery agents with therapeutic effects akin to real cells. To succeed in these applications, these systems need to survive the circulatory conditions. In this review we present strategies that, inspired by the endurance of red blood cells, have enhanced the viability of large, cell-like vehicles for in vivo therapeutic use, particularly focusing on giant unilamellar vesicles. Insights from red blood cells can guide modifications that could transform these platforms into advanced drug delivery vehicles, showcasing biomimicry's potential in shaping the future of therapeutic applications.

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.

Drug-loaded erythrocytes: Modern approaches for advanced drug delivery for clinical use

Scientific organizations worldwide are striving to create drug delivery systems that provide a high local concentration of a drug in pathological tissue without side effects on healthy organs in the body. Important physiological properties of red blood cells (RBCs), such as frequent renewal ability, good oxygen carrying ability, unique shape and membrane flexibility, allow them to be used as natural carriers of drugs in the body. Erythrocyte carriers derived from autologous blood are even more promising drug delivery systems due to their immunogenic compatibility, safety, natural uniqueness, simple preparation, biodegradability and convenience of use in clinical practice. This review is focused on the achievements in the clinical application of targeted drug delivery systems based on osmotic methods of loading RBCs, with an emphasis on advancements in their industrial production. This article describes the basic methods used for encapsulating drugs into erythrocytes, key strategic approaches to the clinical use of drug-loaded erythrocytes obtained by hypotonic hemolysis. Moreover, clinical trials of erythrocyte carriers for the targeted delivery are discussed. This article explores the recent advancements and engineering approaches employed in the encapsulation of erythrocytes through hypotonic hemolysis methods, as well as the most promising inventions in this field. There is currently a shortage of reviews focused on the automation of drug loading into RBCs; therefore, our work fills this gap. Finally, further prospects for the development of engineering and technological solutions for the automatic production of drug-loaded RBCs were studied. Automated devices have the potential to provide the widespread production of RBC-encapsulated therapeutic drugs and optimize the process of targeted drug delivery in the body. Furthermore, they can expedite the widespread introduction of this innovative treatment method into clinical practice, thereby significantly expanding the effectiveness of treatment in both surgery and all areas of medicine.

Scheduled dosage regimen by irreversible electroporation of loaded erythrocytes for cancer treatment

Precise control of cargo release is essential but still a great challenge for any drug delivery system. Irreversible electroporation (IRE), utilizing short high-voltage pulsed electric fields to destabilize the biological membrane, has been recently approved as a non-thermal technique for tumor ablation without destroying the integrity of adjacent collagenous structures. Due to the electro-permeating membrane ability, IRE might also have great potential to realize the controlled drug release in response to various input IRE parameters, which were tested in a red blood cell (RBC) model in this work. According to the mathematical simulation model of a round biconcave disc-like cell based on RBC shape and dielectric characteristics, the permeability and the pore density of the RBC membrane were found to quantitatively depend on the pulse parameters. To further provide solid experimental evidence, indocyanine green (ICG) and doxorubicin (DOX) were both loaded inside RBCs (RBC@DOX&ICG) and the drug release rates were found to be tailorable by microsecond pulsed electric field (μsPEF). In addition, μsPEF could effectively modulate the tumor stroma to augment therapy efficacy by increasing micro-vessel density and permeability, softening extracellular matrix, and alleviating tumor hypoxia. Benefiting from these advantages, this IRE-responsive RBC@DOX&ICG achieved a remarkably synergistic anti-cancer effect by the combination of μsPEF and chemotherapy in the tumor-bearing mice model, with the survival time increasing above 90 days without tumor burden. Given that IRE is easily adaptable to different plasma membrane-based vehicles for delivering diverse drugs, this approach could offer a general applicability for cancer treatment.

Lipid-hybrid cell-derived biomimetic functional materials: A state-of-the-art multifunctional weapon against tumors

Tumors are among the leading causes of death worldwide. Cell-derived biomimetic functional materials have shown great promise in the treatment of tumors. These materials are derived from cell membranes, extracellular vesicles and bacterial outer membrane vesicles and may evade immune recognition, improve drug targeting and activate antitumor immunity. However, their use is limited owing to their low drug-loading capacity and complex preparation methods. Liposomes are artificial bionic membranes that have high drug-loading capacity and can be prepared and modified easily. Although they can overcome the disadvantages of cell-derived biomimetic functional materials, they lack natural active targeting ability. Lipids can be hybridized with cell membranes, extracellular vesicles or bacterial outer membrane vesicles to form lipid-hybrid cell-derived biomimetic functional materials. These materials negate the disadvantages of both liposomes and cell-derived components and represent a promising delivery platform in the treatment of tumors. This review focuses on the design strategies, applications and mechanisms of action of lipid-hybrid cell-derived biomimetic functional materials and summarizes the prospects of their further development and the challenges associated with it.

Maleimide as the PEG end-group promotes macrophage-targeted drug delivery of PEGylated nanoparticles in vivo by enhancing interaction with circulating erythrocytes

Radiotherapy (IR) is capable of enhancing antitumor immune responses. However, IR treatment also aggravates the infiltration of peripheral macrophages into the tumor, resulting in reversing the therapeutic effects of antitumor immunity. Thus, a strategy to effectively prevent tumor infiltration by macrophages may further improved the therapeutic efficacy of radiotherapy. Herein, we found that PEGylated solid lipid nanoparticles with maleimide as PEG end-group (SLN-PEG-Mal) show significantly enhanced adsorption onto RBCs through reacting with reactive sulfhydryl groups on RBCs' surface both in vitro and in vivo, and caused significant changes in the surface properties and morphology of RBCs. These RBCs adsorbed by SLN-PEG-Mal were rapidly removed from circulation due to efficient engulfment by reticuloendothelial macrophages, supporting the usefulness of SLN-PEG-Mal for macrophage-targeted drug delivery. While lacking the use of radioisotope tracing (considered the gold standard for PK/BD studies), our data align with the expected pathway of host defense activation through surface-loaded RBCs. Importantly, injection of paclitaxel-loaded SLN-PEG-Mal effectively inhibited the tumor-infiltration by macrophages, and significantly improved the antitumor immune responses in tumor-bearing mice treated with low-dose irradiation. This study provides insights into the effects of maleimide as PEG end-group on enhancing the interaction between PEGylated nanoparticles and RBCs and offers an effective strategy to inhibit tumor infiltration by circulating macrophages.

Biomembrane nanostructures: Multifunctional platform to enhance tumor chemoimmunotherapy via effective drug delivery

Chemotherapeutic drugs have been found to activate the immune response against tumors by inducing immunogenic cell death, in addition to their direct cytotoxic effects toward tumors, therefore broadening the application of chemotherapy in tumor immunotherapy. The combination of other therapeutic strategies, such as phototherapy or radiotherapy, could further strengthen the therapeutic effects of immunotherapy. Nanostructures can facilitate multimodal tumor therapy by integrating various active agents and combining multiple types of therapeutics in a single nanostructure. Biomembrane nanostructures (e.g., exosomes and cell membrane-derived nanostructures), characterized by superior biocompatibility, intrinsic targeting ability, intelligent responsiveness and immune-modulating properties, could realize superior chemoimmunotherapy and represent next-generation nanostructures for tumor immunotherapy. This review summarizes recent advances in biomembrane nanostructures in tumor chemoimmunotherapy and highlights different types of engineering approaches and therapeutic mechanisms. A series of engineering strategies for combining different biomembrane nanostructures, including liposomes, exosomes, cell membranes and bacterial membranes, are summarized. The combination strategy can greatly enhance the targeting, intelligence and functionality of biomembrane nanostructures for chemoimmunotherapy, thereby serving as a stronger tumor therapeutic method. The challenges associated with the clinical translation of biomembrane nanostructures for chemoimmunotherapy and their future perspectives are also discussed.

Advanced hitchhiking nanomaterials for biomedical applications

Hitchhiking, a recently developed bio-inspired cargo delivery system, has been harnessed for diverse applications. By leveraging the interactions between nanoparticles and circulatory cells or proteins, hitchhiking enables efficient navigation through the vasculature while evading immune system clearance. Moreover, it allows for targeted delivery of nutrients to tissues, surveillance of the immune system, and pathogen elimination. Various synthetic nanomaterials have been developed to facilitate hitchhiking with circulatory cells or proteins. By combining the advantages of synthetic nanomaterials and circulatory cells or proteins, hitchhiking nanomaterials demonstrate several advantages over conventional vectors, including enhanced circulatory stability and optimized therapeutic efficacy. This review provides an overview of general strategies for hitchhiking, choices of cells and proteins, and recent advances of hitchhiking nanomaterials for biomedical applications.

Advances in treatment strategies based on scavenging reactive oxygen species of nanoparticles for atherosclerosis

The development of atherosclerosis (AS) is closely linked to changes in the plaque microenvironment, which consists primarily of the cells that form plaque and the associated factors they secrete. The onset of inflammation, lipid deposition, and various pathological changes in cellular metabolism that accompany the plaque microenvironment will promote the development of AS. Numerous studies have shown that oxidative stress is an important condition that promotes AS. The accumulation of reactive oxygen species (ROS) is oxidative stress's most important pathological change. In turn, the effects of ROS on the plaque microenvironment are complex and varied, and these effects are ultimately reflected in the promotion or inhibition of AS. This article reviews the effects of ROS on the microenvironment of atherosclerotic plaques and their impact on disease progression over the past five years and focuses on the progress of treatment strategies based on scavenging ROS of nanoparticles for AS. Finally, we also discuss the prospects and challenges of AS treatment.

Nature-inspired nanocarriers for improving drug therapy of atherosclerosis

Atherosclerosis (AS) has emerged as one of the prevalent arterial vascular diseases characterized by plaque and inflammation, primarily causing disability and mortality globally. Drug therapy remains the main treatment for AS. However, a series of obstacles hinder effective drug delivery. Nature, from natural micro-/nano-structural biological particles like natural cells and extracellular vesicles to the distinctions between the normal and pathological microenvironment, offers compelling solutions for efficient drug delivery. Nature-inspired nanocarriers of synthetic stimulus-responsive materials and natural components, such as lipids, proteins and membrane structures, have emerged as promising candidates for fulfilling drug delivery needs. These nanocarriers offer several advantages, including prolonged blood circulation, targeted plaque delivery, targeted specific cells delivery and controlled drug release at the action site. In this review, we discuss the nature-inspired nanocarriers which leverage the natural properties of cells or the microenvironment to improve atherosclerotic drug therapy. Finally, we provide an overview of the challenges and opportunities of applying these innovative nature-inspired nanocarriers.

Messenger RNA-Based Therapeutics and Vaccines: What's beyond COVID-19?

With the rapid success in the development of mRNA vaccines against COVID-19 and with a number of mRNA-based drugs ahead in the pipelines, mRNA has catapulted to the forefront of drug research, demonstrating its substantial effectiveness against a broad range of diseases. As the recent global pandemic gradually fades, we cannot stop thinking about what the world has gained: the realization and validation of the power of mRNA in modern medicine. A significant amount of research has now been concentrated on developing mRNA drugs and vaccine platforms against infectious and immune diseases, cancer, and other debilitating diseases and has demonstrated encouraging results. Here, based on the CAS Content Collection, we provide a landscape view of the current state, outline trends in the research and development of mRNA therapeutics and vaccines, and highlight some notable patents focusing on mRNA therapeutics, vaccines, and delivery systems. Analysis of diseases disclosed in patents also reveals highly investigated diseases for treatments with these medicines. Finally, we provide information about mRNA therapeutics and vaccines in clinical trials. We hope this Review will be useful for understanding the current knowledge in the field of mRNA medicines and will assist in efforts to solve its remaining challenges and revolutionize the treatment of human diseases.

Cell-Based Biomaterials for Coronavirus Disease 2019 Prevention and Therapy

Coronavirus disease 2019 (COVID-19) continues to threaten human health, economic development, and national security. Although many vaccines and drugs have been explored to fight against the major pandemic, their efficacy and safety still need to be improved. Cell-based biomaterials, especially living cells, extracellular vesicles, and cell membranes, offer great potential in preventing and treating COVID-19 owing to their versatility and unique biological functions. In this review, the characteristics and functions of cell-based biomaterials and their biological applications in COVID-19 prevention and therapy are described. First the pathological features of COVID-19 are summarized, providing enlightenment on how to fight against COVID-19. Next, the classification, organization structure, characteristics, and functions of cell-based biomaterials are focused on. Finally, the progress of cell-based biomaterials in overcoming COVID-19 in different aspects, including the prevention of viral infection, inhibition of viral proliferation, anti-inflammation, tissue repair, and alleviation of lymphopenia are comprehensively described. At the end of this review, a look forward to the challenges of this aspect is presented.

Liposomal delivery system/adjuvant for tuberculosis vaccine

As reported by the World Health Organization, about 10 million individuals were infected with tuberculosis (TB) worldwide. Moreover, approximately 1.5 million people died of TB, of which 214,000 were infected with HIV simultaneously. Due to the high infection rate, the need for effective TB vaccination is highly felt. Until now, various methodologies have been proposed for the development of a protein subunit vaccine for TB. These vaccines have shown higher protection than other vaccines, particularly the Bacillus culture vaccine. The delivery system and safety regulator are common characteristics of effective adjuvants in TB vaccines and the clinical trial stage. The present study investigates the current state of TB adjuvant research focusing on the liposomal adjuvant system. Based on our findings, the liposomal system is a safe and efficient adjuvant from nanosize to microsize for vaccinations against TB, other intracellular infections, and malignancies. Clinical studies can provide valuable feedback for developing novel TB adjuvants, which ultimately enhance the impact of adjuvants on next-generation TB vaccines.

The Role of Integrins for Mediating Nanodrugs to Improve Performance in Tumor Diagnosis and Treatment

Integrins are heterodimeric transmembrane proteins that mediate adhesive connections between cells and their surroundings, including surrounding cells and the extracellular matrix (ECM). They modulate tissue mechanics and regulate intracellular signaling, including cell generation, survival, proliferation, and differentiation, and the up-regulation of integrins in tumor cells has been confirmed to be associated with tumor development, invasion, angiogenesis, metastasis, and therapeutic resistance. Thus, integrins are expected to be an effective target to improve the efficacy of tumor therapy. A variety of integrin-targeting nanodrugs have been developed to improve the distribution and penetration of drugs in tumors, thereby, improving the efficiency of clinical tumor diagnosis and treatment. Herein, we focus on these innovative drug delivery systems and reveal the improved efficacy of integrin-targeting methods in tumor therapy, hoping to provide prospective guidance for the diagnosis and treatment of integrin-targeting tumors.

Cellular nanovesicles for therapeutic immunomodulation: A perspective on engineering strategies and new advances

Cellular nanovesicles which are referred to as cell-derived, nanosized lipid bilayer structures, have emerged as a promising platform for regulating immune responses. Owing to their outstanding advantages such as high biocompatibility, prominent structural stability, and high loading capacity, cellular nanovesicles are suitable for delivering various immunomodulatory molecules, such as small molecules, nucleic acids, peptides, and proteins. Immunomodulation induced by cellular nanovesicles has been exploited to modulate immune cell behaviors, which is considered as a novel cell-free immunotherapeutic strategy for the prevention and treatment of diverse diseases. Here we review emerging concepts and new advances in leveraging cellular nanovesicles to activate or suppress immune responses, with the aim to explicate their applications for immunomodulation. We overview the general considerations and principles for the design of engineered cellular nanovesicles with tailored immunomodulatory activities. We also discuss new advances in engineering cellular nanovesicles as immunotherapies for treating major diseases.

Engineering cells for precision drug delivery: New advances, clinical translation, and emerging strategies

Cells have emerged as a promising new form of drug delivery carriers owing to their distinguished advantages such as naturally bypassing immune recognition, intrinsic capability to navigate biological barriers, and access to hard-to-reach tissues via onboarding sensing and active motility. Over the past two decades, a large body of work has focused on understanding the ability of cell carriers to breach biological barriers and to modulate drug pharmacokinetics and pharmacodynamics. These efforts have led to the engineering of various cells for tissue-specific drug delivery. Despite exciting advances, clinical translation of cell-based drug carriers demands a thorough understanding of the pressing challenges and potential strategies to overcome them. Here, we summarize recent advances and new concepts in cell-based drug carriers and their clinical translation. We also discuss key considerations and emerging strategies to engineering the next-generation cell-based delivery technologies for more precise, targeted drug delivery.

Impact of Plasmonic Nanoparticles on Poikilocytosis and Microrheological Properties of Erythrocytes

Plasmonic nanoparticles (NP) possess great potential in photothermal therapy and diagnostics. However, novel NP require a detailed examination for potential toxicity and peculiarities of interaction with cells. Red blood cells (RBC) are important for NP distribution and the development of hybrid RBC-NP delivery systems. This research explored RBC alterations induced by noble (Au and Ag) and nitride-based (TiN and ZrN) laser-synthesized plasmonic NP. Optical tweezers and conventional microscopy modalities indicated the effects arising at non-hemolytic levels, such as RBC poikilocytosis, and alterations in RBC microrheological parameters, elasticity and intercellular interactions. Aggregation and deformability significantly decreased for echinocytes independently of NP type, while for intact RBC, all NP except Ag NP increased the interaction forces but had no effect on RBC deformability. RBC poikilocytosis promoted by NP at concentration 50 μg mL-1 was more pronounced for Au and Ag NP, compared to TiN and ZrN NP. Nitride-based NP demonstrated better biocompatibility towards RBC and higher photothermal efficiency than their noble metal counterparts.

Manipulate tumor hypoxia for improved photodynamic therapy using nanomaterials

Due to its low adverse effects, minimal invasiveness, and outstanding patient compliance, photodynamic therapy (PDT) has drawn a great deal of interest, which is achieved through incomplete reduction of O₂ by a photosensitizer under light illumination that produces amounts of reactive oxygen species (ROS). However, tumor hypoxia significantly hinders the therapeutic effect of PDT so that tumor cells cannot be eliminated, which results in tumor cells proliferating, invading, and metastasizing. Additionally, O₂ consumption during PDT exacerbates hypoxia in tumors, leading to several adverse events after PDT treatment. In recent years, various investigations have focused on conquering or using tumor hypoxia by nanomaterials to amplify PDT efficacy, which is summarized in this review. This comprehensive review's objective is to present novel viewpoints on the advancement of oxygenation nanomaterials in this promising field, which is motivated by hypoxia-associated anti-tumor therapy.

Advances in Microfluidics for Single Red Blood Cell Analysis

The utilizations of microfluidic chips for single RBC (red blood cell) studies have attracted great interests in recent years to filter, trap, analyze, and release single erythrocytes for various applications. Researchers in this field have highlighted the vast potential in developing micro devices for industrial and academia usages, including lab-on-a-chip and organ-on-a-chip systems. This article critically reviews the current state-of-the-art and recent advances of microfluidics for single RBC analyses, including integrated sensors and microfluidic platforms for microscopic/tomographic/spectroscopic single RBC analyses, trapping arrays (including bifurcating channels), dielectrophoretic and agglutination/aggregation studies, as well as clinical implications covering cancer, sepsis, prenatal, and Sickle Cell diseases. Microfluidics based RBC microarrays, sorting/counting and trapping techniques (including acoustic, dielectrophoretic, hydrodynamic, magnetic, and optical techniques) are also reviewed. Lastly, organs on chips, multi-organ chips, and drug discovery involving single RBC are described. The limitations and drawbacks of each technology are addressed and future prospects are discussed.

Advances, challenge and prospects in cell-mediated nanodrug delivery for cancer therapy: a review

Nanomedicine offers considerable opportunities to improve drugability and reduce toxicity for tumour therapy. However, the application of nanomedicine has achieved little success in clinical trials due to multiple physiological barriers to drug delivery. Circulating cells are expected to improve the physical distribution of drugs and enhance the therapeutic effect by overcoming various biological barriers in collaboration with nano-drug delivery systems owing to excellent biocompatibility, low immunogenicity and a long-circulation time and strong binding specificity. Nonetheless, we have noticed some limitations in implementing tthe strategy. In this article, we intend to introduce the latest progress in research and application of circulating cell-mediated nano-drug delivery systems, describe the main cell-related drug delivery modes, sum up the relevant points of the transport systems in the process of loading, transport and release, and lastly discuss the advantages, challenges and future development trends in cell-mediated nano-drug delivery.

The role of erythrocytes and erythroid progenitor cells in tumors

In the current research context of precision treatment of malignant tumors, the advantages of immunotherapy are unmatched by conventional antitumor therapy, which can prolong progression-free survival and overall survival. The search for new targets and novel combination therapies can improve the efficacy of immunotherapy and reduce adverse effects. Since current research targets for immunotherapy mainly focus on lymphocytes, little research has been done on erythrocytes. Nucleated erythroid precursor stem cells have been discovered to play an essential role in tumor progression. Researchers are exploring new targets and therapeutic approaches for immunotherapy from the perspective of erythroid progenitor cells (EPCs). Recent studies have shown that different subtypes of EPCs have specific surface markers and distinct biological roles in tumor immunity. CD45⁺ EPCs are potent myeloid-derived suppressor cell-like immunosuppressants that reduce the patient's antitumor immune response. CD45^- EPCs promote tumor invasion and metastasis by secreting artemin. A specific type of EPC also promotes angiogenesis and provides radiation protection. Therefore, EPCs may be involved in tumor growth, infiltration, and metastasis. It may also be an important cause of anti-angiogenesis and immunotherapy resistance. This review summarizes recent research advances in erythropoiesis, EPC features, and their impacts and processes on tumors.

Hemolytic Activity of Nanoparticles as a Marker of Their Hemocompatibility

The potential use of nanomaterials in medicine offers opportunities for novel therapeutic approaches to treating complex disorders. For that reason, a new branch of science, named nanotoxicology, which aims to study the dangerous effects of nanomaterials on human health and on the environment, has recently emerged. However, the toxicity and risk associated with nanomaterials are unclear or not completely understood. The development of an adequate experimental strategy for assessing the toxicity of nanomaterials may include a rapid/express method that will reliably, quickly, and cheaply make an initial assessment. One possibility is the characterization of the hemocompatibility of nanomaterials, which includes their hemolytic activity as a marker. In this review, we consider various factors affecting the hemolytic activity of nanomaterials and draw the reader's attention to the fact that the formation of a protein corona around a nanoparticle can significantly change its interaction with the red cell. This leads us to suggest that the nanomaterial hemolytic activity in the buffer does not reflect the situation in the blood plasma. As a recommendation, we propose studying the hemocompatibility of nanomaterials under more physiologically relevant conditions, in the presence of plasma proteins in the medium and under mechanical stress.

Unlocking the promise of mRNA therapeutics

The extraordinary success of mRNA vaccines against coronavirus disease 2019 (COVID-19) has renewed interest in mRNA as a means of delivering therapeutic proteins. Early clinical trials of mRNA therapeutics include studies of paracrine vascular endothelial growth factor (VEGF) mRNA for heart failure and of CRISPR-Cas9 mRNA for a congenital liver-specific storage disease. However, a series of challenges remains to be addressed before mRNA can be established as a general therapeutic modality with broad relevance to both rare and common diseases. An array of new technologies is being developed to surmount these challenges, including approaches to optimize mRNA cargos, lipid carriers with inherent tissue tropism and in vivo percutaneous delivery systems. The judicious integration of these advances may unlock the promise of biologically targeted mRNA therapeutics, beyond vaccines and other immunostimulatory agents, for the treatment of diverse clinical indications.

A Closed-Loop Autologous Erythrocyte-Mediated Delivery Platform for Diabetic Nephropathy Therapy

Failure to control blood glucose level (BGL) may aggravate oxidative stress and contribute to the development of diabetic nephropathy (DN). Using erythrocytes (ERs) as the carriers, a smart self-regulatory insulin (INS) release system was constructed to release INS according to changes in BGLs to improve patients' compliance and health. To overcome the limited sources of ERs and decrease the risk of transmitting infections, we developed an in vitro, closed-loop autologous ER-mediated delivery (CAER) platform, based on a commercial hemodialysis instrument modified with a glucose-responsive ER-based INS delivery system (GOx-INS@ER). After the blood was drained via a jugular vein cannula, some of the blood was pumped into the CAER platform. The INS was packed inside the autologous ERs in the INS reactor, and then their surface was modified with glucose oxidase (GOx), which acts as a glucose-activated switch. In vivo, the CAER platform showed that the BGL responsively controlled INS release in order to control hyperglycemia and maintain the BGL in the normal range for up to 3 days; plus, there was good glycemic control without the added burden of hemodialysis in DN rabbits. These results demonstrate that this closed-loop extracorporeal hemodialysis platform provides a practical approach for improving diabetes management in DN patients.

Supramolecular erythrocytes-hitchhiking drug delivery system for specific therapy of acute pneumonia

Acute pneumonia is an inflammatory syndrome often associated with severe multi-organ dysfunction and high mortality. The therapeutic efficacy of current anti-inflammatory medicines is greatly limited due to the short systemic circulation and poor specificity in the lungs. New drug delivery systems (DDS) are urgently needed to efficiently transport anti-inflammatory drugs to the lungs. Here, we report an inflammation-responsive supramolecular erythrocytes-hitchhiking DDS to extend systemic circulation of the nanomedicine via hitchhiking red blood cells (RBCs) and specifically "drop off" the payloads in the inflammatory lungs. β-cyclodextrin (β-CD) modified RBCs and ferrocene (Fc) modified liposomes (NP) were prepared and co-incubated to attach NP to RBCs via β-CD/Fc host-guest interactions. RBCs extended the systemic circulation of the attached NP, meanwhile, the NP may get detached from RBCs due to the high ROS level in the inflammatory lungs. In acute pneumonia mice, this strategy delivered curcumin specifically to the lungs and effectively alleviated the inflammatory syndrome.

Antigen-specific immunotherapies in type 1 diabetes

Type 1 diabetes mellitus (T1DM) is an autoimmune disease caused by the destruction of pancreatic beta cells, in which immune system disorder plays an important role. Finding a cure for T1DM and restoring beta cell function has been a long-standing goal. Research has shown that immune regulation with pancreatic islet auto-antigens may be the most specific and safe treatment for T1DM. Immunological intervention using diabetogenic auto-antigens as a target can help identify T1DM in high-risk individuals by early screening of autoantibodies (AAbs) before the loss of pancreatic islet function and thus achieve primary prevention of T1DM. However, induction of self-tolerance in patients with pre-diabetes can also slow down the attack of autoimmunity, and achieve secondary prevention. Antigen-based immune therapy opens up new avenues for the prevention and treatment of T1DM. The zinc transporter 8 (ZnT8) protein, presents in the serum of pre-diabetic and diabetic patients, is immunogenic and can cause T1D autoimmune responses. ZnT8 has become a potential target of humoral autoimmunity; it is of great significance for the early diagnosis of T1D. ZnT8-specific CD8⁺ T cells can be detected in most T1DM patients, and play a key role in the progression of T1D. As an immunotherapy target, it can improve the dysfunction of beta cells in T1DM and provide new ideas for the treatment of T1D. In this review, we summarize research surrounding antigen-specific immunotherapies (ASI) over the past 10 years and the ZnT8 antigen as an autoimmune target to induce self-tolerance for T1DM.

Erythro–Magneto–HA–Virosome: A Bio-Inspired Drug Delivery System for Active Targeting of Drugs in the Lungs

Over the past few decades, finding more efficient and selective administration routes has gained significant attention due to its crucial role in the bioavailability, absorption rate and pharmacokinetics of therapeutic substances. The pulmonary delivery of drugs has become an attractive target of scientific and biomedical interest in the health care research area, as the lung, thanks to its high permeability and large absorptive surface area and good blood supply, is capable of absorbing pharmaceuticals either for local deposition or for systemic delivery. Nevertheless, the pulmonary drug delivery is relatively complex, and strategies to mitigate the effects of mechanical, chemical and immunological barriers are required. Herein, engineered erythrocytes, the Erythro–Magneto–Hemagglutinin (HA)–virosomes (EMHVs), are used as a novel strategy for efficiently delivering drugs to the lungs. EMHV bio-based carriers exploit the physical properties of magnetic nanoparticles to achieve effective targeting after their intravenous injection thanks to an external magnetic field. In addition, the presence of hemagglutinin fusion proteins on EMHVs’ membrane allows the DDS to anchor and fuse with the target tissue and locally release the therapeutic compound. Our results on the biomechanical and biophysical properties of EMHVs, such as the membrane robustness and deformability and the high magnetic susceptibility, as well as their in vivo biodistribution, highlight that this bio-inspired DDS is a promising platform for the controlled and lung-targeting delivery of drugs, and represents a valuable alternative to inhalation therapy to fulfill unmet clinical needs.

Targeted In Vivo Loading of Red Blood Cells Markedly Prolongs Nanocarrier Circulation

Engineering drug delivery systems for prolonged pharmacokinetics (PK) has been an ongoing pursuit for nearly 50 years. The gold standard for PK enhancement is the coating of nanoparticles with polymers, namely polyethylene glycol (PEGylation), which has been applied in several clinically used products. In the present work, we utilize the longest circulating and most abundant component of blood─the erythrocyte─to improve the PK behavior of liposomes. Antibody-mediated coupling of liposomes to erythrocytes was tested in vitro to identify a loading dose that did not adversely impact the carrier cells. Injection of erythrocyte targeting liposomes into mice resulted in a ∼2-fold improvement in the area under the blood concentration versus time profile versus PEGylated liposomes and a redistribution from the plasma into the cellular fraction of blood. These results suggest that in vivo targeting of erythrocytes is a viable strategy to improve liposome PK relative to current, clinically viable strategies.

Red Blood Cell Inspired Strategies for Drug Delivery: Emerging Concepts and New Advances

In the past five decades, red blood cells (RBCs) have been extensively explored as drug delivery systems due to their distinguishing potential in modulating the pharmacokinetic, pharmacodynamics, and biological activity of carried payloads. The extensive interests in RBC-mediated drug delivery technologies are in part derived from RBCs' unique biological features such as long circulation time, wide access to many tissues in the body, and low immunogenicity. Owing to these outstanding properties, a large body of efforts have led to the development of various RBC-inspired strategies to enable precise drug delivery with enhanced therapeutic efficacy and reduced off-target toxicity. In this review, we discuss emerging concepts and new advances in such RBC-inspired strategies, including native RBCs, ghost RBCs, RBC-mimetic nanoparticles, and RBC-derived extracellular vesicles, for drug delivery.

Silver nanoclusters show advantages in macrophage tracing in vivo and modulation of anti-tumor immuno-microenvironment

Macrophage-based nanomedicine represents an emerging powerful strategy for cancer therapy. Unfortunately, some obstacles and challenges limit the translational applications of macrophage-mediated nanodrug delivery system. For instance, tracking and effective cell delivery for targeted tumor sites remain to be overcome, and controlling the states of macrophages is still rather difficult due to their plastic nature in response to external stimuli. To address these critical issues, here, we reported a novel type of silver nanoclusters (AgNCs) with excellent fluorescent intensity, especially long-lasting cell labeling stability after endocytosis by macrophages, indicating promising applications in tracking macrophage-based nanomedicine delivery. Our mechanistic investigations uncovered that these merits originate from the escape of AgNCs from lysosomal degradation within macrophages. In addition, the AgNCs would prime the M1-like polarization of macrophages (at least in part) through the toll-like receptor 4 signaling pathway. The engineered macrophages laden with AgNCs could be employed for lung metastasis breast cancer treatment, showing the effective targeting propensity to metastatic tumors, remarkable regulation of tumor immune microenvironment and inhibition of tumor growth. Collectively, AgNC-trained macrophages appear to be a promising strategy for tumor immune-microenvironment regulation, which might be generalized to a wider spectrum of cancer therapeutics.

Engineering new metabolic pathways in isolated cells for the degradation of guanidinoacetic acid and simultaneous production of creatine

Here we report, for the first time, the engineering of human red blood cells (RBCs) with an entire metabolic pathway as a potential strategy to treat patients with guanidinoacetate methyltransferase (GAMT) deficiency, capable of reducing the high toxic levels of guanidinoacetate acid (GAA) and restoring proper creatine levels in blood and tissues. We first produced a recombinant form of native human GAMT without any tags to encapsulate into RBCs. Due to the poor solubility and stability features of the recombinant enzyme, both bioinformatics studies and extensive optimization work were performed to select a mutant GAMT enzyme, where only four critical residues were replaced, as a lead candidate. However, GAMT-loaded RBCs were ineffective in GAA consumption and creatine production because of the limiting intra-erythrocytic S-adenosyl methionine (SAM) content unable to support GAMT activity. Therefore, a recombinant form of human methionine adenosyl transferase (MAT) was developed. RBCs co-entrapped with both GAMT and MAT enzymes performed, in vitro, as a competent cellular bioreactor to remove GAA and produce creatine, fueled by physiological concentrations of methionine and the ATP generated by glycolysis. Our results highlight that metabolic engineering of RBCs is possible and represents proof of concept for the design of novel therapeutic approaches.

Nanomedicines: A Focus on Nanomaterials as Drug Delivery System with Current Trends and Future Advancement

The rapid advancement of nanomedicine presents novel alternatives that have the potential to transform health care. Targeted drug delivery as well as the synthesis of nanocarriers is a growing discipline that has been intensively researched to reduce the complexity of present medicines in a variety of diseases and to develop new treatment and diagnostic techniques. There are several designed nanomaterials used as a delivery system such as liposomes, micelles, dendrimers, polymers, carbon-based materials, and many other substances, which deliver the drug moiety directly into its targeted body area reducing toxic effect of conventional drug delivery, thus reducing the amount of drug required for therapeutic efficacy and offering many more advantages. Currently, these are used in many applications, including cancer treatment, imaging contrast agents, and biomarker detection and so on. This review provides a comprehensive update in the field of targeted nano-based drug delivery systems, by conducting a thorough examination of the drug synthesis, types, targets, and application of nanomedicines in improving the therapeutic efficiency.