Biomimetic Nanosystems Research Articles

Cell membrane and extracellular vesicle membrane‐coated nanoparticles: An envisaged approach for the management of skin conditions

AbstractCell membrane‐coated biomimetic nanosystems have been recognized as promising drug delivery vehicles in recent years for the management of diverse skin conditions. Nanoparticles (NPs) coated with biomembranes, derived from either cell membranes or subcellular structures (e.g., extracellular vesicles), offer an opportunity to combine the biological interfacial characteristics of the coating alongside with the internal core component at the nanoscale. The biomimetic coating enhances the biocompatibility of NPs and their interaction with the skin, improving skin affinity, contact, and retention. This coating also enables the controlled release of drugs and provides skin‐targeting capabilities, which collectively improve the effectiveness, safety, and stability of topical and transdermal formulations. In this context, the current review delves into the recent progress in using biomimetic NPs for skin therapeutics. Specifically, it examines the various types of coatings, including their origins, heterogeneous functions, and surface molecular repertoires, in great detail. Additionally, this review presents the methods of preparing and characterizing biomimetic‐coated NPs. Furthermore, the potential of bioinspired NPs in treating a range of skin‐related conditions has been meticulously explored. Last, the toxicological aspects of these NPs have been thoroughly examined to provide a thorough summary of the evolution of biomimetic‐coated nanosystems for skin applications.

Biomimetic nanosystems harnessing NIR-II photothermal effect and hypoxia-responsive prodrug for self-amplifying and synergistic tumor treatment

Tumor microenvironment-activated prodrugs have emerged as a promising strategy in precision medicine. However, the endogenous stimuli in the tumor microenvironment are often insufficient and unevenly distributed, impeding efficient and rapid prodrug conversion, necessitating the incorporation of complementary therapeutic strategies to amply treatment effectiveness. This study presents a self-synergistic therapeutic approach that combines hypoxia-activated paclitaxel prodrug (pro-PTX) with near-infrared-II (NIR-II) light-triggered photothermal therapy (PTT) for boosted tumor treatment. Initially, an organic polymer with strong NIR-II light harvesting capability, efficient photo-to-heat conversion, and excellent photostability was meticulously synthesized by introducing electron-withdrawing trifluoromethyl substituent. The high-performance NIR-II photothermal polymer then served as the matrix to encapsulate the hypoxia-responsive pro-PTX prodrug, forming the nanocore, on which the cell membrane derived from natural killer (NK) cells was further cloaked. The biomimetic nanopaltform exhibited a superior affinity towards tumor cells compared to normal cells, owing to the inherent tumor-recognition capability of NK cell membrane proteins. Upon exposure to NIR-II laser, the photothermal agent induced localized hyperthermia, facilitating not only direct tumor eradication but also exacerbating hypoxia within the tumor microenvironment. This, in turn, expedited the release of hypoxia-responsive prodrugs. Consequently, the synergistic effect of NIR-II PTT and chemotherapy efficiently induced cancer cell apoptosis and inhibited tumor growth. The developed nanoplatform, integrating hypoxia-responsive prodrug, high-performance NIR-II PTT agent-mediated complementary phototherapy, and NK cell-inspired active targeting, represents a promising strategy for precise and boosted tumor treatment.

T Cell and Natural Killer Cell Membrane-Camouflaged Nanoparticles for Cancer and Viral Therapies.

Extensive research has been conducted on the application of nanoparticles in the treatment of cancer and infectious diseases. Due to their exceptional characteristics and flexible structure, they are classified as highly efficient drug delivery systems, ensuring both safety and targeted delivery. Nevertheless, nanoparticles still encounter obstacles, such as biological instability, absence of selectivity, recognition as unfamiliar elements, and quick elimination, which restrict their remedial capacity. To surmount these drawbacks, biomimetic nanotechnology has been developed that utilizes T cell and natural killer (NK) cell membrane-encased nanoparticles as sophisticated methods of administering drugs. These nanoparticles can extend the duration of drug circulation and avoid immune system clearance. During the membrane extraction and coating procedure, the surface proteins of immunological cells are transferred to the biomimetic nanoparticles. Such proteins present on the surface of cells confer several benefits to nanoparticles, including prolonged circulation, enhanced targeting, controlled release, specific cellular contact, and reduced in vivo toxicity. This review focuses on biomimetic nanosystems that are derived from the membranes of T cells and NK cells and their comprehensive extraction procedure, manufacture, and applications in cancer treatment and viral infections. Furthermore, potential applications, prospects, and existing challenges in their medical implementation are highlighted.

Erythrocyte membrane-coated nanocarriers modified by TGN for Alzheimer's disease

Alzheimer's disease (AD) is an aging-related neurodegenerative disease, and the main pathological feature was β-amyloid protein (Aβ) deposition. Recently, bioactive materials-based drug delivery system has been widely investigated for the treatment of AD. In this study, we developed a red blood cells (RBC) membrane-coated polycaprolactone (PCL) nanoparticles (NPs) loading with a therapeutic agent for AD, curcumin (Cur). A functional peptide TGNYKALHPHN (TGN) was conjugated to the surface of membrane for blood-brain barrier (BBB) transport (TGN-RBC-NPs-Cur). TGN peptide can be recognized by receptors on the BBB and has great potential for brain transport. To confirm the targeted delivery of Cur to the brain, a cell co-culturing immortalized human cerebral microvascular endothelial cells and human brain astrocytes glioblastoma (hCMEC/D3 and U-118MG) in vitro model was established. As a result, the BBB transporting ratio of TGN-RBC-NPs-FITC was 29.64% at 12 h which was approximately eight-fold than RBC-NPs-FITC. The improvement of drug accumulation in the AD lesion was confirmed by the NPs modified with the BBB-penetrating peptide in the fluorescence imaging and quantitative analysis with UPLC-MS/MS in vivo. The neuroprotective effects were evaluated with new object recognition behavioral test, in vitro AD cell model, dendritic spine stain, GFAP and IBA1 immunofluorescence stain. The spatial learning and memory abilities of the AD model mice treated with TGN-RBC-NPs-Cur were obviously enhanced compared with the AD control mice and were also better than Cur at the same dosage. These results were consistent with the values of protection index of rat adrenal pheochromocytoma cells (PC12 cells) treated by Aβ25–35. TGN-RBC-NPs-Cur increased the dendritic segments densities and restrained activation of microglia and astrocytes of AD mice, as well as reversed cognitive function of AD mice. All of the results demonstrated TGN-RBC-NPs-Cur a promising therapeutic strategy for delaying the progression of AD by designing biomimetic nanosystems to deliver drugs into the brain.

Applications of Nanomedicine in Brain Tumor Therapy: Nanocarrierbased Drug Delivery Platforms, CChallenges, and Perspectives.

The most difficult kind of cancer to treat is brain cancer, which causes around 3% of all cancer-related deaths. The targeted delivery is improved with the use of technologies based on nanotechnology that are both safe and efficient. Because of this, there is now a lot of research being done on brain cancer treatments based on nanoformulations. In this review, the author's primary aim is to elucidate the various nanomedicine for brain cancer therapy. The authors focus primarily on the advancement of nanotechnology in treating brain cancer (BC). This review article gives readers an up-to-date look at publications on sophisticated nanosystems in treating BC, including quantum dots (QDs), nanoparticles (NPs), polymeric micelles (PMs), dendrimers, and solid lipid nanoparticles (SLNs), among others. This article offers insight into the use of various nanotechnology-based systems for therapy as well as their potential in the future. This article also emphasizes the drawbacks of nanotechnology-based methods. Future perspectives for treating brain cancer using proteomics and biomimetic nanosystems are briefly discussed. In this review, we review several aspects of brain cancer therapy, including various nanomedicines, their challenges and future perspectives. Overall, this article gives a thorough overview of both the present state of brain cancer treatment options and the disease itself.

Neutrophil membrane fusogenic nanoliposomal leonurine for targeted ischemic stroke therapy via remodeling cerebral niche and restoring blood-brain barrier integrity.

Ischemic stroke (IS) constitutes the leading cause of global morbidity and mortality. Neuroprotectants are essential to ameliorate the clinical prognosis, but their therapeutic outcomes are tremendously compromised by insufficient delivery to the ischemic lesion and intricate pathogenesis associated with neuronal damage, oxidative stress, inflammation responses, blood-brain barrier (BBB) dysfunction, etc. Herein, a biomimetic nanosystem (Leo@NM-Lipo) composed of neutrophil membrane-fused nanoliposomal leonurine (Leo) is constructed, which can not only efficiently penetrate and repair the disrupted BBB but also robustly remodel the harsh cerebral microenvironment to reverse ischemia-reperfusion (I/R) injury. More specifically, the neutrophil membrane inherits the BBB penetrating, infarct core targeting, inflammation neutralization, and immune evasion properties of neutrophils, while Leo, a naturally occurring neuroprotectant, exerts pleiotropic effects to attenuate brain damage. Remarkably, comprehensive investigations disclose the critical factors influencing the targetability and therapeutic performances of biomimetic nanosystems. Leo@NM-Lipo with a low membrane protein-to-lipid ratio of 1:10 efficiently targets the ischemic lesion and rescues the injured brain by alleviating neuronal apoptosis, oxidative stress, neuroinflammation, and restoring BBB integrity in transient middle cerebral artery occlusion (tMCAO) rats. Taken together, our study provides a neutrophil-mimetic nanoplatform for targeted IS therapy and sheds light on the rational design of biomimetic nanosystems favoring wide medical applications.

Erythrocyte−cancer hybrid membrane-coated reduction-sensitive nanoparticles for enhancing chemotherapy efficacy in breast cancer

Cell-membrane-coated biomimetic nanoparticles (NPs) have attracted great attention due to their prolonged circulation time, immune escape mechanisms and homotypic targeting properties. Biomimetic nanosystems from different types of cell -membranes (CMs) can perform increasingly complex tasks in dynamic biological environments thanks to specific proteins and other properties inherited from the source cells. Herein, we coated doxorubicin (DOX)-loaded reduction-sensitive chitosan (CS) NPs with 4T1 cancer cell -membranes (CCMs), red blood cell -membranes (RBCMs) and hybrid erythrocyte-cancer membranes (RBC-4T1CMs) to enhance the delivery of DOX to breast cancer cells. The physicochemical properties (size, zeta potential and morphology) of the resulting RBC@DOX/CS-NPs, 4T1@DOX/CS-NPs and RBC-4T1@DOX/CS-NPs, as well as their cytotoxic effect and cellular NP uptake in vitro were thoroughly characterized. The anti-cancer therapeutic efficacy of the NPs was evaluated using the orthotopic 4T1 breast cancer model in vivo. The experimental results showed that DOX/CS-NPs had a DOX-loading capacity of 71.76 ± 0.87 %, and that coating of DOX/CS-NPs with 4T1CM significantly increased the NP uptake and cytotoxic effect in breast cancer cells. Interestingly, by optimizing the ratio of RBCMs:4T1CMs, it was possible to increase the homotypic targeting properties towards breast cancer cells. Moreover, in vivo tumor studies showed that compared to control DOX/CS-NPs and free DOX, both 4T1@DOX/CS-NPs and RBC@DOX/CS-NPs significantly inhibited tumor growth and metastasis. However, the effect of 4T1@DOX/CS-NPs was more prominent. Moreover, CM-coating reduced the uptake of NPs by macrophages and led to rapid clearance from the liver and lungs in vivo, compared to control NPs. Our results suggest that specific self-recognition to source cells resulting in homotypic targeting increased the uptake and the cytotoxic capacity of 4T1@DOX/CS-NPs by breast cancer cells in vitro and in vivo. In conclusion, tumor-disguised CM-coated DOX/CS-NPs exhibited tumor homotypic targeting and anti-cancer properties, and were superior over targeting with RBC-CM or RBC-4T1 hybrid membranes, suggesting that the presence of 4T1-CM is critical for treatment outcome.

Biomimetic photosynthetic system: Shedding light on the restoration of cell metabolism

Biomimetic photosynthetic system: Shedding light on the restoration of cell metabolism

Using design of experiments (DoE) to optimize performance and stability of biomimetic cell membrane-coated nanostructures for cancer therapy.

Introduction: Cell membrane-covered biomimetic nanosystems have allowed the development of homologous nanostructures to bestow nanoparticles with enhanced biointerfacing capabilities. The stability of these structures, however, still represents a challenge for the scientific community. This study is aimed at developing and optimizing cell derived membrane-coated nanostructures upon applying design of experiments (DoE) to improve the therapeutic index by homotypic targeting in cancer cells. Methods: Important physicochemical features of the extracted cell membrane from tumoral cells were assessed by mass spectrometry-based proteomics. PLGA-based nanoparticles encapsulating temozolomide (TMZ NPs) were successfully developed. The coating technology applying the isolated U251 cell membrane (MB) was optimized using a fractional two-level three-factor factorial design. All the formulation runs were systematically characterized regarding their diameter, polydispersity index (PDI), and zeta potential (ZP). Experimental conditions generated by DoE were also subjected to morphological studies using negative-staining transmission electron microscopy (TEM). Its short-time stability was also assessed. MicroRaman and Fourier-Transform Infrared (FTIR) spectroscopies and Confocal microscopy were used as characterization techniques for evaluating the NP-MB nanostructures. Internalization studies were carried out to evaluate the homotypic targeting ability. Results and Discussion: The results have shown that nearly 80% of plasma membrane proteins were retained in the cell membrane vesicles after the isolation process, including key proteins to the homotypic binding. DoE analysis considering acquired TEM images reveals that condition run five should be the best-optimized procedure to produce the biomimetic cell-derived membrane-coated nanostructure (NP-MB). Storage stability for at least two weeks of the biomimetic system is expected once the original characteristics of diameter, PDI, and ZP, were maintained. Raman, FTIR, and confocal characterization results have shown the successful encapsulation of TMZ drug and provided evidence of the effective coating applying the MB. Cell internalization studies corroborate the proteomic data indicating that the optimized NP-MB achieved specific targeting of homotypic tumor cells. The structure should retain the complex biological functions of U251 natural cell membranes while exhibiting physicochemical properties suitable for effective homotypic recognition. Conclusion: Together, these findings provide coverage and a deeper understanding regarding the dynamics around extracted cell membrane and polymeric nanostructures interactions and an in-depth insight into the cell membrane coating technology and the development of optimized biomimetic and bioinspired nanostructured systems.

A Biomimetic Metal-Organic Framework Nanosystem Modulates Immunosuppressive Tumor Microenvironment Metabolism to Amplify Immunotherapy.

In the immunosuppressive tumor microenvironment (iTME), lactate secretion by cancer cells facilitates cell escape via M1 to M2 macrophage polarization, and T cell exhaustion. Therefore, lactate is a promising tumor immunotherapy target. In this study, we constructed a biomimetic nanosystem to modulate iTME metabolism to amplify immunogenic cell death (ICD)-induced immunotherapy. Metal-organic frameworks were coated with platelet membranes (PM) for tumor site-specific delivery and rationally designed to carry lactate oxidase (Lox) which catalytically consumed lactate, while oxaliplatin (Oxa) induced ICD. Due to PM-mediated targeting, the biomimetic nanosystem selectively accumulated in tumors and inhibited tumor growth. Encouragingly, due to effective iTME modulation, enhanced cytotoxic T cell infiltration in tumors was observed. Also, tumor-associated macrophage (TAM) phenotypes were polarized from M2 to M1 types, and regulatory T cell (Treg) levels decreased in vivo. Increased CD8+ T to CD4+ T cell ratios in peripheral blood and spleen were also observed. Thus, our biomimetic nanosystem effectively modulated the iTME and inhibited tumor growth by consuming lactate and amplifying ICD-induced immunotherapy. We provide new avenues into cancer immunotherapy, with a specific emphasis on iTME modulation, which lays the foundation for translational biomimetic nanosystems in clinical settings.

Lymph node-targeting nanovaccines for cancer immunotherapy.

Cancer immunotherapies such as tumor vaccines, chimeric antigen receptor T cells and immune checkpoint blockades, have attracted tremendous attention. Among them, tumor vaccines prime immune response by delivering antigens and adjuvants to the antigen presenting cells (APCs), thus enhancing antitumor immunotherapy. Despite tumor vaccines have made considerable achievements in tumor immunotherapy, it remains challenging to efficiently deliver tumor vaccines to activate the dendritic cells (DCs) in lymph nodes (LNs). Rational design of nanovaccines on the basis of biomedical nanotechnology has emerged as one of the most promising strategies for boosting the outcomes of cancer immunotherapy. In recent years, great efforts have been made in exploiting various nanocarrier-based LNs-targeting tumor nanovaccines. In view of the rapid advances in this field, we here aim to summarize the latest progression in LNs-targeting nanovaccines for cancer immunotherapy, with special attention to various nano-vehicles developed for LNs-targeting delivery of tumor vaccines, including lipid-based nanoparticles, polymeric nanocarriers, inorganic nanocarriers and biomimetic nanosystems. Moreover, the recent trends in nanovaccines-based combination cancer immunotherapy are provided. Finally, the rationality, advantages and challenges of LNs-targeting nanovaccines for clinical translation and application are spotlighted.

Construction of Biomimetic-Responsive Nanocarriers and their Applications in Tumor Targeting.

At present, tumors are leading cause of death. Biomimetic nanocarriers for precision cancer therapy are attracting increasing attention. Nanocarriers with a good biocompatible surface could reduce the recognition and elimination of nanoparticles as foreign substances by the immune system, offer specific targeting, and improve the efficacy of precision medicine for tumors, thereby providing outstanding prospects for application in cancer therapy. In particular, cell membrane biomimetic camouflaged nanocarriers have become a research hotspot because of their excellent biocompatibility, prolonged circulation in the blood, and tumor targeting. The objective of this study is to summarize the biological targeting mechanisms of different cell membraneencapsulated nanocarriers in cancer therapy. In this article, the characteristics, applications, and stages of progress of bionic encapsulated nanocarriers for different cell membranes are discussed, as are the field's developmental prospects. The findings on the characteristics of bionic encapsulated nanocarriers for different cell membranes and tumor treatment have been analyzed and summarized. Biomimetic nanosystems based on various natural cell and hybrid cell membranes have been shown to efficiently control targeted drug delivery systems. They can reduce immune system clearance, prolong blood circulation time, and improve drug loading and targeting, thereby enhancing the diagnosis and treatment of tumors and reducing the spread of CTCs. With advances in the development of biomimetic nanocarrier DDSs, novel ideas for tumor treatment and drug delivery have been emerged. However, there are still some problems in biomimetic nanosystems. Therefore, it needs to be optimized through further research, from the laboratory to the clinic to benefit a wide range of patients.

Macrophage Cell Membrane-Cloaked Nanoplatforms for Biomedical Applications.

Biomimetic approaches utilize natural cell membrane-derived nanovesicles to camouflage nanoparticles to circumvent some limitations of nanoscale materials. This emergent cell membrane-coating technology is inspired by naturally occurring intercellular interactions, to efficiently guide nanostructures to the desired locations, thereby increasing both therapeutic efficacy and safety. In addition, the intrinsic biocompatibility of cell membranes allows the crossing of biological barriers and avoids elimination by the immune system. This results in enhanced blood circulation time and lower toxicity in vivo. Macrophages are the major phagocytic cells of the innate immune system. They are equipped with a complex repertoire of surface receptors, enabling them to respond to biological signals, and to exhibit a natural tropism to inflammatory sites and tumorous tissues. Macrophage cell membrane-functionalized nanosystems are designed to combine the advantages of both macrophages and nanomaterials, improving the ability of those nanosystems to reach target sites. Recent studies have demonstrated the potential of these biomimetic nanosystems for targeted delivery of drugs and imaging agents to tumors, inflammatory, and infected sites. The present review covers the preparation and biomedical applications of macrophage cell membrane-coated nanosystems. Challenges and future perspectives in the development of these membrane-coated nanosystems are addressed.

LncRNA-targeting bio-scaffold mediates triple immune effects for postoperative colorectal cancer immunotherapy

Colorectal cancer (CRC) recurrence after surgical resection results in poor clinical outcomes. Long noncoding RNAs (lncRNAs) are emerging new targets for mediating tumorigenesis and immunosuppression within tumor microenvironment. We develop a bio-scaffold encapsulating lncRNA-targeting biomimetic nanosystems for mediating triple immune effects against postoperative CRC recurrence. Liposome (termed as “D”)-decorated CRC cells’ membrane (CM) envelops a plasmid encoding a short hair-pinned RNA (shRNA) against plasmacytoma variant translocation 1 (Pvt1), forming the shPvt1-CM-D nanosystem. This nanosystem and the chemodrug Oxaliplatin (Oxa) are embedded in a hyaluronic acid and alginate-based bio-scaffold for postoperative implantation. (1) ShPvt1-CM-D-mediated Pvt1 knockdown strengthens Oxa-induced immunogenic cell death (ICD). (2) Such tumor antigens released from enhanced ICD and the CM from shPvt1-CM-D act as dual vaccines of dendritic cells. (3) Pvt1 knockdown by shPvt1-CM-D within granulocytic myeloid-derived suppressor cells (G-MDSCs) ameliorates G-MDSC-mediated immunosuppression. The nanosystem-carrying bio-scaffold significantly suppresses perioperative CRC local recurrence by 97.8% with survival rate (SR) of 62.5%. The bio-scaffold generates robust immune memory responses for completely suppressing tumor ectopic rechallenging and metachronous metastasis (SR: 100%). Additionally, the bio-scaffold reduces synchronously distant metastasis by 70.8%. This work presents a potent nanotechnology-facilitated lncRNA-targeting immunotherapy for postoperative CRC treatments.

Biomimetic Nanosystems for the Synergistic Delivery of miR-144/451a for Oral Squamous Cell Carcinoma

Background:The miR-144/451a cluster acts as a tumor suppressor in various tumors by synergistically inhibiting the proliferation, migration, and invasion of oral squamous cell carcinoma (OSCC).Aims:To achieve the synergistic delivery of the miR-144/451a cluster for OSCC treatment by constructing chitosan nanoparticles (CAs) camouflaged with macrophage membranes.Study Design:A cell-culture study.Methods:CAs were prepared using the ionic cross-linking method, and biomimetic nanoparticles coloaded with the miR-144/451a cluster (miR-144-source of macrophage-derived exosomes [MEXO]/CA-miR-451a) were prepared using the uptake–efflux method. The MEXO was detected by a bicinchoninic acid assay. The as-prepared biomimetic nanoparticles were then characterized to determine their protective effects on microRNAs (miRNAs). Moreover, the influence of the miR-144-MEXO/CA-miR-451a nanoparticles on the proliferation, migration, and invasion of OSCCs was evaluated. Finally, the effects of the biomimetic system on the expression of calcium-binding protein 39 (CAB39) and migration inhibitory factor (MIF) were detected using the real-time polymerase chain reaction and Western blot.Results:After coating the CAs with MEXO, their particle size increased from 113.1 ± 3.4 nm to 143.2 ± 14 nm, and their surface potential decreased from 26.34 ± 0.4 mV to −10.3 ± 1.6 mV. The expression of the MEXO marker protein was also observed on the biomimetic nanoparticles’ surface. The system can protect miRNAs from RNase A degradation. Compared with the CAs cotransfected with free miR-144/451a cluster, CAs that are coloaded with miR-144-MEXO/CA-miR-451a nanoparticles substantially reduced the viability (p < 0.001), migration (p = 0.023), and invasion (p = 0.004) of OSCC. These findings revealed the successful construction of biomimetic nanoparticles coloaded with the miR-144/451a cluster. CAB39 and MIF expression in OSCC treated with miR-144-MEXO/CA-miR-451a nanoparticles have significantly decreased compared with the miR-144/451a group (p < 0.05). Thus, the nanoparticles can effectively improve the inhibitory effects of the miR-144/451a cluster on OSCC.Conclusion:This study provided a new idea for the application of gene cotransfection to tumor treatment.

Modified Polyethylene Glycol Encapsulated Iron Oxide Nanoparticles for Accelerated Wound Healing Application

One of the key factors required in tissue engineering/ regeneration is to create a dynamic platform to increase the interaction of cells in response to various stimuli. In this context, facile synthesis of modified polyethylene glycol (FL PEG) encapsulated Iron Oxide nanoparticles [PoeM (Fe) NPs] is reported for its wound healing application in presence of an external magnetic field. Iron Oxide nanoparticles (8 ± 2nm) are synthesized and coated with FL PEG resulting in the formation of PoeM (Fe) NPs. The synthesized nanoparticles are characterized for their UV-Vis absorbance, DLS and TEM. These PoeM (Fe) NPs show excellent biocompatibility and enhanced wound healing activity in L929 fibroblasts when compared with control groups. This study could pave the way for the development of novel biomimetic nanosystems for wound healing applications.

Targeted delivery of PARP inhibitors to neuronal mitochondria via biomimetic engineered nanosystems in a mouse model of traumatic brain injury

Traumatic brain injury (TBI) is known to activate poly (ADP-ribose) polymerase (PARP-1), which leads to pronounced negative effects on mitochondrial DNA (mt-DNA) repair and function. Notably, PARP inhibitors are reported to be beneficial in experimental models of TBI. A targeting strategy for the delivery of neuronal mitochondria-specific PARP inhibitors could result in a greater neuroprotective effect and be a safer approach for TBI treatment. In the present study, we developed the PARP inhibitor olaparib (Ola) as a model drug and devised red blood cell (RBC)-coated nanostructured lipid carriers (RBCNLCs) co-modified with C3 and SS31 peptide (C3/SS31-RBCNLCs) for brain neuronal mitochondria-targeting. Our results indicated that biomimetic nanosystems have the physical and chemical properties of the NLCs, as well as the biological properties of RBC. A high concentration of Ola delivered into brain mitochondria by C3/SS31-RBCNLCs-Ola effectively improved mitochondrial function and prevented neuronal cell death caused by excessive activation of injury-induced mitochondrial PARP (mt-PARP) in vitro and in vivo. Taken together, the results of this study support the preclinical feasibility of developing highly effective nano-drugs as part of precision medicine for TBI. Statement of SignificanceTBI-induced neuronal mitochondria DNA damage activates Poly(ADP-ribose) Polymerase (PARP1) which leads to a pronounced negative effect on mitochondrial DNA repair and mitochondrial function. In recent years, PARP inhibitors showed strong benefits in experimental models of TBI, more importantly PARP inhibitors specially target neuronal mitochondria may play a greater neuroprotective role and may be a safer approach for TBI treatment. Herein, we designed red blood cell (RBC) membrane-coated nanostructure lipid carriers dual-modified with C3 and SS31 (C3/SS31-RBCNLCs) to accomplish these objectives. After encapsulating Olaparib (Ola) as the model PARP inhibitor, the data demonstrated that C3/SS31-RBCNLCs, with brain neuronal mitochondria targeting, can reduce neuronal cell death and improve mitochondrial dysfunction triggered by mitochondrial PARP activation in vitro and in vivo.

Cell membrane coating integrity affects the internalization mechanism of biomimetic nanoparticles

Cell membrane coated nanoparticles (NPs) have recently been recognized as attractive nanomedical tools because of their unique properties such as immune escape, long blood circulation time, specific molecular recognition and cell targeting. However, the integrity of the cell membrane coating on NPs, a key metrics related to the quality of these biomimetic-systems and their resulting biomedical function, has remained largely unexplored. Here, we report a fluorescence quenching assay to probe the integrity of cell membrane coating. In contradiction to the common assumption of perfect coating, we uncover that up to 90% of the biomimetic NPs are only partially coated. Using in vitro homologous targeting studies, we demonstrate that partially coated NPs could still be internalized by the target cells. By combining molecular simulations with experimental analysis, we further identify an endocytic entry mechanism for these NPs. We unravel that NPs with a high coating degree (≥50%) enter the cells individually, whereas the NPs with a low coating degree (<50%) need to aggregate together before internalization. This quantitative method and the fundamental understanding of how cell membrane coated NPs enter the cells will enhance the rational designing of biomimetic nanosystems and pave the way for more effective cancer nanomedicine.

Biomimetic nanomedicine toward personalized disease theranostics

Despite nanoparticle-based drug delivery systems have aroused broad research interest in the biomedical fields, the rising challenges such as easy recognition by the immune system and low accumulation in diseased sites significantly hinder their further clinical translation. Nanoparticles wrapped in cell membrane have emerged as a distinctive strategy to overcome these limitations due to the superior marriage of natural cell membrane and artificial nanomaterials, which endow them with prominent advantages in disease diagnosis and treatment, such as targeted drug transport, prolonged drug half-life, and diminished immunogenicity and cytotoxicity. In this review, we mainly highlight and discuss the evolving progresses and advantages of cell membrane-based biomimetic nanosystems in the detection and treatment of various diseases over the past five years, including oncology, bacterial infections, brain diseases, and inflammatory diseases, which would benefit researchers in better and comprehensively understanding the complicated microenvironment of diseases and developing personalized biomimetic nanomedicines for different diseases. The current challenges and potential opportunities for the future clinical translation of cell membrane coating nanotechnology are also covered.

Macrophage membrane-coated nanocarriers Co-Modified by RVG29 and TPP improve brain neuronal mitochondria-targeting and therapeutic efficacy in Alzheimer's disease mice

Neuronal mitochondrial dysfunction caused by excessive reactive oxygen species (ROS) is an early event of sporadic Alzheimer's disease (AD), and considered to be a key pathologic factor in the progression of AD. The targeted delivery of the antioxidants to mitochondria of injured neurons in brain is a promising therapeutic strategy for AD. A safe and effective drug delivery system (DDS) which is able to cross the blood-brain barrier (BBB) and target neuronal mitochondria is necessary. Recently, bioactive materials-based DDS has been widely investigated for the treatment of AD. Herein, we developed macrophage (MA) membrane-coated solid lipid nanoparticles (SLNs) by attaching rabies virus glycoprotein (RVG29) and triphenylphosphine cation (TPP) molecules to the surface of MA membrane (RVG/TPP-MASLNs) for functional antioxidant delivery to neuronal mitochondria. According to the results, MA membranes camouflaged the SLNs from being eliminated by RES-rich organs by inheriting the immunological characteristics of macrophages. The unique properties of the DDS after decoration with RVG29 on the surface was demonstrated by the ability to cross the BBB and the selective targeting to neurons. After entering the neurons in CNS, TPP further lead the DDS to mitochondria driven by electric charge. The Genistein (GS)- encapsulated DDS (RVG/TPP-MASLNs-GS) exhibited the most favorable effects on reliveing AD symptoms in vitro and in vivo by the synergies gained from the combination of MA membranes, RVG29 and TPP. These results demonstrated a promising therapeutic candidate for delaying the progression of AD via neuronal mitochondria-targeted delivery by the designed biomimetic nanosystems.