Xiaoli Wei

Erythrocyte–Platelet Hybrid Membrane Coating for Enhanced Nanoparticle Functionalization

Cell-membrane-coated nanoparticles have recently been studied extensively for their biological compatibility, retention of cellular properties, and adaptability to a variety of therapeutic and imaging applications. This class of nanoparticles, which has been fabricated with a variety of cell membrane coatings, including those derived from red blood cells (RBCs), platelets, white blood cells, cancer cells, and bacteria, exhibit properties that are characteristic of the source cell. In this study, a new type of biological coating is created by fusing membrane material from two different cells, providing a facile method for further enhancing nanoparticle functionality. As a proof of concept, the development of dual-membrane-coated nanoparticles from the fused RBC membrane and platelet membrane is demonstrated. The resulting particles, termed RBC-platelet hybrid membrane-coated nanoparticles ([RBC-P]NPs), are thoroughly characterized, and it is shown that they carry properties of both source cells. Further, the [RBC-P]NP platform exhibits long circulation and suitability for further in vivo exploration. The reported strategy opens the door for the creation of biocompatible, custom-tailored biomimetic nanoparticles with varying hybrid functionalities, which may be used to overcome the limitations of current nanoparticle-based therapeutic and imaging platforms.

Nanoparticles camouflaged in platelet membrane coating as an antibody decoy for the treatment of immune thrombocytopenia.

Immune thrombocytopenia purpura (ITP) is characterized by the production of pathological autoantibodies that cause reduction in platelet counts. The disease can have serious medical consequences, leading to uncontrolled bleeding that can be fatal. Current widely used therapies for the treatment of ITP are non-specific and can, at times, result in complications that are more burdensome than the disease itself. In the present study, the use of platelet membrane-coated nanoparticles (PNPs) as a platform for the specific clearance of anti-platelet antibodies is explored. The nanoparticles, whose outer layer displays the full complement of native platelet surface proteins, act as decoys that strongly bind pathological anti-platelet antibodies in order to minimize disease burden. Here, we study the antibody binding properties of PNPs and assess the ability of the nanoparticles to neutralize antibody activity both inxa0vitro and inxa0vivo. Ultimately, we leverage the neutralization capacity of PNPs to therapeutically treat a murine model of antibody-induced thrombocytopenia and demonstrate considerable efficacy as shown in a bleeding time assay. PNPs represent a promising platform for the specific treatment of antibody-mediated immune thrombocytopenia by acting as an alternative target for anti-platelet antibodies, thus preserving circulating platelets with the potential of leaving broader immune function intact.

In Situ Capture of Bacterial Toxins for Antivirulence Vaccination

Antivirulence vaccination is a promising strategy for addressing bacterial infection that focuses on removing the harmful toxins produced by bacteria. However, a major challenge for creating vaccines against biological toxins is that the vaccine potency is often limited by lack of antigenic breadth, as most formulations have focused on single antigens, while most bacteria secrete a plethora of toxins. Here, a facile approach for generating multiantigenic nanotoxoids for use as vaccines against pathogenic bacteria by leveraging the natural affinity of virulence factors for cellular membranes is reported. Specifically, multiple virulent toxins from bacterial protein secretions are concurrently and naturally entrapped using a membrane-coated nanosponge construct. The resulting multivalent nanotoxoids are capable of delivering virulence factors together, are safe both in vitro and in vivo, and can elicit functional immunity capable of combating live bacterial infections in a mouse model. Despite containing the same bacterial antigens, the reported nanotoxoid formulation consistently outperforms a denatured protein preparation in all of the metrics studied, which underscores the utility of biomimetic nanoparticle-based neutralization and delivery. Overall this strategy helps to address major hurdles in the design of antivirulence vaccines, enabling increased antigenic breadth while maintaining safety.

Nanoparticulate Delivery of Cancer Cell Membrane Elicits Multiantigenic Antitumor Immunity

Anticancer vaccines train the bodys own immune system to recognize and eliminate malignant cells based on differential antigen expression. While conceptually attractive, clinical efficacy is lacking given several key challenges stemming from the similarities between cancerous and healthy tissue. Ideally, an effective vaccine formulation would deliver multiple tumor antigens in a fashion that potently stimulates endogenous immune responses against those antigens. Here, it is reported on the fabrication of a biomimetic, nanoparticulate anticancer vaccine that is capable of delivering autologously derived tumor antigen material together with a highly immunostimulatory adjuvant. The two major components, tumor antigens and adjuvant, are presented concurrently in a fashion that maximizes their ability to promote effective antigen presentation and activation of downstream immune processes. Ultimately, it is demonstrated that the formulation can elicit potent antitumor immune responses in vivo. When combined with additional immunotherapies such as checkpoint blockades, the nanovaccine demonstrates substantial therapeutic effect. Overall, the work represents the rational application of nanotechnology for immunoengineering and can provide a blueprint for the future development of personalized, autologous anticancer vaccines with broad applicability.

A facile approach to functionalizing cell membrane-coated nanoparticles with neurotoxin-derived peptide for brain-targeted drug delivery

&NA; The blood brain barrier separates the circulating blood from the extracellular fluid in the central nervous system and thus presents an essential obstacle to brain transport of therapeutics. Herein, we report on an effective brain‐targeted drug delivery system that combines a robust red blood cell membrane‐coated nanoparticle (RBCNP) with a unique neurotoxin‐derived targeting moiety. The RBCNPs retain the complex biological functions of natural cell membranes while exhibiting physicochemical properties that are suitable for effective drug delivery. CDX peptide is derived from candoxin and shows high binding affinity with nicotinic acetylcholine receptors (nAChRs) expressed on the surface of brain endothelial cells. Through a facile yet robust approach, we successfully incorporate DCDX peptides onto the surface of RBCNPs without compromising the peptides brain targeting ability. The resulting DCDX‐RBCNPs show promising brain targeting efficiency both in vitro and in vivo. Using a glioma mouse model, we demonstrate that doxorubicin‐loaded DCDX‐RBCNPs have superior therapeutic efficacy and markedly reduced toxicity as compared to the nontargeted drug formulations. While RBCNPs are used as a model system to evaluate the surface modification approach, the reported method can be readily generalized to various types of cell membrane‐derived nanocarriers for broad medical applications. Graphical abstract Figure. No caption available.

Remote Loading of Small Molecule Therapeutics into Cholesterol-Enriched Cell Membrane-Derived Vesicles

The increasing popularity of biomimetic design principles in nanomedicine has led to therapeutic platforms with enhanced performance and biocompatibility. This includes the use of naturally derived cell membranes, which can bestow nanocarriers with cell-specific functionalities. Herein, we report on a strategy enabling efficient encapsulation of drugs via remote loading into membrane vesicles derived from red blood cells. This is accomplished by supplementing the membrane with additional cholesterol, stabilizing the nanostructure and facilitating the retention of a pH gradient. We demonstrate the loading of two model drugs: the chemotherapeutic doxorubicin and the antibiotic vancomycin. The therapeutic implications of these natural, remote-loaded nanoformulations are studied both in vitro and in vivo using animal disease models. Ultimately, this approach could be used to design new biomimetic nanoformulations with higher efficacy and improved safety profiles.

Biomimetic Virulomics for Capture and Identification of Cell-Type Specific Effector Proteins

An unmet challenge in the study of disease is to accurately streamline the identification of important virulence factors. Traditional, genetically driven approaches miss biologically relevant markers due to discordance between the genome and proteome. Here, we developed a nanotechnology-enabled affinity enrichment strategy coupled with multiplexed quantitative proteomics, namely Biomimetic Virulomics, for successful identification of cell-type specific effector proteins of both prokaryotic and eukaryotic pathogens. We highlight the power of Biomimetic Virulomics by capturing known virulence factors in a high-throughput, cell-type guided fashion. Additionally, a comprehensive characterization of the membrane protein component of biomimetics utilized in this strategy is provided. Interfacing cell-derived nanomaterials with multiplexed quantitative proteomics allow for a specific targeting strategy of virulence factors that can be utilized for drug discovery against prominent human diseases.

Nanoparticle Functionalization with Platelet Membrane Enables Multifactored Biological Targeting and Detection of Atherosclerosis

Cardiovascular disease represents one of the major causes of death across the global population. Atherosclerosis, one of its most common drivers, is characterized by the gradual buildup of arterial plaque over time, which can ultimately lead to life-threatening conditions. Given the impact of the disease on public health, there is a great need for effective and noninvasive imaging modalities that can provide valuable information on its biological underpinnings during development. Here, we leverage the role of platelets in atherogenesis to design nanocarriers capable of targeting multiple biological elements relevant to plaque development. Biomimetic nanoparticles are prepared by coating platelet membrane around a synthetic nanoparticulate core, the product of which is capable of interacting with activated endothelium, foam cells, and collagen. The effects are shown to be exclusive to platelet membrane-coated nanoparticles. These biomimetic nanocarriers are not only capable of efficiently localizing to well-developed atherosclerotic plaque, but can also target subclinical regions of arteries susceptible to plaque formation. Using a commonly employed magnetic resonance imaging contrast agent, live detection is demonstrated using an animal model of atherosclerosis. Ultimately, this strategy may be leveraged to better assess the development of atherosclerosis, offering additional information to help clinicians better manage the disease.

Defining Host Responses during Systemic Bacterial Infection through Construction of a Murine Organ Proteome Atlas

Group A Streptococcus (GAS) remains one of the top 10 deadliest human pathogens worldwide despite its sensitivity to penicillin. Although the most common GAS infection is pharyngitis (strep throat), it also causes life-threatening systemic infections. A series of complex networks between host and pathogen drive invasive infections, which have not been comprehensively mapped. Attempting to map these interactions, we examined organ-level protein dynamics using a mouse model of systemic GAS infection. We quantified over 11,000 proteins, defining organ-specific markers for all analyzed tissues. From this analysis, an atlas of dynamically regulated proteins and pathways was constructed. Through statistical methods, we narrowed organ-specific markers of infection to 34 from the defined atlas. We show these markers are trackable in blood of infected mice, and a subset has been observed in plasma samples from GAS-infected clinical patients. This proteomics-based strategy provides insight into host defense responses, establishes potentially useful targets for therapeutic intervention, and presents biomarkers for determining affected organs during bacterial infection.

Remote‐Loaded Platelet Vesicles for Disease‐Targeted Delivery of Therapeutics

The recent emergence of biomimetic nanotechnology has facilitated the development of next-generation nanodelivery systems capable of enhanced biointerfacing. In particular, the direct use of natural cell membranes can enable multivalent targeting functionalities. Herein, we report on the remote loading of small molecule therapeutics into cholesterol-enriched platelet membrane-derived vesicles for disease-targeted delivery. Using this approach, high loading yields for two model drugs, doxorubicin and vancomycin, are achieved. Leveraging the surface markers found on platelet membranes, the resultant nanoformulations demonstrate natural affinity towards both breast cancer cells and methicillin-resistant Staphylococcus aureus. In vivo, this translates to improved disease targeting, increasing the potency of the encapsulated drug payloads compared with free drugs and the corresponding non-targeted nanoformulations. Overall, this work demonstrates that the remote loading of drugs into functional platelet membrane-derived vesicles is a facile means of fabricating targeted nanoformulations, an approach that can be easily generalized to other cell types in the future.