Showing papers by "Guanghui Ma published in 2020"

Biomineralized Bacterial Outer Membrane Vesicles Potentiate Safe and Efficient Tumor Microenvironment Reprogramming for Anticancer Therapy.

Abstract: The highly immunosuppressive tumor microenvironment (TME) in solid tumors often dampens the efficacy of immunotherapy. In this study, bacterial outer membrane vesicles (OMVs) are demonstrated as powerful immunostimulants for TME reprogramming. To overcome the obstacles of antibody-dependent clearance and high toxicity induced by OMVs upon intravenous injection (a classic clinically relevant delivery mode), calcium phosphate (CaP) shells are employed to cover the surface of OMVs, which enables potent OMV-based TME reprograming without side effects. Meanwhile, the pH-sensitive CaP shells facilitate the neutralization of acidic TME, leading to highly beneficial M2-to-M1 polarization of macrophages for improved antitumor effect. Moreover, the outer shells can be integrated with functional components like folic acid or photosensitizer agents, which facilitates the use of the OMV-based platform in combination therapies for a synergic therapeutic effect.

Targeted exosome coating gene-chem nanocomplex as “nanoscavenger” for clearing α-synuclein and immune activation of Parkinson’s disease

Abstract: The most critical problem in the treatment of neurodegenerative diseases is brain neuronal protection, which can be overcome by clearing pathological substances and regulating the immune environment. In the above treatment strategies, the traditional poor drug delivery problem is inevitable. Here, we show an engineering core-shell hybrid system named rabies virus glycoprotein (RVG) peptide-modified exosome (EXO) curcumin/phenylboronic acid-poly(2-(dimethylamino)ethyl acrylate) nanoparticle/small interfering RNA targeting SNCA (REXO-C/ANP/S). It is a nanoscavenger for clearing α-synuclein aggregates and reducing their cytotoxicity in Parkinson's disease neurons. The motor behavior of Parkinson's disease mice is substantially improved after REXO-C/ANP/S treatment. In particular, we demonstrate that REXO-C/ANP/S is also a nanoscavenger for clearing immune activation due to its natural immature dendritic cell EXO coating. Our findings show that REXO-C/ANP/S may serve as a platform for neurodegenerative diseases treatment.

Particulate Alum via Pickering Emulsion for an Enhanced COVID-19 Vaccine Adjuvant.

Abstract: For rapid response against the prevailing COVID-19 (coronavirus disease 19), it is a global imperative to exploit the immunogenicity of existing formulations for safe and efficient vaccines. As the most accessible adjuvant, aluminum hydroxide (alum) is still the sole employed adjuvant in most countries. However, alum tends to attach on the membrane rather than entering the dendritic cells (DCs), leading to the absence of intracellular transfer and process of the antigens, and thus limits T-cell-mediated immunity. To address this, alum is packed on the squalene/water interphase is packed, forming an alum-stabilized Pickering emulsion (PAPE). "Inheriting" from alum and squalene, PAPE demonstrates a good biosafety profile. Intriguingly, with the dense array of alum on the oil/water interphase, PAPE not only adsorbs large quantities of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) antigens, but also harbors a higher affinity for DC uptake, which provokes the uptake and cross-presentation of the delivered antigens. Compared with alum-treated groups, more than six times higher antigen-specific antibody titer and three-fold more IFN-γ-secreting T cells are induced, indicating the potent humoral and cellular immune activations. Collectively, the data suggest that PAPE may provide potential insights toward a safe and efficient adjuvant platform for the enhanced COVID-19 vaccinations.

Biosynthesis of Self-Assembled Proteinaceous Nanoparticles for Vaccination.

Abstract: Recent years have seen enormous advances in nanovaccines for both prophylactic and therapeutic applications, but most of these technologies employ chemical or hybrid semi-biosynthetic production methods. Thus, production of nanovaccines has to date failed to exploit biology-only processes like complex sequential post-translational biochemical modifications and scalability, limiting the realization of the initial promise for offering major performance advantages and improved therapeutic outcomes over conventional vaccines. A Nano-B5 platform for in vivo production of fully protein-based, self-assembling, stable nanovaccines bearing diverse antigens including peptides and polysaccharides is presented here. Combined with the self-assembly capacities of pentamer domains from the bacterial AB5 toxin and unnatural trimer peptides, diverse nanovaccine structures can be produced in common Escherichia coli strains and in attenuated pathogenic strains. Notably, the chassis of these nanovaccines functions as an immunostimulant. After showing excellent lymph node targeting and immunoresponse elicitation and safety performance in both mouse and monkey models, the strong prophylactic effects of these nanovaccines against infection, as well as their efficient therapeutic effects against tumors are further demonstrated. Thus, the Nano-B5 platform can efficiently combine diverse modular components and antigen cargos to efficiently generate a potentially very large diversity of nanovaccine structures using many bacterial species.

Self-healing microcapsules synergetically modulate immunization microenvironments for potent cancer vaccination

Abstract: Therapeutic cancer vaccines that harness the immune system to reject cancer cells have shown great promise for cancer treatment. Although a wave of efforts have spurred to improve the therapeutic effect, unfavorable immunization microenvironment along with a complicated preparation process and frequent vaccinations substantially compromise the performance. Here, we report a novel microcapsule-based formulation for high-performance cancer vaccinations. The special self-healing feature provides a mild and efficient paradigm for antigen microencapsulation. After vaccination, these microcapsules create a favorable immunization microenvironment in situ, wherein antigen release kinetics, recruited cell behavior, and acid surrounding work in a synergetic manner. In this case, we can effectively increase the antigen utilization, improve the antigen presentation, and activate antigen presenting cells. As a result, effective T cell response, potent tumor inhibition, antimetastatic effects, and prevention of postsurgical recurrence are achieved with various types of antigens, while neoantigen was encapsuled and evaluated in different tumor models.

Choice of Nanovaccine Delivery Mode Has Profound Impacts on the Intralymph Node Spatiotemporal Distribution and Immunotherapy Efficacy.

Abstract: Nanovaccines have attracted booming interests in vaccinology studies, but the profound impacts of their delivery mode on immune response remain unrealized. Herein, immunostimulatory CpG-modified tumor-derived nanovesicles (CNVs) are used as a nanovaccine testbed to initially evaluate the impacts of three distinct delivery modes, including mono-pulse CNVs, staggered-pulse CNVs, and gel-confined CNVs. Fundamentally, delivery mode has enormous impacts on the immunomodulatory effects, altering the spatiotemporal distribution of nanovaccine residence and dendritic cell-T cell interaction in lymph nodes, and finally affecting subsequent T cell-mediated immune performance. As a result, the gel-confined delivery mode offers the best therapeutic performance in multiple tumor models. When extending evaluation to examine how the various delivery modes impact the performance of liposome-based nanovaccines, similar trends in intralymph node distribution and antitumor effect are observed. This work provides a strong empirical foundation that nanovaccine researchers should position delivery mode near the top of their considerations for the experimental design, which should speed up nanovaccine development and facilitate efficient selection of appropriate delivery modes in the clinic.

Recent research and development of local anesthetic-loaded microspheres

Abstract: Local anesthetic drugs are widely used in postoperative analgesia, local nerve block in surgery, and in the therapy of chronic pain. Due to their short half-time, a single administration of local anesthetics merely maintains the nerve block for several hours, which cannot meet the long-term analgesia effect needed in clinical treatment. In order to break through this limitation of local anesthetics, research work regarding controlled drug release from microspheres has attracted broad and current interest. This review introduces the recent research and development in local anesthetic-loaded microspheres for future clinical applications, where for an efficient microsphere formulation, the most critical aspects are an optimum preparation method, a high loading efficiency, and an ideal release rate. This review first summarizes the recent preparation methods of local anesthetic-loaded microspheres, which includes emulsion-solvent evaporation, spray-drying, microfluidic droplets, and premix membrane emulsification technology. Next, strategies for increasing the loading efficiency of the drug in microspheres are reviewed based on the solidification conditions, polymer properties, microsphere formulation, including the external water phase, pH, and polymer concentration. Finally, the effects of the preparation conditions, material characteristics, particle characteristics, and hydrogel/microsphere composite systems on the controlled release behavior are summarized.

Synthetic Particles for Cancer Vaccines: Connecting the Inherent Supply Chain.

Abstract: Cancer vaccines have opened a new paradigm for safe and effective antitumor therapy, but they still suffer from shortcomings such as insufficient immunogenicity and immune tolerance, which seldom makes them the first choice in clinic. In fact, similar to providing a high-end product, a robust antitumor effect depends on the inherent supply chain, which attains, processes, and presents tumor-associated antigens via antigen presenting cells to T cells, which then leads to lysis of the cancer cells to release more antigens to complete the supply chain. Under these circumstances, the failure of cancer vaccines can be treated as a blockade or chain rupture. Thus, for effective tumor treatment, the key is to rationally design logistic systems to restore the supply chain.Under these circumstances, this Account summarizes our recent attempts to exploit the immunogenic trait of synthetic particles to enhance the distribution, presentation, and immune activations of the whole priming process in cancer vaccines: (1) Raw material (tumor antigen/signals) procurement: We illustrated the efforts to deliver antigens to antigen presenting cells (APCs) and draining lymph nodes for potent internalizations, and put more emphasis on the structural effect of sizes, charges, shapes, and assembly strategies for the antigen depot, lymph node transfer, and APC endocytosis. (2) Manufacture of cytotoxic T lymphocytes (CTLs) via APC recognition and presentation: We centered on exploiting the softness of two-dimensional graphene and Pickering emulsions to dynamically potentiate the immune recognition, and demonstrating the recent advances in lysosome escape strategies for enhanced antigen cross-presentations. (3) Marketing the accumulations of CTLs and the reversal of an immunosuppressive microenvironment within the tumor: We demonstrated the previous attempts to inherently cultivate the tumor tropism of the T cells via the multiantigenic repertoire and discussed the advances and challenges of combinatory cancer vaccines with an immune checkpoint blockade to reinforce the antitumor efficacy. Collectively, this Account aims to illustrate the potential of the particulate cancer vaccines to recapitalize the inherent host immune responses for the maximum antitumor effect. And by integrating the antitumor supply chain, optimized synthetic particles may shed light on the development of safe and effective particulate cancer vaccines.

Recent Advances in Particulate Adjuvants for Cancer Vaccination

Abstract: By activating/stimulating antigen‐presenting cells (APCs) and efficiently inducing humoral or cellular immune responses, particulate adjuvants have become one of the most ambitious and promising strategies in cancer vaccination. A large number of materials have been studied for their use as particulate adjuvants, including inorganic materials, polymeric materials, liposomes, emulsions, and exosomes. According to their unique physicochemical properties, these particulate adjuvants mainly work in three aspects: antigen delivery, APC activation, and antigen cross‐presentation, and they show great promise in various antitumor applications. This progress report highlights the recent advances in the study of particulate adjuvants, ranging from their materials, functions, and physicochemical properties to their applications in cancer vaccination.

Characterization and stabilization in process development and product formulation for super large proteinaceous particles.

Abstract: Super large proteinaceous particles (SLPPs) such as virus, virus like particles, and extracellular vesicles have successful and promising applications in vaccination, gene therapy, and cancer treatment. The unstable nature, the complex particulate structure and composition are challenges for their manufacturing and applications. Rational design of the processing should be built on the basis of fully understanding the characteristics of these bio-particles. This review highlights useful analytical techniques for characterization and stabilization of SLPPs in the process development and product formulations, including high performance size exclusion chromatography, multi-angle laser light scattering, asymmetrical flow field-flow fractionation, nanoparticle tracking analysis, CZE, differential scanning calorimetry, differential scanning fluorescence, isothermal titration calorimetry , and dual polarization interferometry. These advanced analytical techniques will be helpful in obtaining deep insight into the mechanism related to denaturation of SLPPs, and more importantly, in seeking solutions to preserve their biological functions against deactivation or denaturation. Combination of different physicochemical techniques, and correlation with in vitro or in vivo biological activity analyses, are considered to be the future trend of development in order to guarantee a high quality, safety, and efficacy of SLPPs.

Manipulation of pore structure during manufacture of agarose microspheres for bioseparation.

Abstract: Agarose microspheres with a controllable pore structure were manufactured by varying agarose types and crosslinking degrees. Various agarose could tailor the gel formation of microspheres matrix and thus affect the final pore structures. Small pores in microspheres could be fabricated by agarose with a higher molecular weight, which was demonstrated by the packed column with lower distribution coefficient (Kav ) values measured by gel filtration chromatography. Further, higher Kav values also demonstrated that more and larger pores were formed with increasing the crosslinking degree of agarose microspheres. Either using agarose with a high molecular weight or increasing the crosslinking degree would finally lead to the enhancement of the flow rate during flow performance of packed column as necessary for improving separation efficiency. This provides a foundation for high-resolution chromatography with a controllable separation range as beneficial for downstream process.

In vivo immunological response of exposure to PEGylated graphene oxide via intraperitoneal injection

Abstract: Polyethylene glycol functionalization is believed to have the capacity of endowing nanomaterials with stealth characteristics, which can diminish the arrest by macrophages and adverse immunological response. However, our previous study provided evidences that polyethylene glycol-functionalized graphene oxide (GOP) stimulated a strong immunological response to macrophages despite non-internalization in vitro, raising safety concerns and potential immunostimulation use of GOP. In light of this finding, we herein systematically study the in vivo immunological response upon the exposure to GOP via intraperitoneal injection. Taking cytokines production, cell types in the peritoneal fluid, biochemical index, hematology and histopathology as in vivo indicators, we demonstrate that GOP still remains the stealth-but-activating capacity on macrophages in a time and dose-dependent manner. Specifically, the immune response can be significantly elevated after a single high-dose injection, indicating that GOP can be a new candidate adjuvant for immunotherapy. For multiple low dose injections, the immune response is gentle, temporary, and tolerable, which manifests the biocompatibility of GOP in general drug delivery. The above results can thus provide guidance for safe and rational use of GOP for various biomedical applications.

A Novel Particulate Delivery System Based on Antigen-Zn2+ Coordination Interactions Enhances Stability and Cellular Immune Response of Inactivated Foot and Mouth Disease Virus.

Abstract: The interactions between antigen and adjuvant were among the most significant factors influencing the immunogenicity of vaccines, especially for unstable antigens like inactivated foot and mouth disease virus (iFMDV). Here we propose a novel antigen delivery pattern based on the coordination interaction between transition metal ions Zn2+ chelated to chitosan nanoparticles and iFMDV, which is known to be rich in histidine. The zinc chelated chitosan particles (CP-PEI-Zn) were prepared by cross-linking chitosan particles (CP) with sodium tripolyphosphate (TPP), modifying with metal chelator polyethylenimine (PEI), and subsequent chelating of Zn2+. The coordination interaction was confirmed by analyzing the adsorption and desorption behavior of iFMDV on CP-PEI-Zn by high-performance size exclusion chromatography (HPSEC), while the CP-PEI without chelating Zn2+ loads iFMDV mainly through electrostatic interactions. The iFMDV loaded on CP-PEI-Zn showed better thermal stability than that on CP-PEI, as revealed by a slightly higher transition temperature (Tm) related to iFMDV dissociation. After subcutaneous immunization in female Balb/C mice, antigens loaded on CP-PEI and CP-PEI-Zn all induced higher specific antibody titers, better activation of B lymphocytes, and more effector-memory T cells proliferation than the free antigen and iFMDV adjuvanted with ISA 206 emulsion did. Moreover, CP-PEI-Zn showed superior efficacy to CP-PEI in promoting the proliferation of effector-memory T cells and secretion of cytokines, indicating a more potent cellular immune response. In summary, the CP-PEI-Zn stabilized the iFMDV after loading and promoted both humoral and cellular immune responses, thus reflecting its potential to be a promising adjuvant for the iFMDV vaccine and other unstable viral antigens.

Biomimic strategies for modulating the interaction between particle adjuvants and antigen-presenting cells

Abstract: Developing effective adjuvants is becoming increasingly important for the research of vaccine formulations. The addition of adjuvants could enhance the immune response, reduce the antigen dosage and prolong the protection time. In recent years, biomimetic strategies have been adopted in the design of vaccine adjuvants to achieve better immune protection efficiency. Particularly those particle adjuvants, which could easily mimic the physical and chemical properties of natural pathogens such as morphology and charge, have been developed. This review focuses on the study of bionic particle adjuvants, especially the effect of those particles’ properties on their interaction with antigen-presenting cells (APCs). By mimicking natural pathogens, these particles possess the ability to increase the cellular uptake of antigens, activate APCs, and promote the lysosomal escape of antigens.

Preparation and evaluation of amphipathic lipopeptide-loaded PLGA microspheres as sustained-release system for AIDS prevention.

Abstract: At present, AIDS drugs are typical inhibitors that cannot achieve permanent effects. Therefore, the research of blocking HIV infection is essential. Especially for people in the high-risk environment, long-term prevention is important, because HIV can easily infect cells once the drug is interrupted. However, there is still no long-acting AIDS prevention drug approved. Hence, the purpose of this study is to prepare a fusion inhibitor loaded poly(d, l-lactic-co-glycolic acid) (PLGA) microspheres as a sustained-release system for long-term AIDS prevention. As the HIV membrane fusion inhibitor (LP-98) used in this research is amphiphilic lipopeptide, W1/O/W2 double-emulsion method was chosen, and premix membrane emulsification technique was used for controlling the uniformity of particle size. Several process parameters that can impact drug loading efficiency were summarized: the concentration of LP-98 and PLGA, and the preparation condition of primary emulsion. Finally, the microspheres with high loading efficiency (>8%) and encapsulation efficiency (>90%) were successfully prepared under optimum conditions. Pharmacokinetic studies showed that LP-98-loaded microspheres were capable to continuously release for 24 days in rats. This research can promote the application of sustained-release microspheres in AIDS prevention, and the embedding technique used in this study can also provide references for the loading of other amphipathic drugs.

A novel multiple emulsion enhanced immunity via its biomimetic delivery approach.

Abstract: To generate effective immunity post-vaccination, antigens need to be effectively captured and taken up by antigen-presenting cells (APCs) as a prerequisite. Biomimetic designs that mimic natural pathogen-like properties have provided platforms for antigen delivery. However, the structural dynamic properties of pathogens leading to their efficient internalization have been neglected in most platforms. Herein, we redesigned a special multiple emulsion with chitosan hydrogel nanoparticles inside, mimicking the configurational flexibility and deformational flexibility of pathogens. With the assistance of chitosan-antigen particles, the novel emulsion exhibited amplified deformability and the vaccine-cell contact zone was increased. Additionally, its configurational transitions, which offered sustained exposure of sheltered uptake signals including antigens and stimulator chitosan during endocytosis, resulted in efficient antigen delivery to APCs. Prolonged antigen depot effect, versatile antigen presentation, multiple immunocyte activation, and marked adjuvant-sparing effects were achieved as compared with those in the control groups. As a result, the intracellular emulsion formulation robustly induced both humoral and cellular immunity, especially CTL response, against the foot-and-mouth disease virus (FMDV) with improved biosafety. Our study highlights the positive impact of biomimetic structural dynamic properties on robust vaccine-cell interactions and provides a promising FMDV vaccine candidate.

Green preparation of hydrogel particles‐in‐emulsions for simultaneous enhancement of humoral and cell‐mediated immunity

Abstract: Emulsions are one of the most often used vaccine adjuvant formulations. Although they promote high humoral immunity, the induced cellular immunity is often poor, which restrict their application. To enhance the cellular immunity, some researchers have prepared mixed formulations by adding particles into the aqueous phase of emulsions. However, the particle preparation process usually involves the addition and removal of organic reagents, which is environmentally unfriendly and cumbersome. Moreover, the obtained vaccine adjuvant only induces limited cell-mediated immunity and humoral immunity compared with emulsion-adjuvanted vaccines. Herein, we developed a green and simple method for fabricating a novel nanoparticles-in-emulsions (NPE) formulation. Firstly, a temperature-sensitive hydrogel was used to prepare particles by self-solidification without additional crosslinking reagents. Secondly, the white oil was used as organic phase to avoid the particle washing procedures and organic solvent residues. Moreover, the effect of NPE as vaccine adjuvant was evaluated by using two veterinary vaccines as model antigens. NPE showed advantages than the conventional vaccine formulations in inducing both humoral and cellular immunity. This work provides a facile and broadly applicable approach for preparing nanoparticles-in-emulsions formulation, and presents an effective adjuvant for enhancing immunity against infectious diseases.

Fabrication of inverse core–shell and Janus-structured microspheres of blends of poly(4-butyltriphenylamine) and poly(methyl methacrylate)

Abstract: We here report the facile fabrication of inverse core–shell and Janus structured particles consisting of poly(4-butyltriphenylamine) (PBTPA) and poly(methyl methacrylate) (PMMA) via a solvent evaporation from solution droplets of a polymer blend dispersed in an aqueous phase. Janus structured composite particles in which the PBTPA domain was partially coated by the PMMA domain were obtained using poly(vinyl alcohol) (PVA) as a suspension stabilizer. On the other hand, when sodium dodecyl sulfate (SDS) was added as a surfactant together with PVA, “inverse core–shell” particles in which the PMMA core was covered by the PBTPA shell were formed as well as Janus particles. TEM observation showed that the PMMA core was located at the center of the sphere and PBTPA layer has uniform thickness in inverse core–shell particles. The increase of the composition of PBTPA or the concentration of SDS increased the ratio of the inverse core–shell particles to the Janus ones.

COVID-19 Vaccines: Particulate Alum via Pickering Emulsion for an Enhanced COVID-19 Vaccine Adjuvant (Adv. Mater. 40/2020)

Abstract: For enhanced COVID-19 vaccines, in article number 2004210, Yufei Xia, Guanghui Ma, and co-workers pack licensed alum on a squalene/water interphase Thereby, this century-old adjuvant ?travels through time? in a new form of alum-stabilized Pickering emulsion (PAPE), which not only inherits the clinically acknowledged biosafety, but also demonstrates enhanced cellular uptake and cross-presentation of antigens for potent humoral and cellular responses