Chimeric Nanoparticle Research Articles

Nanoparticle immunoadjuvant complexes augment antigen-specific germinal center responses to enhance humoral immunity

Abstract An alluring strategy for improving protective humoral immunity against infectious diseases would be to directly target the germinal center (GC). Robust GC responses are associated with high titer and high affinity antibody responses. Despite advances in formulation strategies and vaccine design, there remains a critical need for next generation approaches to elicit potent humoral immunity. Multimeric nanoparticles offer enhanced immunogenicity compared with monomeric antigen partially due to potent B cell activation and increased antigen density on the nanoparticle. Here, we investigated whether GC cytokine IL-21 could be displayed on nanoparticles to further enhance immune responses. We designed a chimeric nanoparticle using the GT8-60mer, a germline targeting HIV immunogen, as a model to scaffold IL-21. GT8 and IL-21 scaffolded nanoparticles, termed GT8 IL-21 nanoparticle immunoadjuvant complexes (GT8 IL-21 NIC), increased antigen-specific GC B cells, functional Tfh cell responses, and serum antibody titers relative to the antigen-only GT8-60mer. Additionally, GT8 IL-21 NICs reorganized antigen-specific GC B cell responses to the light zone (LZ) of the GC, the canonical site of antigen-driven selection. Single-cell RNA sequencing of antigen-specific GC B cells from GT8 IL-21 NIC immunized mice demonstrated upregulation of selection-associated gene signatures and a shift in the clonal repertoire. Thus, GC targeting NICs may provide value to drive improved humoral immunity.

PVA and CS cross-linking combined with in situ chimeric SiO2 nanoparticle adhesion to enhance the hydrophilicity and antibacterial properties of PTFE flat membranes.

Herein, a new hydrophilic and antibacterial polytetrafluoroethylene (PTFE) flat MF membrane was fabricated via a low-cost and simple preparation method in which chitosan (CS) was crosslinked with poly(vinyl alcohol) (PVA) using epichlorohydrin (ECH) as a cross-linker followed by in situ chimeric SiO2 nanoparticle adhesion. The surface of the modified membrane had decreased C and F contents, and a large number of hydrophilic groups appeared. The treated membrane had good hydrophilicity and antibacterial properties. Moreover, the PTFE-modified membrane had high separation efficiency and antifouling property for oil-in-water emulsions. Finally, the hydrophilic stability of the PTFE membrane was studied by subjecting it to continuous water rinsing and soaking in solutions of different pH values. The present study demonstrates that this modified membrane has potential practical applications in industrial wastewater recovery.

Bioengineered Norovirus S60 Nanoparticles as a Multifunctional Vaccine Platform.

Homotypic interactions of viral capsid proteins are common, driving viral capsid self-formation. By taking advantage of such interactions of the norovirus shell (S) domain that naturally builds the interior shells of norovirus capsids, we have developed a technology to produce 60-valent, icosahedral S60 nanoparticles through the E. coli system. This has been achieved by several modifications to the S domain, including an R69A mutation to destruct an exposed proteinase cleavage site and triple cysteine mutations (V57C/Q58C/S136C) to establish inter-S domain disulfide bonds for enhanced inter-S domain interactions. The polyvalent S60 nanoparticle with 60 exposed S domain C-termini offers an ideal platform for antigen presentation, leading to enhanced immunogenicity to the surface-displayed antigens for vaccine development. This was proven by constructing a chimeric S60 nanoparticle displaying 60 rotavirus (RV) VP8* proteins, the major RV-neutralizing antigen. These S60-VP8* particles are easily produced and elicited high IgG response in mice toward the displayed VP8* antigens. The mouse antisera after immunization with the S60-VP8* particles exhibited high blockades against RV VP8* binding to its glycan ligands and high neutralizing activities against RV infection in culture cells. The three-dimensional structures of the S60 and S60-VP8* particles were studied. Furthermore, the S60 nanoparticle can display other antigens, supporting the notion that the S60 nanoparticle is a multifunctional vaccine platform. Finally, the intermolecular disulfide bond approach may be used to stabilize other viral-like particles to display foreign antigens for vaccine development.

Immunogenicity evaluation of MS2 phage-mediated chimeric nanoparticle displaying an immunodominant B cell epitope of foot-and-mouth disease virus.

Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals that has caused tremendous economic losses worldwide. In this study, we designed a chimeric nanoparticles (CNPs) vaccine that displays the predominant epitope of the serotype O foot-and-mouth disease virus (FMDV) VP1 131-160 on the surface of MS2 phage. The recombinant protein was expressed in Escherichia Coli and can self-assemble into CNPs with diameter at 25–30 nm in vitro. A tandem repeat peptide epitopes (TRE) was prepared as control. Mice were immunized with CNPs, TRE and commercialized synthetic peptide vaccines (PepVac), respectively. The ELISA results showed that CNPs stimulated a little higher specific antibody levels to PepVac, but was significantly higher than the TRE groups. Moreover, the results from specific IFN-γ responses and lymphocyte proliferation test indicated that CNP immunized mice exhibited significantly enhanced cellular immune response compared to TRE. These results suggested that the CNPs constructed in current study could be a potential alternative vaccine in future FMDV control.

Hyaluronic Acid Layered Chimeric Nanoparticles: Targeting MAPK-PI3K Signaling Hub in Colon Cancer Cells.

Colon cancer has emerged as one of the most devastating diseases in the whole world. Mitogen-activated protein kinase (MAPK)-phosphatidylinsitol-3-kinase (PI3K) signaling hub has gained lots of attention due to its deregulation in colon cancer cells. However, selective targeting of oncogenic MAPK-PI3K hub in colon cancer has remained highly challenging, hence it has mostly been unexplored. To address this, we have engineered a hyaluronic acid layered lipid-based chimeric nanoparticle (HA-CNP) consisting of AZD6244 (MAPK inhibitor), PI103 (PI3K inhibitor), and cisplatin (DNA impairing drug) ratiometrically in a single particle. Electron microscopy (field emission scanning electron microscopy and atomic force microscopy) and dynamic light scattering were utilized to characterize the size, shape, morphology, and surface charge of the HA-CNPs. Fluorescent confocal laser scanning microscopy and flow cytometry analysis confirmed that HA-CNPs were taken up by HCT-116 colon cancer cells by merging of clathrin and CD44 receptor-mediated endocytosis along with macropinocytosis to home into acidic organelles (lysosomes) within 1 h. A gel electrophoresis study evidently established that HA-CNPs simultaneously inhibited MAPK-PI3K signaling hub with DNA damage in HCT-116 cells. These HA-CNPs stalled the cell cycle into G0/G1 phase, leading to induction of apoptosis (early and late) in colon cancer cells. Finally, these HA-CNPs exerted remarkable cytotoxicity in HCT-116 colon cancer cells at 24 h compared to that of the free triple drug cocktail as well as HA-coated dual drug-loaded nanoparticles without showing any cell death in healthy L929 fibroblast cells. These HA-coated CNPs have potential to be translated into clinics as a novel platform to perturb various oncogenic signaling hubs concomitantly toward next-generation targeted colon cancer therapy.

Innovation of a New Virus-Like Nanoparticle Vaccine System for the Specific Aerosol Relative Disease

Human spend a lot of time indoors and indoor air quality (IAQ) has a great effect on quality of life in humans. Traditionally, bioaerosol in IAQs is focused on bacteria and fungus. Airborne viruses, particularly for the nanoparticletype virus, on the bioaerosol particulates are associated with the quality of human health in indoor environment. We establish the human like animal model, like pig, for testing the efficacy of the nano virus like particle (VLP) vaccine for aerosol relative disease. The porcine reproductive and respiratory syndrome virus (PRRSV), which is an airborne and a droplet infection virus coated on the small size of bioaerosol, carries a major infectious disease in the pig raising industry worldwide. There are commercial vaccines including attenuated and inactivated vaccines available, but their efficacy remains to be improved. VLP represents safe and effective vaccine platforms based on nano-technology. The fusion protein of capsid protein (Cap) from the porcine circovirus 2 (PCV2) and the glycoprotein 5 (GP5) from PRRSV were expressed by E. coli system. The fusion protein self-assembled with the GP5 to become a VLP nanoparticle. For testing, BALB/c mice were immunized with 10 μg of chimeric VLP nanoparticle once, which induced neutralization by antibody responses to PRRSV. The VLP nanoparticle vaccine induced high T cell proliferation, not evident in commercial vaccines tested on mice. Our results suggest that the cheaper VLP-based nanoparticle is a possibly viable approach model for specific airborne-relative-diseases human vaccine in the future.

Chimeric Nanoparticle: A Platform for Simultaneous Targeting of Phosphatidylinositol-3-Kinase Signaling and Damaging DNA in Cancer Cells.

Phosphatidylinositol-3-kinase (PI3K) signaling has been hijacked in different types of cancers. Hence, PI3K inhibitors have emerged as novel targeted therapeutics in cancer treatment as mono and combination therapy along with other DNA damaging drugs. However, targeting PI3K signaling with small molecules leads to the emergence of drug resistance and severe side effects to the cancer patients. To address these, we have developed a biocompatible, biodegradable cholesterol-based chimeric nanoparticle (CNP), which can simultaneously load PI103, doxorubicin, and cisplatin in a controlled ratiometric manner. Size, shape, and morphology of these CNPs were characterized by dynamic light scattering (DLS), field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). Increased amounts of PI103, doxorubicin, and cisplatin were released from CNPs through controlled and continuous manner over 120 h at pH = 5.5 compared to neutral pH. The CNPs showed much enhanced in vitro cytotoxicity in HeLa, HL60, MCF7, and MDA-MB-231 cancer cells compared to a free drug cocktail at 24 and 48 h by inducing apoptosis. Confocal laser scanning microscopy (CLSM) imaging revealed that indeed these CNPs were internalized into subcellular lysosomes through endocytosis in a time dependent mode over 6 h and retained inside for 48 h in HeLa, MDA-MB-231, and MCF7 cells. These CNPs showed their efficacy by damaging DNA and inhibiting Akt as a downstream modulator of PI3K signaling in HeLa cervical cancer cells. These CNPs have the potential to open up new directions in next-generation nanomedicine by simultaneous targeting of multiple oncogenic signaling pathways and inducing DNA damage for augmented therapeutic outcome by reducing toxic side effects and overcoming drug resistance.

Abstract 1951: Targeting cancer by a chimeric nanoparticle formulation of Cisplatin and PI828, a PI3 kinase inhibitor

Abstract Combination chemotherapy is the mainstay of cancer regimes. However, additive off target effect of the drugs is still a major drawback of combination therapy. Nanoscale drug delivery systems, through enhanced permeation and retention effect, target the tumour more efficiently while reducing side effects. Combination of Cisplatin, a widely used platinum based chemotherapeutic with PI3 kinase/mTOR inhibitor has shown synergism. In this study, we designed a chimeric nanoparticle of Cisplatin and PI828, a PI3 kinase inhibitor. PI828 was chemically conjugated to cholesterol by a carbamate linkage. Cisplatin was coordinated to a cholesterol-succinic acid derivative via a unique monocarboxylato and OαPt bond. The chimeric nanoparticle was formulated by mixing both the conjugates in definite proportions with phosphatidylcholine and DSPE-PEG. The chimeric naoparticle had a consistent size between 100 to 130 nm determined by dynamic light scattering. The in vitro release kinetics experiment showed slow and sustained release of both the drugs over a time period of 96 hours. In vitro cell proliferation assay expressed cytotoxicity of the chimeric nanoformulation in 4T1, a murine breast cancer cell line and in KRAS upregulated and PTEN suppressed ovarian cancer model cells. We have evaluated the activity of chimeric nanoparticle in a K-Ras(LSL/+)/PTEN(fl/fl) ovarian cancer model, with a luciferase reporter system. The mice treated with chimeric nanoparticle exhibited suppressed tumour growth as well as reduced toxicity as compared to the free drug combination and vehicle treated mice. These results indicate that chimeric nanoformulation can better the outcome of Cisplatin and PI828 combination. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1951. doi:1538-7445.AM2012-1951