An Optimized FI-RSV Vaccine Effectively Protects Cotton Rats and BALB/c Mice without Causing Enhanced Respiratory Disease.

BACKGROUND: Despite considerable efforts toward vaccine development in past decades, no effective vaccines against respiratory syncytial virus (RSV) are available. Recently, we showed that an optimized formalin concentration can preserve prefusion protein (pre-F) on RSV-infected cells and protect mice against RSV infection without causing enhanced respiratory disease (ERD). Here, we sought to further stabilize pre-F on RSV virions by optimizing the production of FI-RSV. METHODS: Freshly produced RSV virions were treated with formalin under different concentrations to obtained an opti-FI-RSV vaccine with high pre-F level. Immunogenicity and safety of opti-FI-RSV were evaluated in Balb/c mice and cotton rats. RESULTS: Using 0.0156-0.1778% formalin, we successfully preserved pre-F on virions. This opti-FI-RSV exhibited improved immunogenicity and efficacy without causing ERD. Surprisingly, opti-FI-RSV, with a pre-F-dominant immunogen, still caused ERD after immunization with a suboptimal dose or when the neutralizing antibody titers declined. ERD was avoided by coadministering opti-FI-RSV with CpG + MPLA adjuvant, which subsequently induced a Th1-biasing immune response and, more importantly, significantly improved antibody avidity. CONCLUSIONS: Our study provides a new method to obtain a novel FI-RSV vaccine with a high pre-F level and may provide a reference for developing other inactivated vaccines. Our findings also emphasize that appropriate adjuvants are critical for nonreplicating vaccines.

Molecular Evolution of Attachment Glycoprotein (G) and Fusion Protein (F) Genes of Respiratory Syncytial Virus ON1 and BA9 Strains in Xiamen, China.

Monitoring viral transmission and analyzing the genetic diversity of a virus are imperative to better understand its evolutionary history and the mechanism driving its evolution and spread. Especially, effective monitoring of key antigenic mutations and immune escape variants caused by these mutations has great scientific importance. Thus, to further understand the molecular evolutionary dynamics of respiratory syncytial virus (RSV) circulating in China, we analyzed nasopharyngeal swab specimens derived from hospitalized children ≤5 years old with acute respiratory tract infections (ARIs) in Xiamen during 2016 to 2019. We found that infants under 6 months of age (52.0%) were the main population with RSV infection. The prevalent pattern "BBAA" of RSV was observed during the epidemic seasons. RSV ON1 and BA9 genotypes were the dominant circulating strains in Xiamen. Interestingly, we observed four Xiamen-specific amino acid substitution combinations in the G protein and several amino acid mutations primarily occurring at antigenic sites Ø and V in the F protein. Our analyses suggest that introduction of new viruses and local evolution are shaping the diversification of RSV strains in Xiamen. This study provides new insights on the evolution and spread of the ON1 and BA9 genotypes at local and global scales. IMPORTANCE Monitoring the amino acid diversity of the RSV G and F genes helps us to find the novel genotypes, key antigenic mutations affecting antigenicity, or neutralizing antibody-resistant variants produced by natural evolution. In this study, we analyzed the molecular evolution of G and F genes from RSV strains circulating in Xiamen, China. These data provide new insights on local and global transmission and could inform the development of control measures for RSV infections.

Enhancing Anti-Tumor Activity of Sorafenib Mesoporous Silica Nanomatrix in Metastatic Breast Tumor and Hepatocellular Carcinoma via the Co-Administration with Flufenamic Acid.

INTRODUCTION: Because tumor-associated inflammation is a hallmark of cancer treatment, in the present study, sorafenib mesoporous silica nanomatrix (MSNM@SFN) co-administrated with flufenamic acid (FFA, a non-steroidal anti-inflammatory drug (NSAID)) was investigated to enhance the anti-tumor activity of MSNM@SFN. METHODS: Metastatic breast tumor 4T1/luc cells and hepatocellular carcinoma HepG2 cells were selected as cell models. The effects of FFA in vitro on cell migration, PGE2 secretion, and AKR1C1 and AKR1C3 levels in 4T1/luc and HepG2 cells were investigated. The in vivo anti-tumor activity of MSNM@SFN co-administrating with FFA (MSNM@SFN+FFA) was evaluated in a 4T1/luc metastatic tumor model, HepG2 tumor-bearing nude mice model, and HepG2 orthotopic tumor-bearing nude mice model, respectively. RESULTS: The results indicated that FFA could markedly decrease cell migration, PGE2 secretion, and AKR1C1 and AKR1C3 levels in both 4T1/luc and HepG2 cells. The enhanced anti-tumor activity of MSNM@SFN+FFA compared with that of MSNM@SFN was confirmed in the 4T1/luc metastatic tumor model, HepG2 tumor-bearing nude mice model, and HepG2 orthotopic tumor-bearing nude mice model in vivo, respectively. DISCUSSION: MSNM@SFN co-administrating with FFA (MSNM@SFN+FFA) developed in this study is an alternative strategy for improving the therapeutic efficacy of MSNM@SFN via co-administration with NSAIDs.

Magnesium and zinc complexes bearing NNO-tridentate ketiminate ligands: synthesis, structures and catalysis in the ring-opening polymerization of lactides.

A series of magnesium and zinc complexes, [(L1-3)2M2(µ-OBn)2] (M = Mg (1-3), Zn (4-6)), have been synthesized by the reaction of NNO-tridentate ketiminate ligands (L1-3-H) and a stoichiometric amount of MgnBu2 (or ZnEt2) and BnOH. In addition, the reaction of these ketiminate ligands (L1-4-H) with a half equivalent of MgnBu2 (or ZnEt2) in toluene provides [M(L1-4)2] (M = Mg (7-10), Zn (11-14)) in good yields. All of these complexes have been fully characterized by NMR spectroscopy and elemental analysis, and the molecular structures of [(L1)2Mg2(µ-OBn)2] (1), [(L3)2Mg2(µ-OBn)2] (3), [(L1)2Zn2(µ-OBn)2] (4), [Mg(L1)2] (7), [Zn(L1)2] (11) and [Zn(L4)2] (14) have been further confirmed by X-ray crystallographic studies. X-ray diffraction studies revealed that complexes 1, 3 and 4 were dimeric in the solid state, bridging through the benzyloxy groups, while the solid-state structures of 7, 11 and 14 revealed a mononuclear species, six-coordinated by N, N, and O atoms of two ketiminate ligands, forming a distorted octahedron around the metal centre. Complexes 1-6 acted as efficient initiators for the ring-opening polymerization of lactides, producing PLAs with controlled molecular weights and narrow molecular weight distributions. Complex 6 [(L3)2Zn2(µ-OBn)2] exhibited the highest activity towards the ROP of lactides. And complexes 1-6 initiated rac-lactide polymerization to afford heterotactic enriched polymers (Pr up to 0.82). In addition, complexes 7-14 were also shown to efficiently catalyze the ring-opening polymerization of lactides in the presence of BnOH.

The theranostic efficiency of tumor-specific, pH-responsive, peptide-modified, liposome-containing paclitaxel and superparamagnetic iron oxide nanoparticles.

BACKGROUND: In the present study, the tumor-specific, pH-responsive peptide H7K(R2)2-modified, theranostic liposome-containing paclitaxel (PTX) and superparamagnetic iron oxide nanoparticles (SPIO NPs), PTX/SPIO-SSL-H7K(R2)2, was prepared by using H7K(R2)2 as the targeting ligand, SPIO NPs as the magnetic resonance imaging (MRI) agent, PTX as antitumor drug. METHODS: The PTX/SPIO-SSL-H7K(R2)2 was prepared by a thin film hydration method. The characteristics of PTX/SPIO-SSL-H7K(R2)2 were evaluated. The targeting effect, MRI, and antitumor activity of PTX/SPIO-SSL-H7K(R2)2 were investigated detail in vitro and in vivo in human breast carcinoma MDA-MB-231 cell models. RESULTS: Our results of in vitro flow cytometry, in vivo imaging, and in vivo MR imaging confirmed the pH-responsive characteristic of H7K(R2)2 in MDA-MB-231 cell line in vitro and in vivo. The results of in vivo MRI and in vivo antitumor activity confirmed the theranostic effect of PTX/SPIO-SSL-H7K(R2)2 in MDA-MB-231 tumor-bearing model. CONCLUSION: Considering all our in vitro and in vivo results, we conclude that we developed targeting modified theranostic liposome which could achieve both role of antitumor and MRI.

Effect of XlogP and Hansen Solubility Parameters on Small Molecule Modified Paclitaxel Anticancer Drug Conjugates Self-Assembled into Nanoparticles.

Small molecule modified anticancer drug conjugates (SMMDCs) can self-assemble into nanoparticles (NPs) as therapeutic NP platforms for cancer treatment. Here we demonstrate that the XlogP and Hansen solubility parameters of paclitaxel (PTX) SMMDCs is essential for SMMDCs self-assembling into NPs. The amorphous state of PTX SMMDCs will also affect SMMDCs self-assembling into NPs. However, the antitumor activity of these PTX SMMDCs NPs decreased along with their XlogP values, indicating that a suitable XlogP value for designing the SMMDCs is important for self-assembling into NPs and for possessing antitumor activity. For higher level XlogP SMMDCs, a degradable linker should be considered in the design of SMMDCs to overcome the problem of lower antitumor activity. It is preferable that the hydrophilic groups in the SMMDCs should be present on the surface of self-assembling NPs.

Improving Solubility and Oral Bioavailability of Febuxostat by Polymer-Coated Nanomatrix.

Here, the mesoporous silica (Sylysia 350) was selected as mesoporous material, hydroxypropyl methylcellulose (HPMC) was selected as crystallization inhibitor, and febuxostat (FBT) was selected as model drug, respectively. The FBT-Sylysia-HPMC nanomatrix (FBT@SHN) was prepared. The characteristics of FBT@SHN were investigated in vitro and in vivo. Our results indicated that the FBT in FBT@SHN was in amorphous form. The solubility and dissolution of FBT in FBT@SHN were significantly increased. The oral bioavailability of FBT in FBT@SHN was greatly improved 5.8-fold compared with that in FBT suspension. This nanomatrix could be used as a drug delivery platform for improving the oral bioavailability.

Improving anti-tumor activity of sorafenib tosylate by lipid- and polymer-coated nanomatrix.

In the present study, we select the Sylysia 350 (Sylysia) as mesoporous material, distearoylphosphatidylethanolamine-poly(ethylene glycol)2000 (DSPE-PEG) as absorption enhancer and hydroxy propyl methyl cellulose (HPMC) as crystallization inhibitor to prepare sorafenib tosylate (SFN) nanomitrix (MSNM@SFN) for improving the anti-tumor activity of SFN. The MSNM@SFN was prepared by solvent evaporation method. The solubility, dissolution, and bioavailability of SFN in MSNM@SFN were also investigated. The anti-tumor activity of MSNM@SFN was evaluated in vitro and in vivo. Our results indicated that the solubility and dissolution of SFN in MSNM@SFN were significantly increased. The oral bioavailability of SFN in MSNM@SFN was greatly improved 7.7-fold compared with that in SFN suspension. The enhanced anti-tumor activity of MSNM@SFN was confirmed in vitro and in vivo experiments. This nanomatrix developed in this study could be a promising drug delivery platform for improving the therapeutic efficacy of poorly water-soluble drugs.

A self-assembling nanomedicine of conjugated linoleic acid-paclitaxel conjugate (CLA-PTX) with higher drug loading and carrier-free characteristic.

The main objective of this study was to demonstrate the proof-of-principle for the hypothesis that conjugated linoleic acid-paclitaxel conjugate (CLA-PTX), a novel fatty acid modified anti-cancer drug conjugate, could self-assemble forming nanoparticles. The results indicated that a novel self-assembling nanomedicine, CLA-PTX@PEG NPs (about 105 nm), with Cremophor EL (CrEL)-free and organic solvent-free characteristics, was prepared by a simple precipitation method. Being the ratio of CLA-PTX:DSPE-PEG was only 1:0.1 (w/w), the higher drug loading CLA-PTX@PEG NPs (about 90%) possessed carrier-free characteristic. The stability results indicated that CLA-PTX@PEG NPs could be stored for at least 9 months. The safety of CLA-PTX@PEG NPs was demonstrated by the MTD results. The anti-tumor activity and cellular uptake were also confirmed in the in vitro experiments. The lower crystallinity, polarity and solubility of CLA-PTX compared with that of paclitaxel (PTX) might be the possible reason for CLA-PTX self-assembling forming nanoparticles, indicating a relationship between PTX modification and nanoparticles self-assembly. Overall, the data presented here confirm that this drug self-delivery strategy based on self-assembly of a CLA-PTX conjugate may offer a new way to prepare nanomedicine products for cancer therapy involving the relationship between anticancer drug modification and self-assembly into nanoparticles.

The anti-tumor efficacy of 3-(2-Nitrophenyl) propionic acid-paclitaxel (NPPA-PTX): a novel paclitaxel bioreductive prodrug.

Hypoxia is an important microenvironmental pressure present in the majority of solid tumors and, so, tumor hypoxia might be considered an attractive target for tumor therapy. One strategy for targeting hypoxia is to develop bioreductive prodrugs. In the present research, we synthesized a bioreductive paclitaxel prodrug, 3-(2-Nitrophenyl) propionic acid-paclitaxel (NPPA-PTX). The stability of NPPA-PTX in PBS and rat plasma was investigated. The anti-tumor activity of NPPA-PTX was also evaluated in vitro and in vivo. The results of our stability study indicated that NPPA-PTX was stable in PBS and rat plasma as well as in the blood circulation. The in vitro and in vivo anti-tumor activity of NPPA-PTX was confirmed in both KB cells and MDA-MB-231 cells. Our results also indicated that NPPA-PTX could completely convert to active PTX in tumor tissues and produced the anti-tumor activity in both KB and MDA-MB-231 tumor-bearing nude mice. We suggest that the dissociated PTX which converted from NPPA-PTX in tumor tissues played a key role in producing anti-tumor activity. Considering all our results, we suggest that NPPA-PTX is a novel bioreductive PTX prodrug which could undergo further evaluation.

Multi-targeting NGR-modified liposomes recognizing glioma tumor cells and vasculogenic mimicry for improving anti-glioma therapy.

Like the anti-angiogenic strategy, anti-vascular mimicry is considered as a novel targeting strategy for glioma. In the present study, we used NGR as a targeting ligand and prepared NGR-modified liposomes containing combretastatin A4 (NGR-SSL-CA4) in order to evaluate their potential targeting of glioma tumor cells and vasculogenic mimicry (VM) formed by glioma cells as well as their anti-VM activity in mice with glioma tumor cells. NGR-SSL-CA4 was prepared by a thin-film hydration method. The in vitro targeting of U87-MG (human glioma tumor cells) by NGR-modified liposomes was evaluated. The in vivo targeting activity of NGR-modified liposomes was tested in U87-MG orthotopic tumor-bearing nude mice. The anti-VM activity of NGR-SSL-CA4 was also investigated in vitro and in vivo. The targeting activity of the NGR-modified liposomes was demonstrated by in vitro flow cytometry and in vivo biodistribution. The in vitro anti-VM activity of NGR-SSL-CA4 was indicated in a series of cell migration and VM channel experiments. NGR-SSL-CA4 produced very marked anti-tumor and anti-VM activity in U87-MG orthotopic tumor-bearing mice in vivo. Overall, the NGR-SSL-CA4 has great potential in the multi-targeting therapy of glioma involving U87-MG cells, and the VM formed by U87-MG cells as well as endothelial cells producing anti-U87-MG cells, and anti-VM formed by U87-MG cells as well as anti-endothelial cell activity.