[Show abstract][Hide abstract] ABSTRACT: Humanized mouse models derived from immune-deficient mice have been the primary tool for studies of human infectious viruses, such as human immunodeficiency virus (HIV). However, the current protocol for constructing humanized mice requires elaborate procedures and complicated techniques, limiting the supply of such mice for viral studies. Here, we report a convenient method for constructing a simple HIV-1 mouse model. Without prior irradiation, NOD/SCID/IL2Rγ-null (NSG) mice were intraperitoneally injected with 1 107 adult human peripheral blood mononuclear cells (hu-PBMCs). Four weeks after PBMC inoculation, human CD45+ cells, and CD3+CD4+ and CD3+CD8+ T cells were detected in peripheral blood, lymph nodes, spleen, and liver, whereas human CD19+ cells were observed in lymph nodes and spleen. To examine the usefulness of hu-PBMC-inoculated NSG (hu-PBMC-NSG) mice as an HIV-1 infection model, we intravenously injected these mice with dual-tropic HIV-1DH12 and X4-tropic HIV-1NL4-3 strains. HIV-1-infected hu-PBMC-NSG mice showed significantly lower human CD4+ T cell counts and high HIV viral loads in the peripheral blood compared with non-infected hu-PBMC-NSG mice. Following highly active antiretroviral therapy (HAART) and neutralizing antibody treatment, HIV-1 replication was significantly suppressed in HIV-1-infected hu-PBMC-NSG mice without detectable viremia or CD4+ T cell depletion. Moreover, the numbers of human T cells were maintained in hu-PBMC-NSG mice for at least 10 weeks. Taken together, our results suggest that hu-PBMC-NSG mice may serve as a relevant HIV-1 infection and pathogenesis model that could facilitate in vivo studies of HIV-1 infection and candidate HIV-1 protective drugs.
Full-text · Article · Nov 2015 · AIDS Research and Human Retroviruses
[Show abstract][Hide abstract] ABSTRACT: To confirm that Korean Food and Drug Administration (KFDA) guidelines are applicable to test the efficacy of mosquito repellents, these guidelines were used to test the efficacy and complete protection times (CPTs) of three representative mosquito repellents: N,N-diethyl-3-methylbenzamide (DEET), citronella, and fennel oil. The repellency of citronella oil decreased over time, from 97.9% at 0 h to 71.4% at 1 h and 57.7% at 2 h, as did the repellency of fennel oil, from 88.6% at 0 h to 61.2% at 1 h and 47.4% at 2 h. In contrast, the repellency of DEET remained over 90% for 6 h. The CPT of DEET (360 min) was much longer than the CPTs of citronella (10.5 min) and fennel oil (8.4 min). These results did not differ significantly from previous findings, and hence confirm that the KFDA guidelines are applicable for testing the efficacy of mosquito repellents.
Full-text · Article · Sep 2015 · Journal of Parasitology Research
[Show abstract][Hide abstract] ABSTRACT: Here, we report a chimeric peptide-tethered fibrin hydrogel scaffold for delivery of human mesenchymal stem cells (hMSC). Osteopontin-derived peptide (OP) was used as an hMSC-tethering moiety. OP showed hMSC adhesion properties and enhanced hMSC proliferation. A natural fibrin-binding protein-derived peptide (FBP) was tested for its ability to tether hMSC to the fibrin gel matrix. FBP loading on fibrin gels was 8.2-fold higher than that of a scrambled peptide (scFBP). FBP-loaded fibrin gels were retained at injection sites longer than scFBP-loaded fibrin gels, showing a 15.9-fold higher photon intensity of fluorescent FBP-grafted fibrin gels than fluorescent scFBP-loaded fibrin gels 48h after injection. On the basis of the fibrin gel-binding properties of FBP and the hMSC-binding and proliferation-supporting properties of OP, we constructed chimeric peptides containing FBP and OP linked with a spacer (FBPsOP). Four days after transplantation, the survival of hMSC in FBPsOP-grafted fibrin gels was 3.9-fold higher than hMSC in fibrin gels alone. Our results suggest the potential of FBPsOP-grafted fibrin gels as a bioactive delivery system for enhanced survival of stem cells.
No preview · Article · Sep 2015 · Colloids and surfaces B: Biointerfaces
[Show abstract][Hide abstract] ABSTRACT: Cervical cancer is strongly associated with chronic human papillomavirus infections, among which HPV16 is the most common. Two commercial HPV vaccines, Gardasil and Cervarix are effective for preventing HPV infection, but cannot be used to treat existing HPV infections. Previously, we developed a human endogenous retrovirus (HERV)-enveloped recombinant baculovirus capable of delivering the L1 genes of HPV types 16, 18, and 58 (AcHERV-HP16/18/58L1, AcHERV-HPV). Intramuscular administration of AcHERVHPV vaccines induced a strong cellular immune response as well as a humoral immune response. In this study, to examine the therapeutic effect of AcHERV-HPV in a mouse model, we established an HPV16 L1 expressing tumor cell line. Compared to Cervarix, immunization with AcHERVHPV greatly enhanced HPV16 L1-specific cytotoxic T lymphocytes (CTL) in C57BL/6 mice. Although vaccination could not remove preexisting tumors, strong CTL activity retarded the growth of inoculated tumor cells. These results indicate that AcHERV-HPV could serve as a potential therapeutic DNA vaccine against concurrent infection with HPV 16, 18, and 58.
Full-text · Article · Jun 2015 · The Journal of Microbiology
[Show abstract][Hide abstract] ABSTRACT: Here, we report the non-covalent functionalization of reduced graphene oxide (rGO) nanosheets using chimeric peptides engineered to have a biologically functional sequence, a spacer sequence, and an rGO-binding sequence. As a model peptide with biological activity, the cell-penetrating peptide buforin IIb (Bu) was used. A stretch of seven consecutive phenylalanine residues (7F) was used as the rGO-binding sequence. Various effects of tetraglycine (4G) and tetra-aspartate (4D) as spacers between the biologically active Bu and the rGO-binding 7F sequences were compared. All chimeric peptides had α-helical structures at the carboxyl-terminal sequence, showing structural similarity to the α-helical structure of Bu alone. Free chimeric peptides composed of 7F-Bu, 7F4G-Bu, or 7F4D-Bu in solution exhibited cell-penetrating abilities similar to that of Bu alone. However, following attachment onto rGO nanosheets, the compositions of the chimeric peptides affected the biological activity of Bu. Following modification, the 7F4D-Bu chimeric peptide yielded higher cellular uptake of the rGO nanosheets than did the other chimeric peptides. The levels of cellular uptake of the rGO nanosheets modified with the chimeric peptides were further evaluated by measuring the photothermal effect after near-infrared laser irradiation. The cells treated with 7F4D-Bu-modified rGO showed the greatest increase in temperature upon irradiation, with the temperature reaching 58.3ºC. The 7F4D-Bu-modified rGO also exhibited the highest photothermal cell-killing activity upon near-infrared laser irradiation. Our results demonstrate the utility of chimeric peptide engineering for simple and facile one-step non-covalent modification of rGO. The chimeric peptide composed of 7F4D can be further used to tether various functional peptides onto rGO nanosheets.
[Show abstract][Hide abstract] ABSTRACT: To develop a novel solid lipid nanoparticles (SLNs)-loaded dual-reverse thermosensitive nanomicelle (DRTN) for intramuscular administration of flurbiprofen with sustained release and reduced toxicity, the DRTN was prepared with flurbiprofen-loaded SLNs, poloxamer 407 (P 407), poloxamer 188 (P 188) and water. Its rheological characterization, release, stability, pharmacokinetics and morphology were evaluated after intramuscular administration to rats. These SLNs were solid at 25 °C and transformed into liquid form at physiological temperature due to their melting point of about 32 °C. Furthermore, the DRTN retained a liquid state at 25 °C and gelled inside the body owing to its gelation temperature of about 34.7 °C, leading to an opposite reversible property of the SLNs. When compared to the hydrogel, it significantly decreased the drug release and exhibited a reduced initial fast release. It sustained a high plasma concentration for 60 h, which was significantly higher when compared to the suspension, indicating enhanced bioavailability. However, it showed a lower plasma concentration, AUC, and Cmax values than that found for the hydrogel, suggesting the retarded release and decreased side effects of the drug. Unlike the hydrogel, it induced no injury to rat muscle as a result of no direct contact of the drug. It was stable for four months. Therefore, this novel DRTN system could be a strong candidate for the intramuscular administration of flurbiprofen.
[Show abstract][Hide abstract] ABSTRACT: Here, we report the immunogenicity of a sublingually delivered, trivalent human papillomavirus (HPV) DNA vaccine encapsidated in a human endogenous retrovirus (HERV) envelope-coated, nonreplicable, baculovirus nanovector. The HERV envelope-coated, nonreplicable, baculovirus-based DNA vaccine, encoding HPV16L1, -18L1 and -58L1 (AcHERV-triHPV), was constructed and sublingually administered to mice without adjuvant. Following sublingual (SL) administration, AcHERV-triHPV was absorbed and distributed throughout the body. At 15 minutes and 1 day post-dose, the distribution of AcHERV-triHPV to the lung was higher than that to other tissues. At 30 days post-dose, the levels of AcHERV-triHPV had diminished throughout the body. Six weeks after the first of three doses, 1×108 copies of SL AcHERV-triHPV induced HPV type-specific serum IgG and neutralizing antibodies to a degree comparable to that of IM immunization with 1×109 copies. AcHERV-triHPV induced HPV type-specific vaginal IgA titers in a dose-dependent manner. SL immunization with 1×1010 copies of AcHERV-triHPV induced Th1 and Th2 cellular responses comparable to IM immunization with 1×109 copies. Molecular imaging revealed that SL AcHERV-triHPV in mice provided complete protection against vaginal challenge with HPV16, HPV18, and HPV58 pseudoviruses. These results support the potential of SL immunization using multivalent DNA vaccine in baculovirus nanovector for induction of mucosal, systemic, and cellular immune responses.
[Show abstract][Hide abstract] ABSTRACT: The intention of this research was to prepare and compare various solubility-enhancing nanoparticulated systems in order to select a nanoparticulated formulation with the most improved oral bioavailability of poorly water-soluble fenofibrate.
The most appropriate excipients for different nanoparticulated preparations were selected by determining the drug solubility in 1% (w/v) aqueous solutions of each carrier. The polyvinylpyrrolidone (PVP) nanospheres, hydroxypropyl-β-cyclodextrin (HP-β-CD) nanocorpuscles, and gelatin nanocapsules were formulated as fenofibrate/PVP/sodium lauryl sulfate (SLS), fenofibrate/HP-β-CD, and fenofibrate/gelatin at the optimized weight ratios of 2.5:4.5:1, 1:4, and 1:8, respectively. The three solid-state products were achieved using the solvent-evaporation method through the spray-drying technique. The physicochemical characterization of these nanoparticles was accomplished by powder X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Their physicochemical properties, aqueous solubility, dissolution rate, and pharmacokinetics in rats were investigated in comparison with the drug powder.
Among the tested carriers, PVP, HP-β-CD, gelatin, and SLS showed better solubility and were selected as the most appropriate constituents for various nanoparticulated systems. All of the formulations significantly improved the aqueous solubility, dissolution rate, and oral bioavailability of fenofibrate compared to the drug powder. The drug was present in the amorphous form in HP-β-CD nanocorpuscles; however, in other formulations, it existed in the crystalline state with a reduced intensity. The aqueous solubility and dissolution rates of the nanoparticles (after 30 minutes) were not significantly different from one another. Among the nanoparticulated systems tested in this study, the initial dissolution rates (up to 10 minutes) were higher with the PVP nanospheres and HP-β-CD nanocorpuscles; however, neither of them resulted in the highest oral bioavailability. Irrespective of relatively retarded dissolution rate, gelatin nanocapsules showed the highest apparent aqueous solubility and furnished the most improved oral bioavailability of the drug (~5.5-fold), owing to better wetting and diminution in crystallinity.
Fenofibrate-loaded gelatin nanocapsules prepared using the solvent-evaporation method through the spray-drying technique could be a potential oral pharmaceutical product for administering the poorly water-soluble fenofibrate with an enhanced bioavailability.
Full-text · Article · Mar 2015 · International Journal of Nanomedicine
[Show abstract][Hide abstract] ABSTRACT: The sub-acute toxic effects following repetitive intramuscular injection of two cervical cancer vaccines newly developed against human papillomaviruse (HPV)16/58/18 and HPV16 were investigated in female ICR (CrljOri: CD1) mice, and the no-observedadverse- effect-level (NOAEL) of the cervical cancer vaccines was estimated.
Female ICR mice (n=15 in each group) were exposed to a 1:1 mixture of two cervical cancer vaccines by repetitive intramuscular injection (once a week, 5 times) for 5 weeks. Mortality, body weight, organ weight, hematological/biochemical parameters, and histopathological effects were examined at different concentrations (0, 1×10(8), 5×10(8), and 2.5×10(9) copies/animal) of the cervical cancer vaccines.
The cervical cancer vaccines did not show toxic responses for body weight, absolute/ relative organ weight, hematological/biochemical parameters, or histopathological parameters.
Female ICR mice exposed to vaccines for cervical cancer did not show any toxic response. We suggest that a NOAEL of the vaccine following repetitive intramuscular injection for 5 weeks is >2.5×10(9) copies/animal.
[Show abstract][Hide abstract] ABSTRACT: Here, we report the pharmacokinetics and in vivo fate of intra-articularly transplanted human mesenchymal stem cells in comparison with those of intravenoulys administered cells. Bone marrow-derived human clonal mesenchymal stem cells (hcMSC) were transplanted to nude mice via intravenous or intra-articular routes. The numbers of hcMSC in blood and tissue samples were measured by quantitative real time-polymerase chain reaction (qPCR) with human Alu as a detection marker. Following intra-articular transplantation, the blood levels of hcMSC peaked 8 h post dose and gradually diminished, showing a 95-fold higher mean residence time than hcMSC delivered via the intravenous route. Unlike intravenously administered hcMSC, intra-articularly injected hcMSC were mainly retained at injection joint sites, where their levels 8 h post-dose were 116-fold higher than those in muscle tissues. Regardless of injection routes, biodistribution patterns did not significantly differ between normal and osteoarthritis-induced mice. Quantitiave analysis using hAlu-specific qPCR revealed that hcMSC levels in joint tissues were significantly higher than those in muscle tissues 120 d post dose. These dramatic differences in kinetic behavior, and fate of intra-articularly transplanted hcMSC compared with intravenously administered hcMSC may provide insights useful for the development of human mesenchymal stem cells for arthritis therapeutics.
Full-text · Article · Dec 2014 · Stem Cells and Development
[Show abstract][Hide abstract] ABSTRACT: Here, we report reduced graphene oxide (rGO) nanosheets coated with an anti-angiogenic anticancer taurocholate derivative of low-molecular-weight heparin (LHT7) as a tumor-targeting nanodelivery platform for anticancer drugs. Surface coating of LHT7 onto rGO was confirmed using fluorescein isothiocyanate-labeled LHT7, monitored as fluorescence quenching due to associated rGO. Unlike plain rGO, LHT7-coated rGO (LHT-rGO) nanosheets maintained a stable dispersion under physiological conditions for at least 24h. Moreover, LHT-rGO provided greater loading capacity for doxorubicin (Dox) compared with uncoated rGO nanosheets. Following intravenous administration into KB tumor-bearing mice, in vivo tumor accumulation of LHT-rGO/Dox was 7-fold higher than that of rGO/Dox 24h post dosing. In tumor tissues, LHT-rGO/Dox was shown to localize not to the tumor vasculature, but rather to tumor cells. Intravenously administered LHT-rGO/Dox showed the greatest anti-tumor effect in KB-bearing mice, reducing tumor volume by 92.5%±3.1% compared to the untreated group 25days after tumor inoculation. TUNEL assays revealed that the population of apoptotic cells was highest in the group treated with LHT-rGO/Dox. Taken together, our results demonstrate that LHT-rGO nanosheets confer improved dispersion stability, tumor distribution and in vivo antitumor effects, and may be further developed as a potential active nanoplatform of various anticancer drugs.
Full-text · Article · Jun 2014 · Journal of Controlled Release
[Show abstract][Hide abstract] ABSTRACT: Despite the progress of conventional vaccines, improvements are clearly required due to concerns about the weak immunogenicity of these vaccines, intrinsic instability in vivo, toxicity, and the need for multiple administrations. To overcome such problems, nanotechnology platforms have recently been incorporated into vaccine development. Nanocarrier-based delivery systems offer an opportunity to enhance the humoral and cellular immune responses. This advantage is attributable to the nanoscale particle size, which facilitates uptake by phagocytic cells, the gut-associated lymphoid tissue, and the mucosa-associated lymphoid tissue, leading to efficient antigen recognition and presentation. Modifying the surfaces of nanocarriers with a variety of targeting moieties permits the delivery of antigens to specific cell surface receptors, thereby stimulating specific and selective immune responses. In this review, we introduce recent advances in nanocarrier-based vaccine delivery systems, with a focus on the types of carriers, including liposomes, emulsions, polymer-based particles, and carbon-based nanomaterials. We describe the remaining challenges and possible breakthroughs, including the development of needle-free nanotechnologies and a fundamental understanding of the in vivo behavior and stability of the nanocarriers in nanotechnology-based delivery systems.
Full-text · Article · Jun 2014 · Asian Journal of Pharmaceutical Sciences
[Show abstract][Hide abstract] ABSTRACT: Previously, we developed a non-replicating recombinant baculovirus coated with human endogenous retrovirus envelope protein (AcHERV) for enhanced cellular delivery of human papillomavirus (HPV) 16L1 DNA. Here, we report the immunogenicity of an AcHERV-based multivalent HPV nanovaccine in which the L1 segments of HPV 16, 18, and 58 genes were inserted into a single baculovirus genome of AcHERV. To test whether gene expression levels were affected by the order of HPV L1 gene insertion, we compared the efficacy of bivalent AcHERV vaccines with the HPV 16L1 gene inserted ahead of the 18L1 gene (AcHERV-HP16/18L1) with that of AcHERV with the HPV 18L1 gene inserted ahead of the 16L1 gene (AcHERV-HP18/16L1). Regardless of the order, the bivalent AcHERV DNA vaccines retained the immunogenicity of monovalent AcHERV-HP16L1 and AcHERV-HP18L1 DNA vaccines. Moreover, the immunogenicity of bivalent AcHERV-HP16/18L1 was not significantly different from that of AcHERV-HP18/16L1. In challenge tests, both bivalent vaccines provided complete protection against HPV 16 and 18 pseudotype viruses. Extending these results, we found that a trivalent AcHERV nanovaccine encoding HPV 16L1, 18L1, and 58L1 genes (AcHERV-HP16/18/58L1) provided high levels of humoral and cellular immunogenicity against all three subtypes. Moreover, mice immunized with the trivalent AcHERV-based nanovaccine were protected from challenge with HPV 16, 18, and 58 pseudotype viruses. These results suggest that trivalent AcHERV-HPV16/18/58L1 could serve as a potential prophylactic baculoviral nanovaccine against concurrent infection with HPV 16, 18, and 58.
[Show abstract][Hide abstract] ABSTRACT: Here, we report that glucagon-like peptide-1 analogue liraglutide could enhance survival of human bone marrow-derived mesenchymal stem cells (hMSCs) following co-delivery in fibrin gel matrix. The hMSCs were treated with various concentrations (≤100 nM) of liraglutide. After 48 h, 100 nM liraglutide-treated hMSCs showed 1.4-fold higher cell viability than untreated hMSCs. Calcein staining for live cells and trypan blue staining for dead cells provided visual evidences that treatment of hMSCs with liraglutide increased cell survival. To evaluate the cell survival of hMSCs after in vivo transplantation, genomic DNA of hMSCs was quantified by quantitative real-time polymerase chain reaction by detecting human Alu element. Four days after transplantation, the survival of hMSCs co-transplanted with liraglutide (1.9 μg/kg) was 7.7-fold higher than that of plain hMSCs formulation. Taken together, our findings suggest the potential of liraglutide as a transplantation adjuvant for increasing in vivo survival of hMSCs.
No preview · Article · Apr 2014 · Journal of Pharmaceutical Investigation
[Show abstract][Hide abstract] ABSTRACT: Estimation of the efficacy of mosquito repellents requires both laboratory and field tests. The results of field tests are more meaningful, but the safety of volunteers in such tests may be a significant concern. In the current study, we compared tests of mosquito repellent efficacy under semifield conditions in an outdoor enclosure with those under laboratory and field conditions. In this study, we assessed the efficacy of N,N-diethyl-meta-toluamide under laboratory conditions with human volunteers and under semifield and field conditions with Centers for Disease Control and Prevention traps and experimental mice. A semifield test may be a suitable replacement for the more difficult field test for assessment of mosquito repellent efficacy. Semifield tests should be considered when developing new guidelines for testing.
Full-text · Article · Mar 2014 · Journal of Medical Entomology