Electrospinning is an effective method to fabricate fibrous scaffolds that mimic the ECM of bone tissue on a nano- to macro-scale. However, a limitation of electrospun fibrous scaffolds for bone tissue engineering is the structure formed by densely compacted fibers, which significantly impedes cell infiltration and tissue ingrowth. To address this problem, several researchers have developed numerous techniques for fabricating 3D fibrous scaffolds with customized topography and pore size.
View Article and Find Full Text PDFPorcine reproductive and respiratory syndrome virus (PRRSV) is major economic problem given its effects on swine health and productivity. Therefore, we evaluated the genetic stability of a codon pair de-optimized (CPD) PRRSV, E38-ORF7 CPD, as well as the master seed passage threshold that elicited an effective immune response in pigs against heterologous virus challenge. The genetic stability and immune response of every 10th passage (out of 40) of E38-ORF7 CPD was analyzed through whole genome sequencing and inoculation in 3-week-old pigs.
View Article and Find Full Text PDFCommercially used porcine respiratory and reproductive syndrome (PRRS) modified live virus (MLV) vaccines provide limited protection with heterologous viruses, can revert back to a virulent form and they tend to recombine with circulating wild-type strains. Codon pair deoptimization (CPD) is an advanced method to attenuate a virus that overcomes the disadvantages of MLV vaccines and is effective in various virus vaccine models. The CPD vaccine against PRRSV-2 was successfully tested in our previous study.
View Article and Find Full Text PDFCodon pair deoptimization (CPD) attenuated type I porcine reproductive and respiratory syndrome virus (PRRSV). Infectious clones covering the full genome of a Korean type I PRRSV (E38) were synthesized, and CPD induced nine synonymous mutants of NSP1 (n = 1) and ORF7 (n = 8). In a trial to rescue live viruses from infectious clones, only four clones with mutations at nt 177 downstream of ORF7 were rescued, which showed a substantial decrease in cellular replication ability.
View Article and Find Full Text PDFBackground: There has been growing concern regarding the impact of air pollution, especially fine dust, on human health. However, it is difficult to estimate the toxicity of fine dust on the human body because of its diverse effects depending on the composition and environmental factors.
Results: In this study, we focused on the difference in the biodistribution of fine dust according to the size distribution of particulate matter after inhalation into the body to predict its impact on human health.
Background: Bone marrow-derived mesenchymal stem cells (BMSCs) and bone morphogenetic protein-2 (BMP-2) have been studied for bone repair because they have regenerative potential to differentiate into osteoblasts. The development of injectable and in situ three-dimensional (3D) scaffolds to proliferate and differentiate BMSCs and deliver BMP-2 is a crucial technology in BMSC-based tissue engineering.
Methods: The proliferation of mouse BMSCs (mBMSCs) in collagen/poly-γ-glutamic acid (Col/γ-PGA) hydrogel was evaluated using LIVE/DEAD and acridine orange and propidium iodide assays.
In recent years, porcine circovirus type 2d (PCV2d) has achieved a dominant position worldwide. Various PCV2d capsid-based vaccines have been used to alleviate concerns regarding the emergence of the variant. This study aimed to determine the dosage of recombinant PCV2d capsid protein to induce protective efficacy against experimental challenge with a virulent PCV2d strain.
View Article and Find Full Text PDFThe objective of this study was to assess protective efficacy of vaccination using CPD-attenuated chimeric PRRSV and Toll like receptor (TLR) agonists (HSP70 c-terminal domain and HSPX) as adjuvants through different inoculation routes. In this study, a chimeric PRRSV composed of two field isolates was synthesized and attenuated by CPD in NSP1 as described in the previous study. The infection of the CPD-attenuated chimeric PRRSV to pigs of 3 weeks-old showed no clinical signs without pathological lesions in necropsy, while it induced improved cross immunity between its parent strains.
View Article and Find Full Text PDFBackground: Mycoplasma hyopneumoniae (M. hyopneumoniae), a representative pathogen causing swine enzootic pneumonia, generally infects piglets vertically. However, it is difficult to ascertain the M.
View Article and Find Full Text PDFTwo type 2 field porcine reproductive and respiratory syndrome viruses (PRRSV) isolated from PRRS-affected swine farms were attenuated by de-optimization of codon pair bias in NSP1. In 3-week-old pigs infection, the attenuated viruses showed significantly lower replication ability than the original viruses without distinct clinical sign and pathological lesions, which were observed in pig infected with the original viruses. Regarding induction of PRRSV specific immunity, the level of the neutralizing antibodies as well as secretion of IFN-γ-SCs in PBMCs was not different between the attenuated viruses and the original viruses.
View Article and Find Full Text PDFTo date, many researchers have studied a considerable number of three-dimensional (3D) cotton-like electrospun scaffolds for tissue engineering, including the generation of bone, cartilage, and skin tissue. Although numerous 3D electrospun fibrous matrixes have been successfully developed, additional research is needed to produce 3D patterned and sophisticated structures. The development of 3D fibrous matrixes with patterned and sophisticated structures (FM-PSS) capable of mimicking the extracellular matrix (ECM) is important for advancing tissue engineering.
View Article and Find Full Text PDFBiochem Biophys Res Commun
February 2018
Viral pathogens have evolved a wide range of tactics to evade host immune responses and thus propagate effectively. One efficient tactic is to divert host immune responses toward an immunodominant decoy epitope and to induce non-neutralizing antibodies toward this epitope. Therefore, it is expected that the amount of decoy epitope in a subunit vaccine can affect the level of neutralizing antibody in an immunized animal.
View Article and Find Full Text PDFInjectable and stimuli-responsive hydrogels have attracted attention in molecular imaging and drug delivery because encapsulated diagnostic or therapeutic components in the hydrogel can be used to image or change the microenvironment of the injection site by controlling various stimuli such as enzymes, temperature, pH, and photonic energy. In this study, we developed a novel injectable and photoresponsive composite hydrogel composed of anticancer drugs, imaging contrast agents, bio-derived collagen, and multifaceted anionic polypeptide, poly (γ-glutamic acid) (γ-PGA). By the introduction of γ-PGA, the intrinsic temperature-dependent phase transition behavior of collagen was modified to a low viscous sol state at room temperature and nonflowing gel state around body temperature.
View Article and Find Full Text PDFMesenchymal stem cells (MSCs) can ameliorate renal injury and accelerate repair of acute kidney injury. Herein, we developed a collagen/poly(γ-glutamic acid) (γ-PGA) hydrogel as an injectable scaffold for the delivery of mouse MSCs (mMSCs) and anti-oxidant drugs into injured sites. By the introduction of γ-PGA into conventional collagen, the viscosity of collagen was reduced at ambient temperature for easy handling, while the elastic and viscous moduli of collagen were increased and a new porous structure was generated near body temperature.
View Article and Find Full Text PDFIn this research, we synthesized bioderived poly(amino acid) hydrogel particles that showed pH-dependent membrane-disrupting properties and controlled cytosolic delivery of antitumor drugs. Poly(γ-glutamic acid) (γ-PGA) that has been produced extensively using bacteria, especially those of species, was modified with cholesterol (γ-PGA/Chol), and the γ-PGA/Chol conjugates were used to form polymeric nanoparticles the size of 21.0±1.
View Article and Find Full Text PDFIn this study, we developed electrostatically self-assembled ternary nanocomplexes as a safe and effective non-viral vector for the delivery of plasmid DNA (pDNA) into human adipose-derived stem cells (hASCs). Although polyethylenimine (PEI) polymers initially showed excellent performance as gene delivery carriers, their broad use has been limited by cytotoxicity resulting from their strong positive charge. To reduce the cytotoxicity, we utilized anionic hyaluronic acid (HA) as a corona layer material for pDNA/PEI binary nanocomplexes.
View Article and Find Full Text PDFA fundamental theoretical question in intelligence research is to what extent the g factor and heritability coefficients of the subtests of an IQ battery are correlated. Five studies from Western countries showed modest to strong positive correlations (range = .43-.
View Article and Find Full Text PDFSG 9R, a rough vaccine strain of Salmonella gallinarum, has been used for the prevention of fowl typhoid and paratyphoid in the world despite the presence of residual virulence. SG 9R-like rough strains have been recently isolated from fowl typhoid cases; however, molecular markers to differentiate SG 9R from field strains are not well-characterized and the molecular mechanisms of SG 9R residual virulence are unclear. Therefore, we analyzed LPS biosynthesis (rfa gene cluster) and virulence genes (spv, SPI-2) of both SG 9R and S.
View Article and Find Full Text PDFWe conducted a molecular epizootiological study of infectious bursal disease (IBD) in Korea by analyzing 85 IBD viruses (IBDVs) obtained from vaccinated or unvaccinated flocks between 1980 and 2007. Phylogenetic analysis of the partial nucleotide sequence of the hypervariable region of the VP2 gene (nucleotides 661-1020) and pathogenicity tests revealed more genetic and phenotypic diversity of IBDV in Korea than has been reported previously. We showed that very virulent IBDVs (vvIBDVs) were already present in Korea in 1986.
View Article and Find Full Text PDFSilica gel chromatography HPLC, El-Mass, and NMR analyses were performed in order to determine the structure obtained from the separation and refinement of the main components of an ethanol extraction of Sargassum siliquastrum, which indicated its antioxidant activity An ethanol extraction of Sargassum siliquastrum demonstrated the strongest antioxidant activities of ethyl acetate when isolated by silica gel chromatography This amounts to 84.9 +/- 1.2% of its 0.
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