Wastewater treatment plants (WWTPs) are important sources of antibiotic resistance genes (ARGs) in aquatic environments. Mobile genetic elements (MGEs) and microbial communities are key factors that affect the proliferation of ARGs. To reveal the effects of WWTPs effluent discharge on the ARGs and microbial community in a coastal area, the structure and distribution of ARGs, MGEs, and microbial community in Shangyu (SY) and Jiaxing (JX) effluent receiving areas (ERAs) and the offshore area of Hangzhou Bay (HB) were investigated via high-throughput quantitative PCR and 16S rRNA high-throughput sequencing.
View Article and Find Full Text PDFThe TLPSOES parameters were optimized by response surface methodology using Box-Behnken design, which were 16.5% w/w of ammonium citrate, 17.5% w/w of ethanol, and 46% w/w of n-hexane at 70 min of stirring time.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
October 2019
A novel combined method of pre-cross-linking and surfactant micelles swelling was proposed in this study to fabricate highly cross-linked and macroporous agarose (HMA) microspheres. Agarose was chemically modified by allylglycidyl ether (AGE) as heterobifunctional cross-linker via its active glycidyl moieties before gel formation and pre-cross-linking was achieved. By this means, the effective concentration of cross-linker presented in agarose gel increased significantly, and thus cross-linking with a high-efficiency was achieved.
View Article and Find Full Text PDFIn this study, we developed the quaternized chitosan microgels without chemical crosslinking as an adjuvant of H5N1 split vaccine. The microgels with pH-sensitivity, positive surface charge and good biocompatibility, have been demonstrated in favor of enhancing both humoral and cellular immune response. However, the detailed mechanism of the chitosan-based microgels to enhance antigen specific immune responses remains unclear.
View Article and Find Full Text PDFInfectious diseases possess a big threat to the livestock industry worldwide. Currently, inactivated veterinary vaccines have attracted much attention to prevent infection due to their safer profile compared to live attenuated vaccine. However, its intrinsic poor immunogenicity demands the incorporation of an adjuvant.
View Article and Find Full Text PDFOur work here, for the first time, reported the use of chitosan-mediated biomimetic silica nanoparticles in enzyme immobilization. In order to make clear the relationship among silicification process, silica nanoparticle structure and immobilized enzyme activity, a mechanism of chitosan-mediated silicification using sodium silicate as the silica source was primarily evaluated. Chitosan was demonstrated effectively to promote the silicification not only in accelerating the aggregation rate of sodium silicate, but also in templating the formation of silica nanoparticles.
View Article and Find Full Text PDFNovel hybrid magnetic cross-linked enzyme aggregates of phenylalanine ammonia lyase (HM-PAL-CLEAs) were developed by co-aggregation of enzyme aggregates with magnetite nanoparticles and subsequent crosslinking with glutaraldehyde. The HM-PAL-CLEAs can be easily separated from the reaction mixture by using an external magnetic field. Analysis by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) indicated that PAL-CLEAs were inlayed in nanoparticle aggregates.
View Article and Find Full Text PDFProtein structure in nanopores is an important determinant in porous substrate utilization in biotechnology and materials science. To date, accurate residue details of pore curvature induced protein binding and unfolding were still unknown. Here, a multiscale ensemble of chromatography, NMR hydrogen and deuterium (H/D) exchange, confocal scanning and molecular docking simulations was combined to obtain the protein adsorption information induced by pore size and curvature.
View Article and Find Full Text PDFAiming to enhance the immunogenicity of H5N1 split vaccine, the development of a novel antigen delivery system based on quaternized chitosan hydrogel microparticles (Gel MPs) with multiple mechanisms of immunity enhancement is attempted. Gel MPs based on ionic cross-linking are prepared in a simple and mild way. Gel MPs are superior as a vaccine delivery system due to their ability to: 1) enhance cellular uptake and endosomal escape of antigens in dendritic cells (DCs); 2) significantly activate DCs; 3) form an antigen depot and recruit immunity cells to improve antigen capture.
View Article and Find Full Text PDFWe evaluated the effect of a β-propiolactone (BPL)-inactivated coxsackievirus A16 (CA16) vaccine, using three immunogenicity evaluation and two animal challenge systems. A CA16 virus strain, named 419, was used as the production strain. Another CA16 strain, named 1131, was isolated and used as the challenge strain in intracerebral inoculation of neonatal mice for the calculation of median lethal dose (LD 50).
View Article and Find Full Text PDFWhole cell tumor vaccine (WCTV), as a potential treatment modality, elicits limited immune responses because of the poor immunogenicity. To address this issue, researchers have attempted to transduce a cytokine adjuvant into tumor cells, but these single-adjuvant WCTVs curtail the high expectations. In present study, we constructed a multi-adjuvant WCTV based on the nanoparticles modified with cell penetrating peptide, which could facilitate the transportation of granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin 2 (IL-2) into tumor cells.
View Article and Find Full Text PDFEdible bird's nest contains lots of glycoproteins. The glycosylation inhomogeneity for glycoprotein often results in wide range of molecular weight and the difficulty for protein separation and charaterization. In this paper, proteins in the edible bird's nest were extracted using multiple extractions, and then digested by PNgase F and trypsin.
View Article and Find Full Text PDFThe microcosmic mechanisms of protein (recombinant human growth hormone, rhGH) incomplete release and stability from amphiphilic poly(monomethoxypolyethylene glycol-co-D,L-lactide) (mPEG-PLA, PELA) microspheres were investigated. PELA with different hydrophilicities (PELA-1, PELA-2, and PELA-3) based on various ratios of mPEG to PLA were employed to prepare microspheres exhibiting a narrow size distribution using a combined double emulsion and premix membrane emulsification method. The morphology, rhGH encapsulation efficiency, in vitro release profile, and rhGH stability of PELA microspheres during the release were characterized and compared in detail.
View Article and Find Full Text PDFZhonghua Zhong Liu Za Zhi
May 2012
Objective: To explore if folic acid/polyamide-amine (FA/PAMAM) enhances the therapeutic effect of miR-7gene therapy for glioma in vivo.
Methods: The miR-7 gene was transfected into U251 glioma cells by FA/PAMAM. The efficiency of gene transfection was assessed by fluorescence microscopy.
A method is herein proposed to produce biodegradable microcapsules by a self-healing of porous microspheres, which were prepared from water-in-oil-in-water (W/O/W) double-emulsion templates. Methoxypoly(ethylene glycol)--poly-dl-lactide (PELA) was dissolved in ethyl acetate (EA) as the oil phase (O) of double emulsion, NaCl and poly(vinyl acetate) aqueous solutions serving as internal and external water phases (W and W), respectively. Porous PELA microspheres were prepared by a two-step emulsification and solvent extraction method.
View Article and Find Full Text PDFBioresour Technol
January 2012
A unique method that applied a multilayer-immobilization strategy was developed to prepare nanofibrous enzymes for biosynthesis. LiCl co-electrospun with polyurethane nanofibers enabled strong physical adsorption of bovine serum albumin (BSA), forming the first layer of protein on the nanofibers; lipase AK was subsequently crosslinked to BSA as an outer layer of enzyme. The content of LiCl in nanofibers was found to be a sensitive factor affecting the activity and stability of the immobilized lipase.
View Article and Find Full Text PDFChitosan-based nanoparticles (NPs) are widely used in drug delivery, device-based therapy, tissue engineering, and medical imaging. In this aspect, a clear understanding of how physicochemical properties of these NPs affect the cytological response is in high demand. The objective of this study is to evaluate the effect of surface charge on cellular uptake profiles (rate and amount) and intracellular trafficking.
View Article and Find Full Text PDFLiCl is a kosmotrope that generally promotes protein salvation in aqueous solutions. Herein we report that LiCl embedded in electrospun polymeric nanofibers interestingly induced an abnormal protein adsorption and substantially augmented the adsorption capacity of the fibers. As a result, equilibrium protein loadings reached over 64% (w/w) of the dry mass of fibers, 9-fold higher than that observed in the absence of the salt.
View Article and Find Full Text PDFCofactor-dependent biotransformations often require consumption of a secondary substrate for cofactor regeneration. Alternatively, two synthetic reactions may be coupled together through cofactor regeneration cycles. Simultaneous production of value-added products from glycerol and xylose was realized in this work through an enzymatic NAD(H) regeneration cycle involving two enzymes.
View Article and Find Full Text PDFAim: Low solubility in water has become an intrinsic property of many anticancer drugs, which poses a hurdle in the translation from the bench to the clinic. In this study, we developed a facile method to prepare 10-hydroxycamptothecin (HCPT) nanocrystallites and testified their feasibility for liver-targeting therapy.
Materials & Methods: HCPT nanocrystallites were prepared under the soft template effect of galactosylated chitosan.
Following its market introduction in 1982, the cross-linked 12% agarose gel media Superose 12 has become widely known as a tool for size exclusion chromatography of proteins and other biological macromolecules. In this review it is shown that, when appropriate mobile phases are used, Superose possesses adsorption properties similar to that of traditional media for hydrophilic interaction liquid chromatography (HILIC). This is illustrated by the separation and purification of low molecular weight compounds such as polyphenols including active components of traditional Chinese medicinal herbs and green tea.
View Article and Find Full Text PDFRecombinant human non-glycosylated erythropoietin (rh-ngEpo) expressed in E. coli was attached to polyethylene glycol (PEG) chains with different sizes and structures. The pharmacokinetic properties and in vivo potency of the PEGylated protein were investigated and comparisons were drawn between the conjugates and glycosylated recombinant Epo (rhEpo).
View Article and Find Full Text PDFRecombinant human erythropoietin produced by mammalian cells contains about 40% carbohydrates which maintain its stability and long residence in body. However, mammalian derived Epo has low yields and high costs of production. In this article, a cost-effective strategy of producing non-glycosylated Epo from Escherichia coli and then PEGylating it to replace the role of sugar chains was investigated.
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