Synthesis and Self-Assembly Behavior of Six-Armed Block Copolymers with pH- and Thermo-Responsive Properties

Xiujuan Huang,Yan Xiao,Meidong Lang 한국고분자학회 2011 Macromolecular Research Vol.19 No.2

A series of amphiphilic six-armed copolymers, containing poly(ε-caprolactone) (PCL) and poly(2-(diethylamino)ethyl methacrylate) (PDEAEMA or PDEA) as the arm and cyclotriphosphazene as the core, were obtained by a combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The star block S(PCL-b-PDEAEMA) copolymers were characterized by ^1H NMR spectroscopy and size exclusive chromatography (SEC). These copolymers could self-assembly into micelles in an aqueous solution at low pH with a low critical aggregation concentration (CAC) in the range of 2 to 10 mg/L, which depend on the composition of the copolymers. The original aggregates could further form larger micelles and/or vesicles by adjusting the external stimulus, which was examined by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The lower critical solution temperature (LCST) of the star copolymers were determined to be 49.7 and 26.3 ℃ at pH 6.5and 7.4, respectively, demonstrating a pH-dependent thermo-response.

Genipin-Crosslinked, Immunogen-Reduced Decellularized Porcine Liver Scaffold for Bioengineered Hepatic Tissue

Xiujuan Wu,Yujia Wang,Qiong Wu,Yi Li,Li Li,Jing Tang,Yujun Shi,Hong Bu,Ji Bao,Mingjun Xie 한국조직공학과 재생의학회 2015 조직공학과 재생의학 Vol.12 No.6

Liver disease affects millions of patients each year worldwide. Decellularized biologic matrices are plausible biomedical materials for bioengineered replacement hepatic tissue. However, one of the concerns for its safe medical application is the lack of objective assessment of the immunogen within the materials and in vivo immune responses to the matrices. The purpose of this study was to produce immunogen- reduced and biocompatible matrices from porcine liver. Whole porcine livers were perfusion decellularized and cross-linked with glutaraldehyde (GA) or genipin (GP). Proteins were extracted, and the migratory response of human leukocytes toward protein extracts was examined using an in vitro migration chamber. In addition, biopsy specimens of decellularized scaffolds were implanted subcutaneously into rodents to investigate scaffold immunogenicity. Histological staining confirmed cellular clearance from pig livers, with removal of nuclei and cytoskeletal components and widespread preservation of structural extracellular molecules. Polymerase chain reaction analysis showed that galactose-alpha-1,3-galactose-beta-1,4-N-acetylglucosamine (1,3 gal), swine leukocyte antigen, and porcine endogenous retrovirus were completely removed in the matrices. Decellularization significantly reduced the migration of monocytes compared with native porcine tissue. Although the proportion of transmigrating lymphocytes was much lower, repeating the cross-linking procedure reduced the migratory response. After implantation for 4 weeks, the decellularized and native samples were degraded, and the GA-treated group demonstrated a severe inflammatory reaction; however, minimal inflammatory cell infiltration was seen in the GPtreated group during the 8-week investigation period. In conclusion, our study provided evidence that GP crosslinking could significantly reduce the immunogenicity of decellularized liver biomaterials.

Characteristics of lipoxygenase-based and lipoxygenase-deficient soy yogurt with modified okara

Xiujuan Wang,Yue Chen,Yuhua Wang,Weichang Dai,Chun Hong Piao,Hansong Yu 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.13

Lipoxygenase-based and lipoxygenase-deficientokara were modified by Kluyveromyces marxianus fermentation,then adding modified okara back to the correspondingsoymilk to prepare soy yogurt. Thephysicochemical properties, texture, and volatile componentsof soy yogurt were characterized. The results showedthat okara modified by Kluyveromyces marxianus fermentationwas rich in soluable dietary fiber and was impartedbetter water-holding capacity, swelling capacity, and oilholdingcapacity. The soy yogurt with the modified okarawas greatly enhanced in its appearance, texture and wasrelatively stable during storage. Moreover, lipoxygenasebasedsoy yogurt had a unique soybean flavor whilelipoxygenase-deficient soy yogurt had a slight beany flavorand soybean flavor. This article guides a bio-modifiedmethod for okara and provides a theoretical basis for thefurther development and application of soy yogurt withhigh dietary fiber as well as lipoxygenase-deficient soyyogurt.

β-Actin regulates interleukin 6-induced p21 transcription by interacting with the Rpb5 and Rpb7 subunits of RNA polymerase II

Xiujuan Tian,Wenjing Qi,Hongyu Chen,Xianlu Zeng,Liping Han,Donghui Mi 한국통합생물학회 2016 Animal cells and systems Vol.20 No.5

In pre-initiation complexes, RNA helicase A interacts with β-actin and acts as a bridging factor linking nuclear actin with RNA polymerase II (Pol II). In addition, β-actin participates in Pol IIdependent transcription elongation by interacting with the positive transcription elongation factor Cdk9. However, many relationships between β-actin and Pol II remain to be identified. In an interleukin 6 (IL-6)-induced p21 expression model, we demonstrated that β-actin knockdown reduced p21 expression. Immunofluorescence analysis showed that the colocalization of β-actin and Pol II increased significantly in cells treated with IL-6. It is known that the Rpb5, Rpb6 and Rpb7 subunits are located at the surface of the enzyme. We next constructed recombinant pcDNA-HA-Rpb5, pcDNA-HA-Rpb6 and pcDNA-HA-Rpb7 plasmids and expressed the three polymerase II subunits in HepG2 cells. We found that β-actin could be immunoprecipitated with HA-Rpb5 and HA-Rpb7. A Glutathione-S-transferase pull-down assay revealed that β-actin was associated with Rpb5 and Rpb7 in vitro. Furthermore, overexpression of Rpb5 and Rpb7 in cells reduced p21 expression significantly, suggesting that Rpb5 and Rpb7 competitively interact with β-actin. This study shows that β-actin associates with Pol II subunits through direct proteinprotein interactions and provides fundamental insight into Pol II transcriptional regulation.

Synthesis of Star-Shaped PCL-Based Copolymers via One-Pot ATRP and Their Self-Assembly Behavior in Aqueous Solution

Xiujuan Huang,Meidong Lang,Yan Xiao 한국고분자학회 2012 Macromolecular Research Vol.20 No.6

A series of star-shaped poly(ε-caprolactone) (PCL)-based diblock and triblock copolymers containing 2-(dimethylamino)ethyl methacrylate (DMAEMA or DMA) and oligo(ethylene glycol)monomethyl ether methacrylate (OEGMA or OEG) were synthesized by one-pot atom transfer radical polymerization (ATRP) using a sixarm PCL-based macroinitiator. The precursor and the resultant copolymers were analyzed via proton nuclear magnetic resonance spectra (1H NMR) and size exclusion chromatography (SEC). The monomer reactivity ratios for DMAEMA (r1) and OEGMA (r2) were estimated to be near unity and r1×r2=1, which indicates the random distribution of the monomers in the final copolymers. Self-assembly behavior of these copolymers was investigated by fluorimetry,1H NMR, dynamic light scattering (DLS), transmission electronic microscopy (TEM), potentiometric titrations, and zeta potential measurements. The results suggested that the star copolymers were responsive to salinity depending on their composition and structure.

Establishment of plant regeneration system in quinquefolius through somatic embryogenesis

Lei Xiujuan 한국약용작물학회 2018 한국약용작물학회 학술대회논문집 Vol.2018 No.2

Investigation of temperature sensitivity of actuation performance for piezoelectric fiber composites

Lin, Xiujuan,Chen, Haiyan,Ma, Yupeng,Fisher, John G.,Huang, Shifeng,Zhang, Dou,Cheng, Xin Elsevier 2017 CERAMICS INTERNATIONAL Vol.43 No.13

<P><B>Abstract</B></P> <P>Piezoelectric fiber composites (PFCs) suffer an extremely wide range of temperatures when used in various aerospace structures where temperature effects on the mechanical properties of PFCs are important. In this paper, the actuation performances of PFCs were studied when they were exposed to environmental temperatures from −15°C to 80°C. The results showed that the actuation performance of PFCs was greatly dependent on the environmental temperature. The free strain values and the calculated piezoelectric coefficients d<SUB>33</SUB> and d<SUB>31</SUB> were initially enhanced with the increase of temperature due to the restricted movement of epoxy molecule in the glassy state. The glass transition temperature range of the composite was broadened due to a large number of small pores on the surface of the Pb(Zr,Ti)O<SUB>3</SUB> (PZT) fibers, when the epoxy molecules inside the pores had different transition behaviors compared with those outside the pores. The actuation performance including free strain performance and actuation capability, as well as the piezoelectric coefficients d<SUB>33</SUB> and d<SUB>31</SUB> decreased as the temperature increased above room temperature, since the deformation of epoxy molecules in the viscoelastic state was irreversible.</P>

DES Software for Computer Interlocking System

Wang Xiujuan,Keyseo Lee,Jaeho Lee,Youngsoo Park,Jaehoon Lee,Hyunduck Jeon,Hojoong Ryoo,Heegap Yang 한국철도학회 2000 철도저널 Vol.3 No.3

DES software is a Computer Aided Design(CAD) tool. It is built based on objected-oriented principle. Utilizing strong processing capability and quick calculation of computer, it can search out all possible routes, and give out interlocking table on the base of chosen routes by user. It can provide a large number of data for computers included in computer interlocking system. It is efficient and reliable.

Sulfur-free exfoliated graphite with large exfoliated volume: Preparation, characterization and its adsorption performance

Qi Zhao,Xiujuan Yu,Xiuwen Cheng,Juan Wu 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

Sulfur-free exfoliated graphite (EG) with large exfoliated volume (760 mL g-1) was prepared throughchemical oxidation, followed by microwave exfoliation. SEM results indicated that well-developednetwork pores in the worm-like structure of EG could be clearly observed. XPS results displayed thatsome functional groups were yielded on the surface of the as-prepared EG. Moreover, the capacity of EGwas evaluated by the adsorption of rodamine B and 4-chlorophenol aqueous solution. Results showedthat EG exhibited high adsorption capacity for RhB and 4-CP, which could be attributed to the functionalgroups and well-developed network pores in the worm-like EG.

Peptides as drug delivery vehicles across biological barriers

Debadyuti Ghosh,Xiujuan Peng,Jasmim Leal,Rashmi P. Mohanty 한국약제학회 2018 Journal of Pharmaceutical Investigation Vol.48 No.1

Peptides are small biological molecules that are attractive in drug delivery and materials engineering for applications including therapeutics, molecular building blocks and cell-targeting ligands. Peptides are small but can possess complexity and functionality as larger proteins. Due to their intrinsic properties, peptides are able to overcome the physiological and transport barriers presented by diseases. In this review, we discuss the progress of identifying and using peptides to shuttle across biological barriers and facilitate transport of drugs and drug delivery systems for improved therapy. Here, the focus of this review is on rationally designed, phage display peptides, and even endogenous peptides as carriers to penetrate biological barriers, specifically the blood–brain barrier (BBB), the gastrointestinal tract (GI), and the solid tumor microenvironment (T). We will discuss recent advances of peptides as drug carriers in these biological environments. From these findings, challenges and potential opportunities to iterate and improve peptide-based approaches will be discussed to translate their promise towards the clinic to deliver drugs for therapeutic efficacy.