pH-Sensitive Degradable Hydrophobe Modified 1.8 kDa Branched Polyethylenimine as “Artificial Viruses” for Safe and Efficient Intracellular Gene Transfection

Meng Zheng,Zhiyuan Zhong,Chunmei Yang,Fenghua Meng,Rui Peng 한국고분자학회 2012 Macromolecular Research Vol.20 No.3

1.8 kDa branched polyethylenimine (PEI) was modified with pH-sensitive degradable acetal containing hydrophobe, 2,4,6-trimethoxybenzylidene-tris(hydroxymethyl)ethane (TMB-THME), to enhance its DNA condensation under extracellular conditions as well as to achieve active DNA release inside cells. PEI-(TMBTHME)n conjugates in the amount of 1.8 kDa were prepared with varying degrees of substitution (DS) from 3.0, 5.7 to 10.1. Notably, dynamic light scattering (DLS) measurements showed that all three 1.8 kDa PEI-(TMB-THME)n conjugates could effectively condense DNA into nano-sized particles (189-197 nm) at N/P ratios ranging from 20/1 to 80/1. The surface charges of PEI-(TMB-THME)n polyplexes depending on DS and N/P ratios varied from +22 to +28 mV,which were comparable to or slightly higher than the unmodified 1.8 kDa PEI counterparts (~+22 to +23 mV). Under a mildly acidic condition mimicking that of endosomes, interestingly, 1.8 kDa PEI-(TMB-THME)n polyplexes were quickly unpacked to release DNA because of the pH-induced acetal degradation that transforms hydrophobic modification into hydrophilic modification. MTT assays demonstrated that all PEI-(TMB-THME)n polyplexes displayed low cytotoxicity (>80%) to 293T, and HeLa cells at N/P ratios ranging from 20/1 to 60/1. The in vitro gene transfection studies showed that the transfection activity of 1.8 kDa PEI was significantly enhanced by modifications with TMBTHME,in which transfection efficiencies increased with increasing DS. For example, 1.8 kDa PEI-(TMBTHME)10.1 polyplexes displayed 250-fold and 80-fold higher transfection efficiencies than those of the unmodified 1.8 kDa PEI counterparts in 293T and HeLa cells, respectively, which were approximately 4-fold and 2-fold higher than that of 25 kDa PEI control. The superior transfection activity of 1.8 kDa PEI-(TMB-THME)10.1 polyplexes was also confirmed by confocal laser scanning microscopy (CLSM), which showed efficient delivery of DNA into the nuclei of 293T cells following 4 h transfection. Modification of low molecular weight PEI with pH-sensitive degradable hydrophobe has appeared to be highly promising in the development of “artificial viruses” for safe and efficient gene transfer.

Algicidal Activity of a Dibenzofuran-Degrader Rhodococcus sp

( Meng Hui Wang ),( Peng Peng ),( Yu Mei Liu ),( Rui Bao Jia ),( Li Li ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.2

Rhodococcus sp. strain p52, a previously isolated dibenzofuran degrader, could effectively inhibit the growth of cyanobacteria, including species of Microcystis, Anabaena, and Nodularia. When strain p52 was inoculated at the concentration of 7.7×107 CFU/ml, 93.5% of exponentially growing Microcystis aeruginosa (7.3×106 cells/ml initially) was inhibited after 4 day. The threshold concentration for its algicidal activity against M. aeruginosa was 7.7×106 CFU/ml. Strain p52 exerted algicidal effect by synthesizing extracellular substances, which were identified as trans-3-indoleacrylic acid, DL-pipecolic acid, and L-pyroglutamic acid. The effective concentrations of trans-3-indoleacrylic acid and DL-pipecolic acid against M. aeruginosa were tested to be 0.5 mg/l and 5 mg/l, respectively.

H-형태 양친매성 펜타블록 공중합체의 화학효소적 합성과 자기회합거동 평가

Peng Chen,Ya Peng Li,Can Jin Li,Xin Lei Meng,Bao Zhang,Ming Zhu,Yan-jing Liu,Jing Yuan Wang 한국고분자학회 2013 폴리머 Vol.37 No.3

H-shaped amphiphilic pentablock copolymers (PSt)2-b-PCL-b-PEO-b-PCL-b-(PSt)2 was synthesized via chemoenzymatic method by combining enzyme-catalyzed ring-opening polymerization (eROP) of ε-caprolactone (ε-CL) and atom transfer radical polymerization (ATRP) of styrene. By this process, we obtained copolymers with controlled molecular weight and low polydispersity. The structure and composition of the obtained copolymers were characterized by nuclear magnetic resonance (NMR), gel permeation chromatography (GPC) and infrared spectroscopy analysis (IR). The crystallization behavior of the copolymers was analyzed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The crystallization behavior of the H-shaped block copolymers demonstrated a PCL dominate crystallization. The self-assembly behavior of the copolymers was investigated in aqueous media. The hydrodynamic diameters of the copolymer micelles in aqueous solution were measured by dynamic light scattering (DLS). The morphology of the copolymer micelles was observed by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The hydrodynamic diameters of spherical micelles declined gradually with the increase of the hydrophobic chain lengths of the copolymers. The critical micelle concentration (CMC) values were determined from fluorescence emission, and it was found that the CMCs decreased with an increase of PSt hydrophobic block lengths.

Chemoenzymatic Synthesis of Dual-responsive Amphiphilic Block Copolymers and Drug Release Studies

Peng Chen,Ya-Peng Li,Shu-Wei Wang,Xin-Lei Meng,Ming Zhu,Jing-Yuan Wang 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

Dual-responsive amphiphilic block copolymers were synthesized by combining enzymatic ring-opening polymerization (eROP) of ε-caprolactone (CL) and ATRP of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA). The obtained block copolymers were characterized by gel permeation chromatography (GPC), 1H NMR and FTIR-IR. The critical micelle concentration (CMC) of copolymer was determined by fluorescence spectra, it can be found that with hydrophilic block (PDMAEMA) increasing, CMC value of the polymer sample increased accordingly, and the CMC value was 0.012 mg/mL, 0.025 mg/mL and 0.037 mg/ mL for PCL50-b-PDMAEMA68, PCL50-b-PDMAEMA89, PCL50-b-PDMAEMA112, PCL50-b-PDMAEMA89 was chosen as drug carrier to study in vitro release profile of anti-cancer drug (taxol). The temperature and pH dependence of the values of hydrodynamic diameter (Dh) of micelles, and self-assembly of the resulting block copolymers in water were evaluated by dynamic light scattering (DLS). The result showed that with the temperature increasing and pH decreasing, the Dh decreased. Drug-loaded nanoparticles were fabricated using paclitaxel as model. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) had been explored to study the morphology of the hollow micelles and the nanoparticles, revealing well-dispersed spheres with the average diameters both around 80 nm. In vitro release kinetics of paclitaxel from the nanoparticles was also investigated in different conditions (pH and temperature, etc.), revealing that the drug release was triggered by temperature changes upon the lower critical solution temperature (LCST) at pH 7.4, and at 37 °C by an increase of pH.

Chemoenzymatic Synthesis of Dual-responsive Amphiphilic Block Copolymers and Drug Release Studies

Chen, Peng,Li, Ya-Peng,Wang, Shu-Wei,Meng, Xin-Lei,Zhu, Ming,Wang, Jing-Yuan Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

Dual-responsive amphiphilic block copolymers were synthesized by combining enzymatic ring-opening polymerization (eROP) of ${\varepsilon}$-caprolactone (CL) and ATRP of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA). The obtained block copolymers were characterized by gel permeation chromatography (GPC), $^1H$ NMR and FTIR-IR. The critical micelle concentration (CMC) of copolymer was determined by fluorescence spectra, it can be found that with hydrophilic block (PDMAEMA) increasing, CMC value of the polymer sample increased accordingly, and the CMC value was 0.012 mg/mL, 0.025 mg/mL and 0.037 mg/mL for $PCL_{50}$-b-$PDMAEMA_{68}$, $PCL_{50}$-b-$PDMAEMA_{89}$, $PCL_{50}$-b-$PDMAEMA_{112}$, $PCL_{50}$-b-$PDMAEMA_{89}$ was chosen as drug carrier to study in vitro release profile of anti-cancer drug (taxol). The temperature and pH dependence of the values of hydrodynamic diameter (Dh) of micelles, and self-assembly of the resulting block copolymers in water were evaluated by dynamic light scattering (DLS). The result showed that with the temperature increasing and pH decreasing, the Dh decreased. Drug-loaded nanoparticles were fabricated using paclitaxel as model. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) had been explored to study the morphology of the hollow micelles and the nanoparticles, revealing well-dispersed spheres with the average diameters both around 80 nm. In vitro release kinetics of paclitaxel from the nanoparticles was also investigated in different conditions (pH and temperature, etc.), revealing that the drug release was triggered by temperature changes upon the lower critical solution temperature (LCST) at pH 7.4, and at $37^{\circ}C$ by an increase of pH.

An Instant Interest Oriented Recommendation Agent Based on SVDD and Schedule

Peng Min-jing,Liu Meng,Zhu Ming-liang 보안공학연구지원센터(IJUNESST) 2014 International Journal of u- and e- Service, Scienc Vol.7 No.4

Heat-Shock Protein 70 as a Tumor Antigen for in vitro Dendritic Cell Pulsing in Renal Cell Carcinoma Cases

Meng, Fan-Dong,Sui, Cheng-Guang,Tian, Xin,Li, Yan,Yang, Chun-Ming,Ma, Ping,Liu, Yun-Peng,Jiang, You-Hong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.20

Immunological functions of heat shock proteins (HSPs) have long been recognized. In this study we aimed to efficiently purify HSP70 from renal cell carcinoma and test it as a tumor antigen for pulsing dendritic cells in vitro. HSP70 was purified from renal cell carcinoma specimens by serial column chromatography on Con A-sepharose, PD-10, ADP-agarose and DEAE-cellulose, and finally subjected to fast protein liquid chromatography (FPLC). Dendritic cells derived from the adherent fraction of peripheral blood mononuclear cells were cultured in the presence of IL-4 and GM-CSF and exposed to tumor HSP70. After 24 hours, dendritic cells were phenotypically characterized by flow cytometry. T cells obtained from the non-adherent fraction of peripheral blood mononuclear cells were then co-cultured with HSP70-pulsed dendritic cells and after 3 days T cell cytotoxicity towards primary cultured renal cell carcinoma cells was examined by Cell Counting Kit-8 assay. Dendritic cells pulsed in vitro with tumor-derived HSP70 expressed higher levels of CD83, CD80, CD86 and HLA-DR maturation markers than those pulsed with tumor cell lysate and comparable to that of dendritic cells pulsed with tumor cell lysate plus TNF-${\alpha}$. Concomitantly, cytotoxic T-lymphocytes induced by HSP70-pulsed dendritic cells presented the highest cytotoxic activity. There were no significant differences when using homologous or autologous HSP70 as the tumor antigen. HSP70 can be efficiently purified by chromatography and induces in vitro dendritic cell maturation in the absence of TNF-${\alpha}$. Conspecific HSP70 may effectively be used as a tumor antigen to pulse dendritic cells in vitro.

Major Determinants and Long-Term Outcomes of Successful Balloon Dilatation for the Pediatric Patients with Isolated Native Valvular Pulmonary Stenosis: A 10-Year Institutional Experience

Meng-Luen Lee,Jui-Wen Peng,Guo-Jhueng Tu,San-Yi Chen,Jyong-You Lee,Shu-Lin Chang 연세대학교의과대학 2008 Yonsei medical journal Vol.49 No.3

Purpose: We report herein major determinants and long- term outcomes of balloon dilatation (BD) for 27 pediatric patients with isolated native valvular pulmonary stenosis (VPS). Materials and Methods: From May 1997 to May 2003, 27 pediatric patients with VPS (pressure gradients≧ 40mmHg) were enrolled in this retrospective study. Single- balloon maneuver was applied in 26 patients, and double- balloon maneuver in 1. After BD, the pressure gradients were documented simultaneously by pullback maneuver by cardiac catheterization and echocardiography within 24 hours, at 1- month, 3-month, 1-year, and 4-to-10-year follow-ups. Results: Before BD, the echocardiographic gradients ranged from 40 to 101mmHg (61±19, 55), and from 40 to 144mmHg (69 ±32, 60) by pressure recordings. After BD, the gradients ranged from 12 to 70mmHg (29±13, 27) by pressure recording (p<0.001), and from 11 to 64mmHg (27±12, 26) by echocardiography within 24 hrs (p<0.001). The ratios of the systolic pressure of the right ventricle to those of the left ventricle were 55 to 157% (89±28, 79%) before BD, and 30 to 79% (47±13, 42%) after BD (p<0.001). Follow-up (7.7±5.7, 4.5 years) echocardiographic gradients ranged from 11 to 61mmHg (25±11, 24). Two patients did not have immediate success owing to infundibular spasm. Improved right ventricular compliance could be accounted for the ultimate success in these 2 patients. The ultimate successful rate was 100%. Conclusion: BD can achieve excellent long-term outcomes in the pediatric patients with isolated native VPS.

One-Step Hydrothermal Synthesis of CoNi2S4 for Hybrid Supercapacitor Electrodes

Peng Liu,Yanwei Sui,Fuxiang Wei,Jiqiu Qi,Qingkun Meng,Yaojian Ren,Yezeng He 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

In this study, a simple one-step hydrothermal method was developed to prepare a novel hierarchical CoNi2S4 nanostructure similar to rambutan fruit. The surface microstructural study clearly visualized that the rambutan-like CoNi2S4 consists of nanorods grown directly on the surface of spherical core structures. The close attachment of the nanorods to the spheres increased the active areas of the electrode, which facilitates efficient charge transport from the nanorods to the spherical core structure. CoNi2S4 with a rambutan-like hierarchical structure showed an excellent specific capacitance of 944 F g -1 at 1 A g -1, considerable rate capacitance (75.6% retention at 10 Ag -1) and excellent cycling life (91.1% retention after 5000 circulations) in the three-electrode system. Besides, the assembled hybrid supercapacitor based on CoNi2S4 and reduced graphene oxide exhibited a high specific energy density of 23.58 Wh kg -1 at the power density of 800 W kg -1.

Inhibition of Bone Resorption by Econazole in Rat Osteoclast-like Cells through Suppressing TRPV5

Peng Yan,Tang Li,Meng Bo,Liu Die,Liang Xing 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.6

Osteoclasts are primary bone resorption cells and intervention in osteoclast activation is considered an effective therapeutic approach to treatment of bone diseases involving osteoclasts. TRPV5 was detected in osteoclasts and it has been thought to take part in the transportation of the degraded calcium in the resorption lacuna, which is essential for bone resorption. The aim of the present study was to examine the effects of a modulator of calcium dynamics, econazole, on the expression of TRPV5 and bone resorption activity in rat osteoclast-like cells (OLCs). OLCs were obtained by co-culturing rat bone marrow cells with osteoblasts and then culturing with different concentrations of econazole (0.01, 0.1, 1.0, 10.0 μmol/L). Cell counting and staining protocols were used to determine whether econazole influenced the survival of OLCs. Expression of TRPV5 in response to econazole treatment was assessed by western blotting. Bone resorption activity of OLCs was determined by measuring the resorption area of dentin slices with a microscope and a digital image analysis system. Additionally, Ca^2+ inside OLCs was tested. We found that econazole inhibited expression of TRPV5 in a dose dependent manner while it had no influence on the survival of OLCs and it therefore inhibited bone resorption activity in rat OLCs. Ca^2+ inside OLCs increased, suggesting a limited compensatory mechanism to make up for inhibition of TRPV5 effects.