Synthesis, Phase Behavior, and Simulated In vitro Degradation of Novel HTPB-b-PEG Polyurethane Copolymers

Yan-Ling Luo,Yan Miao,Feng Xu 한국고분자학회 2011 Macromolecular Research Vol.19 No.12

Two types of polyurethanes with alternating and random block architectures, hydroxyl-terminated liquid polybutadiene and poly(ethylene glycol) block copolymers (HTPB-alt-PEG and HTPB-co-PEG), were synthesized using a coupling reaction route between the hydroxyl groups and the isocyanate groups. The chemical and crystal structures were characterized using Fourier transform-infrared spectroscopy (FTIR) and X-ray diffraction, while phase behavior was examined using scanning electron microscopy (SEM) and differential scanning calorimetry. The biodegradation in a simulated human body fluid was investigated through mass loss, SEM, and FTIR. The experimental results indicated that all of the polyurethane samples bore the microphase separation structure, and the separation degree depended on the sequence structure and molecular weight (MW) of PEG and further affected their in vitro degradation. The driving force was related to the restricted movement of the molecular segments, the crystallization of the soft/hard phases, and/or the hydrogen bonding interactions between the hard segments. The surface morphological change of the degraded samples further demonstrated that the degradation became serious as the PEG MW increased and that the random block copolymers decomposed more easily than the alternating copolymers. The block polymer materials are expected to be incorporated into specific applications in related biomedical fields.

Fabrication and Characterization of Copper Nanoparticles in PVA/PAAm IPNs and Swelling of the Resulting Nanocomposites

Yan-Ling Luo,Li-Li Chen,Feng Xu,Qiang-Suo Feng 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.5

Well-dispersed copper nanoparticles were fabricated using poly(vinyl alcohol)/polyacrylamide interpenetrating polymer networks (PVA/PAAm IPNs) as a nanoreactor template. The synthesis of the IPNs hydrogels was achieved in the presence of glutaraldehyde and N,N'-methylene-bis-acrylamide. The resulting PVA/PAAm/Cu nanocomposite hydrogels were characterized, and the swelling and mechanical properties were investigated. The results indicated that the copper nanoparticles had a spherical shape with a size range from 10 to 20 nm. The complexation of PVA in PVA/PAAm IPNs with Cu 2+played an important role in avoiding the aggregation of copper nanoparticles and providing particle size and size distribution controllability and stability. Although the swelling capacity of the nanocomposite hydrogels was slightly lower than that of the control, they had better compression mechanical properties. The water uptake and mechanical properties can be easily tuned by changing the component ratios to meet the requirements of specific applications, such as drug controlled release or tissue engineering.

Pretreatment Serum Amyloid A and C-reactive Protein Comparing with Epstein-Barr Virus DNA as Prognostic Indicators in Patients with Nasopharyngeal Carcinoma: A Prospective Study

Qiu-Yan Chen,Qing-Nan Tang,Lin-Quan Tang,Wen-Hui Chen,Shan-Shan Guo,Li-Ting Liu,Chao-Feng Li,Yang Li,Yu-Jing Liang,Xue-Song Sun,Ling Guo,Hao-Yuan Mo,Rui Sun,Dong-Hua Luo,Yu-Ying Fan,Yan He,Ming-Yuan C 대한암학회 2018 Cancer Research and Treatment Vol.50 No.3

Purpose The measuring Epstein-Barr virus (EBV) DNA is an important predictor of nasopharyngeal carcinoma (NPC). This study evaluated the predictive value of pretreatment serum amyloid A (SAA) and C-reactive protein (CRP) comparing with EBV DNA in patients with NPC. Materials and Methods In an observational study of 419 non-metastatic NPC patients, we prospectively evaluated the prognostic effects of pretreatment SAA, CRP, and EBV DNA on survival. The primary endpoint was progress-free survival (PFS). Results The median level of SAA and CRP was 4.28 mg/L and 1.88 mg/L, respectively. For the high- SAA group (> 4.28 mg/L) versus the low-SAA ( 4.28 mg/L) group and the high-CRP group (> 1.88 mg/L) versus the low-CRP ( 1.88 mg/L) group, the 5-year PFS was 64.5% versus 73.1% (p=0.013) and 65.2% versus 73.3% (p=0.064), respectively. EBV DNA detection showed a superior predictive result, the 5-year PFS in the EBV DNA  1,500 copies/mL group was obviously different than the EBV DNA < 1,500 copies/mL group (62.2% versus 77.8%, p < 0.001). Multifactorial Cox regression analysis confirmed that in the PFS, the independent prognostic factors were including EBV DNA (hazard ratio [HR], 1.788; p=0.009), tumour stage (HR, 1.903; p=0.021), and node stage (HR, 1.498; p=0.049), but the SAA and CRP were not included in the independent prognostic factors. Conclusion The results of SAA and CRP had a certain relationship with the prognosis of NPC, and the prognosis of patients with high level of SAA and CRP were poor. However, the predictive ability of SAA and CRP was lower than that of EBV DNA.

Combination of Tumor Volume and Epstein-Barr Virus DNA Improved Prognostic Stratification of Stage II Nasopharyngeal Carcinoma in the Intensity Modulated Radiotherapy Era: A Large-Scale Cohort Study

Qiu-Yan Chen,Shao-Yan Guo,Lin-Quan Tang,Tong-Yu Lu,Bo-Lin Chen,Qi-Yu Zhong,Meng-Sha Zou,Qing-Nan Tang,Wen-Hui Chen,Shan-Shan Guo,Li-Ting Liu,Yang Li,Ling Guo,Hao-Yuan Mo,Rui Sun,Dong-Hua Luo,Chong Zha 대한암학회 2018 Cancer Research and Treatment Vol.50 No.3

Purpose Little is known about combination of the circulating Epstein-Barr viral (EBV) DNA and tumor volume in prognosis of stage II nasopharyngeal carcinoma (NPC) patients in the intensity modulated radiotherapy (IMRT) era. We conducted this cohort study to evaluate the prognostic values of combining these two factors. Materials and Methods By Kaplan-Meier, we compare the differences of survival curves between 385 patients with different EBV DNA or tumor volume levels, or with the combination of two biomarkers mentioned above. Results Gross tumor volume of cervical lymph nodes (GTVnd, p < 0.001) and total tumor volume (GTVtotal, p < 0.001) were both closely related to pretreatment EBV DNA, while gross tumor volume of nasopharynx (GTVnx, p=0.047) was weakly related to EBV DNA. EBV DNA was significantly correlated with progress-free survival (PFS, p=0.005), locoregional-free survival (LRFS, p=0.039), and distant metastasis-free survival (DMFS, p=0.017), while GTVtotal, regardless of GTVnx and GTVnd, had a significant correlation with PFS and LRFS. The p-values of GTVtotal for PFS and LRFS were 0.008 and 0.001, respectively. According to GTVtotal and pretreatment EBV DNA level, patients were divided into a low-risk group (EBV DNA 0 copy/mL, GTVtotal < 30 cm3; EBV DNA 0 copy/mL, GTVtotal  30 cm3; or EBV DNA > 0 copy/mL, GTVtotal < 30 cm3) and a high-risk group (EBV DNA > 0 copy/mL, GTVtotal  30 cm3). When patients in the low-risk group were compared with those in the high-risk group, 3-year PFS (p=0.003), LRFS (p=0.010), and DMFS (p=0.031) rates were statistically significant. Conclusion Pretreatment plasma EBV DNA and tumor volume were both closely correlated with prognosis of stage II NPC patients in the IMRT era. Combination of EBV DNA and tumor volume can refine prognosis and indicate for clinical therapy.

Synthesis and Micellization of Thermosensitive PNIPAAm-b-PLA Amphiphilic Block Copolymers Based on a Bifunctional Initiator

Feng Xu,Yan-Ling Luo,Ting-Ting Yan 한국고분자학회 2011 Macromolecular Research Vol.19 No.12

The thermo-sensitive amphiphilic block copolymer poly(N-isopropylacrylamide)-block-poly(D,L-lactide)(PNIPAAm-b-PLA) was synthesized using a simple free radical copolymerization route based on a bifunctional initiator, 2,2-azobis(2-methylpropion amidine) dihydrochloride followed by the ring-opening polymerization of D,L-actide in the presence of a Sn(Oct)_2 catalyst. The chemical structure of the PNIPAAm-b-PLA copolymers was verified using Fourier transform-infrared spectrophotometry and nuclear magnetic resonance, and the molecular weight and polydispersity index were examined using gel permeation chromatography. The amphiphilic PNIPAAm-b-PLA block copolymers could self-assemble into spherically shaped micelles in an aqueous solution with a transmission electron microscopy diameter range of 40-56 nm and a dynamic laser scattering hydrodynamic diameter of 90-200 nm. This behavior depends on the environmental temperature, the hydrophobic interactions among PNIPAAm molecular chains, the intermolecular hydrogen bonding between the PNIPAAm chains and water molecules, and the intramolecular hydrogen bonding between the -CONH_2 groups. The copolymers held a critical micellization concentration of 4.93-7.21 mg·L^-1 and a low critical solution temperature of 31.15-32.62 ℃ being more or less affected by their compositions, PLA or PNIPAAm block length, and polymerization temperature. The as-prepared PNIPAAm-b-PLA block polymers are anticipated to be applied as candidate drug release carriers.

The investigation of pH threshold value on the corrosion of steel reinforcement in concrete

Qi Pu,Yan Yao,Ling Wang,Xingxiang Shi,Jingjing Luo,Yifei Xie 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.3

The aim of this study is to investigate the pH threshold value for the corrosion of steel reinforcement in concrete. A method was designed to attain the pH value of the pore solution on the location of the steel in concrete. Then the pH values of the pore solution on the location of steel in concrete were changed by exposing the samples to the environment (CO25%, RH 40%) to accelerate carbonation with different periods. Based on this, the pH threshold value for the corrosion of steel reinforcement had been examined by the methods of half-cell potential and electrochemical impedance spectra (EIS). The results have indicated that the pH threshold value for the initial corrosion of steel reinforcement in concrete was 11.21. However, in the carbonated concrete, agreement among whether steel corrosion was initiatory determined by the detection methods mentioned above could be found.

Redox-responsive PAEFc-b-PDMAEMA amphiphilic block copolymer self-assembly micelles: Physicochemical properties and anticancer drug controlled release

Yuan Wang,Yan-Ling Luo,Feng Xu,Ya-Shao Chen,Wei Tang 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.48 No.-

Ferrocene-containing amphiphilic block copolymers, poly(2-acryloyloxyethyl ferrocenecarboxylate)-block-poly(2-(dimethylamino) ethyl methacrylate) (PAEFc-b-PDMAEMA), were synthesized via sequen-tial ATRP, and self-assembled into globular nanoscaled micelle aggregates. The copolymer micellesexhibited reversible redox on-off switch feature, which was mediated by using H2O2, KMnO4, NaClO andFeCl3 as a model of oxidants and ascorbic acid as a model of reductants. The micelle nanoparticles wereused to load and deliver anticancer drug, 10-hydroxycamptothecine,finding that the encapsulated drugwas rapidly delivered by selectively responding to redox environments in cancer cells. MTT assays wereperformed to uncover cytotoxicity of the developed copolymer micelles and potentiality used for cancertherapy.

XRCC1 Polymorphisms are Associated with Cervical Cancer Risk and Response to Chemotherapy: a Systematic Review and Meta-analysis

Shuai, Han-Lin,Luo, Xin,Yan, Rui-Ling,Li, Jian,Chen, Dan-Liang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Background: Functional single nucleotide polymorphisms of x-ray repair cross-complementing protein 1 (XRCC1) have been suspected to contribute to uterine cervical cancer risk for a long time; however, most previous case-control studies were small sized and biased. Additionally, recent studies suggested that XRCC1 polymorphisms could be a biomarker of response to platinum-based chemotherapy. Methods: A comprehensive search was conducted to retrieve eligible studies and odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to measure association strength. Results: A total of 13 studies were identified and analyzed. We found that the Arg194Trp polymorphism (Trp vs. Arg, OR=1.342, 95% CI: 1.176) was associated with increased risk of cervical cancer, while no significant association was found with Arg280His (His vs. Arg, OR=1.059, 95% CI: 0.863, 1.299) or Arg399Gln (Gln vs. Arg, OR=1.144, 95% CI: 0.938, 1.394). As for response to platinum-based chemotherapy, the variant XRCC1 399Gln allele (Gln vs. Arg, OR=0.345, 95% CI: 0.163, 0.729) was linked with a poor response; however, the Arg194Trp polymorphism (TrpArg vs. ArgArg, OR=6.421, 95% CI: 1.573, 26.205) predicted a good response. Conclusion: The Arg194Trp polymorphism of XRCC1 increases risk of cervical cancer; the variant 399Gln allele predicts poor response to platinum-based chemotherapy, while the Arg194Trp polymorphism indicates a good response.

Listeria monocytogenes Serovar 4a is a Possible Evolutionary Intermediate Between L. monocytogenes Serovars 1/2a and 4b and L. innocua

Jian Shun Chen,Ling Li Jiang,Xue Yan Chen,Xiao Kai Luo,Yang Chen,Ying Yu,Guo Ming Tian,Dong You Liu,Wei Huan Fang 한국미생물 · 생명공학회 2009 Journal of microbiology and biotechnology Vol.19 No.3

Tri-stimuli responsive carbon nanotubes covered by mesoporous silica graft copolymer multifunctional materials for intracellular drug delivery

Rui-Qian Zhang,Zhan-Qing Liu,Yan-Ling Luo,Feng Xu,Ya-Shao Chen 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-

To overcome premature drug leakage and instability in drug delivery systems, we designed tri-stimuliresponsive multiwalled carbon nanotubes covered by mesoporous silica graft poly(N-isopropylacryla-mide-block-poly(2-(4-formylbenzoyloxy) ethyl methacrylate) multifunctional materials via disulfidelinkages (MWCNTs@MSN-s-s-g-PNIPAM-b-PFBEMA). The multifunctional materials could covalentlybind and physically load anticancer drug doxorubicin (DOX), and exhibited pH-, temperature- andreductant-induced multi-stimuli responsiveness, significantly enhancing drug loading capacity andimproving the release dynamics of drug. The DOX-loaded multifunctional materials exhibited theoptimal release behavior in cancer environments compared with in normal cells upon simultaneouslytriggered by these stimuli. It meant that the MWCNTs@MSN-s-s-g-PNIPAM-b-PFBEMA could serve asefficient gatekeepers to control the mesopore on–off and thus to modulate drug release. Themultifunctional materials were proved to be low toxic, whereas the DOX-loaded counterparts had almostthe same toxicity as free DOX to cancer cells. Therefore, the developed multifunctional materials can beused as promising drug controlled delivery platforms for cancer therapy.