The Effect of Curcumin on Breast Cancer Cells

Dongwu Liu,Zhiwei Chen 한국유방암학회 2013 Journal of breast cancer Vol.16 No.2

Curcumin, which is extracted from the plant Curcuma longa, has been used in the therapeutic arsenal for clinical oncology. Curcumin has chemopreventive and antitumoral activities against some aggressive and recurrent cancers. The expressions and activities of various proteins, such as inflammatory cytokines and enzymes, transcription factors, and gene-products linked with cell survivals and proliferation, can be modified by curcumin. Moreover, curcumin decreases the toxic effect of mitomycin C. Though curcumin has shown highly cytotoxic to some cancer cell lines, curcumin is insoluble and instable in water. The solubility of curcumin could be enhanced by utilizing the solubilizing properties of rubusoside. In addition, the selective delivery of synthetic analogs or nanotechnology-based formulations of curcumin to tumors may improve the chemopreventive and chemotherapeutic effects. The focus of this short review is to describe how curcumin participates in antitumor processes in breast cancer cells.

Winding strategy of driving cable based on dynamic analysis of deployment for deployable antennas

Yiqun Zhang,Dongwu Yang,Zihan Sun,Na Li,Jianghua Du 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.11

An optimization method for the winding strategy of the driving cable is proposed based on a dynamic analysis of the AstroMesh antenna deployment. First, considering the effects of the cable net and friction, the driving force for deployment is deduced according to energy conservation. Thereafter, an optimization model is constructed, with the objective of minimum deployment driving power, using design variables consisting of control parameters of the winding length curve of the driving cable; this curve is described by the Bezier curve. Moreover, corresponding to the winding process of the driving cable before and after optimization, deployment experiments for a 2-m aperture deployable antenna prototype are conducted. Finally, the validity and rationality of the optimization method are verified by comparing the simulation and experimental results.

확장 용이한 블록 조립식 전동 모빌리티 초경량 탄소복합재 샤시플랫폼 연구

윤희승(Huiseung Yun),서동우(dongwu seo),강재영(jaeyoung Kang),안창섭(changseop AN),공도현(Dohyun Kong) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5

Synergistic Inhibitory Effect of Berberine and d-Limonene on Human Gastric Carcinoma Cell Line MGC803

Xiu-Zhen Zhang,Ling Wang,Dongwu Liu,Guang-Yan Tang,Hongyu Zhang 한국식품영양과학회 2014 Journal of medicinal food Vol.17 No.9

This study aims at evaluating the anticancer effects of berberine hydrochloride (berberine) and d-limonene, alone and in combination, on human gastric carcinoma cell line MGC803 to determine whether berberine and d-limonene work synergistically and elucidate their mechanisms. MGC803 cells were treated with berberine and d-limonene, alone and in combination, for 24–48 h. The inhibitory effects of these drugs on growth were determined by MTT assay. The combination index and drug reduction index were calculated with the Chou–Talalay method based on the median-effect principle. Flow cytometry and laser scanning confocal microscopy were employed to evaluate the effects of both drugs on cell-cycle perturbation and apoptosis, generation of reactive oxygen species (ROS), mitochondrial membrane potential, and expression of Bcl-2 and caspase-3 in MGC803 cells. Berberine or d-limonene alone can inhibit the growth of MGC803 cells in a doseand time-dependent manner. Berberine and d-limonene at a combination ratio of 1:4 exhibited a synergistic effect on anti-MGC803 cells. The two drugs distinctly induced intracellular ROS generation, reduced the mitochondrial transmembrane potential (DCm), enhanced the expression of caspase-3, and decreased the expression of Bcl-2. The combination of berberine and d-limonene showed more remarkable effects compared with drugs used singly in MGC803 cells. The combination of berberine and d-limonene exerted synergistic anticancer effects on MGC803 cells by cell-cycle arrest, ROS production, and apoptosis induction through the mitochondria-mediated intrinsic pathway.

Global sensitivity analysis for cablenetwork antennas by Kriging models with a sensitivity-based accuracy indicator

Naigang Hu,Yiqun Zhang,Guigeng Yang,Dongwu Yang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.8

Various uncertainties existing in the manufacturing process, such as imperfect cable lengths and uncertain boundary node locations, will unavoidably deteriorate the shape precision of cable-network antennas. In this paper, an adaptive Kriging-based method is developed to investigate the global sensitivity of uncertain parameters and discover the influential factors. Existing strategies in literature usually use relative error of function values to measure the metamodel accuracy and then to determine when the sequential sampling process should be stopped. However, these indicators are mostly developed based on function values, not the sensitivity indices. Therefore, it is difficult to determine how small the indicators should be for efficiently defining an accurate metamodel for sensitivity analysis. In this paper, a straightforward sensitivity-based indicator is developed to measure the metamodel accuracy, which is defined as the weighted average of absolute errors of sensitivity values between two successive iterations. A use-controlled threshold, combined with the new indicator, can provide an automatic stopping criterion for the adaptive metamodel building process. The proposed method can provide a uniform framework to detect the convergence status effectively for problems with different uncertainties and dimensions. A numerical example and two cable-network antenna examples considering different manufacturing uncertainties are illustrated to validate the new method.

Polydopamine (PDA) coatings with endothelial vascular growth factor (VEGF) immobilization inhibiting neointimal formation post zinc (Zn) wire implantation in rat aortas

Jiayin Fu,Qiongjun Zhu,Zhezhe Chen,Jing Zhao,Shaofei Wu,Meng Zhao,Shihui Xu,Dongwu Lai,Guosheng Fu,Wenbin Zhang 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Bioresorbable stents are designed to provide temporary mechanical support to the coronary arteries and then slowly degrade in vivo to avoid chronic inflammation. Zinc (Zn) is a promising material for bioresorbable stents; However, it can cause inflammation and neointimal formation after being implanted into blood vessels. Methods To improve biocompatibility of Zn, we first coated it with polydopamine (PDA), followed by immobilization of endothelial vascular growth factor (VEGF) onto the PDA coatings. Adhesion, proliferation, and phenotype maintenance of endothelial cells (ECs) on the coated Zn were evaluated in vitro. Then, a wire aortic implantation model in rats mimicking endovascular stent implantation in humans was used to assess vascular responses to the coated Zn wires in vivo. Thrombosis in aortas post Zn wire implantation, degradation of Zn wires in vivo, neointimal formation surrounding Zn wires, and macrophage infiltration and extracellular matrix (ECM) remodeling in the neointimas were examined. Results In vitro data showed that the PDA-coated Zn encouraged EC adhesion, spreading, proliferation, and phenotype maintenance on its surfaces. VEGF functionalization on PDA coatings further enhanced the biocompatibility of Zn to ECs. Implantation of PDA-coated Zn wires into rat aortas didn’t cause thrombosis and showed a faster blood flow than pure Zn or the Zn wires coated with VEGF alone. In addition, the PDA coating didn’t affect the degradation of Zn wires in vivo. Besides, the PDA-coated Zn wires reduced neointimal formation, increased EC coverage, decreased macrophage infiltration, and declined aggrecan accumulation in ECM. VEGF immobilization onto PDA coatings didn’t cause thrombosis and affect Zn degradation in vivo as well, and further increased the endothelization percentage as compared to PDA coating alone, thus resulting in thinner neointimas. Conclusion These results indicate that PDA coatings with VEGF immobilization would be a promising approach to functionalize Zn surfaces to increase biocompatibility, reduce inflammation, and inhibit neointimal formation after Zn implantation in vivo.