1.Reversal of Drug Resistance in Human Ovarian Cancer Cell Lines by c-jun Antisense
Xiaoping GAO ; Weiyue HAN ; Zhongrong LIU ; Bogang LI
Chinese Journal of Cancer Biotherapy 1996;0(04):-
Objective: To investigate reversal of drug resistance in human ovarian cancer cells by c-jun antisense. Methods: A c-jun antisense was applied to treat resistant and sensitive A2780 cell lines, and to observe the expression levels of c-jun, ?-GCS and GSH in two cell lines. Results: c-jun antisense inhibit c-jun gene expression in resistance cell lines . The mRNA level of the key enzyme in GSH synthesis, ?-glutamyl cysteine synthetase, was also reduced. The GSH content in resistant cells was dropped about 75 % . MTT analysis show that the resistant cells IC_(50) to cisplatin was dropped from 40 ?mol/L to 1.0 ?mol/L after a c-jun antisense treatment. No significant effect was observed in senstive cells (0.2 ?mol/L). Conclusion: A c-jun antisense can inhibit its gene expression in cells, and GSH synthesis in resistant cell was also inhibited. The resistant cells could be reversed to the level of sensitive cells.
2.Recent developments of researches on calcium phosphate cements.
Journal of Biomedical Engineering 2009;26(1):202-205
The research of calcium phosphate cement (CPC) has been developing for more than 20 years. In this review, we present a brief introduction to recent advances in researches on apatite CPC, brushite CPC, composite CPC materials; on factors affecting CPC capability and application; and on new application of CPC. The view that emphasizes the significance of studies on CPC with quicker degradation and osteoblast activity is put forward, particularly.
Absorbable Implants
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Bone Cements
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chemistry
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therapeutic use
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Bone Substitutes
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chemistry
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therapeutic use
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Calcium Phosphates
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chemistry
;
therapeutic use
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Humans
3.Effects of collagen on the properties of TTCP/MCPM bone cement.
Journal of Biomedical Engineering 2010;27(2):328-331
Bone cement samples were made of tetracalcium phosphate (TTCP) and monocalcium phosphate monohydrate(MCPM) powder (Ca/P = 1.67) by using water and 5.24 mg/ml of self-made type I collagen sol as hardening liquid with the solid-liquid ratio of 3:1, their setting time and compressive strength were tested. The results showed that: the compressive strength of TTCP/MCPM bone cement containing collagen could increase from 17.8 +/- 1.9 MPa to 22.7 +/- 1.6 MPa, but its setting time hasn't been significantly affected; the compressive strength of both samples immersed in simulated body fluid (SBF) could increase, and the growth rate of the sample containing collagen increased especially; both samples immersed in SBF for 4d and 14d, whose compressive strength could increase to 31.8 +/- 3.9 MPa (collagen)/19.5 +/- 1.3 MPa and 38.1 +/- 3.1 MPa (collagen)/21.9 +/- 2.2 MPa. According to the IR analysis before and after the collagen was mineralized, it showed that: after the collagen was mineralized, the characteristic peaks of the collagen's amide I band showed red-shift, while the amide II band and the amide III band nearly disappeared, suggesting that chemical action occurred between the collagen and hydroxyapatite (HA), which should be the basis of the enhancement on the TTCP/MCPM bone cement caused by collagen; while according to the SEM and XRD patterns of the sample surface before and after the samples were immersed in SBF, it showed that: the immersion in SBF changed brushite (DCPD) into HA, at the same time, large number of new HA deposited, making the samples' surface more dense and smooth. It was not only the enhancement mechanism of immersion in SBF, but also showed the coagulating and hardening process of TTCP/MCPM bone cement was that: the DCPD was generated firstly, then it changed into HA.
Bone Cements
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chemistry
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Calcium Phosphates
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chemistry
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Collagen Type I
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chemistry
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Compressive Strength
4.Synthesis of phenyloxyisobutyric acid derivatives and their antidiabetic activity in vitro
Qingle ZENG ; Heqing WANG ; Huan LUO ; Xiaoping GAO ; Zhongrong LIU ; Bogang LI ; Fengpeng WANG ; Yufen ZHAO
Acta Pharmaceutica Sinica 2006;41(2):108-114
Aim To design and synthesize new phenyloxyisobutyric acid analogues as antidiabetic compounds. Methods Eight new target compounds were synthesized by combination of lipophilic moieties and acidic moiety with nucleophilic replacement or Mitsunobu condensation. The eight compounds were confirmed by 1H NMR, 13C NMR, IR and MS. Results In vitro insulin-sensitizing activity (3T3-L1adipocyte) demonstrated, that the cultured glucose concentration of up-clear solution detected with GODpioglitazone, compounds A and B were added to the insulin-resistant system. Conclusion In vitro insulin-sensitizing activity of target compound A is in between that of rosiglitazone and pioglitazone, and activity of target compound B is slightly less than that of pioglitazone.
5.Effects of the variation in components of DLC on protein adsorption.
Bogang LI ; Yunqing KANG ; Guangfu YIN ; Changqiong ZHENG
Journal of Biomedical Engineering 2004;21(2):193-195
Diamond-like carbon(DLC) was prepared by means of plasma source ion implantation-ion beam enhanced deposition. Through the heat treatment upon DLC in air and in depressed Ar gas, the DLC rich in graphite, DLC rich in diamond, and other kinds of DLC used in the study were obtained respectively. For the three kinds of DLC, the components of carbonaceous phase were analysed by X-ray photoelectron spectroscopy (XPS), the adsorptive amounts of human serum albumin (HSA), human serum fibrinogen (HFG) and human serum immunoglobin (IgG) on their surfaces in the condition of constant temperature were determined by radio isotope 125I labelling method. Results showed the graphite phase and diamond phase in DLC increased by two times or so respectively after the aforementioned different heat treatment. In pace with the increase of these foreign phases, the adsorptive amounts of HFG and IgG on DLC greatly increase but the adsorptive amounts of HSA on DLC decrease; furthermore, there is a change from non-selective adsorption of three human serum proteins into selective adsorptions of HFG and IgG prior to HSA. These results indicate that the foreign phases in DLC such as graphite, diamond, C-H phase and C-O phase have a great effect on protein adsorption on DLC and hence a negative effect on the hemocompatibility of DLC. The mechanisms for the increase of graphite phase and diamond phase in the process of heat treatment were also discussed in this paper.
Adsorption
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Biocompatible Materials
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chemistry
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Carbon
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chemistry
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Diamond
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chemistry
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Fibrinogen
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metabolism
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Humans
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Immunoglobulin G
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metabolism
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Proteins
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metabolism
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Serum Albumin
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metabolism
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Surface Properties
6.Effects of carbon phase components on platelets adhesion for diamond like carbon (DLC).
Bogang LI ; Jie YIN ; Guangfu YIN ; Juanjuan NA ; Changqiong ZHENG
Journal of Biomedical Engineering 2004;21(6):905-909
In the present paper, adhesive test, morphology observation, classified counting and deformation index calculation of the platelets on seven DLC samples made by different processes were carried out after XPS analysis, respectively. Then the effects of carbon phase components on amounts and deformation index of the platelets adhered to the samples were investigated by using the analysis of T-type correlation degree in the grey system theory. It has been shown from results that the amounts and the deformation index of the platelets adhered to the DLC samples made by plasma source ion implantation-ion beam enhanced deposition (PSII-IBED) are obviously less than those of DLC samples made by plasma CVD. The correlation degrees (negative) between the DLC carbon phase and the amounts as well as the deformation index of platelets are much more than those of the other four carbon phase components; besides, larger correlation degrees (positive) only appear between the deformation index of platelets and the C-H carbon phase or C-O carbon phase. It has been indicated that: (1) the effect of DLC carbon phase on platelets adhesion is much greater than that of the other four carbon phase components, the key to improvement in the hemocompatibility of DLC is to increase the DLC carbon phase content; (2) it is necessary to restrain the form or decrease the C-H carbon phase content and C-O carbon phase content so as to control their promotive action on deformation of the platelets adhered to the surface of DLC; (3) using PSII-IBED process to prepare DLC is helpful to improving the hemocompatibility of DLC. These conclusions are essential for designing and improving the deposition process of DLC.
Biocompatible Materials
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Carbon
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chemistry
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Diamond
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chemistry
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Humans
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Male
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Materials Testing
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Models, Biological
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Platelet Adhesiveness
7.Analysis of correlation degree between phase components and adsorptive amounts of serum proteins for DLC film.
Bogang LI ; Yunqing KANG ; Guangfu YIN ; Changqiong ZHENG
Journal of Biomedical Engineering 2004;21(4):549-553
In the present paper, the influence of carbon phase components of three kinds of diamond like carbon (DLC) films, viz. DLC, DLC rich in graphite and DLC rich in diamond films, on adsorption of human serum albumin (HSA), human serum fibrinogen (HFG) and immunoglobin (IgG) was quantitatively analyzed by use of T-type correlation degree in the grey system theory. Through the analysis, the rational explanation for adsorptive amounts variations of the serum proteins with phase components in the experiment is reached and some essential conclusions have been obtained: (1) The effect of graphite phase and C-H phase on HSA adsorption are greater than that of other phase components; with the increase of these two phase coumponents, the adsorptive amounts of HSA decrease; (2) The powerful influence on HFG adsorption stems from DLC phase and C-O phase; with the decrease of DLC phase or the increase of C-O phase, the adsorptive amounts of HFG increase; (3) All of the carbon phase components have only limited influence on IgG adsorption in positive or negative fashion with a little difference in degree; (4) DLC phase has both effects of enhancing adsorption for HSA and weakening adsorption for HFG and IgG, thus its influence on the hemocompatibility of DLC films is much more important than that of other phase components.
Adsorption
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Carbon
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chemistry
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Coated Materials, Biocompatible
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chemistry
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Diamond
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chemistry
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Humans
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Materials Testing
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Membranes, Artificial
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Serum Albumin
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chemistry
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Surface Properties
8.A feasibility study on use of surface and interface properties for evaluating hemocompatibility of carbonaceous biomaterials.
Bogang LI ; Anfu KANG ; Guangfua YIN ; Changqiong ZHENG
Journal of Biomedical Engineering 2005;22(3):452-455
In order to evaluate diamond like carbon film (DLC), DLC containing Si, graphite, diamond film (DF), low temperature isotropic carbon film (LTIC) and SiC, we investigated the correlations between surface energy parameters and hemocompatibility indices such as kinetic clotting time, hemolysis and platelet consumption. An analysis of T-type correlation degree in the Grey system theory was performed. The results showed: (1) all of correlation degrees between kinetic clotting time and polar surface energy parameters were positive, but for critical surface tension, the correlation degree was negative; among five of surface energy parameters, interface tension had the highest relation degree (0.63) with kinetic clotting time, and critical surface tension (-0.43) took the second place; (2) on the contrary, all of correlation degrees between hemolysis and polar surface energy parameters were negative, but for critical surface tension, the correlation degree was positive; and that which had closer correlations with hemolysis were still interface tension (-0.43) and critical surface tension (0.29); (3) critical surface tension had the highest relation degree (0.68) with platelet consumption, and surface tension (0.32) took the second place; (4) kinetic clotting time possessed higher negative correlation degrees with hemolysis (-0.57) and platelet consumption (-0.36). These data indicate that kinetic clotting time depended on a balance between the polarity of surface and the limited humidifying of water on the surface, and that platelet consumption was based on good humidification and power polarity of surface, while hemolysis was promoted by the aid of chromatic dispersion action stemming from the surface and fully humidifying of water on the surface. There was "seesaw effect" between kinetic clotting time and hemolysis or platelet consumption, hence the hemocompatibility of carbonaceous biomaterials could be equivalently evaluated by using kinetic clotting time as an index. It has been confirmed: (1) successive occurrences, including adhesion, deformation and collection of platelets on the material surfaces as results of protein adsorption, are the major mechanism of blood coagulation of carbonaceous materials; (2) the hemocompatibility of carbonaceous biomaterials can be evaluated by using critical surface tension as an index. These findings may underpin the hemocompatibility evaluation of carbonaceous biomaterials based on surface properties.
Adsorption
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Biocompatible Materials
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chemistry
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Blood Platelets
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cytology
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Carbon
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chemistry
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Diamond
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chemistry
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Feasibility Studies
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Graphite
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chemistry
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Hemolysis
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Platelet Adhesiveness
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Surface Properties
9.Study of the bone-like apatite's depositing induced by collagen I with its mechanism.
Jianglei TU ; Fuqiang GUO ; Chunchun LU ; Bogang LI
Journal of Biomedical Engineering 2011;28(1):99-103
The collagen I was made with the dialysis method of enzymolysising the pig skin, and the static deposition in vitro of calcium phosphate was comparative studied by X-ray diffraction (XRD) and infrared spectroscopy (FTIR) under the condition of pH7. 4, Ca/P 1.67 and whether adding the collagen I into the system. Then the chemical composition of the sedimentary product and the diversification of the collagen I 's IR and Raman spectra (RS) before and after the mineralization were analyzed. The results showed that,under the physiological pH condition that there was not any collagen I, though Ca/P reached up to 1.67, the sedimentary product was CaHPO4 x 2H2O yet, however, after adding collagen I into the system, the bone-like apatite was deposited, which proved that collagen I indeed had the effects on the inducing of the bone-like apatite's mineralization in vitro; there was obviously mutual coordination action between collagen I and its mineralization product--bone-like apatite, which caused that amide peak I red-shifted, amide peak II and amide peak III decreased significantly or disappeared on the IR of collagen I, which maybe was the mechanism that how collagen I induced the depositing of the bone-like apatite.
Animals
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Apatites
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metabolism
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Collagen Type I
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pharmacology
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Osteogenesis
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drug effects
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Skin
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chemistry
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Swine
10.Study on relationship between hemocompatibility and protein adsorption for DLC.
Bogang LI ; Guangfu YIN ; Yunqing KANG ; Changqiong ZHENG ; Xinting HE
Journal of Biomedical Engineering 2002;19(4):547-551
In this paper, the adsorption of human serum albumin(HSA), human serum fibrinogen (HFG) and human serum immunoglobin(IgG) on diamond like carbon film(DLC) has been studied in comparison with diamond film (DF) and graphite. The isothermal adsorption of the protein solution with single component and the competitive adsorption of binary protein system have been investigated by radio isotope 125I labelling method. Results showed that (1) the adsorptive amounts of three proteins on three material surfaces are all increased with the increasing concentration of protein solution, then the adsorption tends to reach an equilibrium; (2) the adsorptive amounts of three protein on graphite far exceed that on DLC and DF; (3) the adsorptive amounts of HSA on DLC are more than that on DF, while the adsorptive amounts of HFG and IgG on DF and graphite are apparently more than that on DLC; (4) the differences among the adsorptive amounts of three proteins on DLC are small, but adsorptive amounts of HFG and IgG on DF and graphite are much more than that of HSA; (5) the relative competitive adsorption ability of three proteins on DF and graphite is HFG > IgG > HSA, but on DLC, the sequence is HFG approximately HSA > IgG. Comparing with HSA, HFG has no apparent competitive adsorption superiority to DLC. These results indicate that there is no apparent difference for the adsorption of three human serum proteins on DLC, but the adsorption of HFG and IgG on DF and graphite takes precedence of various degrees. It probably makes a rational explanation for the result of hemocompatibility tests in vitro that DLC is superior to, DF and graphite.
Adsorption
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Biocompatible Materials
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chemistry
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Blood Proteins
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chemistry
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Diamond
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chemistry
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Fibrinogen
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chemistry
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Humans
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Immunoproteins
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chemistry
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In Vitro Techniques
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Materials Testing
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Membranes, Artificial
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Serum Albumin
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chemistry