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.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
3.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
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therapeutic use
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Humans
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.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
6.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
7.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
8.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
9.Energy mechanism of effects of carbon phase components on hemocompatibility for DLC.
Bogang LI ; Ming XUE ; Guangfu YIN ; Jie YIN ; Changqiong ZHENG
Journal of Biomedical Engineering 2005;22(2):235-237
The correlations between surface energy parameters and carbon phase components in six diamond like carbon film (DLC) samples made in different ways and processing conditions were further investigated using the analysis of T-type correlation degree in the Grey system theory based on our earlier studies such as the determination of carbon phase and surface energy parameters, the analyses of carbon phase components, surface energy parameters and adhesive characteristic of platelets for DLC. The results showed: (1) as a whole critical surface tension has the closest relation with carbon phase components, chromatic dispersion branch of surface tension takes the second place, but for the other four parameters, the correlation is weak; (2) DLC phase has larger negative correlation (degrees -0.57, -0.33) with critical surface tension and chromatic dispersion branch of surface tension, while its correlation degrees with the other four parameters related to polarity are all positive values smaller than 0.20; (3) C-H phase and C-O phase have larger positive correlation (degrees 0.48, 0.25) with critical surface tension. We have come to three conclusions (1) DLC phase plays a dominant part in hemocompatibilioty of DLC by powerfully decreasing humidification and limitedly increasing polarity; (2) the energy mechanism of platelet deformation enhanced by C-H phase and C-O phase involves increasing the critical surface tension of DLC; (3) the hemocompatibility of DLC can be evaluated by using the critical surface tension as index and using the content of DLC phase and additional content limitation of C-H phase and C-O phase as standard. This study has provided a theoretical basis for evaluating the hemocompatibility of DLC based on surface properties.
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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Humans
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Male
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Materials Testing
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Membranes, Artificial
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Models, Biological
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Platelet Adhesiveness
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drug effects
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Surface Properties
10.Analysis of Grey correlation between surface energy and adhesive characteristic of platelet for DLC.
Bogang LI ; Jie YIN ; Juanjuan NA ; Guangfu YIN ; Changqiong ZHENG
Journal of Biomedical Engineering 2005;22(1):20-24
In this study, the diamond like carbon (DLC) samples made from different processes and processing conditions, were subjected to the test of platelet adhesion. The surface energy parameters such as surface tension, critical surface tension, interface tension, adhesive power, and polar branch and chromatic dispersion branch of surface tension based on determining balanced contact angle of ethanol, water and different ratios of ethanol/water solution on surfaces of the samples were calculated, respectively. Then the effects of these parameters on the amounts and deformation index of the platelets adhering to the samples were assessed by analyzing the T-type correlation degree in the Grey system. The results showed: (1) all degrees of correlation between surface energy parameters and adhesion amounts of platelet are positive, but for deformation index, the correlation degrees are negative except for critical surface tension; (2) the adhesion amounts of platelet increase with the rising polar branch of surface tension, while the deformation index increases with rising chromatic dispersion branch of surface tension; (3) Both adhesion amounts and deformation index of platelet are positively correlated with critical surface tension to a higher degrees; (4) the effects of polar branch of surface tension on adhesion amounts and deformation index of platelet keep pace with the surface tension, interface tension and adhesive power. Thus two important conclusions have been obtained: (1) the adhesive characteristic of platelets to the surface of DLC is closely related with the surface energy of DLC; the hemocompatibility of DLC is decided by the balance between the polarity of DLC surface and the limited humidifying water on the surface; there is a blood compatible range delimited by critical surface tension; (2) adhesion and deformation of platelets on surface of DLC have different energy mechanism: polar surface is advantageous to the adhesion, while the deformation is achieved with the aid of chromatic dispersion action stem from the surface.
Biocompatible Materials
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chemistry
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Carbon
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chemistry
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Diamond
;
chemistry
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Humans
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Materials Testing
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Platelet Adhesiveness
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Surface Properties