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
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therapeutic use
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Humans
3.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.
4.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
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.Probe into the platelets adhesion to carbonaceous biomaterials.
Bogang LI ; Juanjuan NA ; Guangfu YIN ; Jie YIN ; Changqiong ZHENG
Journal of Biomedical Engineering 2004;21(1):12-15
In order to clarify the mechanism of blood coagulation for carbonaceous biomaterials, the plasma rich in platelet was obtaining through the centrifugation of fresh human blood containing anticoagulant. Adhesive tests of platelets to surfaces of DLC, diamond film(DF) and graphite was carried out at 37 degrees C. Then, morphology observation, counting and deformation index calculation of the platelets adhering to surfaces of the three kinds of materials were analyzed by SEM. It has been shown that there is no any platelet on the surface of DLC, but on DF and graphite, a lot of platelets are observed with serious deformation of type III-V. The adhesive amounts of platelet on the surface of graphite are more than those on DF, but deformation index of platelets on the surface of DF is more than that on graphite. Three major conclusions have been obtained through comparative analyses with our previous researches and related literatures: (1) Adhesion, deformation and collection of platelets occurred in succession on material surfaces resulting from protein adsorption are the major mechanism of blood coagulation of carbonaceous materials; (2) Deformation degree of platelets is more important hemocompatibility index than consumption ratio of platelets for carbonaceous materials; (3) The purer the DLC, the better is the hemocompatibility. These conclusions possess important directive function for improving and designing carbonaceous materials used in artificial mechanical heart valves.
Biocompatible Materials
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Blood Platelets
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pathology
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Carbon
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Diamond
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Graphite
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Humans
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In Vitro Techniques
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Materials Testing
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Platelet Adhesiveness
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Surface Properties
7.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
8.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
9.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
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chemistry
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Humans
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Materials Testing
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Platelet Adhesiveness
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Surface Properties
10.Analysis of FT-IR-ATR spectra of serum proteins adsorbed on carbonaceous materials.
Bogang LI ; Juanjuan NA ; Jie YIN ; Guangfu YIN
Journal of Biomedical Engineering 2006;23(5):1052-1055
To clarify the reason causing difference of serum proteins adsorbability on different carbonaceous materials, FT-IR-ATR spectra of human serum albumin (HSA) and human serum fibrinogen(HFG) before and after adsorbing on diamond like carbon film (DLC),diamond film (DF) and graphite were analyzed. It has been shown that there are hydrogen bond because of -NH at the interfaces of HSA-DLC, HFG-DF and HFG-graphite. Based on the results, earlier research conclusion that the adsorbability of HSA on DLC higher than that on DF and graphite, but on DF and graphite the adsorption of HFG takes precedence can be explained rationally.
Adsorption
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Blood Proteins
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metabolism
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Diamond
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chemistry
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Graphite
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chemistry
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Humans
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Hydrogen Bonding
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In Vitro Techniques
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Membranes, Artificial
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Spectroscopy, Near-Infrared