1.Screening of the effective cellulose-degradable strain and its application in the production of cellulose bioethanol
Pengfei GAO ; Daidi FAN ; Pei MA ; Yane LUO ; Xiaoxuan MA ; Chenhui ZHU ; Junfeng HUI
Journal of Pharmaceutical Analysis 2009;21(3):184-188
Strains from the cellulose-containing environment were collected. Primary screening(by filter-paper Hutchison solid culture medium and sodium carboxymethylcellulose solid culture medium) and reelection(by filter-paper inorganic salt culture medium and sodium carboxymethylcellulosc Congo red coltnre medium) indicated that five strains obtained were best suited for high performance cellulose degradation. Determination of sodium carboxymethylcellulose activity(CMCA) and filter paper activity(FPA) was accomplished for each of the five. The strongest of the five in CMCA and FPA was applied to the production of cellulose bioethanol by separate hydrolysis and fermentation(SHF) and simultaneous saccharification and fermentation(SSF) respectively.
2.Optimization of Recombinant E. coli High-density Fermentation for Expressing Human-like CollagenⅡ
Haiyan CHANG ; Daidi FAN ; Yane LUO ; Xiaoxuan MA ; Yu MI ; Chenhui ZHU ; Lei CHI
Microbiology 1992;0(06):-
To study and optimize the fermentation parameters for expressing human-like collagenⅡduring E. coli high-density fermentation. The effects of pH, temperature, dissolved oxygen and induction instant on the cell growth and human-like collagenⅡproduction were investigated to optimize the fermentation conditions. The results demonstrated that the following conditions were beneficial for cell growth and foreign gene expression, controlling pH in phase induction at 6.8 and initial pH at 6.5, maintaining fermentation temperature and dissolved oxygen concentration was controlled at 34?C and 20% respectively, and implementing induction at the later logarithmic growth phase. Under the optimized condition, the cell density and human-like collagenⅡyield could reach 88.4 g/L and 14.2 g/L, respectively.
3.Anaerobic Biohydrogen Production Bacteria Selection and Its Optimization of Biohydrogen Fermentation Process
Shanshan LI ; Daidi FAN ; Xiaoxuan MA ; Yane LUO ; Yu MI ; Pei MA ; Chenhui ZHU ; Junfeng HUI
Microbiology 2008;0(09):-
This research adopted silt as the sample,and the five highest hydrogen production performing strains contained in the sample were isolated. The strain whose hydrogen production was the highest was identified as Enterobacter cloacae by the analysis of 16S rDNA sequencing and comparison. It is showed by Plackett-Burman Experimental Design that only glucose,citric buffer and reducing agent had significant effects on hydrogen production by Enterobacter cloacae FML-C1. The path of steepest ascent was undertaken to approach the optimal response region of those three factors. Central Composite Design(CCD) and Response Surface Methodology(RSM) were employed to investigate the interaction of the variables and to ascertain the optimal values of the factors,which finally led to the maximum hydrogen production(VH2) . The theoretical optimal medium conditions were:glucose 21.5 g/L,citric buffer 13.6 mL/L,reducing agent10.0 mL/L. The five tentative tests matched this model well. The final VH2 was up to 2347.4 mL/L,which was 127.42% enhanced in comparison to the original. The result shows that PB experiment design and RSM analytical method work well in selecting factors which have significant influences on the hydrogen production and,moreover,achieve the ideal optimal result.
4.Effects of rare ginsenoside on idiopathic pulmonary fibrosis
Lei YAO ; Linlin QU ; Daidi FAN
Journal of China Pharmaceutical University 2023;54(5):607-613
To investigate whether rare ginsenosides could alleviate idiopathic pulmonary fibrosis (IPF), C57BL/6 mice were randomly divided into control group, bleomycin (BLM)-induced IPF group, rare ginsenoside Rk1 group, rare ginsenoside Rk3 group, rare ginsenoside Rh4 group and rare ginsenoside Rg5 group.All mice except those in the control group were given bleomycin injection.The IPF model was established by BLM for 28 days.The treatment group was given ginsenoside intragastrically at the same time.After the experiment, the lung tissues of mice were collected and the pathological changes of the mice lungs were observed.The content of hydroxyproline (HYP) in mouse lung tissue was measured.The expression of IPF-related genes in mouse lung tissues was detected.In in vitro experiments, Medical Research Council cell strain-5 (MRC-5) was used to induce IPF cell model using transforming growth factor-β1 (10 ng/mL).The effects of four saponins on the expression of IPF-related genes were analyzed by MTT assay, HYP content determination and RT-qPCR.All four rare ginsenosides could effectively alleviate the pathological process such as alveolar structure destruction caused by IPF, reduce the content of HYP, and down-regulate the expression of IPF-related genes, indicating that rare ginsenosides can effectively alleviate IPF.
5.Preparation and properties of novel human-like collagen-silk fibroin scaffold for blood vessel.
Chenhui ZHU ; Daidi FAN ; Xiaoxuan MA ; Wenjiao XUE ; Junfeng HUI ; Lan CHEN ; Zhiguang DUAN ; Pu MA
Chinese Journal of Biotechnology 2009;25(8):1225-1233
In order to improve tensile property of vascular scaffold, we blended silk fibroin with novel human-like collagen with the mass ratio of 9:1, 7:3 and 5:5 (W/W), and then fabricated blood vessel tubular graft by freeze-drying process. We studied microstructure, mechanical properties, elements composites, degradability and biocompatibility of vascular scaffolds. These results showed that tubular scaffold with mass ratio 7:3 exhibited interconnected porous structure with pore size at (60 +/- 5) microm and porosity of 85%; achieved the desirable mechanical property (strain of 50% +/- 5% and stress of 332 +/- 16 kPa); had relatively slow degradation rate; could enhance cell adhesion and proliferation and had superior biocompatibility.
Biocompatible Materials
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chemistry
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Biomechanical Phenomena
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Blood Vessels
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physiology
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Collagen
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chemistry
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Fibroins
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chemistry
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Humans
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Materials Testing
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Porosity
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Tissue Engineering
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methods
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Tissue Scaffolds
6.Characterization and biocompatibility of human-like collagen-hyaluronic acid scaffold for blood vessel.
Xiujuan SUN ; Daidi FAN ; Chenhui ZHU ; Xiaoxuan MA ; Yane LUO ; Lan CHEN ; Jiaqing GUO
Chinese Journal of Biotechnology 2009;25(4):591-598
Human-like collagen (HLC) was cross-linked with hyaluronic acid by genipin in different ratio. The concentrations of hyaluronic acid in the mixture were 0, 0.01%, 0.05% and 0.1%. The blood vessel tubular grafts were then fabricated by freeze-drying. Microstructure, element composite, mechanical properties, cytotoxicity grade, and biocompatibility of different vascular scaffold groups were studied by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), tensile test, burst pressure experiment, cytotoxicity experiment, endothelial cells planted in blood vessel scaffolds and hypodermic embedding of mice. The results showed that HLC-HA (0.05%) tubular scaffold exhibited interconnected well-distributed and porous structure and porosity of 94.38%; achieved the desirable mechanical property with stress of (1000.8 +/- 7.9) kPa and burst pressure of (1058.6 +/- 8.2) kPa, hypocytotoxicity, favourable cytocompatibility, hisocompatibility and disposition of degradation.
Adhesives
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chemistry
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Animals
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Biocompatible Materials
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chemistry
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Biomimetic Materials
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chemistry
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Blood Vessels
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drug effects
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physiology
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Collagen
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chemistry
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Humans
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Hyaluronic Acid
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chemistry
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Iridoid Glycosides
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Iridoids
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chemistry
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Materials Testing
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Mice
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Tissue Engineering
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instrumentation
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methods
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Tissue Scaffolds
7.Heat-killed Lactobacillus murinus confers neuropro-tection against dopamine neuronal loss by targeting NLRP3 inflammasome
Daidi LI ; Hongxia FAN ; Feng ZHANG
Chinese Journal of Pharmacology and Toxicology 2023;37(7):521-522
OBJECTIVE In this study,the effects of live Lactobacillus murinus(L.m)and heat-killed L.muri-nus(H-k L.m)on DA neuronal damage in rats and the underlying mechanisms were investigated.METHODS Male SD rats were randomly divided into five groups:vehicle group,L.m/H-k L.m(1×109 cfu)group,6-OHDH group,6-OHDH + L.m/H-k L.m(1×107 cfu)group,and 6-OHDH + L.m/H-k L.m(1×109 cfu)group.Wild-type and NLRP3 knockout mice were divided into three groups:sham(vehicle),6-OHDH,and 6-OHDH + H-k L.m(1×109 cfu).The model was established after five weeks of pre-administration.Motor ability of experimental mice was assessed by rotarod,mine,and stepping experiments;the expression of dopaminergic neuron markers—tyro-sine hydroxylase(TH),microglial cell markers—ionized calnexin 1(IBA-1),and NOD-like receptor family protein 3(NLRP3)in the substantia nigra was detected by immunohistochemistry and immunofluorescence experi-ments.The expression changes of TH,IBA-1,NLRP3,apoptosis-associated microparticle protein(ASC),cas-pase 1,and inflammatory factors such as interleukin-1β(IL-1β),IL-18,and tumor necrosis factor-α(TNF-α)were detected by immunoblotting experiments.RESULTS H-k L.m ameliorated 6-OHDH-induced motor dysfunctions and loss of substantia nigra DA neurons,while no protec-tion was shown in live L.m treatment.At the same time,H-k L.m reduced the activation of NLRP3 inflammasome in microglia and the secretion of pro-inflammatory factors,thus inhibiting the development of neuroinflammation.Fur-thermore,H-k L.m failed to display its original neuropro-tective properties in NLRP3 inflammasome knockout mice.CONCLUSION H-k L.m conferred neuroprotec-tion against DA neuronal loss via the inhibition of microglial NLRP3 inflammasome activation,these findings provide a promising potential for future applications of L.m,and also beneficial strategy for PD treatment.
8.Ginsenoside Rk3 is a novel PI3K/AKT-targeting therapeutics agent that regulates autophagy and apoptosis in hepatocellular carcinoma
Linlin QU ; Yannan LIU ; Jianjun DENG ; Xiaoxuan MA ; Daidi FAN
Journal of Pharmaceutical Analysis 2023;13(5):463-482
Hepatocellular carcinoma(HCC)is the third leading cause of cancer death worldwide.Ginsenoside Rk3,an important and rare saponin in heat-treated ginseng,is generated from Rg1 and has a smaller mo-lecular weight.However,the anti-HCC efficacy and mechanisms of ginsenoside Rk3 have not yet been characterized.Here,we investigated the mechanism by which ginsenoside Rk3,a tetracyclic triterpenoid rare ginsenoside,inhibits the growth of HCC.We first explored the possible potential targets of Rk3 through network pharmacology.Both in vitro(HepG2 and HCC-LM3 cells)and in vivo(primary liver cancer mice and HCC-LM3 subcutaneous tumor-bearing mice)studies revealed that Rk3 significantly inhibits the proliferation of HCC.Meanwhile,Rk3 blocked the cell cycle in HCC at the G1 phase and induced autophagy and apoptosis in HCC.Further proteomics and siRNA experiments showed that Rk3 regulates the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)pathway to inhibit HCC growth,which was validated by molecular docking and surface plasmon resonance.In conclusion,we report the discovery that ginsenoside Rk3 binds to PI3K/AKT and promotes autophagy and apoptosis in HCC.Our data strongly support the translation of ginsenoside Rk3 into novel PI3K/AKT-targeting ther-apeutics for HCC treatment with low toxic side effects.
9.Industrial development and biomedical application prospect of recombinant collagen.
Rongzhan FU ; Daidi FAN ; Wanjuan YANG ; Liang CHEN ; Ci QU ; Shulin YANG ; Liming XU
Chinese Journal of Biotechnology 2022;38(9):3228-3242
Recombinant collagen, as an alternative to natural collagen, has the potential to be widely used in biomaterials, biomedicine, etc. Diverse recombinant collagens and their variants can be industrially produced in a variety of expression systems, which lays a foundation for exploring and expanding the clinical application of recombinant collagens. We reviewed different expression systems for recombinant collagens, such as prokaryotic expression systems, yeast expression systems, as well as plant, insect, mammal, and human cell expression systems, and introduced the advantages, potential applications, and limitations of recombinant collagen. In particularly, we focused on the current progress in the recombinant collagen production, including recombinant expression system construction and hydroxylation strategies of recombinant collagen, and summarized the current biomedical applications of recombinant collagen.
Animals
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Biocompatible Materials
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Collagen/biosynthesis*
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Humans
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Hydroxylation
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Recombinant Proteins/biosynthesis*
10.Production of gastric-mucosa protective collagen Ⅲ by Pichia pastoris.
Weina LI ; Zifang SHANG ; Zhiguang DUAN ; Linbo LI ; Jing HE ; Daidi FAN
Chinese Journal of Biotechnology 2017;33(4):672-682
To improve collagen production by recombinant Pichia pastoris, we applied Placket-Burman and Box-Behnken design to optimize the fermentation medium. Through Placket-Burman design, three variables in the medium (concentration of yeast extract, peptone and glycerol) were selected for having significant effect on cell dry weight. Through Box-Behnken design regression coefficients analysis, a secondary degree polynomial equation was established, and the optimum levels of the three variables were yeast extract 1.13%, peptone 1.61% and glycerol 0.86%. During the growth period, an average cell dry weight of 4.41 g/L was obtained after 12 h fermentation, increased by 26%. Through high density fermentation, the production of recombinant human collagen (Ⅲ) was up to 4.71 g/L in 22 L fermentor. The recombinant human collagen (Ⅲ) exhibited good results to repair acetic acid induced gastric ulcer in rats.