Most of the anticancer drugs have some limitations in clinical application,such as poor solubility,low targeting and cytotoxicity to normal tissue and organ.The application of drug carriers offers a solution of these problems to a certain extent.In recent years,some materials such as polymers,liposomes,carbon nanotubes (CNTs) were used as carriers of anticancer drugs.The utilization of these carriers improved drug targeting and reduced adverse reactions by targeted modification of carriers which ensured the slow release of the drugs and maintained the plasma concentration.In these carriers,CNTs,as a novel nano-material,have attracted more attention in nanomedical applications.CNTs not only possess nanoscaled diameter,hollow structure and large aspect ratio,resulting in large drug capacity,but also can selectively absorb near infrared lights and transform them into thermal energy,according to the research finding.The functionalized drug-loaded CNTs in combination with thermotherapy shows potential,which is expected to become a new targeting therapy of cancer.In this paper,the basic structure of CNTs,the application of CNTs as drug carriers,and the recent development of functionalized CNTs as drug carriers combined with thermotherapy in tumor therapy were summarized.

Background: SEPT9 gene methylation is a specific biomarker of colorectal cancer, and its peripheral blood expression level can assess the risk of colorectal cancer. Aims: To investigate the clinical significance of detection of peripheral blood SEPT9 gene methylation and glycoprotein tumor markers in the diagnosis of colorectal cancer. Methods: A total of 57 normal controls, 61 colorectal adenoma and 71 colorectal cancer patients from Dec. 2016 to Apr. 2017 at the First Affiliated Hospital of Soochow University were enrolled. The peripheral blood SEPT9 gene methylation was detected by PCR fluorescence probe method, and levels of tumor markers CEA, CA125, CA19-9, CA72-4 and CA211 were determined. ROC curve was used to analyze the diagnostic value of above-mentioned indices for colorectal cancer. Logistic regression equation was established and used to evaluate the diagnostic value of SEPT9 gene combined with CEA. Results: The positivity rates of SEPT9 gene methylation in normal control group, adenoma group and colorectal cancer group were 0, 6.6% and 52.1%, respectively. CEA level in colorectal cancer group was significantly higher than that in normal control group and adenoma group (P<0.05). ROC curve analysis showed that AUC of SEPT9, CEA, combination of the two indicators for the diagnosis of colorectal cancer were 0.817, 0.707 and 0.793, respectively. Logistic regression analysis showed that the OR of SEPT9 and CEA for the diagnosis of colorectal cancer were 1.394 (1.198-1.762) and 1.325 (0.997-1.622), respectively. Conclusions: The positivity rate of peripheral blood SEPT9 gene methylation is significantly increased with the progress of disease, and the diagnostic value for colorectal cancer is high. The combination of peripheral blood SEPT9 gene methylation and CEA is helpful for improving the early screening rate of colorectal cancer.

Objective To prepare stable aqueous dispersions of chitosan/multi-walled carbon nanotubes (CS/MWCNTs) composites,and observe the effects of CS/MWCNTs on the growth of human umbilical vein endothelial cells (HUVEC).Methods CS/MWCNTs composites were prepared by electrostatic interactions between negatively charged MWCNTs and positively charged low-molecular-weight CS.The prepared CS/MWCNTs were characterized by transmission electron microscopy and Zetasizer nano-analyser.The cellular uptake of the fluorescently labeled CS/MWCNTs was observed by laser confocal microscopy after incubating with HUVEC for 24 h at different concentrations.In vitro cytotoxicity and cellular reactive oxygen were also detected.Results When the mass ratio of low-molecular-weight CS to MWCNTs was equal or greater than 10∶1,the CS/MWCNTs can be stabilized in solution.Cellular uptake experiments showed that the CS/MWCNTs could enter into the cells and locate mainly in the cytoplasm.Cytotoxicity study showed that the CS/MWCNTs composites was less toxic than MWCNTs alone at high concentration (10 and 20 μg/ml).However,there was no significant differencein the level of cellular reactive oxygen between the two groups (P＜0.05).Conclusions CS/MWCNTs composites showed low cytotoxicity and high stability,which would be a promising carrier for drug delivery.

Objective:To compare the difference and correlation of HPLC and enzyme-multiplied immunoassay test( EMIT) for the determination of CsA in human whole blood. Methods:A total of 119 clinical samples at different concentrations of CsA were collected and respectively determined by HPLC and EMIT. The difference and correlation of the two determination methods were investigated. Results:There was significant difference in the blood concentrations of CsA determined by HPLC and EMIT(P<0. 05). CsA concen-tration determined by EMIT was 26. 2 ng·ml-1 higher than that determined by HPLC, and 95% CI was (14. 6-37. 7) ng·ml-1 . A satisfactory correlation was achieved between the two methods(r=0. 997 4). Conclusion:There is statistically significant difference in the CsA concentration in whole blood respectively determined by EMIT and HPLC. Attention should be paid to CsA monitoring by E-MIT and HPLC, and relevant adjustment should be carried out.

Objective To evaluate the role of spinal dopamine D2 receptors in a rat model of neuropathic pain.Methods Thirty healthy male Sprague-Dawley rats,aged 6-8 weeks,weighing 180-200 g,wcre randomly divided into 5 groups (n =6 each) using a random number table:control group (group C),sham operation group (group S),neuropathic pain group (group NP),normal saline group (group N) and dopamine D2 receptor agonist quinpirole group (group Q).Neuropathic pain was produced by chronic constriction injury of the sciatic nerve (CCI) in rats anesthetized with intraperitoneal 2％ pentobarbital sodium 40 mg/kg.At 7 days after CCI,normal saline 10 μl was injected intrathecally over 30 s in group N,and quinpirole 10 μg (in 10 μl of normal saline) was injected intrathecally over 30 s in group Q.At 1 day before CCI,3 and 7 days aher CCI,and 30 min and 1,2,4,8 and 16 h after administration,mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured.Results There was no significant difference in MWT and TWL at each time point between group C and group S.MWT was significantly lower,and TWL was shorter at T1-8 in NP,N and Q groups than in C and S groups.Compared with group N,no significant change was found in MWT and TWL at each time point in N group,and MWT was significantly increased,and TWL was prolonged at T4-6 in group Q.Conclusion Inhibited function of spinal dopamine D2 receptors is involved in the maintenance of neuropathic pain in rats.

ObjectiveTo isolate and identify endothelial progenitor cells (EPCs) from human umbilical cord,and to study the cell proliferation and gene transfection of green fluorescent protein plasmid in vitro.MethodsEPCs were isolated from human umbilical cord in enzyme digestion method.The biological characteristics of EPCs were identified by flow cytometry and laser confocal microscope.The enhanced green fluorescent protein (EGFP) gene transfection mediated by EPCs was investigated using Lipofectamine 2000 as transfection reagent.ResultsEndothelial progenitor cells isolated from umbilical cord formed typical endothelial cell colony 9 days later.These cellsdisplayed an improved positive expression of CD133 and kinase insert domain receptor (KDR).The endotheliallineage characteristics of expanded cells were confirmed by fluorescein isothiocyanate (FITC)-UEA-1 binding and DiI-ac-LDL uptake assay with the aid of laser confocal microscope.The transfection results demonstrated high expression of EGFP taking EPCs as host cell.ConclusionEndothelial progenitor cells isolated from umbilical cord can be propagated and induced to differentiate into endothelial cells in the appropriate culture conditions.EPCs demonstrated to be an ideal carrier for gene and cell therapy.

ObjectiveConjugation of fluorescent dye onto plasmid DNA was investigated in order to monitor delivery process of plasmid DNA.MethodsPlasmid was activated with bromine,stored for different timeintervals at 4 ℃ or room temperature,and subsequently coupled with 1,10-diaminodecane to prepare aminemodified plasmid DNA.Amine-modified plasmid was then reacted with isothiocyanate (FITC) for fluorescent labeling,and the labeling ratio was calculated after purification.The effect of storage conditions (time/temperature) of bromine-actived plasmid (BP) on fluorescent labeling efficacy was estimated,and the cell transfection efficiency of fluorescent plasmid-lipofectamine complex was observed.The fluorescent plasmid delivered by lipofectamine 2000 in A10 cells was observed by laser scanning confocal microscope (LSCM) and flow cytometry.ResultsThe experimental data showed that prolonged storage time of bromine-activated DNA had a negative effect on the labeling ratio,and lower storage temperature had a positive effect on the labeling ratio.It also demonstrated that FITC modification had no effect on the transfection efficiency of plasmid-lipofectamine complex as compared with that of unlabeled plasmid-lipofectamine complex,and FITC modified plasmid had enough fluorescent intensity to monitor cell uptake with flow cytometer and sub-cellular distribution with LSCM.ConclusionA facile method for conjugating fluorescent dye onto plasmid was established in the study,and could be utilized to trace the plasmid delivery for investigating the transfection mechanism.

Objective To investigate the impact of chitosan and alkylated chitosan DNA nanoparticles on the function of human naive CD4+T cells.Methods The secretion of cytokines (IL-4 and TNF-γ) was observed after the co-incubation of human naive CD4+T cells with nanoparticles 12 h,24 h and 48 h,respectively.ResultsNone of the nanoparticles induced the production of cytokines ( IL-4 and TNF-γ ).Conclusion Chitosan and alkylated chitosan DNA nanoparticles will not induce the differentiation of human naive CD4+ T cells into T1 or T2 and may be considered as a safe gene carrier.

Objective To generate recombinant Pichia pastoris for high-copy expression of human tissue factor pathway inhibitor (TFPI). Methods The cDNA encoding human TFPI was inserted into the expression vector pPIC9K and the constructed expression vector rhTFPI-pPIC9K was confirmed by restriction endonuclease analysis and DNA sequencing. The recombinant plasmids were subsequently transformed into Pichia pastoris GS115 cells, and the transformants were confirmed by PCR amplification of the genomic DNA.The recombinant Pichia pastoris with high copies of TFPI cDNA was screened by G418 selection. Western blot and TFPI ELISA Kit were employed to analyzing. The temperature, time and concentration of methanol for the induction of recombinant protein were optimized. Results PCR analysis and DNA sequencing confirmed the successful construction of the expression vector rhTFPI-pPIC9K. Real time quantitative PCR and Western blot analysis demonstrated the positive correlation between TFPI expression level and the copy number of TFPI cDNA in Pichia pastoris cells. Optimization of the induction condition significantly elevated the expression level and activity of TFPI (9.95±0.78 mg/L and 3.91±1.37 U/mL). Conclusion The Pichia pastoris strain with high copy of TFPI expression was successfully constructed, which lays a solid foundation for the further investigation on the function of TFPI and its application in the prevention and therapy of diseases.

Studies have found that depression is closely related to the hyperactivity of the hypothalamo–pituitary–adrenal (HPA) axis, which is manifested in increases in HPA axis-related hormones CRH, ACTH and CORT contents. Traditional Chinese medical acupuncture can down-regulate HPA axis levels to produce a marked antidepressant effect. However, at present there is no HPA axis mechanism analysis of the antidepressant effect of acupuncture. From two aspects: the relationship between depression and HPA axis, and clinical and animal mechanism studies of the antidepressant effect of acupuncture by regulating the HPA axis, an analysis has been made to provide a more powerful scientific basis and the idea of further in-depth study for clinical acupuncture treatment of depression.