Objective To explore the effects of vinblastine on abcb4 tumor resistance gene expression in early development zebrafish and lay an important foundation for multi-drug resistant antineoplastic screening in zebrafish model.Methods Zebrafish embryos of 0.5~1.5 hours post-fertilization were exposured to different concentrations of vinblastine, and then calculated the IC50 of vinblastine.Zebrafish embryos of 0.5~1.5 hours post-fertilization were treated with different concentrations of vinblastine and embryo culture medium respectively, and then observed zebrafish embryo development in 24~120 hours post-fertilization and recorded the number of death, hatch and malformation.Evaluating the impact of vinblastine on abcb4 gene expression in zebrafish with quantitative real-time PCR and whole-mount in situ hybridization by collecting zebrafish embryos exposed to different concentrationsof vinblastine.Results Vinblastine IC50 in zebrafish embryos was 3.08 μmol/L.The mRNA level of abcb4 gene in vinblastine treated embryos was significantly increased compared to blank control group.Moreover, abcb4 gene positive hybridization signals were found in the small intestine of zebrafish embryos after 120 hours post-fertilization and also found in the brain and heart of zebrafish embryos by the method of whole-mount in situ hybridization.Conclusions Vinblastine can significantly increase the expression level of abcb4 tumor resistancegene in early development zebrafish embryos, which indicates that zebrafish can be used as a tumor resistant drug screening model.

Hydroxyethyl chitin (HECH) is a water soluble chitin derivative made by etherification of chitin, ethylene chlorohydrin was used as etherification reagent in this reaction. A novel interpenetrating polymer network (IPN) composed of HECH/PAA was prepared. The IR spectra confirmed that HECH/PAA was formed through chemical bond interaction. The sensitivity of this hydrogel to temperature and pH was studied. The swelling ratio of this hydrogel in artificial intestinal juice is much greater than that in artificial gastric juice. The IPN hydrogel exhibited a typical pH-sensitivity, and its degree of swelling ratio increased with the increase of temperature. The sustained-release drug system of Dichlofenac potassium was prepared by using HECH/PAA as the drug carrier. The release experiment showed a perfect release behavior in artificial intestinal juice. This IPN is expected to be used as a good drug delivery system of enteric medicine.
Acrylates ; administration & dosage ; chemistry ; Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; Chitin ; administration & dosage ; analogs & derivatives ; chemistry ; Delayed-Action Preparations ; Diclofenac ; administration & dosage ; Drug Carriers ; chemical synthesis ; Drug Delivery Systems ; Hydrogel, Polyethylene Glycol Dimethacrylate ; administration & dosage ; chemistry ; Hydrogen-Ion Concentration

Objective To investigate the effects of gefitinib on early embryonic development and expression of abcb4 tumor resistance genes in zebrafish.Methods Zebrafish were adopted as experimental animals and divided into gefitinib group,mixture of doxorubicin and gefitinib group and blank group.Zebrafish embryos of 0.5-1.5 hours after fertilization(0.5-1.5 hpf) were exposed to different concentrations of gefitinib,and then embryo development of zebrafish in 24-120 hpf was observed and the number of death,hatch and malformation was recorded.The embryo mortality was calculated under different concentrations of gefitinib at different time points,and the numerical value of IC50 was calculated;Hatching rates of zebrafish embryo in 48 hpf and 72 hpf and malformation rates of zebrafish embryo in 120 hpf were calculated.The zebrafish embryos exposed to different concentrations of gefitinib in different groups were collected,and the expressionof abcb4 gene in zebrafish embryos was detected by real-time quantitative PCR.Results Gefitinib IC50 in zebrafish embryos was 16.18 μmol/L.Compared with the control group,higher dosage (20 μmol/L) of gefitinib in other two groups significantly decreased hatching rates of embryos,and had obvious embryonic lethal effects and teratogenic effects.Moreover,the mRNA levels of the abcb4 gene in the zebrafish embryos of gefitinib group were not significantly changed,whereas the mRNA levels of the abcb4 gene in mixture of doxorubicin and gefitinib group were significantly different(P＜0.05).Conclusion Gefitinib has no significant effects on the expression of abcb4 tumor resistance gene in early development of zebrafish embryos(P＞0.05),but it can reverse the drug resistant effects of doxorubicin,suggesting that zebrafish can construct tumor resistance model.