Synthesis and biocompatibility of ethynylated open ring derivatives of polyasparamide / 中国生化药物杂志

Objective To synthesize a new ethynylated open ring derivatives of polyasparamide as functional drug carrier.Methods L-phenylalanine methyl ester hydrochloride was prepared using L-phenylalanine and then was used for ring opening reaction of polysuccinimide.To synthesize the target product of PSI-Phe-OMe-PA, the obtained polyasparamide-g-phenylalanine derivatives ( PSI-Phe-OMe) was further ring opened by propargylamine.The structure of PSI-Phe-OMe-PA was confirmed by 1 H NMR.The biocompatibility of PSI-Phe-OMe-PA was evaluated by MTT method, inverted microscope observation and cell cycles analysis ( propidium iodide staining ) .Results The ring-opening rate of polyasparamide by L-phenylalanine methyl ester and propargylamine was 40%and 100%, respectively.All results of biocompatibility studies indicated that PSI-Phe-OMe-PA may be a good candidate for functional drug carrier.Conclusion Based on the ring-opening capability of amino-group and the specificity of click reaction, L-phenylalanine methyl ester hydrochloride and propargylamine were used successively to react with polyasparamide.PSI-Phe-OMe-PA is a biocompatible functional drug carrier.

Application of multimodal imaging in stem cell research / 中华核医学与分子影像杂志

In recent years,stem cell research has been developing quickly in biological science.As the key of regenerative medicine,stem cell therapy becomes another innovative treatment following drug therapy and surgery.In vivo stem cell tracking,including optical imaging,radionuclide imaging and MRI,can trace the viability,distribution and function of engrafted cells.Multimodal imaging integrates two or more types of imaging techniques to obtain the combined advantages of each technology,and therefore is able to accurately and effectively trace stem cell in vivo,hopefully promoting its clinical transformation.This paper reviews the application of multimodal imaging in stem cell research.

The Effect of Amino Acid Configuration on the Biodistribution of Peptide Nanofiber / 天津医药

Objective To compare the biodistribution difference of peptide nanofibers, which were self-assembled by peptide composed of L-or D-amino acids, respectively, and provide the guidance for the in vivo applications of peptide nanofibers. Methods The Nap-GFFYGRGD (L-peptide) and Nap-GDFDFDYGRGD (D-peptide, F and Y were D-configura-tion) were synthesized with solid phase peptide synthesis (SPPS). The structure of the two peptides was identified by nuclear magnetic resonance spectroscopy (1H NMR) and high-resolution mass spectrometry (HR-MS). The two peptides could self-assemble into nanofibers during the cooling process after being boiled. The morphology of the nanofibers was observed with transmission electron microscope (TEM). The peptides were radiolabeled with iodine-125 and self-assembled into nanofi-bers, which were then administered into BALB/c mice via tail vein. The blood samples were collected and then mice were sacrificed at 1, 3, 6 and 12 hours. The main organs (heart, liver, spleen, lung, kidney, stomach, large intestine, small intes-tine, muscle and brain) were isolated and weighed. The radioactivity of organs was detected with a gamma counter. Results The two peptides could self-assemble into nanofibers with diameter of 10-20 nanometers. There were no significant differ-ences in the diameter and morphology between two naofibers. There was significant difference in the biodistribution between two nanofibers. The blood concentration of D-fiber was (8.17±0.32)%ID/g at one hour after injection and then cleared rapid-ly from the blood. The blood concentration of L-fiber was (5.96±0.30)%ID/g at one hour after injection and maintained at a stable level for six hours. The L-fiber was mainly distributed in stomach while the D-fiber was mainly accumulated in liver. Conclusion The configuration of amino acids (D/L) could affect the biodistribution of peptide nanofibers dramatically, which may provide the guidance for the medical applications of peptide nanofibers.

Advanced research on prostate cancer stem cell-related tumor markers / 中国肿瘤临床

Prostate cancer is one of the most common malignant tumors in males. Endocrine therapy is currently the main treatment for patients with advanced prostate cancer. Although this therapy frequently results in tumor shrinkage, it is not curative, and the majority of patients eventually develop hormone-refractory prostate cancer. Recent studies suggested that prostate cancer stem cells serve a key function in the occurrence, development, and metastasis of prostate cancer. Therefore, targeted therapy of prostate cancer stem cells may be effective for the treatment of prostate cancer. Prostate cancer stem cell markers must be identified to facilitate studies on prostate cancer radical treatment schemes, especially the specific markers of this disease. Previous research on prostate cancer stem cell markers mainly focus on CD44 and CD133. Along with in-depth studies, a substantial number of new markers have been found with research development. This review summarizes the widely studied and recently discovered markers found in the field of prostate cancer stem cells.

Inhibitory effect of 17aα-D-homo-ethynylestradiol-3-acetae combined with irradiation on melanoma B16 growth / 中华放射医学与防护杂志

Objective To investigate the antitumor effect of 17aα-D-homo-ethynylestradiol-3-acetae on the mice transplanted with melanoma (B16) tumor cells,and to explore the possible synergistic effect with irradiation.Methods IRM-2 mice transplanted with B16 cells were randomly classified into control group,irradiation group,17aα-D-homo-ethynylestradiol-3-acetae drug ( high dose,medium dose,low dose) groups,and drug and irradiation combination group.Mice in drug group and the combination group were intraperitoneally injected with 5,7.5,and 10 mg/kg drug for 7 days.Mice in the irradiation and combination group received 1 Gy total body irradiation at 4 d after drug injection and then once a day for 5 days.The tumor inhibition efficiency,the number of bone marrow cells,thymus indices,and spleen indices were evaluated.Results Tumor weights in each drug group were significantly lower than those of the control( t =4.58,9.07,6.67,P ＜ 0.05 ).Drug combinated with 137Csγ-rays enhanced the antitumor effect so that the tumor weights in the combination group were significantly decreased ( t =8.06,10.35,6.71,P ＜0.05 ) in comparison with the control groups.Moreover,the numbers of marrow nucleated cells,thymus index and spleen index in the drug group were higher than those in the control group ( t =2.64,3.80,2.84,P ＜ 0.05 ).Conclusions 17aα-D-homo-ethynylestrudiol-3-acetae can inhibit cell growth of B16 melanoma in mice and may also have radioprotective effect on the hematopoietic system and immune system of mice.

Human Hexastatin genetic optimization, protein expression, purification and preliminary application / 国际生物医学工程杂志

ObjectiveTo optimize human Hexastatin gene,to express,purify protein and conduct activity experimental research,and to provide a theoretical basis for further study of Hexastatin.MethodsHuman Hexastatin gene was optimized and synthesized.It was connected to the pET28a expression vector,induced to express by isopropyl β-D-1-thiogalactopyranoside(IPTG),and optimized induction conditions.After the ultrasonication of bacterial cells and inclusion bodies,the recombinant fusion protein was purified with Ni-NTA chromatographic column,analyzed and identified by SDS-PAGE and Western Blot,and conduct activity experimental research in vitro by MTT.ResultsConstructed production was pET28a-Hexastatin expression plasmid.The human Hexastatin protein was expressed in E.coli BL21 the high level and accounted for 45.1％ of the total bacterial protein.The purification of recombinant protein purified with Ni-NTA chromatographic column reached 90％,and the concentration was 80 μg/ml.Human Hexastatin protein can restrain the growth of C6,MCF-7 and human vascular endothelial cell (HMEC) cells,and inhibition ratio reach to 72.9％±3.6％,48.8％±2.9％,52.7％±2.5％,respectively through MTT test.ConclusionThe optimized human Hexastatin protein was expressed successfully,which confirmed the inhibition to tumour cells.It is a new way for anti-angiogenesis therapy of tumour.

Expression and purification of soluble recombinant Hexastatin in E.coli / 中国生化药物杂志

purpose To construct the expression vector of Hexastatin gene,to express and to purify the recombinant protein for further activity research.Methods The human Hexastatin gene was isolated by RT-PCR from EC9706 cells total RNA and cloned into pMDl8-T for sequencing.Then the Hexastatin gene was subcloned into pMAL-c4x expression vector and induced to express by IPTG.The recombinant fusion protein was purified with Amylose Resin Heads.Results RT-PCR product was about 687 bp and its sequence was the same as that of Hexastatin reported.The recombinant protein was expressed in E.coli BL21 with high level and the soluble protein accounted for 24.8% of the total bacterial protein,The purification of recombinant protein purified with Amylose Resin Heads reached more than 90%.Conclusion The cloning,expression and purification of human Hexastatin have laid a foundation for its anti-angiogenesis therapy for tumor.