ABSTRACT
<p><b>OBJECTIVE</b>To investigate the property of genipin-crosslinked silk fibroin(SF)/chitosan(CS) microspheres for slow releasing of bovine serum albumin (BSA).</p><p><b>METHODS</b>BSA-loaded genipin-crosslinked SF/CS microspheres were prepared by emulsion cross-linking technique. The micropheres were observed for surface morphology and size distribution under scanning electron microscope (SEM), and X-ray diffractometry (XRD) and fourier transform infrared spectroscopy (FTIR) were used to analyze their structural characteristics. BCA method was used for determining the drug entrapment, loading rate and cumulative drug release in 21 days.</p><p><b>RESULT</b>The microspheres were spherical and showed a smooth surface with an average diameter of 7.84∓0.97 µm. The drug entrapment efficiency of the microspheres was (50.16∓4.32)% with a drug loading ratio of (1.25∓0.11)% and a cumulative release of the total drug of (75.2∓2.53)% in 21 days.</p><p><b>CONCLUSION</b>Genipin-crosslinked SF/CS microspheres have a high drug entrapment efficiency and possess good capacity of sustained drug release.</p>
Subject(s)
Chitosan , Chemistry , Delayed-Action Preparations , Emulsions , Fibroins , Chemistry , Iridoids , Chemistry , Microscopy, Electron, Scanning , Microspheres , Particle Size , Spectroscopy, Fourier Transform Infrared , X-Ray Diffraction , X-RaysABSTRACT
<p><b>OBJECTIVE</b>The purpose of this study was to investigate the regulatory role of tyrosine kinase 2 with immunoglobulin-like and epidermal growth factor homology domains (Tie2) on apoptosis and proliferation in the endothelial cells.</p><p><b>METHODS</b>RNA interference (RNAi) technique was used to silence Tie2 gene expression by transfecting an expression vector containing short hairpin RNA(shRNA) for Tie2 into human umbilical vein endothelial cells (HUVECs). Real time quantitation reverse transcriptase polymerase chain reaction (QRT-PCR) and Western blot were used to monitor Tie2 mRNA, as well as protein expression. The proliferation of HUVECs was examined by methyl thiazolyl tetrazolium (MTT), and the apoptosis was detected under microscope. HUVECs transfected with pGenesil-hk was negative control, and HUVECs transfected with nothing was empty control.</p><p><b>RESULTS</b>Tie2 mRNA expression was down-regulated 24 h and 48 h after transfection, and Tie2 protein expression was significantly down-regulated at 24 h and 48 h (P< 0.05), especially 48 h after transfection. The apoptosis rate was conspicuously higher in experimental group than in negative control and empty control group after 48 h (P<0.05). The growth monitoring showed that proliferation was also markedly inhibited in experimental group (P<0.05) compared with two control groups.</p><p><b>CONCLUSION</b>Down-regulated expression of Tie2 by RNAi can promotes apoptosis of HUVECs and has an anti-proliferation activity effect on them.</p>
Subject(s)
Humans , Apoptosis , Cell Line, Tumor , Cell Proliferation , Down-Regulation , EGF Family of Proteins , Human Umbilical Vein Endothelial Cells , Immunoglobulins , RNA Interference , RNA, Messenger , RNA, Small Interfering , TYK2 Kinase , TransfectionABSTRACT
<p><b>OBJECTIVE</b>To study the effection of suppression murine melanoma growth by Intratumor injection of recombinant attenuated salmonella carrying heat shock protein 70 and herpes simplex virus thymidine kinase genes.</p><p><b>METHODS</b>Plasmids PCMV-mtHSP70-IRES-TK were electro-transferred into salmonella typhimurium SL7207 to construct recombinant salmonella typhimurium. In vivo, Recombinant bacteria were injected into the mouse melanoma and the antitumor effection was observed. The survival period was recorded and safety analysis for this vaccine in each group.</p><p><b>RESULTS</b>In vivo, the mtHSP70/HSV-tk recombinant bacteria can suppress tumor growth significantly and extend survival. After recombinant Salmonella, 10(9) CFU/mL, was administered as an intratumoral injection, No diarrhea were observed. During therapy, body weight did not change markedly.</p><p><b>CONCLUSION</b>Results of the animal experiment suggests intratumor injection of recombinant attenuated salmonella typhimurium containing mtHSP70 and HSV-tk genes, has targeting ability against B16 tumor cell and could significantly inhibit tumor growth .</p>
Subject(s)
Animals , Mice , Bacterial Proteins , Genetics , Allergy and Immunology , Cancer Vaccines , Genetics , Allergy and Immunology , Pharmacology , Genetic Therapy , Methods , HSP70 Heat-Shock Proteins , Genetics , Allergy and Immunology , Melanoma, Experimental , Microbiology , Pathology , Therapeutics , Mice, Inbred C57BL , Mycobacterium tuberculosis , Genetics , Salmonella typhimurium , Genetics , Allergy and Immunology , Simplexvirus , Genetics , Skin Neoplasms , Therapeutics , Thymidine Kinase , Genetics , Allergy and Immunology , Vaccines, Attenuated , Genetics , Allergy and Immunology , Pharmacology , Vaccines, DNA , Genetics , Allergy and Immunology , PharmacologyABSTRACT
MicroRNAs(miRNAs) are small non-coding RNAs of 20-24nt(about 22nt) in length that mediate gene expression at the post-transcriptional level by degrading or repressing target messenger RNAs (mRNAs).Angiogenesis plays an important role in occurrence and development of cancers which involves multiple signaling pathways.miRNAs can regulate the signaling pathways in which their target genes are involved.Therefore,to study the miRNAs regulation of tumor angiogenesis slgnaling pathways will contribute to cancer diagnosis and treatment.