Preparation and property evaluation of graphene oxide based silver nanoparticles composite materials / 生物医学工程学杂志

We prepared silver nanoparticles/polyethyleneimine-reduction graphene oxide (AgNP/rGO-PEI) composite materials, and evaluated their quality performance in our center. Firstly, we prepared AgNP/rGO-PEI, and then analysed its stability, antibacterial activity, and cellular toxicity by comparing the AgNP/rGO-PEI with the silver nanoparticles (PVP/AgNP) modified by polyvinylpyrrolidone. We found in the study that silver nanoparticles (AgNP) distributed relatively uniformly in AgNP/rGO-PEI surface, silver nanoparticles mass fraction was 4.5%, and particle size was 6-13 nm. In dark or in low illumination light intensity of 3 000 lx meter environment (lux) for 10 days, PVP/AgNP aggregation was more obvious, but the AgNP/rGO-PEI had good dispersibility and its aggregation was not obvious; AgNP/rGO-PEI had a more excellent antibacterial activity, biological compatibility and relatively low biological toxicity. It was concluded that AgNP/rGO-PEI composite materials had reliable quality and good performance, and would have broad application prospects in the future.

Small interfering RNA targeting vascular endothelial growth factor gone inhibits proliferation of gallbladder cancer cells: An in vitro and in vivo experiment / 中国组织工程研究

BACKGROUND: Previous studies demonstrated that proliferation of cancer cells can be inhibited via RNA interference on the expression of vascular endothelial growth factor (VEGF). However, few studies report RNA interference on the expression of VEGF in gallbladder carcinoma, OBJECTIVE: To design and screen shRNA targeting VEGF, and to observe the effect of small interfering RNA targeting on proliferation of gallbladder cancer cells. METHODS: The VEGF-shRNA fragment was synthetized and connected with pCYU6/GFP/Neo-shRNA plasmid vector, shRNA was transfected into gallbladder cancer cells. The gallbladder carcinoma models of nude mice were prepared and randomly divided into blank control, negative control and experimental groups, With 6 animals in each group. ShRNA was injected into tumor. Cell growth was detected by fluorescence microscope MTT. The RNA interference efficiency was examined by fluorescent quantitative RT-PCR. Changes of tumor volume were also observed. RESULTS AND CONCLUSION: Gallbladder cancer cells ware shrunk with round shapes and a part of cells were dead after RNA interference on VEGF. shRNA-VEGF1 and shRNA-VEGF2 could signiticently inhibit mRNA gene expression of VEGF, the inhibition ratio was 86% and 82%, respectively. The tumor volume of the experimental group was smaller than the other groups, with slowly growth (P < 0.05). No obvious changes were found in the blank control and negative control groups. The constructed hVEGF-shRNA vector markedly decreases VEGF gene expression and inhibits cellular proliferation, eventually, to treat gallbladder cancer.

Determination of content and entrapment efficiency of clindamycin phosphate liposome / 生物医学工程学杂志

This study was conducted to prepare and determine the content and entrapment efficiency of Clindamycin Phosphate liposome. Evaporating and Ultrasound method was used for preparing Clindamycin Phosphate liposome. HPLC was used for determining the concentration and the entrapment efficiency of Clindamycin Phosphate liposome. The results indicated that Clindamycin Phosphate had a good linear relation in a range of 5.0-50.0 microg/ml. The entrapment efficiency of Clindamycin Phosphate liposome in three groups reached 52.26%, 50.13%, 53.75% respectively. Accordingly, the technique of preparing Clindamycin Phosphate liposome was noted to be feasible, and the method of quality control was shown simple and accurate.

Construction and screening of plasmid expression vectors containing short hairpin RNA targeting at vascular endothelial growth factor gene of GBC-SD cells / 中国组织工程研究

BACKGROUND: Previous reseamh has proved that RNA interference can inhibit vascular endothelial growth factor (VEGF) gene expression of colon carcinoma, carcinoma of prostate, and retinoblastoma. However, RNA interference inhibiting VEGF of carcinoma of gallbladder was not reported. OBJECTIVE: To construct a plasmid expression vector coding for the short hairpin RNA (shRNA) targeting hVEGF165 mRNA. DESIGN, TIME AND SETTING: A gene engineering study was performed at National Hepatobiliary & Enteric Surgery Research Center, Xiangya Hospital, Central South University from 2008 to 2009.MATERIALS: Human GBC-SD was provided by Tumor Research Institute of Tongji University. METHODS: Four pairs of shRNAs that targeted at VEGF gene were designed. The eukaryotic expression plasmids (named shRNA1-4) were constructed and identified using restriction enzyme analysis. The plasmids were then transfected into GBC-SD cells via liposome2000. The transfection rate of recombinant plasmids was measured at 48 hours after transfection. MAIN OUTCOME MEASURES: Enzyme analysis of recombinant plasmid; transfection rate; VEGF mRNA expression determined using fluorescent polymerase chain reaction. RESULTS: shRNA plasmid vector targeting at VEGF gene was successfully constructed, in particular, pDC316-EGFP-U6-shRNA2 was the most effective. The expression plasmids were confirmed by restriction enzyme analysis. The transfection rate of recombinant plasmids in GBC-SD cells was approximately 58.6%. shRNA could inhibit VEGF mRNA expression, in particular, the inhibitory rate of RNA2 was the highest by 86%.CONCLUSION: The shRNA eukaryotic expression plasmid targeting at VEGF gene is constructed and selected successfully, and it can remarkably inhibit VEGF expression of GBC-SD cells. Additionally, the inhibitory effect of RNA2 is the greatest.

Remodeling of skin nerve fibers during wound healing / 中国矫形外科杂志

[Objective]To observe changes of skin reinnervation during burn wound healing and determine remodeling of nerve fibers.[Method]Wound tissue and scars were harvested.Collagen was determined with modified Masson trichrome staining and nerve fibers were labeled with neuro filament protein by immunofluorescent technique.Three dimension reconstruction of nerve fibers regenerated was observed under laser scanning confocal microscope.[Result]The CVF(collagen volume fraction) increased during the process of wound healing.The regenerated nerve fibers were sparse,short and small,which was significant lower the normal control.The skin reinnervation improved during the wound healing process and came to peak NVF(nerve fiber volume fraction) in proliferative stage.Disintegration and fragmentation were observed frequently in samples from proliferative stage,which seldom occurred during mature stage.[Conclusion]The remodeling of skin nerve fibers comprises a sequential process of increasing number,shape distortion during wound healing and then disintegration,number decrease and normal shape.

Prevention and treatment of complications in choledochoscopic removal of gallstones / 中国普通外科杂志

Objective To explore the causes,prevention and treatment of common complications in stone extraction by choledochoscopy after bile duct operation.Methods The clinical data of 165 cases with complications after stone extraction by choledochoscopy in 1379 treated cases during 7 years were analyzed.Results The common unfavorable reactions of nausea,vomiting,abdominal pain and diarrhea occurred in 107 cases,and were alleviated by controlling the amount and rapidity of the infused sterilized water during choledochoscopy.Chills and fever occurred in 25 cases and were controlled by adequate T tube drainage and antibiotics.Bile duct hemorrhage occurred in 11 cases,including automatic hemostasis in 5 cases,hemostasis after infusing thrombin by T tube in 5 cases and hemostasis after infusing thrombin by vein in 1 case.Biliary fistula from sinus tract perforation occurred in 3 cases,and in these,T tube was successtully re-inserted in 1 case and T tube was inserted by reoperation in 2 cases.T-tube tract could not admit the choledochoscope in 19 cases,and were treated by re-choledochoscopy after gradual T-tube dilataton in 12 cases,but the sinus tract close to common bile duct was completely obstructed in 7 cases.Conclusions Choledochoscopic removal of retained stones is a safe procedure but unfavorable reactions and complications are not uncommon.The severe complications,such as bile duct hemorrhage and biliary fistula,should be prevented and appropriately treated.

Effect of amino-functional Fe_3O_4 nanoparticles-mediated pcDNA3.1(+)-p53 on HepG2 Cells in vitro / 中国普通外科杂志

0.05).(2) The transfection rate and velocity could be increased by addition of extra-magnetic field.(3) Transfected-p53 obviously inhibited the growth of HepG2 at G1 phase;the growth inhibition rate of HepG2 was 46%.Conclusions(1) FFN is a good vector for gene transfection,it can successfully transfect the gene into target cells.(2) Transefected-p53 can effectively inhibit the growth of HepG2.This result can establish a foundation for animal experimental research of gene therapy of malignancy.

A comparative study of CT diagnosis and operative findings in advanced gastric carcinoma / 中国普通外科杂志

Objective To explore the value of CT in the preoperative assessment of resectability of advanced gastric carcinoma.Methods The relation of CT findings and operative data in 93 cases of advanced gastric carcinoma were retrospectively analyzed.Results There were 23 cases of fundus and cardia carcinoma,59 cases of carcinoma of gastric corpus,and 11 cases of carcinoma of antrum.All cases showed increased thickness of gastric wall in various degrees,some of the cases showed tumor growth in the gastric wall,ulcer of the mucosa,stricture of gastric cavity and cardia,increased thickness of cardiac wall,and invasion of lower esophagus and perigastric organs.The accuracy of location and definitive diagnosis by CT,compared to gastroscopic biopsy and postoperative pathology,was considerable,and the detecting rate of tumor by CT was 100 %.CT had important reference value in preoperative evaluation of tumor resectability.The excision rate in the predicted operable group was 93.3 %;in the predicted unresectable group,the non-excision rate was 75.0%.Conclusions Preoperative CT diagnosis of gastric carcinoma has important clinical significance.CT provides a high reference value for assessing the resectability of gastric carcinoma,and it is worthy of widespread use.

Treatment of refractory intrahepatic and extrahepatic bile duct stones by choledochoscope holmium laser combined with electrohydraulic lithotripsy / 中国普通外科杂志

Objective To inverstigate the effect and safety of refractory intrahepatic and extrahepatic bile duct stones treated by choledochoscope holmium laser combined with electrohydraulic lithotripsy.Methods The cllnical data of 67 cases of postoperative intrahepatic and extrahepatic bile duct stones treated with combined endoscopic holmium laser and electrohydraulic lithotripsy were analysed retrospectively.Results After 1 to 7 times of biliary endoscopic holmium laser electrohydraulic lithotripsy treatment,65 patients had complete removal of all residual stones with the success rate of 97%,and without complications.Conclusions After holmium laser combined with electrohydraulic lithotripsy,the effect of choledochoscopic removal of intrahepatic and extrahepatic bile duct residual stones can be greatly improved It is a safe method for treatment of refractory intra-and extra-hepatic bile duct stones.