Anti-tumor activity of yeast vesicle biomimetic nanomedicine with the ability of active tumor penetration / 药学学报

The dense extracellular matrix (ECM) of the tumor severely limits the deep penetration of nanomedicine and weakens its anti-tumor effect. Based on this, the yeast vesicle biomimetic nanomedicine with active deep penetration ability of tumor tissue was designed and developed for enhanced tumor therapy. Results of characterization showed that the yeast cell vesicles (YCV) displayed a spherical morphology with diameter of around 100 nm and was well dispersed. Then the chemotherapeutic drug doxorubicin (DOX) was selected as a model drug, and DOX was loaded into YCV to obtain YCV/DOX through electrostatic interaction, the encapsulation efficiencies of DOX were calculated as 82.5%. The drug release profile of YCV/DOX implied that DOX release showed a manner of pH-dependent, it may be that pH has affected the electrostatic effect of YCV and DOX. Compared with liposomes (Lipo), in vitro cell experiments showed that YCV from natural sources had stronger permeability in three-dimensional multicellular spheres. It is speculated that the mechanism may be good deformation capacity of YCV. A 4T1 xenograft tumor model was established to evaluate the therapeutic efficacy of YCV/DOX. The results suggested that YCV/DOX has stronger tumor tissue penetration ability and could effectively inhibit the tumor growth. All animal experiments were performed in line with national regulations and approved by the Animal Experiments Ethical Committee of Zhengzhou University. This study brings new ideas for the development of biomimetic nanomedicine to overcome the ECM of solid tumors.

Neuroprotective effects of Yiqihuoxue calm wind capsule on ischemic stroke in rats / 中国天然药物

Stroke remains the third leading cause of death and of adult disability worldwide. Vascular occlusion, followed by ischemic cascade, leads to irreversible tissue injury. Recombinant tissue plasminogen activator is the only FDA approved drug for the current treatment of acute ischemic stroke. However, traditional Chinese medicine has a long history and rich clinical experience in the treatment and rehabilitation of ischemic stroke. Using a classical middle cerebral artery occlusion (MCAO) stroke model, we tested the effectiveness of Yiqihuoxue calm wind (YCW) capsule on neurological function, gross pathology and oxidative stress status in MCAO rats. YCW capsule (3.36 and 6.72 g·kg of crude drug) could significantly lower Longa's score and superoxide dismutase (SOD) level, together with less necrotic cells and infarcted area. In addition to elevated MDA and downregulated iNOS expression, YCW capsule exhibited its neuroprotective effects via free radical scavenging and NO inhibition.

Modified (Wu's) esophagectomy for a huge thoracic esophageal squamous cell carcinoma 18.3 cm in length / 南方医科大学学报

An esophageal squamous cell carcinoma measuring 18.3 cm in length and 5 cm in diameter was found in the mediastinum of a 53-year man. The patient underwent a modified 3-stage esophagectomy and an esophagogastrostomy at the cervical level (Wu's method). The operation was performed smoothly and the patient recovered uneventfully after the operation. The patient was followed up for 6 months after discharge and reported no difficulties in eating with improved quality of life. This case represents the world's longest esophageal cancer that had been surgically removed. Local advanced esophageal cancer should be removed immediately to prevent potential occurrence of esophageal obstruction, tracheoesophageal fistula or aorto-esophageal fistula.

Preparation and in vitro and in vivo study of antisense oligodeoxynucleotides-loaded cationic liposomes / 药学学报

The aim of the paper is to prepare stable antisense oligodeoxynucleotides-loaded cationic liposomes and evaluate the transfection efficiency of asODN to MCF-7 oophoroma cells and study their distribution to different tissues in mice. Antisense oligodeoxynucleotides (asODN)-loaded cationic liposomes were prepared by a thin film-adsorption-lyophilization method which is simple and can overcome crucial pharmaceutical defects (e.g. instability) of liposomes during storage. The morphology was investigated by transmission electron microscope. The size and surface charge of the liposomes were determined by laser particle analyter. The dissociated ligodeoxynucleotides were separated from the liposomes by sephadex column and the entrapment efficiency was determined by using an ultraviolet photometer. Trehalose, mannitol, and glycine were suitable for lyophilization especially trehalose. The resulting liposomes were global microcapsule in a narrow particle size with a mean diameter of 175 nm and 320 nm before and after lyophilization, and a high zeta potentials of +32 mV. The dissociated asODN were separated from the liposomes by sephadex G-50 column and the entrapment coefficient of asODN was 88.4% pre and 83.2% post-lyophilization separately for trehalose. The growth of MCF-7 oophoroma cells were inhibited in vitro obviously (P < 0.05) and transfection efficiency of asODN was 18%, 26%, 44% after 2 h, 4 h and 8 h, respectively. The formulation and method can be used to prepare stable cationic liposomes which can effectively inhibit the growth of MCF-7 oophoroma cells and obtain a high transfection efficiency. This system can improve distribution amount of asODN to tissues especially tumors in mice.

Effect of nanosize delivery system for ASODN against hTERT on the expression of telomerase in the esophageal cancer EC9706 cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the inhibitory effect of nanoparticle-mediated antisense oligodeoxynucleotide (ASODN) of human telomerase reverse transcriptase (hTERT) on telomerase in the esophageal cancer EC9706 cells.</p><p><b>METHODS</b>Line-polyethylenimine (L-PEI) was used to condense ASODN into nanoparticle and to couple NGR peptides into targeting nanoparticle, and the prepared L-PEI/ASODN complexes were transfected into the EC9706 cells. Cellular uptake of L-PEI/ASODN complexes was detected by laser confocal scanning microscopy. MTT assay was used to detect the inhibitory rate of EC9706 cell growth. The level of hTERT mRNA and its protein expression were measured by RT-PCR and immunohistochemistry, respectively. Annexin V FITC/PI double labeling was used to detect cell apoptosis. The distribution of drug in nude mice was observed by laser confocal scanning microscopy, and the growth and morphology of the tumor was examined.</p><p><b>RESULTS</b>The L-PEI-mediated ASODN uptake was enhanced. After transfection, the inhibitory rate of EC9706 cells was time-dependant and there was a significant difference between control cell group and L-PEI/ASODN group (P < 0.05). At 48 h after transfection, the level of hTERT mRNA was decreased significantly compared with that of control cell group (P < 0.05), and the expression of hTERT protein was negative. There was apparent apoptosis in EC9706 cells after transfection with L-PEI/ASODN complexes. For the two NGR/L-PEI/ASODN groups, fluorescence was observed in the liver, kidney, lung and tumor tissues of nude mice, and their uptake intensity was time-dependent. The mean volume of tumors in the two NGR/L-PEI/ASODN groups was significantly smaller than those in blank control group and SODN group (P < 0.05). Apoptotic bodies were detected in the tumors of L-PEI/ASODN group.</p><p><b>CONCLUSION</b>The NGR/L-PEI/ASODN nanoparticles can effectively reach into the human esophageal cancer xenograft and inhibit the tumor growth in nude mice, and this may provide a theoretical and experimental basis for gene therapy for human esophageal squamous cell carcinoma.</p>

Inhibition of A549 cells by polybutylcyanoacrylate nanoparticles loaded with antisense oligodeoxynucleotide of hTERT mRNA / 药学学报

<p><b>AIM</b>To investigate the effect of nanoparticles for antisense oligodeoxynucleotide (ASODN) of hTERT mRNA on A549 cells.</p><p><b>METHODS</b>The cationic polybutylcyanoacrylate nanoparticles (NPs) were prepared by an emulsion polymerization process in the presence of DEAE-dextran. Antisense oligodeoxynucleotides were loaded on the particles by adsorption. The cytotoxicity of NPs and proliferation of A549 cells were detected by MTT assay. Intracellular fluorescence intensity after transfecting the 5'-FITC-labelled ASODN (FASODN) and cell cycles were determined by flow cytometry (FCM). Inverse microscope was used to observe the modality of A549 cell transfected by NPs for ASODN. The protein expression of hTERT was measured by immunocytochemistry.</p><p><b>RESULTS</b>The cytotoxicity increased evidently with the increasing concentration of NPs over 2.5 g x L(-1). The intracellular fluorescence in FASODN-NP group was obviously stronger than that in FASODN group (NPs free) after transfection for 24 h (P < 0.01). The inhibitory rate for cell modality change and proliferation after the treatment with ASODN-NP at 72 h reached peak , 62.4% , 44.6% and 36.4% for ASODN1-NP group, ASODN2-NP group and ASODN3-NP group, respectively; The cell cycle in ASODN-NP group varied observably compared with control group and sense oligodeoxynucleotide-nanoparticle (SODN-NP) group and the cell cycle was blocked in G1 phase, the cell number in S phase decreased obviously (P < 0.01); The hTERT protein expression of ASODN-NP group reduced clearly.</p><p><b>CONCLUSION</b>ASODN-NP of hTERT can inhibit the proliferation of A549 cells effectively and cause the change of cell cycle, restraint of protein expression of hTERT and cell viability.</p>

Site-directed mutagenesis of NisinZ and properties of NisinZ mutants / 生物工程学报

According to the knowledge gained from engineering of nisinZ, using plasmid pHJ201 DNA as template, NisinZ was mutated by site-directed mutagenesis, NisinZ mutant T8S contains Serine at position 8 instead of Threonine, NisinZ mutant N27K/H31K contains Lysine at position 27 and 31, respectively, instead of Asparagine and Histidine and NisinZ mutant T2S/ H31K contains dehydrobutyrine and Lysine at position 2 and 31 instead of dehydroalanine and Histidine. They are cloned into pMG36e and expressed in L. Lactis NZ9800, the expression products of these mutants purified by Sephadex CM-25 and Sephadex G-25 chromatography, some properties of NisinZ mutants (T8S, T2S/H31K and N27K/H31K) were studied. The results showed that the spectrum of antimicrobial activity and solubility of these mutants had not been changed, their antimicrobial activities were found to be slightly lower than that of the wild-type NisinZ. but mutants T8S and T2S/H31K showed higher stability, which were significantly more stable than wild-type NisinZ at 55 approximately 100 degrees C and pH7 approximately 9.

Food-grade gene expression systems for lactic acid bacteria / 生物工程学报

Lactic acid bacteria (LAB) are important industrial microorganism used in the production and preservation of food-stuffs. Recently, considerable advances have been made in the genetics and molecular biology of LAB. These have resulted in the construction of food-grade gene expression systems for these bacteria. This paper aims to review the essential features for food-grade systems, food-grade selection markers, food-grade controlled gene expression and food-grade inducible signaling molecule, and recent developments on food-grade cloning and expression systems for LAB. These gene expression systems have great potential for studies on gene expression and regulation in LAB and a variety of bioprocessing application in industrial fermentations.