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The targeting of anti-tumor drugs is an important means of tumor treatment and reducing drug side effects. Oxygen-depleted hypoxic regions in the tumour, which oxygen consumption by rapidly proliferative tumour cells, are generally resistant to therapies. Magnetotactic bacteria (MTB) are disparate array of microorganism united by the ability to biomineralize membrane-encased, single-magnetic-domain magnetic crystals (magnetosomes) of minerals magnetite or greigite. MTB by means of flagella, migrate along geomagnetic field lines and towards low oxygen concentrations. MTB have advantage of non-cytotoxicity and excellent biocompatibility, moreover magnetosomes (BMs) is more powerful than artificial magnetic nanoparticles(MNPs). This review has generally described the biological and physical properties of MTB and magnetosomes, More work deals with MTB which can be used to transport drug into tumor based on aerotactic sensing system as well as the competition of iron which is a key factor to proliferation of tumor. In addition, we summarized the research of magnetosomes, which be used as natural nanocarriers for chemotherapeutics, antibodies, vaccine DNA. Finally, We analyzed the problems faced in the tumor treatment using of MTB and bacterial magnetosomes and prospect development trends of this kind of therapy.
Subject(s)
Bacteria , Ferrosoferric Oxide , Gram-Negative Bacteria , Magnetics , Magnetosomes , Neoplasms/therapyABSTRACT
Objective To investigate the physicochemical properties and immunogenicity of virus like particles(VLPs) in two different conformations assembled from the essential capsid protein VP1 of GⅡ.4 norovirus(NoV) in Hansenula polymorpha. Methods NoV GⅡ.4 VLPs in two different conforma-tions were prepared from high-density fermentation of recombinant engineered strains and VLPs purification. Physicochemical properties of the two forms of VLPs were identified by Western blot,size-exclusion high per-formance liquid chromatography (SEC-HPLC), dynamic light scattering(DLS) and transmission electron microscopy. Serum VLPs binding activities and blocking activities against VLPs binding to histo-blood group antigen(HBGA-VLPs) were evaluated after immunization of BALB/c mice with the two forms of VLPs. Re-sults VLPs of two different diameters with high homogeneity were obtained after purification. DLS results showed that particle sizes of two VLPs were 53.98 nm and 45.18 nm,respectively. The two VLPs were sim-ilar in binding abilities to HBGA receptors. Serum VLPs binding activities and blocking activities against HBGA-VLPs were found higher in NoV-VLP-L than NoV-VLP-S,but the difference was not statistically sig-nificant (P>0.05). Conclusion VLPs in two different conformations were obtained by expressing NoV GⅡ.4 VP1 proteins in Hansenula polymorpha. Though they were similar in physicochemical properties and immunogenicity,the NoV-VLP-L might be potential antigen candidates for the development of recombinant human norovirus vaccine.
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BACKGROUND:Articular cartilage injuries can result from a variety of causes. Conventional therapy cannot obtain the optimal clinical results. Low-intensity pulsed ultrasound has been shown to promote the repair of injured articular cartilage. OBJECTIVE:To investigate the effects of low-intensity pulsed ultrasound on the repair of injured articular cartilage. METHODS:Twenty New Zealand white rabbits were used to establish knee arthritis models and equal y randomized into study and control groups, respectively. Rabbits in the study group received low-intensity pulsed ultrasound treatment, and sham low-intensity pulsed ultrasound treatment was given in the control group. At 8 weeks after treatment, pathological change and histological scores in articular cartilage tissue col ected from both groups were determined. Moreover, the ultrastructure and type II col agen expression of chondrocytes were determined. Matrix metal oproteinase-13 mRNA expression was detected by quantitative real-time PCR. RESULTS AND CONCLUSION:At 8 weeks after treatment, toluidine blue staining showed a disordered arrangement of cel s, decreased number of cartilage cel s in each layer and cluster in the control group. Light disordered arrangement of cel s, decreased appearance of the superficial layer cel s and the cluster phenomenon were observed in the study group. Articular cartilage tissue scores were significantly decreased in the study group compared with the control group (P<0.05). The chondrocytes were smal , enlarged intracel ular mitochondria and rough endoplasmic reticulum, cytoplasmic swel ing, col agen fibrils coarse, wel developed Golgi apparatus, and nuclear fragmentation were observed in the control group. In addition, the normal structure of organel es disappeared and cel degeneration was observed in the control group. In the study group, the size of chondrocytes and the Golgi complex and other organel es were normal, and the protein polysaccharide granules were observed in the cytoplasm and membrane. The mRNA expression of matrix metal oproteinase-13 in the study group was significantly lower than that in the control group (P<0.05). Type II col agen immunoreactivity in the study group was stronger than that in the control group. No incision infection, suppuration, red swel ing appeared in al rabbits. Our results suggest that low-intensity pulsed ultrasound can be used for the treatment of articular cartilage injury by al eviating the degradation of col agen type II and inhibiting the expression of matrix metal oproteinase-13.
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Objective To investigate the value of ultrasound in typing of epididymal tuberculosis on the clinical treatment . Methods The sonographic characteristics and treatment outcomes were analyzed in 125 patients with epididymal tuberculosis . Results In 125 patients with epididymal tuberculosis ,5 types were divided:( 1 ) Diffusive type ( 37 cases ) presented images of the epididymal diffuse enlargement , abnormal shape ,not smooth surface and inhomogeneous reduced in echogenicity ,13 cases were treated conservatively and 24 cases underwent surgical treatment after failure of conservative treatment . (2) Mass type (24 cases) showed images of hypoechoic mass lesion of caput epididymidis or cauda epididymidis ,4 cases were treated with surgical operation and 20 cases were treat with conservative therapy . (3) Abscess type ( 33 cases) manifested images of irregular liquid anechoic of caput epididymidis and cauda epididymidis , poor ultrasound penetration ,and unclear border . (4) Ulcer‐fistula type (9 cases) revealed images of liquid hypoechoic caput epididymidis or cauda epididymidis extend to the surface of the scrotum . ( 5) Testicular involvement type (22 cases) detected inhomogeneous hypoechoic mass lesion within the testicle and unclear border . The patients of abscess type ,ulcer‐fistula type and testicular involvement type were all treated surgically . Conclusions Ultrasonic diagnosis of epididymal tuberculosis provided a reliable basis for clinical treatment scheme and it was worth recommending .
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OBJECTIVE:To optimize the extraction technology of total saponins from Coreopsis tinctoria. METHODS:Etha-nol leaching technology was adopted. Based on single factor test,the extraction technology was optimized by orthogonal test using extraction temperature,ethanol volume fraction,extraction time,solid-liquid ratio as factors,extraction rate of total saponins as in-dex. The optimized technology was validated. RESULTS:The optimal technology was that ratio of solid to liquid was 1:30 (C. tinctoria-60% ethanol),extracting for 2 h at 50 ℃. Validation test showed that average extraction rate of total saponins was 6.8%(RSD=0.85%,n=3). CONCLUSIONS:The optimized technology can be used for the extraction of total saponins from C. tinc-toria and keep stable.