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OBJECTIVE： To prepare Adriamycin hydrochloride （DOX） magnetic thermosensitive liposome （MTSL）， investigate its physicochemical properties， magnetic effect and photothermal effect， so as to provide reference for tumor chemo- therapy and photodynamic/photothermal therapy. METHODS： Using DOX as model drug， TiO2@Fe3O4 as photosensitizers and magnetic materials， DOX-TiO2@Fe3O4-MTSL was prepared with membrane dispersion method. The morphology and dispersibility were observed； particle size and Zeta potential were detected； encapsulation efficiency of the liposome were determined by centrifugal ultrafiltration and HPLC. Its paramagnetism property was also detected by magnetometer. Compared with DOX solution， in vitro release behavior of the liposome was investigated by dialysis method， and the release curves at different temperatures （at 37， 43 ℃） were compared. The photothermal conversion effect of the liposome and the production of reactive oxygen species （ROS） in human breast cancer MCF-7 cells were investigated by near infrared laser irradiation at 808 nm. RESULTS： Prepared DOX-TiO2@Fe3O4-MTSL was brown-black with good water dispersion， and was spherical in shape and uniform in size under electron microscopy. Average particle size was 250.6 nm； polydispersity index was 0.107； Zeta potential was （－7.76±3.41）mV； encapsulation efficiency was （92.3±3.2）％. Under the external magnetic field， the liposome could move in a directional direction and had obvious paramagnetism. Compared with DOX solution， the liposomes released slowly and showed obvious sustained- release characteristics. Compared with at 37 ℃， the drug release of liposome speeded up significantly at 43 ℃.With the increase of laser （808 nm） irradiation time， the temperature of the liposome kept rising， which had obvious photothermal conversion effect and could induce the increase of ROS in MCF-7 cells. CONCLUSIONS： DOX-TiO2@Fe3O4-MTSL is prepared succe- ssfully， which has uniform appearance， good physical and chemical properties. It has obvious paramagnetism sustained release effect and photothermal conversion efficiency， and can promote ROS production in MCF-7 cells under near infrared laser irradiation at 808 nm.
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@#The abuse of antibiotics has been increasing bacterial resistance, which means there is a need to develop methods for the efficient detection and effective treatment of multiresistant bacterial infections. As one of graphene-based materials, graphene quantum dots (GQDs) have distinct mechanical, electrical, and optical properties, including a small size, a large surface area-to-volume ratio, biocompatibility, antimicrobial activity and tunable photoluminescence. Therefore, GQDs are expected to be widely used as antimicrobial materials, drug delivery carriers and photosensitizers in antibacterial applications. In this review, we focus on their synthesis, characteristics and antimicrobial applications in oral medicine.
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OBJECTIVE: To study the damaging effect of nano-neodymium oxide( Nano-Nd_2O_3) on rat adrenal pheochromocytoma cell PC12. METHODS: PC12 cells in the logarithmic growth phase were divided into control group and 7 drug treatment groups. The control group was not treated with Nano-Nd_2O_3. The drug treatment groups were treated with 7 different dosing with the final mass concentrations of 3. 13,6. 25,12. 50,25. 00,50. 00,75. 00,100. 00 mg/L of NanoNd_2O_3 for 24 hours,then the follow-up selected experimental concentration were 3. 13,6. 25,12. 50,25. 00,50. 00 and75. 00 mg/L. The CCK-8 essay was used to detect the cell viability. The levels of glutathione( GSH) and superoxide dismutase( SOD) in the cells were measured by enzyme-linked immunosorbent assay. The expression of B cell lymphoma-2( Bcl-2),Bcl-2 associated X protein( Bax) and Caspase-3 protein were detected by Western blot. RESULTS: The survival rate,GSH level and Bcl-2/Bax ratio of PC12 cells decreased with the increase of the Nano-Nd_2O_3 dose,and showed doseresponse relationship( P < 0. 01). The SOD activity of PC12 cells in Nano-Nd_2O_3 group of 12. 50,25. 00,50. 00 and75. 00 mg/L were lower than that of control group( P < 0. 05). The ratio of Caspase-3/β-actin in PC12 cells was higher than that in control group( P < 0. 05). In the range of 0. 00-25. 00 mg/L of Nano-Nd_2O_3,with the increase of NanoNd_2O_3 dose,the ratio of Caspase-3/β-actin in PC12 cells increased gradually,and showed a dose-response relationship( P < 0. 01). CONCLUSION: Nano-Nd_2O_3 can induce oxidative stress in PC12 cells,leading to the decrease of Bcl-2/Bax ratio,activate Caspase-3 expression,and than inhibits cell proliferation in a dose-dependent manner.
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Objective: To provide a new manufacturing method for the artificial seeds of Dendrobium officinale. Methods: The artificial seeds were manufactured by taking protocorms of D. officinale as the materials entrapped with the consideration of the effects of testa components and artificial endosperm on the germination and seedling of the artificial seeds. Results: The better conditions of the artificial seeds are manufactured in the fundamental artificial endosperm made by MS + 0.5 mg/L BA + 0.5 mg/L NAA +3 g/L AC + 30 g/L sodium alginate + 3 g/L chlorothalonil mixture reacted in 2% CaCl2 for 15 min; For the higher germination and seedling rate, 15 g/L cassava starch and 10 g/L water retaining agent can be added into the artificial endosperm components, respectively; For the higher germination rate, 10 g/L nano-SiO 2 (better planting rate) and 10 g/L Nano-TiO2 can be added into the artificial testa, respectively. The highest seedling rate was obtained by adding 10 g/L nano-SiO2. Conclusion: A manufacturing method of the artificial seeds of D. officinale has been established for the higher germination and seedling rates.
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Nano-materials have been increasingly widely used in various fields with the progression in science and technology. While bringing benefit to our life, their toxic effects also come to our attention. In this paper we review the cytotoxic effects and some problems of several kinds of nano-materials (carbon-based nano-materials, metal and metallic oxides and other nano-materials), considering the physicochemical characteristics of nano-materials, research methods of the nanomaterial cytotoxic effects, and the cytotoxcity of nano-materials. Finally, we also discuss the research focus of the area and issues need to be addressed, hoping to provide a guide for bio-safety research of nano-materials.
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The recent research progress of photo-catalyzed degradation of organic pollutants by TiO2 is reviewed,the characteristics of hydrothermal method and the prepared processes of TiO2 were discussed,the photo-catalyzed mechanism under UV and visible light and the application of degradation of sewage using TiO2 nanomaterials from five aspects were described in this paper. The main problems existing in the studies of TiO2,the research directions,and the development prospects were also discussed.
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The organic pollutants in the air is so harmful to human health and is difficult to be degraded.However,to degrade the organic pollutants with nano-materials by photocatalysis reaction can get a good effect.The basic principle of photocatalysis reaction of the nano-materials was explained and the different degradation effects for organic pollutants were compared in this paper.The application of nanosize TiO_2 was briefly described and meanwhile the affecting factors and the methods to improve the catalysis efficiency were discussed.
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[Objective] To evaluate the cellular biocompatibility of the nano poly(L-lactic acid)-block-poly(?-caprolactone)(Nano-PLLA-b-PCL)with canine articular cells and its feasibility as a scaffold for the cartilage tissue engineering.[Methods]Nano-PLLA-b-PCL was made by liquid-liquid phase separation.Canine articular cells were isolated and multiplied in vitro.The passage 3 cells were seeded onto the PLLA-b-PCL films and cultured in the 2-dimensional environment.The cytotoxicity was measured with MTT assay.Cellular Morphological changes were observed by phase-contrast microscopy and Hoechst33342 fluorometric method.Another passage 3 cells were seeded onto the Nano-PLLA-b-PCL scaffolds(experiment group),PLLA-b-PCL scaffolds(control group)and cultured in the 3-dimensional environment for 3 weeks.The ratio of cell adhesion was detected by cell counting method.The morphological changes of cells were observed by scanning electron microscopy.The protein content in seeded cells were determined by bioinchoninic acid assay(BCA).The content of DNA was quantified using Hoechst33258 assay.[Results]MTT assay showed the PLLA-b-PCL had no cytotoxicity.The seeded cells adhered and proliferated well into the Nano-PLLA-b-PCL scaffolds,and they maintained good cell phenotype.After 21-day cell culture within the Nano-PLLA-b-PCL scaffolds,the chondrocyte DNA and protein contents increased with time.Moreover,the content of DNA and protein was higher in the experiment group than that in the control group,respectively(P
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A trend to effective treatment of tumor by means of multidisciplinary approaches, especially the occurrence of new techniques should be noticed. Herein we try firstly to give the definition and several main sorts oftumor targeting at present. The recent researches and development of passive targeting, field-assisted targeting, and molecular targeting using nano-materials or based on nanotechnology have been emphatically described. And within this mentioned description the existing problems and the possible solving methods have been analyzed and discussed.
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Nano-materials are immensely applied in piezoelectric, electrochemical, optical, magnetic biosensors based on clearly unique nature of it. The important role of nano-materials in biosensors is expounded and the latest application of novel functional nano -materials in biosensor is introduced emphatically, such as nanoparticles, nanotubes, nanowires, quantum dots and nanofibers. The researches make clear that nano-materials can provide momentous value in enhancing performance of biosensors, such as sensitivity, detection range, and repetitiveness of biosensors, as immobilization materials or carriers.