Application of magnetic iron oxide nanoparticles in magnetic resonance/photothermal dual-modal imaging / 药学学报

In this study, water-dispersible magnetic iron oxide (Fe3O4) nanoparticles were synthesized with solvothermal method. The nanoparticles were characterized with a transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The in vitro magnetic resonance response and photothermal conversion characteristics of the nanoparticles were evaluated. In addition, the cellular uptake, cytotoxicity and biodistribution were studied. Finally, magnetic resonance/photothermal dual-modal imaging effect of the as-synthesized Fe3O4 nanoparticles was investigated in the tumor-bearing mice. The results showed that the obtained magnetic nanoparticles were uniform with a mean diameter of about 125 nm. Moreover, the superparamagnetic Fe3O4 nanoparticles showed remarkable magnetic resonance response and photothermal conversion properties. The results of cellular experiments showed that the cell viability was nearly 85% even the concentration of the nanoparticles was up to 1 000 μg·mL-1, an indicator of good biocompatibility. In addition, the nanoparticles could be taken up by the tumor cells and then located in the cytoplasm. After intravenous injection, the nanoparticles were tended to enrich in the tumor over time, which is helpful in achieving dual-modal magnetic resonance/photothermal imaging. In sum, the obtained Fe3O4 nanoparticles showed great potential to be applied for multi-modal bio-imaging which may play an important role in the diagnosis of tumors.

Preparation and in vitro evaluation of doxorubicin-loaded magnetic iron oxide nanoparticles / 药学学报

PEG-modified magnetic Fe3O4 (Fe3O4-PEG) nanoparticles were sythesized using a solvothermal reaction and characterized with transmission electron microscopy (TEM) and thermo gravimetric analysis (TGA). The photothermal effect and photothermal destruction of cancer cells were evaluated. Then the doxorubicin loaded Fe3O4-PEG (DOX-Fe3O4-PEG) nanoparticles were prepared. The cytotoxicity and combined chemotherapy/photothermal therapy (PTT) effect were investigated. Uniform PEG coated Fe3O4 nanoparticles with particle size of 155 nm were obtained in the experiment. The loading and release of doxorubicin on Fe3O4-PEG were pH-dependent. The drug loading capacity in water was 21%. The results of MTT indicated a good biocompatiblity of Fe3O4-PEG nanoparticles and high cytotoxicity of DOX-Fe3O4-PEG. In combined therapy experiment, photothermal therapy demonstrated unambiguously enhanced chemotherapy efficacy. In conclusion, the obtained Fe3O4-PEG nanoparticles which exhibit good photothermal effect and drug loading capacity can be used for chemotherapy and photothermal therapy. The synergetic anti-tumor activity indicates the potential for the combined application of chemotherapy and photothermal therapy in cancer treatment.

[Performance analysis and radiometric correction of novel molecular hyperspectral imaging system].

Integrating molecular imaging technology and hyperspectral technology, a novel molecular hyperspectral imaging (MHSI) system based on AOTF was presented. The system consists of microscope, spectrometer, matrix CCD, image collection card and computer. The system's performance was synthetically evaluated referring every part's performance. The spectral range of the MHSI system is from 550 to 1 000 nm. Two hundred twenty five bands can be continuously captured at a time. The spectral resolution is less than 2 nm. The spatial resolution is about 0.061 5 microm. CCD acquisition speed achieved 2.612 5 s x B(-1) in the integration mode and about 0.11 micros x B(-1) in the non-integration mode. Due to the infection of lamp, a spectral curve extracted directly from the original hyperspectral data can not truly present biochemical character and needs to be corrected. The paper proposes the gray correction coefficient algorithm with spatial dimension and spectral dimension, and gives concrete realization of the algorithm. Taking the sample of leukemia blood, by comparing the single-band images, pseudo-color images and spectra before and after correction, the results indicate the effectiveness of correction algorithm. The corrected data is effective for subsequent analysis.

[Molecular hyperspectral imaging (MHSI) system and application in biochemical medicine].

A novel molecular hyperspectral imaging (MHSI) system based on AOTF (acousto-optic tunable filters) was presented. The system consists of microscope, AOTF-based spectrometer, matrix CCD, image collection card and computer. The spectral range of the MHSI is from 550 to 1 000 nm. The spectral resolution is less than 2 nm, and the spatial resolution is about 0.3 microm. This paper has also presented that spectral curves extracted from the corrected hyperspectral data of the sample, which have been preprocessed by the gray correction coefficient, can more truly represent biochemical characteristic of the sample. The system can supply not only single band images in the visible range, but also spectrum curve of random pixel of sample image. This system can be widely used in various fields of biomedicine, clinical medicine, material science and microelectronics.

[An intelligent optometry system based on Client/Server Mode].

The optometry in physical examinations is conducted manually at present and this method is neither precise nor efficient. After studying the standard logarithmic visual acuity charts which is popular in our country, we have designed an optometry system based on Client/Server Computing Mode. The system's architecture and its working principle are also presented in the article.