Irregular-Shaped Fe3O4 Nanoparticles-Mediated Magneto-Mecha nical Force for Killing Tumor Cell / 医用生物力学

Objective To investigate tumor cell killing effect of superparamagnetic Fe3O4 nanoparticles with cubic phase through magneto-mechanical force under a low-frequency vibrating magnetic field ( VMF). Methods A kind of strong magnetic and irregular-shaped Fe3O4 nanoparticles with cubic phase was synthesized by coprecipitation method. The Fe3O4 nanoparticles were exposed to a self-developed VMF and cell killing efficiency of the Fe3O4-mediated magneto-mechanical force was investigated. Results VMF alone had no effects on cell viability. After Fe3O4 nanoparticles were added, the cell viability significantly decreased with prolonging the VMF treatment time and increasing the Fe3O4 nanoparticle concentration. Lactate dehydrogenase released by damaged cells also increased with prolonging the VMF exposure time. Conclusions The irregular-shaped Fe3O4 nanoparticles can transfer magneto-mechanical force to tumor cells under VMF, cause structural damage of cells and result in cell death. The VMF generator developed in this study has simple structure and it is safe for use and convenient for operation. The developed magnetic nanoparticles and the corresponding cancer cell killing technique have the potential for clinical transformation.

Application of quantum dots fluorescent nanoprobes in following the migration of inflammatory cells from local tissue to draining lymph node / 生物医学工程学杂志

Quantum dots (QDs) have favorable physical and photochemical properties. In this work, we used QDs fluorescent nanoprobes to follow the migration of inflammatory cells from local tissue to draining lymph node in inflammation resolution. Electric pulse stimulation was used to establish inflammation model in mouse tibialis anterior. QDs injected to inflammatory tissue were found to aggregate and endocytosed by inflammatory cells. While in the draining lymph node, QDs mainly distributed in the T cell area. TEM and confocal observation showed that most of QDs in the draining lymph node were located in the endosomes of monocytes/macrophages. Our work shows that QDs can be used as fluorescent probes to follow migration of cells especially phagocytic cells. Thus QDs may be explored in application in immunology research.

Preparation and characterization of quantum dots-peptides bioconjugations and their specificity related to recognizing tumor cells / 生物医学工程学杂志

Water-soluble CdTe quantum dots synthesized in aqueous solution have been conjugated with peptide LyP-1 using N-Succinimidyl 3-[2-pyridyldithio]-propionate (SPDP) as a cross-linking reagent. Capillary electrophoresis (CE), UV-Vis absorption and photoluminescent (PL) spectra suggested that the peptide had been successfully linked to the QDs. The QDs-peptides conjugates could specifically recognize the lung adenoma cancer cells (SPCA-1), but did not recognize promyelocytic leukemia cells (HL-60).

Effect of temperature on concentration of active components extracted from medicinal herb / 中草药

Object To develop a mathematical model on the relationship between the temperature used in the course of extraction of medicinal herbs and the concentration of active component obtained Methods Based on the kinetic model on medicinal herb extraction process reported in our previous article *, diffusion coefficient and concentration gradient varying with temperature were further studied Results The process which tanshinone was extracted from Salvia miltiorrhiza Bge at different temperatures showed that the model could well match the experimental data Conclusion The relation between the temperature and the concentration of active component could be described by this model