The Preparation Of Multifunctional Nanoparticles And Their Use Of Inducing K562 Cells Apoptosis

Nanotechnology is an emerging subject developed from multiprinciples and it enjoys a wide application prospect in biology, medicine, materials, environment, chemistry and so on. The exploration and application of nanomaterials plays a core role in the development of nanoscience. Recently, with the constantly penetration of nanoscience to life science, it has been an important frontier area to utilize nanobiological technology and solve great problems so as to advance the development of nanobiological technology. Nano-fluorescent materials, magnetic materials are paid more attention in life science and medical areas. This paper is focused on the research of the complex which are composed of nanoparticles and bio-molecules and the application of the complex in the inducing K562 Cells apoptosis.(1)A thin silica-coating layer encapsulating the bareγ-Fe2O3 nanoparticles and organic fluorescent dyestuff FITC was formed by a base-catalyzed hydrolysis and polymerization reaction of tetraethoxysilane (TEOS) in reverse microemulsion. The surface of the nanoparticles was modified with active agent. The experimental results show that the structure of core-shell is successfully synthesized and the synthesized nanoparticle has uniform size in diameter, very fine monodispersion in suitable condition and good fluorescent intensity.(2)RNA interference is the post-transcriptional gene silence induced by dsRNA. In this paper, quantum dots were used as a vector and conjugated with a double-stranded siRNA. Through phagorytosis this conjugate can be successfully transferred into K562 cells. The double-stranded siRNA (siRNAs) were designed to knock down the bcr/abl oncogene in leukaemia K562 cells. Using such a construct, the delivery and transfection of the siRNA can be monitored by the presence of fluorescent QDs in the conjugates. QDs not only exhibit superior photostability for labeling cells but also work as a good vector that successfully transfers siRNA into cells. Cell proliferation was illustrated by MTT assay and cell apoptosis by FACS. Our data suggests that this QD-siRNA conjugate can efficiently inhibit the viability of K562 cells and induce apoptosis. Thus, QDs can be considered strong tools for functional analysis of RNAi. The delivery and conjunction of these self-track QD-siRNA complexes will be helpful for research of in vivo gene silence.(3)Based on the theory of the nano technology and the antisense, semiconductor nanoparticles (quantum dots)-nucleotides complexes were synthesized. The antisense nucleotides with specific sequence were conjugated to the surface of the red quantum dots to form the quantum dots-antisense nucleotides complexes. After cultured with the K562 cells, the complexes could specifically locate in the nucleus of the cells and induced the apoptosis of the cancer cells. The results were characterized by the laser confocal fluorescence microscope and other equipments. All results indicated that the red quantum dots-antisense nucleotides complexes located in the chromosome in the nucleus of the cells .And, more importantly, the experiment made the course of the cancer cell apoptosis induced by the antisense nucleotides visible, which supplied a technology platform for the diagnosis and treat of the cancer in medical area.