Anti-tumor effects of brucine immuno-nanoparticles on hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma is difficult to diagnose early, and most patients are already in the late stages of the disease when they are admitted to hospital. The total 5-year survival rate is less than 5%. Recent studies have showed that brucine has a good anti-tumor effect, but high toxicity, poor water solubility, short half-life, narrow therapeutic window, and a toxic dose that is close to the therapeutic dose, which all limit its clinical application. This study evaluated the effects of brucine immuno-nanoparticles (BIN) on hepatocellular carcinoma. MATERIALS AND METHODS: Anionic polymerization, chemical modification technology, and phacoemulsification technology were used to prepare a carboxylated polyethylene glycol-polylactic acid copolymer carrier material. Chemical coupling technology was utilized to develop antihuman AFP McAb-polyethylene glycol-polylactic acid copolymer BIN. The size, shape, zeta potential, drug loading, encapsulation efficiency, and release of these immune-nanoparticles were studied in vitro. The targeting, and growth, invasion, and metastasis inhibitory effects of this treatment on liver cancer SMMC-7721 cells were tested. RESULTS: BIN were of uniform size with an average particle size of 249 ± 77 nm and zeta potential of -18.7 ± 4.19 mV. The encapsulation efficiency was 76.0% ± 2.3% and the drug load was 5.6% ± 0.2%. Complete uptake and even distribution around the liver cancer cell membrane were observed. CONCLUSION: BIN had even size distribution, was stable, and had a slow-releasing effect. BIN targeted the cell membrane of the liver cancer cell SMMC-7721 and significantly inhibited the growth, adhesion, invasion, and metastasis of SMMC-7721 cells. As a novel drug carrier system, BIN are a potentially promising targeting treatment for liver cancer.

Functionalized halloysite nanotube-based carrier for intracellular delivery of antisense oligonucleotides.

Halloysites are cheap, abundantly available, and natural with high mechanical strength and biocompatibility. In this paper, a novel halloysite nanotube [HNT]-based gene delivery system was explored for loading and intracellular delivery of antisense oligodeoxynucleotides [ASODNs], in which functionalized HNTs [f-HNTs] were used as carriers and ASODNs as a therapeutic gene for targeting survivin. HNTs were firstly surface-modified with γ-aminopropyltriethoxysilane in order to facilitate further biofunctionalization. The f-HNTs and the assembled f-HNT-ASODN complexes were characterized by transmission electron microscopy [TEM], dynamic light scattering, UV-visible spectroscopy, and fluorescence spectrophotometry. The intracellular uptake and delivery efficiency of the complexes were effectively investigated by TEM, confocal microscopy, and flow cytometry. In vitro cytotoxicity studies of the complexes using MTT assay exhibited a significant enhancement in the cytotoxic capability. The results exhibited that f-HNT complexes could efficiently improve intracellular delivery and enhance antitumor activity of ASODNs by the nanotube carrier and could be used as novel promising vectors for gene therapy applications, which is attributed to their advantages over structures and features including a unique tubular structure, large aspect ratio, natural availability, rich functionality, good biocompatibility, and high mechanical strength.

[A new method for isolating CD34(+) cells based on complex of magnetic nanoparticles and antibody].

The purpose of this study was to synthesize the complex of magnetic nanoparticles and antibody, and to apply them to isolate the CD34(+) cells from umbilical cord blood, then to evaluate its separation efficiency. The complex of magnetic nanoparticles and antibody was used to separate CD34(+) cells from umbilical cord blood in the outer magnetic field because of its superparamagnetism, specific identification and function of combination with CD34(+) cells. Scanning electron microscopy was used to observe the morphology of the separated CD34(+) cells. Flow Cytometer was applied to evaluate the sorting efficiency of magnetic nanoparticles, liquid culture and colony culture were taken to assay proliferation and differentiation capacity of the separated CD34(+) cells. The results showed that the CD34(+) cells from umbilical cord blood were isolated fast and effectively by the complex of magnetic nanoparticles and monoclonal antibody. Moreover, the isolated CD34(+) cells still maintained its normal morphology, highly proliferative and differentiative capacity. It is concluded that the complex of magnetic nanoparticles and monoclonal antibody has been successfully synthesized and developed as a technique which efficiently and quickly isolates CD34(+) cells from umbilical cord blood.

Magnetic force microscopy analysis of apoptosis of HL-60 cells induced by complex of antisense oligonucleotides and magnetic nanoparticles.

Magnetic force microscopy (MFM) has been employed to observe antisense oligonucleotides (ASOs)-coupled silica-coated magnetic iron oxide nanoparticles (SMNPs) internalized into human leukemia (HL-60) cells. The experiment demonstrated that the ASOs-coupled SMNPs delivery into the cells really occurred. The nanoparticles were internalized into the cells and the apoptotic topography can be directly visualized simultaneously with MFM technology. These present observations offer direct morphology evidence on studying the apoptosis of tumor cells and provide useful information for better design of new diagnostic and therapeutic tools in tumor treatment.

Polymerase chain reaction of nanoparticle-bound primers.

Using one or two primers respectively bound to the surface of Au nanoparticles (AuNPs) or magnetic nanoparticles (MNPs), polymerase chain reaction (PCR) based on nanoparticles was systemically studied, agarose gel electrophoresis and atomic force microscopy (AFM) were respectively used to detect and observe the PCR product. The results obtained indicated that with either one or two primers respectively bound to the nanoparticle surface, PCR can proceed successfully under optimized condition and is subject to certain rules, consequently a symmetric PCR technique and an asymmetric PCR technique based on nanoparticles have been developed. A kind of nanostructured aggregates can be constructed by a symmetric PCR using two nanoparticle-bound primers.

[Ion fluorescence probe detecting the formation of triplex DNA].

The fluorescence of Tb3+ is not quenched after the rare earth ion is combined with DNA. The fluorescence intensity is related not only to the kinds of bases of DNA but also to the kinds of DNA. The rare earth ion Tb3+ was used as the fluorescence probe to detect the formation of triplex DNA. The results show that the fluorescence intensity of Tb3+ combined with polydA is much stronger than that of Tb3+ combined with polydT, which testifies that the fluorescence intensity is related to the kinds of bases combined with Tb3+. The results also demonstrate that the rare earth ion can be used to detect those three forms of DNA though their fluorescence peak positions are similar when Tb3+ as a fluorescence probe is combined with single strand DNA (ssDNA), double helix DNA (dsDNA), and triple helix DNA (tsDNA), respectively. However, their intensities are quite different. The fluorescence intensity of Tb3+ combined with ssDNA-Tb3+ is the largest. And the fluorescence intensity of Tb3+ combined with tsDNA-Tb3+ takes the second place. The minimum peak intensity belongs to the contribution of Tb3+ coupled with dsDNA-Tb3+. The reason is that the capability of energy transference of ssDNA, dsDNA and tsDNA is different. The different degree of energy transference influences the intensities of Tb3+. The influences of pH and the metal ion on the formation of triplex DNA were also studied. The authors found that the neutral pH and high valence metal ion are beneficial to the formation of ts-DNA.