Viral mimicking ternary polyplexes: a reduction-controlled hierarchical unpacking vector for gene delivery.

Reduction-controlled hierarchical unpacking is proposed for the development of virus-mimicking gene carriers. Disulfide-bond-modified hyaluronic acid (HA) is deposited onto the surface of diselenide-conjugated oligoethylenimine/DNA polyplexes to form DNA/OEI-SeSex/HA-SS-COOH (DOS) polyplexes. The cleavage of the disulfide and diselenide bonds is triggered by the gradient GSH level at the tumor site and inside the cells. The transfection efficiency of DOS show significant enhancement over DNA/poly(ethylene imine) (DP) in vitro and in vivo.

Photodynamic activity of viral nanoparticles conjugated with C60.

The development of viral nanoparticles (VNP) displaying multiple copies of the buckyball (C(60)) and their photodynamic activity is described. VNP-C(60) conjugates were assembled using click chemistry. Cell uptake and cell killing using white light therapy and a prostate cancer cell line is demonstrated.

Label-free chemiresistive immunosensors for viruses.

We report development, characterization, and testing of chemiresistive immunosensors based on single polypyrrole (Ppy) nanowire for highly sensitive, specific, label free, and direct detection of viruses. Bacteriophages T7 and MS2 were used as safe models for viruses for demonstration. Ppy nanowires were electrochemically polymerized into alumina template, and single nanowire based devices were assembled on a pair of gold electrodes by ac dielectrophoretic alignment and anchored using maskless electrodeposition. Anti-T7 or anti-MS2 antibodies were immobilized on single Ppy nanowire using EDC-NHS chemistry to fabricate nanobiosensor for the detection of corresponding bacteriophage. The biosensors showed excellent sensitivity with a lower detection limit of 10(-3) plaque forming unit (PFU) in 10 mM phosphate buffer, wide dynamic range and excellent selectivity. The immunosensors were successfully applied for the detection of phages in spiked untreated urban runoff water samples. The results show the potential of these sensors in health care, environmental monitoring, food safety and homeland security for sensitive, specific, rapid, and affordable detection of bioagents/pathogens.

[Advancement on thrombolytic characteristic, function and clinical application of different fibrinolytic enzymes].

Cardio-cerebral vascular diseases endanger people's health very seriously. Thrombolytic therapy is effective in curing thrombotic diseases at present. Microorganism is an important source of thrombolytic drug. Plasminogen activators are widely used as thrombolytic drugs clinically, while they are still exists some defects. This article analyzed research and development status of kinds of thrombolytic drugs from microorganisms, and evaluated their clinical efficacy and safety, aiming at showing the direction to search new and effective thrombolytic drugs and prevent and treat thromboembolic disease.

[Establishment of bioassay method for antivirus potency of radix isatidis based on chemical fluorometric determination].

In the present study, the in vitro inhibitory activity of extracts from radix isatidis on neuraminidase (NA) was investigated by the chemical fluoremetic determination to establish the quality control method for antivirus action of radix isatidis. The initial study indicated that radix isatidis had obvious in vitro inhibitory activity on NA with IC50 = (0.90 +/- 0.20) mg (herb) x mL(-1). The correlation between logarithmic dose and reaction rate showed a "S" shape and a linear curve (linear equation, y = 8.7259 + 1.2169 x log(D), R = 0.9992) when the reaction rate was converted to probit-quite similar to Tamiflu's reaction curve, which hinted that radix isatidis had the same inhibitory function on NA as Tamiflu. According to the reaction type and the regularity of "parallel lines of qualitative effect", the experimental condition was optimized and a statistic method was confirmed based on the principle of bioassay statistic. Then the bioassay method for antivirus potency of radix isatidis based on fluorometric determination was established. The results of bio-potency assay showed the qualitative differences of radix isatidis samples sensitively and quantitatively. Meanwhile, this method has good reproducibility with RSD = 5.78% and reliability. The quality bioassay control method based on chemical fluorometric determination can reflect the pharmaco-dynamic features of Chinese medicine herb.

Inorganic nanoparticles for transfection of mammalian cells and removal of viruses from aqueous solutions.

Owing to their small size, synthetic nanoparticles show unprecedented biophysical and biochemical properties which may foster novel advances in life-science research. Using flame-spray synthesis technology we have produced non-coated aluminum-, calcium-, cerium-, and zirconium-derived inorganic metal oxide nanoparticles which not only exhibit high affinity for nucleic acids, but can sequester such compounds from aqueous solution. This non-covalent DNA-binding capacity was successfully used to transiently transfect a variety of mammalian cells including human, reaching transfection efficiencies which compared favorably with classic calcium phosphate precipitation (CaP) procedures and lipofection. In this straightforward protocol, transfection was enabled by simply mixing nanoparticles with DNA in solution prior to addition to the target cell population. Transiently transfected cells showed higher production levels of the human secreted glycoprotein SEAP compared to isogenic populations transfected with established technologies. Inorganic metal oxide nanoparticles also showed a high binding capacity to human-pathogenic viruses including adenovirus, adeno-associated virus and human immunodeficiency virus type 1 and were able to clear these pathogens from aqueous solutions. The DNA transfection and viral clearance capacities of inorganic metal oxide nanoparticles may provide cost-effective biopharmaceutical manufacturing and water treatment in developing countries.