Coagulation factor IX gene transfer to non-human primates using engineered AAV3 capsid and hepatic optimized expression cassette

Hepatic gene transfer with adeno-associated viral (AAV) vectors shows much promise for the treatment of the X-linked bleeding disorder hemophilia B in multiple clinical trials. In an effort to further innovate this approach and to introduce alternative vector designs with potentially superior features into clinical development, we recently built a vector platform based on AAV serotype 3 because of its superior tropism for human hepatocytes. A vector genome with serotype-matched inverted terminal repeats expressing hyperactive human coagulation factor IX (FIX)-Padua was designed for clinical use that is optimized for translation using hepatocyte-specific codon-usage bias and is depleted of immune stimulatory CpG motifs. Here, this vector genome was packaged into AAV3 (T492V + S663V) capsid for hepatic gene transfer in non-human primates. FIX activity within or near the normal range was obtained at a low vector dose of 5 x 10(11) vector genomes/kg. Pre-existing neutralizing antibodies, however, completely or partially blocked hepatic gene transfer at that dose. No CD8(+) T cell response against capsid was observed. Antibodies against the human FIX transgene product formed at a 10-fold higher vector dose, albeit hepatic gene transfer was remarkably consistent, and sustained FIX activity in the normal range was nonetheless achieved in two of three animals for the 3-month duration of the study. These results support the use of this vector at low vector doses for gene therapy of hemophilia B in humans

Porosity, Pore Size Distribution and Chloride Permeability of Shotcrete Modified with Nano Particles at Early Age

Nano particles have been found to be effective in enhancing many properties of regular concretes. However, there is little information on the effect of nano particles on shotcrete. In fact, if similar positive effect of nano particles can also appear in shotcrete, they will greatly benefit the wide application of shotcrete in more and more repair and strengthening of structures in civil engineering, especially in corrosive environments. In this study, through experiments on 70 specimens, the effects of nano SiO2, CaCO3 and Al2O3 particles on the early-age porosity, pore size distribution, compressive strength and chloride permeability of shotcrete were investigated.Test results indicated that nano SiO2 particles significantly increased the compressive strength and chloride penetration resistance; nano Al2O3 and CaCO3 particles had slight enhancing effect on the compressive strength; nano CaCO3 particles were most effective in promoting the chloride penetration resistance of shotcrete. As a conclusion, nano SiO2 particles were recommended when both early age compressive strength and chloride penetration resistance were crucial, and nano CaCO3 particles were recommended when only chloride penetration resistance was concerned for their high cost-effectiveness

Bioinspired Peptide for Imaging Hg²⁺ Distribution in Living Cells and Zebrafish Based on Coordination-Mediated Supramolecular Assembling

Peptides with modular structure provide a tailorable platform for constructing responsive supramolecular assemblies, which are attractive as functional biomaterials and smart sensors. In this work, the feasibility of regulating small peptides assembly with molecular design and metal ion recognition was demonstrated. Tripeptides were designed and found to have diverse response and self-assembly behavior to Hg²⁺. The incorporation of an aggregation-induced emission fluorophore TPE enabled the visualization of Hg²⁺ recognition and the assembly phenomenon. A structural analogue (Pep<b>2</b>) to γ-glutathione was identified with high specificity and nanomolar response to Hg²⁺ both in buffer solution and living cells. Driven by the coordination force and noncovalent intramolecular stacking, assembling of twisted nanofibers from Pep<b>2</b>-TPE and Hg²⁺ were observed. Benefiting from its biocompatibility, fast and switchable fluorescence response, Pep<b>2</b>-TPE was applied for imaging and monitoring Hg²⁺ distribution in living cells and zebrafish. With good permeability to plasma membrane and tissues, Pep<b>2</b>-TPE indicated the preferential distribution of Hg²⁺ in cell nucleoli and brain of zebrafish, which is related with the deleterious effect of inorganic mercury in living biosystems

Fluorescence Turn-On Chemosensor for Highly Selective and Sensitive Detection and Bioimaging of Al³⁺ in Living Cells Based on Ion-Induced Aggregation

Herein, a new fluorescence turn-on chemosensor 2-(4-(1,2,2-triphenylvinyl)­phenoxy)­acetic acid (TPE-COOH) specific for Al³⁺ was presented by combining the aggregation-induced-emission (AIE) effect of tertaphenylethylene and the complexation capability of carboxyl. The introduction of carboxylic group provides the probe with good water-solubility which is important for analyzing biological samples. The recognition toward Al³⁺ induced the molecular aggregation and activated the blue fluorescence of the TPE core. The high selectivity of the probe was demonstrated by discriminating Al³⁺ over a variety of metal ions in a complex mixture. A detection limit down to 21.6 nM was determined for Al³⁺ quantitation. Furthermore, benefiting from its good water solubility and biocompatibility, imaging detection and real-time monitoring of Al³⁺ in living HeLa cells were successfully achieved. The AIE effect of the probe enables high signal-to-noise ratio for bioimaging even without multiple washing steps. These superiorities make this probe a great potential for the functional study and analysis of Al³⁺ in complex biosystems