Synthesis, Crystal Structures and Luminescence Properties of Three New Cadmium 3D Coordination Polymers.

: The new rigid planar ligand 2,5-bis(3-(pyridine-4-yl)phenyl)thiazolo[5,4-d]thiazole (BPPT) has been synthesized, which is an excellent building block for assembling coordination polymer. Under solvothermal reaction conditions, cadmium ion with BPPT in the presence of various carboxylic acids including (1,1'-biphenyl)-4,4'-dicarboxylic acid (BPDC), isophthalic acid (IP), and benzene-1,3,5-tricarboxylic acid (BTC) gave rise to three coordination complexes, viz, [Cd(BPPT)(BPDA)](BPPT)n (1), [Cd(BPPT) (IP)] (CH3OH) (2), and [Cd3(BPPT)3(BTC)2(H2O)2] (3). The structures of 1, 2, and 3 were characterized by single crystal X-ray diffraction. The IR spectra as well as thermogravimetric and luminescence properties were also investigated. Complex 1 is a two-dimensional (2D) network and further stretched to a 3D supramolecular structure through π-π stacking interaction. The complexes 2 and 3 show 3D framework. The complexes 1, 2, and 3 exhibited luminescence property at room temperature.

Preparation and In Vitro Evaluation of a Nano Ultrasound Contrast Agent Targeting Pancreatic Cancer.

To prepare a nano-sized ultrasound contrast agent that specifically targets pancreatic cancer cells and to evaluate its targeting effect In Vitro. PLGA-PEG-NHS was synthesized using PLGA, NHS, and PEG and detected using 1H-NMR. PLGA-PEG-NHS and PFOB were used to prepare PLGA nano contrast agent coated with PFOB by emulsification and volatilization, and then a hedgehog antibody was conjugated. The morphology of the nano contrast agent was observed using a transmission electron microscope, and its particle size and potential were measured using the dynamic light scattering method. The entrapment and drug loading efficiency of the nano contrast agent was measured using gas chromatography-mass spectrometry. The In Vitro release characteristics of the nano contrast agent was measured using the dialysis method. Human pancreatic cancer cell lines SW1990 and CFPAC1 were cultured in medium containing the nano contrast agent. The targeting ability of the nano contrast agent was qualitatively and quantitatively verified using fluorescence microscopy and flow cytometry. The average particle size of the targeted ultrasound contrast agent was 198.9 nm, zeta potential was -31.8 mv, entrapment rate was 63.7±3.9%, drug loading efficiency was 14.3±0.9%, and drug release was 85.3% in 48 h. In Vitro cell experiments showed that the targeted ultrasound contrast agent strongly bound to SW1990 cells with high expression of hedgehog antigen, but no specific binding was detected in CFPAC-1 cells which lack the hedgehog antigen. The nano ultrasound contrast agent prepared by emulsification and volatilization method can be potentially used for the diagnosis of pancreatic cancer.

In vivo gene transfer using sulfhydryl cross-linked PEG-peptide/glycopeptide DNA co-condensates.

Recent interest in sulfhydryl cross-linked nonviral gene delivery systems, designed to trigger the intracellular release of DNA, has inspired studies to establish their utility in vitro. To determine if this concept can be extrapolated to in vivo gene delivery, sulfhydryl cross-linking peptides (dp 20), derivatized with either an N-glycan or polyethylene glycol (PEG), were used to generate sulfhydryl cross-linked gene formulations. The biodistribution, metabolism, cell-type targeting, and gene expression of sulfhydryl cross-linked PEG-peptide/glycopeptide DNA co-condensates were examined following i.v. dosing in mice. Optimal targeting to hepatocytes was achieved by condensing (125)I-DNA with an add-mixture of 10 mol % triantennary glycopeptide, 5 mol % PEG-peptide, and 85 mol % backbone peptide. Four backbone peptides were substituted into the formulation to examine the influence of peptide metabolism and disulfide bond strength on the rate of DNA metabolism and the level of gene expression in vivo. The half-life of DNA in liver was extended from 1 to 3 h using a backbone peptide composed of d-amino acids, whereas substituting penicillamine for cysteine failed to further increase the metabolic stability of DNA. Optimized gene delivery formulations transiently expressed secreted alkaline phosphatase in mouse serum for 12 days. The results suggest that disulfide bond reduction in liver hepatocytes proceeds rapidly, followed by peptide metabolism, ultimately limiting the metabolic half-life of sulfhydryl cross-linked DNA condensates in vivo.

Comparative stability of repackaged metoprolol tartrate tablets.

The stability of metoprolol tartrate tablets packaged in original high density polyethylene containers and repackaged in USP Class A unit-dose blister packs was investigated. Studies were conducted at 25 degrees C/60% relative humidity (RH) for 52 weeks and at 40 degrees C/75% RH for 13 weeks. The potency, dissolution, water content, loss on drying and hardness of the drug products were analyzed. Results indicated no differences in the stability between the tablets in both packages stored under 25 degrees C/60% RH. No difference in potency was found in both packages under either condition. However, a significant weight increase due to moisture uptake was observed for the repackaged tablets stored under 40 degrees C/75% RH. The weight increase was accompanied by a decrease in tablet hardness (6.5-0 kp) and a increase in dissolution rate (51-92%) in 5 min. Near-infrared (NIR) chemical imaging also monitored moisture uptake of the tablet non-invasively through the package. The observed changes in product stability may adversely affect the products bioavailability profile, even though the potency of the active drug remained within USP specification range of 90-110%. Study results suggest product quality can be negatively impacted even when using USP Class A repackaging materials.