Dendrimer biocompatibility and toxicity.

The literature on open-framework materials has shown numerous examples of porous solids with additional structural, chemical, or physical properties. These materials show promise for applications ranging from sensing, catalysis and separation to multifunctional materials. This critical review provides an up-to-date survey to this new generation of multifunctional open-framework solids. For this, a detailed revision of the different examples so far reported will be presented, classified into five different sections: magnetic, chiral, conducting, optical, and labile open-frameworks for sensing applications. (413 references.)

Old materials with new tricks: multifunctional open-framework materials.

This article reviews the recent trends, developments, and future applications of bio-based polymers produced from renewable resources. Bio-based polymers are attracting increased attention due to environmental concerns and the realization that global petroleum resources are finite. Bio-based polymers not only replace existing polymers in a number of applications but also provide new combinations of properties for new applications. A range of bio-based polymers are presented in this review, focusing on general methods of production, properties, and commercial applications. The review examines the technological and future challenges discussed in bringing these materials to a wide range of applications, together with potential solutions, as well as discusses the major industry players who are bringing these materials to the market.

/pdf/current-progress-on-bio-based-polymers-and-their-future-1tqmkeshuf.pdf

Current progress on bio-based polymers and their future trends

Lipid nanoparticles for improved topical application of drugs for skin diseases.

Polymers occupy a major portion of materials used for controlled release formulations and drug-targeting systems because this class of materials presents seemingly endless diversity in topology and chemistry. This is a crucial advantage over other classes of materials to meet the ever-increasing requirements of new designs of drug delivery formulations. The polymer architecture (topology) describes the shape of a single polymer molecule. Every natural, seminatural, and synthetic polymer falls into one of categorized architectures: linear, graft, branched, cross-linked, block, star-shaped, and dendron/dendrimer topology. Although this topic spans a truly broad area in polymer science, this review introduces polymer architectures along with brief synthetic approaches for pharmaceutical scientists who are not familiar with polymer science, summarizes the characteristic properties of each architecture useful for drug delivery applications, and covers recent advances in drug delivery relevant to polymer architecture.

Polymer Architecture and Drug Delivery

Novel transdermal drug delivery system with polyhydroxyalkanoate and starburst polyamidoamine dendrimer.

Mechanism of enhancement effect of dendrimer on transdermal drug permeation through polyhydroxyalkanoate matrix.

Montmorillonite, a bioinert clay mineral, was examined as a novel vector for an oral gene-delivery system. The complex of montmorillonite and plasmid DNA encoding the enhanced green fluorescent protein (EGFP) gene was prepared at various weight ratios, and then transfected into cultured intestinal epithelial cells (IEC-6) in vitro. The EGFP gene was clearly transcribed when the transfection was performed using the montmorillonite-plasmid complex at a weight ratio of 0.05:1. In contrast, no gene expression was detected by reverse transcription-polymerase chain reaction (RT-PCR) analysis when the transfection was performed with naked plasmid. Various plasmid preparations were given orally to mice, and the gene expression in the stomach and small intestine was examined by RT-PCR. Although no gene expression was detected in the mice receiving an oral administration of naked plasmid or polyethyleneimine-plasmid complex, the EGFP gene complexed with montmorillonite was expressed in the small intestine. These results indicate that montmorillonite protected the plasmid DNA from the acidic environment in the stomach and DNA-degrading enzymes in the intestine, and successfully delivered it into cells of the small intestine.

https://www.jstage.jst.go.jp/article/bpb/27/12/27_12_2049/_pdf

Protective effect of montmorillonite on plasmid DNA in oral gene delivery into small intestine.

The title compound, a new polymorphic phase of dicobalt diphosphate, Co2P2O7, was prepared by hydrothermal methods. The structure contains CoO6 coordination octahedra and P2O7 radicals. The CoO6 radicals, connected by edge sharing, form six-membered rings, which are further interconnected to form two-dimensional zigzag sheets parallel to (001). The P2O7 groups link these sheets to build three-dimensional networks.

Structure d'un Diphosphate Synthétique de Cobalt: Co2P2O7

Dielectric measurements were carried out on suspensions of montmorillonite clay exchanged with three different counterions: sodium, ammonium, and tetramethylammonium (TMA). Only two dielectric absorption peaks could be identified for the clay sample with the TMA counterion, whereas three peaks were found for the two inorganic counterions. The dielectric process observed at around 10 GHz is due to the orientation of bulk water molecules, judging from the relaxation time and relaxation strength. The relaxation strength of the process occurring at around 10 MHz was compared with the coefficient of adiabatic compressibility obtained from ultrasound velocity measurements. The increase in the relaxation strength with decreasing compressibility indicates that the process at around 10 MHz is caused by the orientation of bound water molecules on the clay samples. The relaxation strength of the process occurring at around 10 MHz for the TMA sample was remarkably small. Furthermore, the network structure of the bound water molecules can be characterized by a property peculiar to the TMA sample, taking into account the value of its Cole-Cole parameter. Results for the relaxation strength of the process occurring at around 100 kHz were compared with those for electrophoretic mobility. This comparison revealed that discrimination between bound ions and ions in the diffuse double layer is important, and both the relaxation and electrophoretic results could be satisfactorily explained by surface polarization of the clay.

Junji Yamakawa

Papers

Novel transdermal drug delivery system with polyhydroxyalkanoate and starburst polyamidoamine dendrimer.

Mechanism of enhancement effect of dendrimer on transdermal drug permeation through polyhydroxyalkanoate matrix.

Protective effect of montmorillonite on plasmid DNA in oral gene delivery into small intestine.

Structure d'un Diphosphate Synthétique de Cobalt: Co2P2O7

Effects of the counterion on dielectric spectroscopy of a montmorillonite suspension over the frequency range 105–1010 Hz