Reverse hexagonal mesophase (HII) liq. crystals are provided and relating therapeutic and non-therapeutic applications are demonstrated. [on SciFinder(R)]

This invention relates to novel complex dendrimer-lyotropic liq. crystal systems for drug delivery,. A second generation polypropylenimine dendrimer was solubilized into lamellar, diamond reverse cubic and reverse hexagonal lyotropic mesophases composed of glycerol monooleate and water. [on SciFinder(R)]

The structural, dynamic, and kinetic aspects of the HII systems based on glycerol monooleate (GMO), phosphatidylcholine (PC), triacylglycerol (TAG), and water were investigated by dielec. spectroscopy in a frequency range of 10-2-106 Hz, and a temp. range of 290-320 K. Three distinct processes as well as a temp.-activated dc cond. were detected and examd. These were assigned to the reorientation of the GMO polar heads, the tangential movement of counterions at the interface, the transport of TAGs through the lipids tails, and the ion mobility within the water cylinders. Upon addn. of PC, the crit. temp. (T0) of the dehydration of the GMO headgroups increased. The optimal concn. found for structural stabilization of the HII mesophase was 10 wt% PC, since it imparted the strongest bonding at the interfacial layer and increased the assocn. between the lipid tails. Within the HII cluster, TAG percolated and shifted between the hexagonal rods themselves. The present study demonstrated the benefit of controlling the crit. temp. of the HII mesophase partial dehydration and softening, as well as the percolation of TAGs. These factors influence the diffusion mode of embedded drugs in the physiol. temp. range. [on SciFinder(R)]

In the first part of this study, a computer aided EPR anal. was performed to intensively study the Cu(II) complexation behavior of different dendrimers: (a) a series of PPI dendrimers ranging up to the fifth generation that had either a dense maltose or maltotriose shell; (b) sulfonated or carboxylated carbosilane dendrimers; (c) self-assembling amine- terminated dendrons. The Cu(II) coordination and symmetry of the generated complexes depend on the dendrimer chem. structure, the functionalization in the periphery, dendrimer generation and the ratio of the copper and dendrimer concns. As generation increased, the glycodendrimers showed (a) increased nitrogen coordination in a axial symmetry, due to the increased no. of nitrogen sites in the dendrimer interior, and (b) a rhombic structure which forms in the congested dendrimer periphery where the sugar units are also able to coordinate the copper ions. [on SciFinder(R)]

Improved technologies for the encapsulation, protection, release and enhanced bioavailability of food ingredients and nutraceutical components are vital to the development of future foods. Encapsulation technologies and delivery systems for food ingredients and nutraceuticals provides a comprehensive guide to current and emerging techniques.Part one provides an overview of key requirements for food ingredient and nutraceutical delivery systems, discussing challenges in system development and analysis of interaction with the human gastrointestinal tract. Processing technologies for enca

A review. Liq. crystal (LC) science and technol. have made important contributions to nanoscience and nanotechnol. in areas such as medical diagnostics, drug-delivery, and high-tech devices. Their main nanotechnol. contribution is their ability to provide new synthetic procedures and the self-assembly of nanoscale materials with controlled uniformity of size, shape, and dimensionality. The self-assembly of the liq. cryst. systems, particularly of the lyotropic LC type, enables the incorporation of lipophilic and hydrophilic reagents that meet to react at the interface. Therefore the properties of reactions and products are governed by the host system and by the external conditions which directly affect the LC host or template. This article attempts to present an overview of current research in the fields of synthesis and self-assembly of nanomaterials using mainly lyotropic LCs, and partially thermotropic LCs, as direct and reverse templates. [on SciFinder(R)]

A review. Liq. crystal (LC) science and technol. have made important contributions to nanoscience and nanotechnol. in areas such as medical diagnostics, drug delivery, and in high-tech devices. The major nanotechnol. contribution is their capability to provide new preparative procedures, self-assembly, and alignment of nanoscale materials with controlled uniform size, shape, and dimensionality. The self-assembly of the liq. cryst. systems, particularly the lyotropic LC type, enables the integration of lipophilic and hydrophilic reagents that meet to react at the interface. Therefore the reaction and the products properties are governed by the host liq. cryst. medium and by the external conditions (e.g., light, heat, chem. environment, and elec. and magnetic field), which directly affect the LC hosting system. This review attempts to give an overview of current research in the fields of prepn., self-assembly, and alignment of nanomaterials using mainly lyotropic LCs and partially thermotropic LCs as direct and reverse templates. [on SciFinder(R)]

Damages to articular cartilage that are caused by trauma, age-related diseases (arthritis, arthrosis) and/or phys. stress pose major medical problems. A possible soln. is to introduce a biodegradable sponge-like scaffold contg. cartilage-forming cells. In the current work we developed a model for a partially calcified functional biomedical membrane with a gradient of calcium phosphate crystal d. to form the interface between bone and a sponge-like cell contg. scaffold for cartilage regeneration. The membrane consists of a biocompatible, biodegradable, partially calcified hydrogel, in our case gelatin was used. One part is an org.-inorg. nanocomposite consisting of nanocryst. calcium phosphate particles, formed in situ within the hydrogel, while the other part is the hydrogel without inorg. crystals. The exptl. method used was one-dimensional single diffusion. Gelatin gels contg. calcium or phosphate ions, resp., were exposed from the upper side to a soln. of the other constituent ion (i.e. a sodium phosphate soln. was allowed to diffuse into a calcium contg. gel and vice versa). SEM (E-SEM), EDX, XRD and ATR-FTIR spectroscopy confirmed the existence within the gel of a d. gradient of carbonate apatite crystals, with a dense top layer extending several microns into the gel. Ca/P at. ratios were in the range characteristic of calcium deficient apatites. The effect of different exptl. parameters on the calcification process within the gelatin membranes is discussed. [on SciFinder(R)]

Micro- and macrostructural behaviors of three different lyotropic liq. crystals (LLCs) loaded with a dendrimer, namely second generation poly(propylene imine) (PPI-G2), were studied by rheol. and ESR (EPR). The three mesophases were L$\alpha$, Q224, and HII composed of glycerol monooleate (GMO) and water-PPI-G2 soln. (and d-$\alpha$-tocopherol (vitamin E) in the case of HII). We characterized the impact of PPI-G2 interactions with the components of the host mesophases on their structural characteristics on different length scales. The incorporation of PPI-G2 within the L$\alpha$ and HII systems induced the formation of more elastic hexagonal systems with a solid-like behavior, while in the Q224 system a different trend with a liq.-like behavior was obsd. As a result, the dendrimer induced a remarkable change in both the structural and viscoelastic properties of the systems. Hence, the microenvironment in the interface region within the systems was monitored by computer-aided EPR using 5-doxylstearic acid (5-DSA) as a pH-dependent probe. The microviscosity ($\tau$) and order (S) of systems were sensitive to the PPI-G2 presence: when PPI-G2 concn. increased, $\tau$ and S increased in both the L$\alpha$ and Q224 systems. In the HII systems two trends were obsd., reflecting a decrease in $\tau$ and S up to 10 wt.% PPI-G2 and subsequently their increase at higher dendrimer concns. PPI-G2 interacted strongly with the GMO hydroxyl groups in the L$\alpha$ phase, with the water mols. in the Q224 systems. In the HII mesophase strong interactions with both the water and GMO hydroxyl mols. were detected. [on SciFinder(R)]

A review on phytosterol vegetable oil organogels, phospholipid microemulsion organogels, wax-based organogels, and 12-hydroxystearic acid vegetable oil organogels. [on SciFinder(R)]

Penetratin, a cell penetrating peptide is embedded within a reversed hexagonal (HII) mesophase for improved transdermal delivery of sodium diclofenac (Na-DFC). The HII mesophase serves as the solubilization reservoir and gel matrix whereas penetratin is the transdermal penetration enhancer for the drug. The systems were characterized and the interactions between the components were detd. by SAXS, ATR-FTIR and SD-NMR. High affinity of Na-DFC to glycerol monooleate (GMO) was revealed, assocd. with increasing the order within the water channels. This affinity is enhanced upon heating and seems to be assocd. with GMO dehydration. Penetratin (PEN) is entrapped at the hydrophilic region of the HII mesophase, between the GMO headgroups, reducing the order of the system and decreasing the size of the hexagonal domains. The transdermal delivery rate of Na-DFC through porcine skin, from the HII mesophases, was enhanced by PEN and so also the cumulative transport crossing the skin. PEN induced accelerated drug diffusion through the stratum corneum, towards the different skin layers. The transdermal delivery enhancement is explained from the results of the ATR-FTIR anal. It seems that PEN accelerates the structural transition of skin lipids from hexagonal to liq. The disordering results in enhanced diffusion of Na-DFC through the stratum corneum, followed by enhanced overall penetration of the drug. [on SciFinder(R)]

A review. Nonlamellar lipid-based liq. cryst. structures, such as cubic, hexagonal, and sponge phases, have potential as delivery systems in pharmaceutical, food, and cosmetic applications. This is due to the space-dividing nature of these phases, which features mono- or bicontinuous networks of both hydrophilic and hydrophobic domains. To utilize these nonlamellar liq. cryst. structures as delivery vehicles, it is crucial to understand how they interact with and respond to different types of interfaces. The progress in the area of liq. cryst. lipid-based nanoparticles opens up new possibilities for prepn. of well-defined surface films with well-defined nanostructure. Apart from the relevance to drug delivery, such studies create opportunities for new applications for functionalized and tunable surface coatings as well. This review will focus on recent progress in the formation of nonlamellar dispersion and its interfacial properties at the solid-liq. and biol. relevant interfaces. Various exptl. techniques on the study of interfacial interactions of these cryst. structures will be discussed. [on SciFinder(R)]

A review. The most prominent feature of surfactants is their ability to self-assoc. and form discrete aggregates in aq. dispersions. Among the various self-assembled structures that are produced (vesicles, membranes, liq. crystals, etc.), micelles represent the simplest class of assocn. colloids, and are widely used as nano-architectures for different applications. In spite of the vast literature, a complete understanding of all the exptl. evidences related to the micellization process is still a work in progress. In particular, the thermodn. and kinetics of micellization provide the crucial concepts for the control of dissocn. and reconstruction of micelles, such as in the solubilization, stabilization and delivery of active ingredients, and in cosmetics, detergents, food technol., and in pharmaceutical formulations. In this contribution, we offer an overview of the various structures formed by self-assembling amphiphilic mols. in water. The basic thermodn. involved in self-assembly is described, and an overview of the exptl. techniques used in the characterization of the structure and properties of these nanostructures is given. [on SciFinder(R)]

A review on immunonanoparticles (immunoNPs) as promising drug-targeting, colloidal carriers, that can ensure the specific recognition of the antigen site and, using the colloidal delivery system, release cytotoxic agents close to the inaccessible pathol. target tissues-over-expressing tumor antigen. The main approaches used for the coupling of monoclonal antibodies (MAbs) to NPs are reviewed. In addn., the preclin. achievements of NP formulations conjugated to various MAbs are described and updated. Also addressed is the synergistic importance of the MAbs as targeting moieties on immunoNP formulations as compds. that not only target specific pathol. organs, but also ensure increased therapeutic activity of the drug-loaded NPs by actually internalizing them within the desired cells. [on SciFinder(R)]