Preparation, characterization and in vivo evaluation of pH sensitive, safe quercetin-succinylated chitosan-alginate core-shell-corona nanoparticle for diabetes treatment.

The study aims for development of an efficient polymeric carrier for evaluating pharmaceutical potentialities in modulating the drug profile of quercetin (QUE) in anti-diabetic research. Alginate and succinyl chitosan are focused in this investigation for encapsulating quercetin into core-shell nanoparticles through ionic cross linking. The FT-IR, XRD, NMR, SEM, TEM, drug entrapment and loading efficiency are commenced to examine the efficacy of the prepared nanoparticles in successful quercetin delivery. Obtained results showed the minimum particle size of ∼91.58nm and ∼95% quercetin encapsulation efficiently of the particles with significant pH sensitivity. Kinetics of drug release suggested self-sustained QUE release following the non-fickian trend. A pronounced hypoglycaemic effect and efficient maintenance of glucose homeostasis was evident in diabetic rat after peroral delivery of these quercetin nanoparticles in comparison to free oral quercetin. This suggests the fabrication of an efficient carrier of oral quercetin for diabetes treatment.

Splay-bend elasticity of a nematic liquid crystal with T-shaped molecules.

We measured the splay (K11) and bend (K33) elastic constants in the nematic phase of a liquid crystal with T-shaped molecules. We find that the ratio, K33/K11 ≃1 in the entire nematic range except very close to the nematic to Sm-A (SN) transition. Both K33 and K11 show pretransitional divergence as the SN transition is approached from higher temperature. The ratio, K33/K11 suggests that the length (L) to effective width (D) ratio (i.e., L/D ) is significantly smaller due to the presence of long and flexible lateral group, compared to that of rigid rodlike molecules. It is argued that apart from the extra contribution to the elasticity the long and flexible lateral group also has a significant contribution to the suppression of the splay fluctuations in the onset of smectic short-range fluctuation. The structure of the Sm-A phase is investigated by using small angle x-ray diffraction, and a possible arrangement of the molecules in the Sm-A layer is proposed.

Novel mesogenic azobenzene dimer at air-water and air-solid interfaces.

We have synthesized a novel mesogenic azobenzene molecule and studied its monolayer film properties at air-water interface (Langmuir film) and air-solid interface (Langmuir-Blodgett film). The material, H-shaped dimer bis[5-(4'-n-dodecyloxy benzoyloxy)-2-(4''-methylphenylazo)phenyl] adipate (12D1H) exhibits a smectic C phase between 51 and 48 degrees C on cooling. Surface manometry studies showed the formation of a stable monolayer at the air-water interface. Brewster angle microscopy (BAM) showed that liquid domains coexisting with the gas region at large area transformed to a uniform liquid phase with increasing surface density and finally to a collapsed state. We have carried out atomic force microscope (AFM) studies on Langmuir-Blodgett (LB) films transferred onto freshly cleaved hydrophilic mica substrate. The AFM images showed domains of height of about 3.8 nm, which corresponds to the estimated height of the molecule confirming the formation of monomolecular film. On a hydrophobic silicon substrate, the LB transfer yields a bilayer film, which dewets to form uniform nanodroplets of diameter of about 100 nm and height in the range 10-50 nm. Our analysis indicated that the mechanism involved in the formation of nanodroplets can be attributed to spinodal dewetting. The 12D1H molecule containing an azobenzene group undergoes a trans to cis transformation in the presence of ultraviolet light. Our surface manometry studies showed that the monolayer in the presence of ultraviolet light was more stable with a collapse pressure three times that of the monolayer in the dark.