Microencapsulation of Cassia fistula Flower Extract with Chitosan and its Antibacterial Studies.

BACKGROUND: The plant used in the present study is Cassia fistula, which belongs to the family Leguminosae and has been used in traditional medicinal systems due to the presence of a copious amount of Phytochemicals with various properties. AIMS: This study is focused on the extraction of phytochemicals from the Cassia fistula flower and its subsequent encapsulation into chitosan matrix for applications in drug delivery. Chitosan is approved by FDA for its use in Pharmaceutical industries. METHODS: As described by several analytical techniques such as FT-IR, NMR, Thermal analysis, and SEM, the microsphere thus prepared by the current study is predicted to release the desired extract with medicinal properties in a controlled manner, allowing for more convenient and desired levels of drug administration. The swelling study and release study of the prepared microsphere have been carried out in physiological pH 2 and 7.4. NMR study has shown that sitosterol and friedelin have been encapsulated successfully into the chitosan matrix. RESULTS: The microspheres have shown up to 80% swelling in pH 2 upto 8 days, and 60% of the in- -vitro controlled drug release has also been found in pH 2 upto 2 days. The thermal studies using TGA and DSC supported the thermal stabilities of CS beads, CFFE and CFFE-CS beads, Also, it showed the dispersion of the CFFE in the cavities of the Chitosan matrix. CONCLUSION: The Biomedical application of the synthesized CFFE-CS beads has also been reported on the basis of their antibacterial studies.

Casting of carbon cloth enrobed polypyrrole electrode for high electrochemical performances.

The present investigation deals with the fabrication of a novel flexible and highly conductive PPy electrode. This was made by festooning PPy nanoparticles on carbon cloth (CC) by using chemical liquid process. The developed porous PPy@CC composite have good flexibility with low weight (1.1 mg) and high electrical conductivity (89 Ω-1cm-1). Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction spectroscopy (XRD) confirmed the formation of PPy on carbon cloth. Scanning electron micrographs (SEM) reveals that the PPy nanoparticles are encapsulated in carbon cloth. The fabricated carbon cloth has been used for solid-state symmetrical supercapacitors (SC) and low-cost material for electrode in potential energy storage devices. These film electrodes showed much superior electrochemical performance i.e. high stability under different current density, encouraging energy density, lower internal resistivity and higher specific capacitance. Synthesized flexible PPy@CC composite electrodes have brilliant applications in various kinds of electrochemical energy storage devices.

Convenient and ultra-sensitive fluorescence detection of bovine serum albumin by using Rhodamine-6G modified gold nanoparticles in biological samples.

This study comprises a convenient, rapid and very sensitive method for the determination of bovine serum albumin (BSA). The technique is based on fluorescence resonance energy transfer (FRET) between Rhodamine-6G (R6G) acting as donor and gold nanoparticles (AuNPs) acting as acceptors. This method takes advantage of AuNPs that have high quenching efficiency, therefore the absorption spectra range shifts from 521 to 635 nm when aggregation of the AuNPs takes place. Furthermore, when R6G was electrostatically self-adsorbed to the citrate-stabilized AuNPs surface the fluorescence intensity was quenched. After addition of BSA, the fluorescence intensity of the R6G recovered as BSA induced aggregation of the AuNPs and the adsorbed R6G was released to the solution. The recovery of intensity displays a linear relationship with BSA concentration over the range from 0.8 × 10-11  M to 5.6 × 10-11  M. The detection limit for BSA was found to be 4.58 × 10-11  M. The proposed method exhibited rapid analysis with high selectivity for BSA determination in human urine, blood and serum samples.

Ring-opening polymerization by lithium catalysts: an overview.

This critical review summarizes recent developments in the preparation and application of lithium catalysts/initiators such as, alkyl lithium, alkoxy lithium and bimetallic lithium compounds for ring-opening polymerization (ROP). The ROP of cyclic esters, cyclic carbonates, cyclo-silazanes, cyclo-silanes, cyclo-siloxanes, cyclo-carboxylate, cyclic phosphirene and quinodimethanes are covered in this review. The present paper emphasizes the polymerization kinetics and the control exhibited by the different types of lithium initiators/catalysts. For the cases where useful properties, such as high molecular weight, narrow PDI, or stereocontrol, have been observed, a more detailed examination of the mechanistic studies of the catalysts/initiators are provided. Furthermore, this review also focuses on the synthesis of block copolymers and graft copolymers by ROP principle. The topics covered in this review regarding lithium compounds toward ROP will be of interest to inorganic, organic and organometallic chemists, material, polymer and catalytic scientists due to its unique mode of activation as compared to transition and inner transition-metals. In addition, use of these compounds in catalysis is steadily growing, because of the complementary reactivity toward ROP as compared to other metals. Finally, some aspects and opportunities which may be of interest in the future are suggested (143 references).