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991.
Shankar Swaminathan Pradeep R. Vavia Francesco Trotta Roberta Cavalli Simonetta Tumbiolo Luca Bertinetti Salvatore Coluccia 《Journal of inclusion phenomena and macrocyclic chemistry》2013,76(1-2):201-211
Nanosponges (NS) are a recently developed class of hyper-branched polymers, nano-structured to form three dimensional meshwork; obtained by reacting cyclodextrins with a cross linker like diphenyl carbonate. Herein, we report an anomalous behavior of NS with regards to physical and morphological characteristics and drug encapsulation behavior by minor synthetic modification. Two distinct forms viz. crystalline and para-crystalline of NS were identified and extensively characterized by use of high resolution transmission electron microscopy (HR-TEM), X-ray powder diffraction (XRPD), scanning electron microscope, atomic force microscope, optical microscope and Fourier transform infra-red attenuated total reflectance spectroscopy (FTIR-ATR). Dimension of the crystal lattice was found to be equal to 0.61 nm. Higher magnifications clearly showed a zone axis with a hexagonal symmetry as that of beta-cyclodextrin. XRPD patterns were in concurrence with the HR-TEM results. Solubility studies with a model drug dexamethasone (DEX) showed more than three folds increase in the solubility of the drug in the crystalline NS as compared to the para-crystalline ones. Percent drug association and drug loading for DEX was found to be higher in the crystalline type of NS. An In vitro drug kinetic study evidenced a faster release of DEX from the crystalline type NS. The particle sizes of the formulations were as follows: crystalline NS: 688.6 ± 38.0 nm, para-crystalline NS: 702.2 ± 21.2 nm with polydispersity indices of 0.155 and 0.132; zeta-potential of ?26.55 ± 1.7 and ?23.42 ± 2.1 respectively. Differential scanning calorimetry and thermogravimetric analysis revealed that both forms encapsulated the drug satisfactorily. FTIR-ATR and Raman spectroscopy showed weak interactions. Crystallinity of NS was thus found to be an important factor in solubilization, in vitro kinetics and encapsulation behavior and can be tuned to give a tailored drug release profile or formulation characteristics. 相似文献
992.
A review of the industrial applications of Mössbauer Spectroscopy is presented underlining the powerfulness and usefulness of the technique in the control and optimization of the production processes. A few examples are reported concerning the developments of thin protective coatings for structural parts and media for the magnetic recording field. 相似文献
993.
Vikas Kumar Alessio Gambetta Cristian Manzoni Roberta Ramponi Giulio Cerullo Marco Marangoni 《Pramana》2010,75(6):1129-1134
We demonstrate a new approach to CARS spectroscopy by efficiently synthesizing synchronized narrow-bandwidth (less than 10
cm−1) pump and Stokes pulses (frequency difference continuously tunable upto ≈3000 cm−1) based on spectral compression together with second harmonic generation (in periodically-poled nonlinear crystals) of femtosecond
pulses emitted by a single compact Er-fibre oscillator. For a far better signal to non-resonant background contrast, interferometric
CARS (I-CARS) is demonstrated and CARS signal enhancement upto three orders of magnitude is achieved by constructive interference
with an auxiliary local oscillator at anti-Stokes field, also synthesized by spectral compression of pulses emitted from the
same fibre oscillator. 相似文献
994.
995.
996.
Preparation of 1-methylpyrrole-2-acetonitrile, 1-methyl-5-(4-methylbenzoyl) pyrrole-2-acetonitrile and 2-(6-methoxy-2-naphthyl)propionitrile by treatment of 1-methylpyrrole-2-carboxaldehyde, 1-methyl-5-(4-methylbenzoyl)pyrrole-2-carboxaldehyde and, respectively, 6-methoxy-2-acetylnaphthalene with tosylmethylisocyanide (TosMIC) is described. This one-step synthetic procedure is very useful to obtain the nitrile precursors of tolmetin and naproxen, two clinically important non-steroidal antiinflammatory agents (NSAIAs). 相似文献
997.
Francesco Tisato Fiorenzo Refosco Marina Porchia Matteo Tegoni Valentina Gandin Cristina Marzano Maura Pellei Grazia Papini Lara Lucato Roberta Seraglia Pietro Traldi 《Rapid communications in mass spectrometry : RCM》2010,24(11):1610-1616
Electrospray ionization mass spectrometry was usefully employed for the characterization of three phosphino copper(I) complexes of medicinal interest. This technique revealed that the original [CuL4]+ pro‐drugs (L = hydrophilic tertiary phosphine) underwent dissociation with production of coordinative unsaturated [CuL3]+ and [CuL2]+ species, which represented key intermediates for the activation of potential biological properties. The more favoured was the displacement of the ligands from the [CuL4]+ parent complex, the more favoured was in turn the possibility for the metal ion to directly interact with biological substrates, including pharmacological targets related to cancer proliferation. An inverse correlation between the stability and the cytotoxic activity of the three copper(I) complexes investigated has been clearly established. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
998.
999.
Paola Manca Maria I. Pilo Giovanni Casu Serafino Gladiali Gavino Sanna Roberta Scanu Nadia Spano Antonio Zucca Chiara Zanardi Diego Bagnis Luca Valentini 《Journal of polymer science. Part A, Polymer chemistry》2011,49(16):3513-3523
A novel polythiophene bearing a pendant terpyridine moiety has been synthesized by electrochemical polymerization of a new thiophene monomer, namely 4′‐(2,2′:5′,2″‐terthien‐3′‐ethynyl)‐2,2′:6′,2″‐terpyridine (TAT). The insertion of a conjugated ethynyl spacer between the terthiophene and the terpyridine fragments provides for an effective extension of the delocalization of electrons within the structural unit and the polymer as a whole. The synthesis and characterization of the relevant monomer, the electrosynthesis of the corresponding polymer and its electrochemical, UV–visible spectroelectrochemical and IR characterization are described. Finally, a comparison between the electrochemical, spectroscopic, and spectroelectrochemical properties of PTAT and the analogue, saturated‐spacer PTTT (TTT = 4′‐[(2,2′:5′,2″‐terthien‐3′‐yl)methoxy]‐2,2′:6′,2″‐terpyridine) polymer is discussed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
1000.