Search results for " Cyclodextrins"

Two components hydrogels formed by host-guest interactions

Two-Component Hydrogels Formed by Cyclodextrins and Dicationic Imidazolium Salts

2014

In the framework of our recent interest in studying the gelling behaviour of imidazolium salts, we took into account the possibility of obtaining two-component hydrogels by combining cyclodextrins and dicationic imidazolium salts. In particular, we used diimidazolium salts differing in the alkyl chain length and in the size, shape, and coordination ability of the anion, namely the 3,3′-di-n-decyl- and 3,3′-di-n-dodecyl-1,1′-(1,4- phenylenedimethylene)diimidazolium dibromide, and 3,3′-di-n-dodecyl-1, 1′-(1,4-phenylenedimethylene)diimidazolium ditetrafluoroborate and dihexafluorophosphate. As far as cyclodextrins are concerned, to gain information on the effects of different sized cyclic olig…

Supramolecular functionalization and concomitant enhancement in properties of Au25 clusters

2014

We present a versatile approach for tuning the surface functionality of an atomically precise 25 atom gold cluster using specific host-guest interactions between ?-cyclodextrin (CD) and the ligand anchored on the cluster. The supramolecular interaction between the Au25 cluster protected by 4-(t-butyl)benzyl mercaptan, labeled Au25SBB18, and CD yielding Au25SBB18�?�CDn (n = 1, 2, 3, and 4) has been probed experimentally using various spectroscopic techniques and was further analyzed by density functional theory calculations and molecular modeling. The viability of our method in modifying the properties of differently functionalized Au25 clusters is demonstrated. Besides modifying their optoe…

Nanoassemblies Based on Supramolecular Complexes of Nonionic Amphiphilic Cyclodextrin and Sorafenib as Effective Weapons to Kill Human HCC Cells

2015

Sorafenib (Sor), an effective chemiotherapeutic drug utilized against hepatocellular carcinoma (HOC), robustly interacts with nonionic amphiphilic cyclodextrin (aCD, SC6OH), forming, in aqueous solution, supramolecular complexes that behave as building blocks of highly water-dispersible colloidal nanoassemblies. SC6OH/Sor complex has been characterized by complementary spectroscopic techniques, such as UV-vis, steady-state fluorescence and anisotropy, resonance light scattering and H-1 NMR. The spectroscopic evidences and experiments carried out in the presence of an adamantane derivative, which competes with drug for CD cavity, agree with the entrapment of Sor in aCD, pointing out the role…

Temperature-controlled poly(propylene) glycol hydrophobicity on the formation of inclusion complexes with modified cyclodextrins. A DSC and ITC study.

2011

The study highlighted the main forces driving the formation of hydroxypropyl-cyclodextrins (HP-CDs) + poly(propylene) glycol 725 g mol(-1) inclusion complexes. The temperature parameter was chosen as the variable to modulate the hydrophobicity of the polymer, and consequently ITC experiments as functions of temperature as well as DSC measurements were done in a systematic way. The polymer is not included into HP-α-CD, it is strongly bound to HP-β-CD and it is floating in HP-γ-CD. The stability of the inclusion complexes is entropy controlled. The gain of the entropy is a unique result compared to the opposite literature findings for inclusion complexes based on polymers and CDs. This peculi…

Complexes of amphiphilic cyclodextrins and tributiltin(IV) porphyrin derivatives as potential nanotherapeutics against melanoma.

2013

Porphyrin tributyltin(IV) complexes for a novel approach in the tratment of human melanoma

2012

Melanoma is the most deadly form of skin cancer, largely refractory to existing therapies. The study of porphyrin derivatives as potential anti-tumor drugs has been an interesting field of investigation in the last years. Recently, a photo-independent cytotoxic effect of (Bu3Sn)4TPPS in the blocking melanoma cell proliferation an inducing a morphology cell change was investigated.[1] Amphiphilic CD (ACyD) provides more water soluble and adaptable nanovectors through modulation of the balance between hydrophobic and hydrophilic chains at both CD sides. ACyD can be conveniently tailored by covalently appending fluorescent label or receptor-targeting glycosyl- groups and can encapsulate conven…

HYALURONIC ACID-BETA CYCLODEXTRINS HYDOGEL FOR THE TREATMENT OF SEVERE CORNEAL DISEASES

2016

Ring opening polymerization of cyclic esters with metal free catalysts

2012

Thermodynamics of binding between α- and β-cyclodextrins and some p-nitro-aniline derivatives: reconsidering the enthalpy–entropy compensation effect

2004

Abstract The thermodynamics of binding between native α- and β-cyclodextrin towards several p -nitro-aniline derivatives was examined, in order to gain further insights about the occurrence of different interaction modes for the two hosts. Valuable information was achieved regarding the ‘expanded hydrophobic sphere’ of α-cyclodextrin. Furthermore, very interesting and unexpected aspects of the behavior of β-cyclodextrin were enlightened, such as the crucial role played by hydrogen bond interactions. Experimental data were examined under the perspective of the ‘enthalpy–entropy compensation effect’, and some ideas about this topic are discussed.