170,039 research outputs found
Porphyrin tributyltin(IV) complexes for a novel approach in the tratment of human melanoma
No full textMelanoma 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
conventional and phototherapeutic drugs.[2] The aim of this work was to design biomimetic
nanoassemblies based on non-ionic and hydrophilic ACyD (SC6OH) for delivery of poor
water soluble organotin(IV)-porphyrin complexes in melanoma cancer cell. Nanoassemblies
were prepared by dispersion in water of (Bu3Sn)4TPPS/SC6OH organic film at 1:5 molar ratio
and characterized by a combination of spectroscopic and morphological techniques. Size
distribution, charge, drug encapsulation efficiency and in vitro release were investigated.
Intracellular delivery, cytotoxicity, nuclear morphology and cell growth kinetics were
evaluated by fluorescence microscopy on A375 human melanoma cells. UV-vis and emission
spectroscopy of (Bu3Sn)4TPPS/SC6OH show shifts of the peculiar bands of organotin(IV)-
porphryin complex by interaction with supramolecular nanoaggregates of ACyD in aqueous
solution. Mean size was within the range 100-120 nm. ξ-potential was negative for all the
formulations (–16 mV in (Bu3Sn)4TPPS/SC16OH system with loading capacity of 18%).
Delivering of (Bu3Sn)4TPPS by ACyD with respect to free (Bu3Sn)4TPPS provoke a more
efficient internalization, a higher cytotoxic effect inducing apoptotic cell death and at lower
concentrations a cellular morphology change blocking cell proliferation. In conclusion the
strategy of entrapping anticancer drug based on poor water-soluble porphyrin organotin
complexes in ACyD nanocarriers is here proposed as new photo-independent therapeutic
approaches against melanoma.
References
[1] M.A. Costa, F. Zito, M.R. Emma, L. Pellerito, T. Fiore, C. Pellerito, G. Barbieri, Int. J. Oncol. 2011, 38,
693.
[2] A. Mazzaglia, Photodynamic Tumor Therapy with Cyclodextrin Nanoassemblies. In: Cyclodextrins in
Pharmaceutics, Cosmetics, and Biomedicine: Current and Future Industrial Applications, E. Bilensoy
(Ed.); John Wiley & Sons, Inc.: Hoboken, 2011; pp. 343-361
Infrared Absorption Spectroscopy
No full textInfrared (IR) absorption spectroscopy is one of the most important analytical techniques available to study different kinds of samples including solids, semisolids, biological materials, films, liquids, solutions, and gases. IR spectroscopy not only uses the so-called infrared absorption, but also other techniques such as the attenuated total reflection method, diffuse reflectance method, reflection-absorption method, photoacoustic spectroscopy, and emission spectroscopy. IR spectroscopy is a technique based on the vibrations of the atoms of a molecule. An infrared spectrum is obtained by passing infrared radiation through a sample and determining what fraction of the incident radiation is absorbed at a particular energy. Fourier transform infrared (FTIR) spectrometry is based on the use of an interferometer. A common FTIR spectrometer consists of a source, an interferometer, a sample holder, and a detector. Transmission spectroscopy is based upon the absorption of infrared radiation at specific wavelengths as it passes through a sample
Biological activity studies on organotin(IV)n+ complexes and parent Compounds
No full textThis review summarized the literature and own data on the parent organotin(IV) compounds and complexes formed with biologically active ligands
Bu2Sn(N-acetyl-L-cysteinate) antitumor activity on HepG2 cells
No full textMany drugs currently used in anticancer therapies, act by activating cytotoxic death by apoptosis. This death mechanism is often accompanied by mitochondrial events (intrinsic apoptosis) or the activation of death receptors (extrinsic pathway
Diorganotin(IV) N-acetyl-L-cysteinate complexes: Synthesis, solid state, solution phase, DFT and biological investigations.
No full textDiorganotin(IV) complexes of N-acetyl-L-cysteine (H2NAC; (R)-2-acetamido-3-sulfanylpropanoic acid) have
been synthesized and their solid and solution-phase structural configurations investigated by FTIR,
Mössbauer, 1H, 13C and 119Sn NMR spectroscopy. FTIR results suggested that in R2Sn(IV)NAC (R=Me, Bu,
Ph) complexes NAC2− behaves as dianionic tridentate ligand coordinating the tin(IV) atom, through estertype
carboxylate, acetate carbonyl oxygen atom and the deprotonated thiolate group. From 119Sn Mössbauer
spectroscopy it could be inferred that the tin atom is pentacoordinated, with equatorial R2Sn(IV) trigonal
bipyramidal configuration. In DMSO-d6 solution, NMR spectroscopic data showed the coordination of one
solvent molecule to tin atom, while the coordination mode of the ligand through the ester-type carboxylate
and the deprotonated thiolate group was retained in solution. DFT (Density Functional Theory) study
confirmed the proposed structures in solution phase as well as the determination of the most probable stable
ring conformation. Biological investigations showed that Bu2SnCl2 and NAC2 induce loss of viability in HCC
cells and only moderate effects in non-tumor Chang liver cells. NAC2 showed lower cytotoxic activity than
Bu2SnCl2, suggesting that the binding with NAC2− modulates the marked cytotoxic activity exerted by
Bu2SnCl2. Therefore, these novel butyl derivatives could represent a new class of anticancer drugs
ORGANOSTAGNO(IV) COMPLESSI CON N-ACETILCISTEINA AD ATTIVITÀ ANTITUMORALE, PROCEDIMENTO PER LA LORO PRODUZIONE E LORO USO.
No full text
Effects of tri-n-butyltin(IV) chloride on neurulation of Ciona intestinalis (Tunicata, Ascidiacea): an ultrastructural study
No full textThis paper reports the cytotoxic effects of tri-n-butyltin (IV) chloride, TBTCl, on the neurulation
process of the ascidian Ciona intestinalis. Exposure of the embryos at early neurula stage in 10−5 and
10−7 M TBT (IV) chloride solutions for 1–2 h provoked the irreversible arrest of their development.
Morphological and ultrastructural observations suggested that most probably there are two principal
causes determining the neurulation process block. The first is due to the TBT effects of inhibiting
the polymerization and/or degradation of microfilaments and microtubules, proteins that constitute
the cytoskeleton. The lack of orientation and extension of both microtubules and microfilaments
of actin prevent the shape changes and mobility of neural plate blastomeres indispensable to the
neurulation process. The second cause is certainly determined by the ultrastructural modification
whichmitochondria undergo. The ultrastructural anomalies showed by these organules are so serious
as to impede their proper functionality with consequent inhibition of oxidative phosphorylation and
ATP synthesis, remarkable metabolic processes that occur during ascidian neurulation
Coordination Properties of an ACE Inhibitor, Captopril Towards Me2Sn(IV)2+ in Aqueous Solution and Biological Aspects of Some Dialkyltin(IV) Derivatives of This Ligand
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