Encapsulating TGF-beta 1 Inhibitory Peptides P17 and P144 as a Promising Strategy to Facilitate Their Dissolution and to Improve Their Functionalization

Transforming growth factor-beta (TGF beta 1) is considered as a master regulator for many intracellular signaling pathways, including proliferation, differentiation and death, both in health and disease. It further represents an oncogenic factor in advanced tumors allowing cancer cells to be more invasive and prone to move into the metastatic process. This finding has received great attention for discovering new therapeutic molecules against the TGF beta 1 pathway. Among many TGF beta 1 inhibitors, peptides (P17 and P144) were designed to block the TGF beta 1 pathway. However, their therapeutic applications have limited use, due to lack of selection for their targets and their possible recognition by the immune system and further due to their potential cytotoxicity on healthy cells. Besides that, P144 is a highly hydrophobic molecule with less dissolution even in organic solution. Here, we aimed to overcome the dissolution of P144, as well as design nano-delivery strategies to protect normal cells, to increase cellular penetration and to raise the targeted therapy of both P17 and P144. Peptides were encapsulated in moieties of polymer hybrid protein. Their assembly was investigated by TEM, microplate spectrum analysis and fluorescence microscopy. SMAD phosphorylation was analyzed by Western blot as a hallmark of their biological efficiency. The results showed that the encapsulation of P17 and P144 might improve their potential therapeutic applications

Single- and multi-photon excited fluorescence from serotonin complexed with B-cyclodextrin

The fluorescence of serotonin on binding with B-cyclodextrin has been studied using both steady-state and time-resolved methods. Steady state fluorescence intensity of serotonin at 340 nm showed ~ 30% increase in intensity on binding with Ka ~ 60 dm3 mol 1 and the fluorescence lifetimes showed a corresponding increase. In contrast, the characteristic green fluorescence (‘hyperluminescence’) of serotonin observed upon multiphoton near-infrared excitation with sub-picosecond pulses was resolved into two lifetime components assigned to free and bound serotonin. The results are of interest in relation to selective imaging and detection of serotonin using the unusual hyperluminescence emission and in respect to recent determinations of serotonin by capillary electrophoresis in the presence of cyclodextrin. The results also suggest that hyperluminescence occurs from multiphoton excitation of a single isolated serotonin molecule

The Use of Nanoparticles in Otoprotection

The inner ear can be insulted by various noxious stimuli, including drugs (cisplatin and aminoglycosides) and over-acoustic stimulation. These stimuli damage the hair cells giving rise to progressive hearing loss. Systemic drugs have attempted protection from ototoxicity. Most of these drugs poorly reach the inner ear with consequent ineffective action on hearing. The reason for these failures resides in the poor inner ear blood supply, the presence of the blood-labyrinthine barrier, and the low permeability of the round window membrane (RWM). This article presents a review of the use of nanoparticles (NPs) in otoprotection. NPs were recently used in many fields of medicine because of their ability to deliver drugs to the target organs or cells. The studies included in the review regarded the biocompatibility of the used NPs by in vitro and in vivo experiments. In most studies, NPs proved safe without a significant decrease in cell viability or signs of ototoxicity. Many nano-techniques were used to improve the drugs' kinetics and efficiency. These techniques included encapsulation, polymerization, surface functionalization, and enhanced drug release. In such a way, it improved drug transmission through the RWM with increased and prolonged intra-cochlear drug concentrations. In all studies, the fabricated drug-NPs effectively preserved the hair cells and the functioning hearing from exposure to different ototoxic stimuli, simulating the actual clinical circumstances. Most of these studies regarded cisplatin ototoxicity due to the wide use of this drug in clinical oncology. Dexamethasone (DEX) and antioxidants represent the most used drugs in most studies. These drugs effectively prevented apoptosis and reactive oxygen species (ROS) production caused by ototoxic stimuli. These various successful experiments confirmed the biocompatibility of different NPs and made it successfully to human clinical trials

Effect of 2-Hydroxypropyl-β-cyclodextrin on Solubility of Sparingly Soluble Drug Derivatives of Anthranilic Acid

Guest-host complex formation of three drug derivatives of anthranilic acid, mefenamic acid, niflumic acid, and flufenamic acid with 2-hydroxypropyl-β-cyclodextrin (2HP-β-CD) in aqueous solutions was investigated using “Phase solubility study” with UV-vis spectrophotometry. Solubility of sparingly soluble drugs has been improved by addition of 2HP-β-CD at two temperatures 298.15 K and 310.15 K and two pH values 2 and 7. The influence of different 2HP-β-CD concentration on solubility of drugs at different pH and temperatures has been investigated. The 2HP-β-CD-drug complex stability constants (Ks), and dissociations constants (Kd), as well as the thermodynamic parameters of reaction, i.e., the free energy change (ΔG), the enthalpy change (ΔH) and the entropy change (ΔS), were determined. The experimental data indicated formation of 1:1 inclusion complexes, which were found effective binders increasing the solubility of drugs

Stereodifferentiation in the intramolecular singlet excited state quenching of hydroxybiphenyl-tryptophan dyads

The photochemical processes occurring in diastereomeric dyads (S, S)-1 and (S, R)-1, prepared by conjugation of (S)-2-(2-hydroxy-1,1'-biphenyl-4-yl) propanoic acid ((S)-BPOH) with (S)- and (R)-Trp, have been investigated. In acetonitrile, the fluorescence spectra of (S, S)-1 and (S, R)-1 were coincident in shape and position with that of (S)-BPOH, although they revealed a markedly stereoselective quenching. Since singlet energy transfer from BPOH to Trp is forbidden (5 kcal mol(-1) uphill), the quenching was attributed to thermodynamically favoured (according to Rehm-Weller) electron transfer or exciplex formation. Upon addition of 20% water, the fluorescence quantum yield of (S)-BPOH decreased, while only minor changes were observed for the dyads. This can be explained by an enhancement of the excited state acidity of (S)-BPOH, associated with bridging of the carboxy and hydroxy groups by water, in agreement with the presence of water molecules in the X-ray structure of (S)-BPOH. When the carboxy group was not available for coordination with water, as in the methyl ester (S)-BPOHMe or in the dyads, this effect was prevented; accordingly, the fluorescence quantum yields did not depend on the presence or absence of water. The fluorescence lifetimes in dry acetonitrile were 1.67, 0.95 and 0.46 ns for (S)-BPOH, (S, S)-1 and (S, R)-1, respectively, indicating that the observed quenching is indeed dynamic. In line with the steady-state and time-resolved observations, molecular modelling pointed to a more favourable geometric arrangement of the two interacting chromophores in (S, R)-1. Interestingly, this dyad exhibited a folded conformation in the solid state.Financial support from the Spanish Government (CTQ2010-14882, BES-2008-003314, JCI-2011-09926, PR2011-0581), from the Generalitat Valenciana (Prometeo 2008/090) and from the Universitat Politecnica de Valencia (PAID 05-11, 2766) is gratefully acknowledged.Bonancía Roca, P.; Vayá Pérez, I.; Markovitsi, D.; Gustavsson, T.; Jiménez Molero, MC.; Miranda Alonso, MÁ. (2013). Stereodifferentiation in the intramolecular singlet excited state quenching of hydroxybiphenyl-tryptophan dyads. Organic and Biomolecular Chemistry. 11(12):1958-1963. https://doi.org/10.1039/c3ob27278hS195819631112Jiménez, M. C., Pischel, U., & Miranda, M. A. (2007). Photoinduced processes in naproxen-based chiral dyads. Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 8(3), 128-142. doi:10.1016/j.jphotochemrev.2007.10.001Abad, S., Pischel, U., & Miranda, M. A. (2005). Wavelength-Dependent Stereodifferentiation in the Fluorescence Quenching of Asymmetric Naphthalene-Based Dyads by Amines. The Journal of Physical Chemistry A, 109(12), 2711-2717. doi:10.1021/jp047996aAbad, S., Vayá, I., Jiménez, M. C., Pischel, U., & Miranda, M. A. (2006). Diastereodifferentiation of Novel Naphthalene Dyads by Fluorescence Quenching and Excimer Formation. ChemPhysChem, 7(10), 2175-2183. doi:10.1002/cphc.200600337Bonancía, P., Vayá, I., Climent, M. J., Gustavsson, T., Markovitsi, D., Jiménez, M. C., & Miranda, M. A. (2012). Excited-State Interactions in Diastereomeric Flurbiprofen–Thymine Dyads. The Journal of Physical Chemistry A, 116(35), 8807-8814. doi:10.1021/jp3063838Paris, C., Encinas, S., Belmadoui, N., Climent, M. J., & Miranda, M. A. (2008). Photogeneration of 2-Deoxyribonolactone in Benzophenone−Purine Dyads. Formation of Ketyl−C1′ Biradicals. Organic Letters, 10(20), 4409-4412. doi:10.1021/ol801514vBelmadoui, N., Encinas, S., Climent, M. J., Gil, S., & Miranda, M. A. (2006). Intramolecular Interactions in the Triplet Excited States of Benzophenone–Thymine Dyads. Chemistry - A European Journal, 12(2), 553-561. doi:10.1002/chem.200500345Lhiaubet-Vallet, V., Boscá, F., & Miranda, M. A. (2007). Stereodifferentiating Drug−Biomolecule Interactions in the Triplet Excited State:  Studies on Supramolecular Carprofen/Protein Systems and on Carprofen−Tryptophan Model Dyads. The Journal of Physical Chemistry B, 111(2), 423-431. doi:10.1021/jp066968kVayá, I., Pérez-Ruiz, R., Lhiaubet-Vallet, V., Jiménez, M. C., & Miranda, M. A. (2010). Drug–protein interactions assessed by fluorescence measurements in the real complexes and in model dyads. Chemical Physics Letters, 486(4-6), 147-153. doi:10.1016/j.cplett.2009.12.091Seedher, N., & Bhatia, S. (2005). Mechanism of interaction of the non-steroidal antiinflammatory drugs meloxicam and nimesulide with serum albumin. Journal of Pharmaceutical and Biomedical Analysis, 39(1-2), 257-262. doi:10.1016/j.jpba.2005.02.031SEEDHER, N., & BHATIA, S. (2006). Reversible binding of celecoxib and valdecoxib with human serum albumin using fluorescence spectroscopic technique. Pharmacological Research, 54(2), 77-84. doi:10.1016/j.phrs.2006.02.008Nanda, R. K., Sarkar, N., & Banerjee, R. (2007). Probing the interaction of ellagic acid with human serum albumin: A fluorescence spectroscopic study. Journal of Photochemistry and Photobiology A: Chemistry, 192(2-3), 152-158. doi:10.1016/j.jphotochem.2007.05.018Zhou, B., Li, R., Zhang, Y., & Liu, Y. (2008). Kinetic analysis of the interaction between amphotericin B and human serum albumin using surface plasmon resonance and fluorescence spectroscopy. Photochemical & Photobiological Sciences, 7(4), 453. doi:10.1039/b717897bVahedian-Movahed, H., Saberi, M. R., & Chamani, J. (2011). Comparison of Binding Interactions of Lomefloxacin to Serum Albumin and Serum Transferrin by Resonance Light Scattering and Fluorescence Quenching Methods. Journal of Biomolecular Structure and Dynamics, 28(4), 483-502. doi:10.1080/07391102.2011.10508590Katrahalli, U., Kalalbandi, V. K. A., & Jaldappagari, S. (2012). The effect of anti-tubercular drug, ethionamide on the secondary structure of serum albumins: A biophysical study. Journal of Pharmaceutical and Biomedical Analysis, 59, 102-108. doi:10.1016/j.jpba.2011.09.013El-Kemary, M., Gil, M., & Douhal, A. (2007). Relaxation Dynamics of Piroxicam Structures within Human Serum Albumin Protein. Journal of Medicinal Chemistry, 50(12), 2896-2902. doi:10.1021/jm061421fTormo, L., Organero, J. A., Cohen, B., Martin, C., Santos, L., & Douhal, A. (2008). Dynamical and Structural Changes of an Anesthetic Analogue in Chemical and Biological Nanocavities. The Journal of Physical Chemistry B, 112(43), 13641-13647. doi:10.1021/jp803083yTardioli, S., Lammers, I., Hooijschuur, J.-H., Ariese, F., van der Zwan, G., & Gooijer, C. (2012). Complementary Fluorescence and Phosphorescence Study of the Interaction of Brompheniramine with Human Serum Albumin. The Journal of Physical Chemistry B, 116(24), 7033-7039. doi:10.1021/jp300055cVayá, I., Jiménez, M. C., & Miranda, M. A. (2007). Excited-State Interactions in Flurbiprofen−Tryptophan Dyads. The Journal of Physical Chemistry B, 111(31), 9363-9371. doi:10.1021/jp071301zCallis, P. R., & Burgess, B. K. (1997). Tryptophan Fluorescence Shifts in Proteins from Hybrid Simulations:  An Electrostatic Approach. The Journal of Physical Chemistry B, 101(46), 9429-9432. doi:10.1021/jp972436fLakowicz, J. R. (2000). On Spectral Relaxation in Proteins†¶‖. Photochemistry and Photobiology, 72(4), 421. doi:10.1562/0031-8655(2000)0722.0.co;2Schuler, B., & Eaton, W. A. (2008). Protein folding studied by single-molecule FRET. Current Opinion in Structural Biology, 18(1), 16-26. doi:10.1016/j.sbi.2007.12.003Shen, X., & Knutson, J. R. (2001). Subpicosecond Fluorescence Spectra of Tryptophan in Water. The Journal of Physical Chemistry B, 105(26), 6260-6265. doi:10.1021/jp010384vBeechem, J. M., & Brand, L. (1985). Time-Resolved Fluorescence of Proteins. Annual Review of Biochemistry, 54(1), 43-71. doi:10.1146/annurev.bi.54.070185.000355Callis, P. R. (1997). [7] 1La and 1Lb transitions of tryptophan: Applications of theory and experimental observations to fluorescence of proteins. Flourescence Spectroscopy, 113-150. doi:10.1016/s0076-6879(97)78009-1Basarić, N., & Wan, P. (2006). Competing Excited State Intramolecular Proton Transfer Pathways from Phenol to Anthracene Moieties. The Journal of Organic Chemistry, 71(7), 2677-2686. doi:10.1021/jo0524728Lukeman, M., & Wan, P. (2003). Excited-State Intramolecular Proton Transfer ino-Hydroxybiaryls:  A New Route to Dihydroaromatic Compounds. Journal of the American Chemical Society, 125(5), 1164-1165. doi:10.1021/ja029376yKeck, J., Kramer, H. E. A., Port, H., Hirsch, T., Fischer, P., & Rytz, G. (1996). Investigations on Polymeric and Monomeric Intramolecularly Hydrogen-Bridged UV Absorbers of the Benzotriazole and Triazine Class. The Journal of Physical Chemistry, 100(34), 14468-14475. doi:10.1021/jp961081hVollmer, F., & Rettig, W. (1996). Fluorescence loss mechanism due to large-amplitude motions in derivatives of 2,2′-bipyridyl exhibiting excited-state intramolecular proton transfer and perspectives of luminescence solar concentrators. Journal of Photochemistry and Photobiology A: Chemistry, 95(2), 143-155. doi:10.1016/1010-6030(95)04252-0Lukeman, M., & Wan, P. (2002). A New Type of Excited-State Intramolecular Proton Transfer:  Proton Transfer from Phenol OH to a Carbon Atom of an Aromatic Ring Observed for 2-Phenylphenol1. Journal of the American Chemical Society, 124(32), 9458-9464. doi:10.1021/ja0267831Jiménez, M. C., Miranda, M. A., Tormos, R., & Vayá, I. (2004). Characterisation of the lowest singlet and triplet excited states of S-flurbiprofen. Photochem. Photobiol. Sci., 3(11-12), 1038-1041. doi:10.1039/b408530bWeller, A. (1982). Photoinduced Electron Transfer in Solution: Exciplex and Radical Ion Pair Formation Free Enthalpies and their Solvent Dependence. Zeitschrift für Physikalische Chemie, 133(1), 93-98. doi:10.1524/zpch.1982.133.1.093Winget, P., Cramer, C. J., & Truhlar, D. G. (2004). Computation of equilibrium oxidation and reduction potentials for reversible and dissociative electron-transfer reactions in solution. Theoretical Chemistry Accounts, 112(4). doi:10.1007/s00214-004-0577-0ÇAKIR, S., & BÇER, E. (2010). SYNTHESIS, SPECTRAL CHARACTERIZATION AND ELECTROCHEMISTRY OF VANADIUM(V) COMPLEX WITH TRYPTOPHAN. Journal of the Chilean Chemical Society, 55(2). doi:10.4067/s0717-9707201000020002

An electrochemically active green synthesized polycrystalline NiO/MgO catalyst: Use in photo-catalytic applications

For many years, research scientists have aided communities in their tremendous efforts towards environmental remediation. Due to their high physical and chemical stability, metal oxide nanoparticles (NPs) have been used as metal catalysts to remedy this issue. This article reviews green approaches for the synthesis of metal oxide nanoparticles, in aqueous bio-reductive polyphenols from punica granatum peel extract and the degradation of organic pollutants. The bimetallic nanocomposite of face-centred cubic NiO/MgO pseudocapacitors were successfully prepared via the polyphenols of punica granatum peel extracts. X-ray diffraction spectroscopy (XRD) successfully provide evidence of polycrystalline face-centre cubic nanocomposite (high crystallinity index (Icry) > 1) while revealing their interplanar distance. The spherical and irregular particle distribution of the binary NiO/MgO nanocomposite (at different calcination temperatures) was assessed by high resolution-TEM. FTIR, GC–MS and EDS provided evidence of the proposed mechanism during coordination between polyphenols and metal precursors. The popular “egg box model” is referred to in the case of polyphenols-metal interaction. The unique feature of two consecutive chelation site per repeat that provides a favourable entropic contribution to the inter-chain association is produced by this model governed by electrostatic interactions. Based on the obtained results, new structural models of Ni2+/Mg2+-polyphenols (punicalagin) complexes were proposed. UV–vis and Cyclic voltammetry confirmed the growth and band gap energies of the nanocomposite. NiO/MgO nanocomposite was found to be excellent photocatalysts for the degradation of methylene orange and methylene blue under the illumination of artificial light irradiation. The experiments demonstrated that MB in aqueous solution was more efficiently photo-degraded (87%) than MO (73%) using NiO/MgO nanocomposite as photocatalysts within 10 min of exposure. Conclusively, the nanocomposite was found to be more efficient compared to other reported oxides.ISI & Scopu

Photoactive assemblies of organic compounds and biomolecules: drug-protein supramolecular systems

[EN] The properties of singlet and triplet excited states are strongly medium-dependent. Hence, these species constitute valuable tools as reporters to probe compartmentalised microenvironments, including drug@protein supramolecular systems. In the present review, the attention is focused on the photophysical properties of the probe drugs (rather than those of the protein chromophores) using transport proteins (serum albumins and 1-acid glycoproteins) as hosts. Specifically, fluorescence measurements allow investigating the structural and dynamic properties of biomolecules or their complexes. Thus, the emission quantum yields and the decay kinetics of the drug singlet excited states provide key information to determine important parameters such as the stoichiometry of the complex, the binding constant, the relative degrees of occupancy of the different compartments, etc. Application of the FRET concept allows determining donor-acceptor interchromophoric distances. In addition, anisotropy measurements can be related to the orientation of the drug within the binding sites, where the degrees of freedom for conformational relaxation are restricted. Transient absorption spectroscopy is also a potentially powerful tool to investigate the binding of drugs to proteins, where formation of encapsulated triplet excited states is favoured over other possible processes leading to ionic species (i. e. radical ions), and their photophysical properties are markedly sensitive to the microenvironment experienced within the protein binding sites. Even under aerobic conditions, the triplet lifetimes of protein-complexed drugs are remarkably long, which provides a broad dynamic range for identification of distinct triplet populations or for chiral discrimination. Specific applications of the laser flash photolysis technique include the determination of drug distribution among the bulk solution and the protein binding sites, competition of two types of proteins to bind a 3 drug, occurrence of drug-drug interactions within protein binding sites, enzymatic-like activity of the protein or determination of enantiomeric compositions. The use of proteins as supramolecular hosts modifies the photoreactivity of encapsulated substrates by providing protection against oxygen or other external reagents, by imposing conformational restrictions in the binding pockets, or by influencing the stereochemical outcome. In this review, a selected group of examples is presented including decarboxylation, dehalogenation, nucleophilic addition, dimerisation, oxidation, Norrish type II reaction, photo-Fries rearrangement and 6 electrocyclisationFinancial support from the Spanish Government (CTQ2010-14882, JCI-2011-09926, RyC-2007-00476), from the EU (PCIG12-GA-2012-334257), from the Universitat Politènica de València (SP20120757) and from the Consellería de Educació, Cultura i Esport (PROMETEOII/2013/005, GV/2013/051) is gratefully acknowledged.Vayá Pérez, I.; Lhiaubet-Vallet, VL.; Jiménez Molero, MC.; Miranda Alonso, MÁ. (2014). Photoactive assemblies of organic compounds and biomolecules: drug-protein supramolecular systems. Chemical Society Reviews. 43:4102-4122. https://doi.org/10.1039/C3CS60413FS410241224