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The Design And Synthesis Of Novel Chalcogenopyrylium Dyes For Use As Therapeutic Sensitizers In Photodynamic Therapy
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Book Synopsis The Design and Synthesis of Novel Chalcogenopyrylium Dyes for Use as Therapeutic Sensitizers in Photodynamic Therapy by : Nancy Kristin Brennan
Download or read book The Design and Synthesis of Novel Chalcogenopyrylium Dyes for Use as Therapeutic Sensitizers in Photodynamic Therapy written by Nancy Kristin Brennan and published by . This book was released on 2002 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Design and Synthesis of Novel Chalcogenopyrylium Dyes as Agents for Photodynamic Therapy by : Kristi Anne Leonard
Download or read book The Design and Synthesis of Novel Chalcogenopyrylium Dyes as Agents for Photodynamic Therapy written by Kristi Anne Leonard and published by . This book was released on 2000 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Design and Synthesis of Chalcogenoxanthylium Dyes for Use as Photosensitizers in Photodynamic Therapy (PDT) and Photodynamic Antimicrobial Chemotheraphy (PACT) by :
Download or read book The Design and Synthesis of Chalcogenoxanthylium Dyes for Use as Photosensitizers in Photodynamic Therapy (PDT) and Photodynamic Antimicrobial Chemotheraphy (PACT) written by and published by . This book was released on 2006 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photodynamic therapy (PDT) is an FDA-approved treatment of various cancers in the United States. Photodynamic antimicrobial chemotherapy (PACT) is a technique that is now being reinvestigated as a cleansing technique for the blood supply that offers several advantages to currently used techniques. Each of these treatments uses a photosensitizer (drug) that localizes in or around the tumor or blood pathogen, light and molecular oxygen to cause cell or pathogen death selectively. The currently used photosensitizers in both treatments have certain limitations including: long-term skin photosensitivity, weak absorption of light, and absorption of light of too short a wavelength for optimal penetration in tissue and red blood cell damage. New photosensitizers that overcome these deficiencies would provide clinical options for the treatment of certain types of cancer and cleansing of the blood supply. We have synthesized structural analogues of rhodamine 123 to address the limitations of rhodamine 123 as a photosensitizer. The photophysical properties of a series of chalcogenoxanthylium dyes were studied in which the substitution of sulfur, selenium and tellurium for oxygen in the xanthylium chromophore gave a proportionally larger increases in the quantum yield for the generation of singlet oxygen and these dyes now absorb light of longer wavelengths than rhodamine. This suggests that these novel analogues are potent photosensitizers. These new analogues have given information regarding the structural components necessary for the optimization of biological and light harvesting properties of these heavy-atom rhodamine photosensitizers for use in PDT and PACT.
Book Synopsis Chalcogenopyrylium Dyes with Anchors to Nanoparticle and Semiconductor Surfaces by : Matthew Allen Bedics
Download or read book Chalcogenopyrylium Dyes with Anchors to Nanoparticle and Semiconductor Surfaces written by Matthew Allen Bedics and published by . This book was released on 2015 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface enhanced Raman scattering (SERS) has gained widespread attention as a biomedical imaging technique due to its multiplexing capabilities and the low limits of detection (LODs) of SERS-nanoprobes. The library of available reporter molecules, which are used to generate unique SERS spectra, was previously limited to commercially available dyes or a small group of cyanine reporters. Herein, the design and synthesis of a novel group of chalcogenopyrylium SERS reporters is described. These dyes have a high affinity for Au and absorption maxima that range into the NIR region. These reporter molecules enabled the use of the 1280 nm laser, which was previously incompatible with SERS imaging. Also, nanoprobe LODs using these dyes as reporters are lower than any previously documented systems, with a 100 aM LOD using a 785 nm excitation and multiple examples of fM to pM LODs using a 1064 nm or 1280 nm excitation source. Nanoprobes functionalized with these compounds have also been successfully utilized in vivo, and produce more intense SERS spectra as compared to a commonly used cyanine reporter. Dye sensitized solar cells (DSSCs) have produced considerable interest as an alternative to conventionally used Si-based solar cells. Specifically, DSSCs that use metal-free organic dyes as sensitizers are important due to the lower cost and the use of earth abundant materials as starting materials. Herein, a group of chalcogenopyrylium dyes were appended with an anchoring group to TiO2, which enables the use of these dyes as sensitizers. Structural modifications were used to extend absorption maxima into the near-infrared region of the light spectrum and to evaluate the effect that dye aggregation has on device performance. The monomethine dyes successfully produced a photocurrent, with incident photon to current efficiency values as high as 20%. Aggregation was found to benefit these systems due to the spectral broadening of aggregated dyes, and consequent increased range of wavelengths that produce a photocurrent.
Book Synopsis American Doctoral Dissertations by :
Download or read book American Doctoral Dissertations written by and published by . This book was released on 2002 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis of Novel Chalcogenopyrylium Dyes for Dye-sensitised Solar Cells by : Chi Wing Szeto
Download or read book Synthesis of Novel Chalcogenopyrylium Dyes for Dye-sensitised Solar Cells written by Chi Wing Szeto and published by . This book was released on 2015 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: Novel chalcogenopyrylium dyes for dye-sensitized solar cells were synthesized, including monomethine dyes with different chalcogenopyrylium cores, dyes with phosphonate or symmetrical carboxylic acid anchoring groups, and dyes with electron-donating triphenylamine and N, N-dimethylphenylamine moieties. The synthetic strategy for chalcogenopyrylium dyes is to generate the key chalcogenopyranone intermediate initially, followed by condensation with 4-methylpyrylium dyes. The reactive anchoring carboxylic acid group was protected in the synthesis by an ethyl ester and the deprotection method of these dyes is developed in this thesis.
Book Synopsis Dissertation Abstracts International by :
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2003 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Facilated Design and Synthesis of Chalcogen Containing Xanthenones and Xanthylium Dyes by :
Download or read book The Facilated Design and Synthesis of Chalcogen Containing Xanthenones and Xanthylium Dyes written by and published by . This book was released on 2005 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: The heavy-atom analogues of tetramethylrosamine have shown to be effective photosensitizers for Photodynamic Therapy (PDT), Photodynamic Antimicrobial Therapy (PACT), and for the inhibition of P-gp in vitro. In order to investigate these applications further, improvements to the synthetic route must be made, as the available routes were ineffective at delivering the products on a gram or larger scale. Each of these applications shares a common starting material, the 2,7 bis(dimethylamino)chalcogenoxanthen-9-one. Improving the yields for these photosensitizers in the separate applications meant facilitating the synthesis of chalcogenoxanthenones. Improvements made to the previous synthetic route are discussed, and a new method of ring closure to form chalcogenoxanthenones is also discussed. These methods facilitate a practical synthesis of the sulfur, selenium, and tellurium xanthenones. Subsequently, the first tellurium-containing analogue of tetramethylrosamine has now been synthesized. These improvements to the synthesis have also allowed a gram-scale production of chalcogenoxanthylium dyes.
Book Synopsis Synthesis, Photophysical Properties, and Biological Evaluation of Novel Chalcogenorhodamine Dyes for Applications in P-gp Inhibition, Reversible Fluorescence Probes, and Photodynamic Therapy of Cancer by : Gregory Allen Schamerhorn
Download or read book Synthesis, Photophysical Properties, and Biological Evaluation of Novel Chalcogenorhodamine Dyes for Applications in P-gp Inhibition, Reversible Fluorescence Probes, and Photodynamic Therapy of Cancer written by Gregory Allen Schamerhorn and published by . This book was released on 2014 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based upon the promising results of previous libraries that incorporated a thioamide/amide "switch", we have prepared a new library of thiorhodamine analogues in order to more closely examine the effects of isolated structural modifications on P-gp activity. Biological examination of these thiorhodamines suggested that P-gp expressing cells exhibit "selection rules" with respect to incorporation of amide and/or thioamide functionality; rates of transport by the pump for amide-bearing derivatives were more rapid than for thioamides. The results of this library suggested that appropriate functionalization of rhodamine dyes could allow one to tune their in vivo properties to be desirable for a particular application. To this end, we have prepared several libraries of selenorhodamine dyes and examined them for their ability to function as photosensitizers in the photodynamic therapy of malignant cells, as well as in the selective depletion of alloreactive T cells in extracorporeal photopheresis. Thioamide-bearing dyes were found to be effective photosensitizers in photodynamic therapy (PDT), whereas amide-bearing dyes showed desirable activity in extracorporeal photopheresis. Recently, the use of tellurorosamine dyes as reversible fluorescent probes for the continuous monitoring of reactive oxygen species in vivo was reported. Such probes are based on the Te(II)/Te(IV) redox cycle. We have evaluated several tellurorosamine dyes for their potential use as reversible probes, explored various methods of their oxidation, and examined their chemical stabilities under cell-like conditions. Oxidized analogues of tellurorosamine dyes in which the 9-phenyl substituent has been functionalized with ortho-methyl groups display increased hydrolytic stability relative to those bearing solely hydrogens at ortho-positions. Our original examination of thiorhodamine dyes and their effects on P-gp activity also showed that dyes having fused ring moieties at the 3-amino position resulted in decreased ATPase stimulation and increased binding affinity relative to those having dimethylamino fragments at the 3-amino position. Hence, we have developed synthetic routes towards rhodamine dyes having fused rings at both the 3- and 6-amino positions in an effort to develop novel, potent inhibitors of P-gp. Initial results suggest that selenorhodamines having fused ring moieties at both the 3- and 6-amino positions are more effective photosensitizers in PDT of cancer cells than those having fused rings only at the 3-amino position. Furthermore, oxidized analogues of tellurorosamine dyes functionalized with fused rings at both the 3- and 6-amino positions display increased hydrolytic stability relative to the analogous 3,6-bis(dimethylamino) tellurorosamine derivatives.
Book Synopsis Handbook Of Photodynamic Therapy: Updates On Recent Applications Of Porphyrin-based Compounds by : Ravindra K Pandey
Download or read book Handbook Of Photodynamic Therapy: Updates On Recent Applications Of Porphyrin-based Compounds written by Ravindra K Pandey and published by World Scientific. This book was released on 2016-03-24 with total page 563 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this book is to present the recent applications of photodynamic therapy (PDT) in treating cancer and other diseases. The limitations associated with current PDT agents, and the synthetic designs that have been used in various laboratories are also discussed. The utility of certain tumor-avid agent for cancer imaging (fluorescence, PET, MRI) is also summarized. The book also includes the use of delivery vehicles, including nanoparticles in improving the tumor-specificity of the desired agents. The book is basically focused on the translational approach of drug development. By providing certain specific examples, a clear concept of moving a 'product' from the bench to bed-side is also discussed.To have a clear concept of drug development the book is divided in three parts — Medicinal Chemistry, Mechanistic and Clinical studies. Each part includes the contributions from the leading scientists with extensive experience in the respective field. The handbook is assembled by renowned scientists Dr Dougherty, known as the father of PDT, Dr Kessel, well known for his contributions on mechanism of PDT and Dr Pandey for his inventions in developing improved agents for PDT and cancer-imaging.
Book Synopsis Novel Dye Sensitizers Endowed With Promising Biological Potency by : Rasha E. E l-Mekawy
Download or read book Novel Dye Sensitizers Endowed With Promising Biological Potency written by Rasha E. E l-Mekawy and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book reported that the literature survey of the chemistry of three different types of photosensitizers as porphyrins, phthalocyanines and cyanine dyes. The development of one- pot reactions represents a great challenge in organic synthesis today. Indeed, this strategy allows the construction of highly complex molecules from relatively simple reagents under developed reaction condition. The promising biological activity of them and their expedient synthetic strategy were investigated. Furthermore, the obtained results were discussed, 132 novel compounds were synthesized and evaluated for in vitro cytotoxicity against four different tumor cells, in addition to their antioxidant activity. Also, they evaluated as photodynamic therapy. Structures of the newly synthesized compounds were inferred by computational chemistry, analytical and spectral data.
Book Synopsis Chalcogenopyrylium Dyes by : Peter R. Virkler
Download or read book Chalcogenopyrylium Dyes written by Peter R. Virkler and published by . This book was released on 2001 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Design and Synthesis of NIR BODIPY Dyes by : Samuel Gorman Awuah
Download or read book Design and Synthesis of NIR BODIPY Dyes written by Samuel Gorman Awuah and published by . This book was released on 2012 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Design and Synthesis of Novel Rhodamine-based Compounds for Selective Lanthanide(III) Ion Sensing and Photocytotoxicity Studies by : Fangfang Wei
Download or read book Design and Synthesis of Novel Rhodamine-based Compounds for Selective Lanthanide(III) Ion Sensing and Photocytotoxicity Studies written by Fangfang Wei and published by . This book was released on 2021 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rhodamine derivatives have been found to sense transition metal ions selectively, and the related chemosensing behavior has been studied extensively. Drastic color changes and emission enhancements have been observed as a result of spirolactam ring-opening during the stimulation of certain transition metal ions. Because lanthanide ions are known to prefer higher coordination numbers than transition metal ions, the utilization of this preference is a potential strategy for exploring rhodamine-based chemosensors for selective lanthanide ion sensing. In addition to their application as chemosensors, rhodamine organic dyes can also be incorporated into luminescent transition metal systems and function as photosensitizers for efficient photodynamic therapy (PDT). Furthermore, introducing anti-cancer drugs into rhodamine-transition metal hybrid systems can yield synergistic effect that cause tumor cell death. In this thesis, we focus on the molecular design, characterization, properties, mechanisms, and practical application of rhodamine-based chemosensors and photosensitizers. In Chapter 1, the development of rhodamine-derivative-based chemosensors and rhodamine-containing transition metal complexes is summarized. In Chapter 2, a series of rhodamine-derivative-containing macrocycle compounds are designed, synthesized, and characterized. One macrocycle compound called MR1 was determined to exhibit selective sensing towards Tb( I) and Dy( I) ions with high sensitivity. Based on binding constants and high-resolution mass spectrometry measurement results, sensing mechanisms of MR1 for Tb( I) and Dy( I) ions are proposed. Furthermore, MR1 exhibits high stability and reusability for Ln( I) ion absorption in the solid state. This is the first example of rhodamine derivatives as fluorescent probes for Ln( I) ions. The molecular i structures of the macrocycle compounds are defined as follows: In Chapter 3, a series of rhodamine-appended Ir( I) complexes with different cyclometallating ligands are designed and synthesized, and the relationship between singlet oxygen (1O2) generation efficiency and the energy level of the Ir( I)-based triplet metal-to-ligand charge transfer (3MLCT) excited state (T1') is investigated and correlated. In addition to the direct population of the rhodamine triplet excited state (T1) through the intersystem crossing process, the T1' state acting as a relay could provide an additional pathway to generate the rhodamine T1 state, leading to enhanced 1O2 generation ability. More importantly, this study provides a novel concept for the molecular design and exploration of other photosensitizers for efficient PDT. The molecular structures of rhodamine-containing Ir( I) complexes are defined as follows: In Chapter 4, the mechanism proposed in Chapter 3 is verified to be adaptable not only in an iridium( I) system but also in a platinum( ) system. 1O2 generation ability is significantly enhanced by reducing the energy gap between the Pt( )-iv based 3MLCT state (T1') and rhodamine singlet state (S1). Furthermore, the in vitro PDT effect is significantly enhanced by introducing anti-cancer drugs into a rhodamine-tethered Pt( ) system. The molecular structures of Pt5 with high 1O2 generation ability and Pt6 with the best in vitro PDT performance are defined as follows:
Book Synopsis Design, Synthesis, and Biological Evaluation of Potential Photodynamic Therapy Dyes by : Todd Simard
Download or read book Design, Synthesis, and Biological Evaluation of Potential Photodynamic Therapy Dyes written by Todd Simard and published by . This book was released on 2001 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Design and Syntheses of Dyes for Biological Applications by : Cliferson Thivierge
Download or read book Design and Syntheses of Dyes for Biological Applications written by Cliferson Thivierge and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The challenges in modern biological imaging applications are two-fold: (i) to develop better methods of imaging, and (ii) develop dyes that are suitable for these methods. This dissertation deals with the design and synthesis of dyes mainly by modification of known dyes to make them suitable for modern biological applications. Towards this aim, novel ways of derivatizing BODIPY dyes are explored. One method involves extending the conjugation via phenyl acetylene units, pushing fluorescence wavelengths near 600 nm. A different approach deals with C-H functionalization of BODIPY in which the fluors are functionalized with acrylate units, extending their fluorescence to the red. The BODIPY dyes developed are then incorporated in through-bond energy transfer cassettes. We examine the factors affecting energy transfer efficiencies by synthesizing analogs of the cassettes and also studying the electrochemical behavior of the donor and acceptor parts. The concept of through-bond energy transfer is incorporated into conjugated polymers by random incorporation of BODIPY dyes into polyfluorenes. The ideal ratio of fluorene to BODIPY parts was found to be 4:1. The BODIPY doping agents result in dispersed emissions when excited the polyfluorene polymers. Concurrently, the polyfluorene backbone acts as an energy harvester for the BODIPY dyes, in effect increasing their molar absorptivities. Finally the use of BODIPY dyes as photodynamic therapeutic agents was examined. We found that BODIPY dyes are efficient at producing reactive oxygen species when halogens are attached directly on the BODIPY core. Furthermore, the mechanism of cell death by using such agents was elucidated. Attachment of the most promising agent to polyglutamic acid is done to promote the EPR effect. Lastly we develop a potentially new type of PDT agent that absorbs strongly above 800 nm, permitting its use in deep tissue PDT.
Book Synopsis "Design, Synthesis, and Photophysical Properties of Novel Chalcogenorhodamine Dyes for Various Applications" by : Mark William Kryman
Download or read book "Design, Synthesis, and Photophysical Properties of Novel Chalcogenorhodamine Dyes for Various Applications" written by Mark William Kryman and published by . This book was released on 2015 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Chalcogenorhodamine dyes bearing thioamide or amide moieties are transported at different rates by P-gp, with amide-containing dyes being transported more rapidly than the analogous thioamide derivatives. Additionally, thiorhodamine dyes with fused ring moieties at the 3-amino position have shown decreased ATPase stimulation and increased binding affinity for P-gp relative to the analogous dimethylamino dyes. Based on these results, a synthetic route toward a new rhodamine precursor with fused ring moieties at both 3- and 6- amino positions, the bis(julolidyl) xanthone (57-E), was developed. The two julolidyl moieties impart added rigidity, increased lipophilicity, and bathochromic shifts in the wavelength of maximum absorption in the resulting dyes. The thioamide- and amide-containing bis(julolidyl) selenorhodamines are more effective photosensitizers in the PDT of P-gp-expressing cancer cells, with EC50 values an order of magnitude lower than previously reported selenium-containing photosensitizers. The bis(julolidyl) selenorhodamine 6 is rapidly transported by P-gp, localizes in the mitochondria of cancer cells, and selectively photodepletes malignant T cells while sparing T cells necessary for healthy immune function. Several tellurorhodamines with phenyl, 2-methylphenyl, and 2,4,6-trimethylphenyl substituents at the 9-position were prepared and evaluated for their potential use as reversible fluorescence probes based on a Te(II)/Te(IV) redox cycle. While the tellurides were essentially nonfluorescent ([phi]FL
