Synthesis, photophysicochemical properties and photodynamic therapy activities of indium and zinc phthalocyanines when incorporated into Pluronic polymer micelles
- Authors: Motloung, Banele Mike
- Date: 2020
- Subjects: Indium , Zinc , Phthalocyanines , Polymers , Photochemotherapy , Micelles
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167529 , vital:41489
- Description: This thesis reports on the syntheses, photophysicochemical properties and photodynamic therapy activities of symmetrical metallophthalocyanines (MPcs) when alone or when incorporated into Pluronic polymer micelles. The Pcs contain either zinc or indium as central metals and have phenyldiazenylphenoxy, pyridine-2-yloxy and benzo[d]thiazol-2-ylthio as ring substituents. Spectroscopic and microscopic techniques were used to confirm the formation MPcs with micelles. The photophysics and photochemistry of the Pcs were assessed when alone and with micelles. All the studied Pcs showed good photophysicochemical behavior with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yields. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy atom effect obtained from the former. The in vitro dark cytotoxicity and photodynamic therapy of the Pc complexes and conjugates against MCF7 cells was tested. All studied Pc complexes alone and with micelles showed minimum dark toxicity making them applicable for PDT. All complexes displayed good phototoxicity < 50% cell viability (except for complex 2 > 50% cell viability) at concentrations ≤100 μg/mL, however the conjugates showed < 45% cell viability at concentrations ≤ 100 μg/mL, probably due to the small micellar size and EPR effect. The findings from this work show the importance of incorporating photosensitizers such as phthalocyanines into Pluronic polymers micelles and making them water soluble and ultimately improving their photodynamic effect.
- Full Text:
- Date Issued: 2020
- Authors: Motloung, Banele Mike
- Date: 2020
- Subjects: Indium , Zinc , Phthalocyanines , Polymers , Photochemotherapy , Micelles
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167529 , vital:41489
- Description: This thesis reports on the syntheses, photophysicochemical properties and photodynamic therapy activities of symmetrical metallophthalocyanines (MPcs) when alone or when incorporated into Pluronic polymer micelles. The Pcs contain either zinc or indium as central metals and have phenyldiazenylphenoxy, pyridine-2-yloxy and benzo[d]thiazol-2-ylthio as ring substituents. Spectroscopic and microscopic techniques were used to confirm the formation MPcs with micelles. The photophysics and photochemistry of the Pcs were assessed when alone and with micelles. All the studied Pcs showed good photophysicochemical behavior with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yields. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy atom effect obtained from the former. The in vitro dark cytotoxicity and photodynamic therapy of the Pc complexes and conjugates against MCF7 cells was tested. All studied Pc complexes alone and with micelles showed minimum dark toxicity making them applicable for PDT. All complexes displayed good phototoxicity < 50% cell viability (except for complex 2 > 50% cell viability) at concentrations ≤100 μg/mL, however the conjugates showed < 45% cell viability at concentrations ≤ 100 μg/mL, probably due to the small micellar size and EPR effect. The findings from this work show the importance of incorporating photosensitizers such as phthalocyanines into Pluronic polymers micelles and making them water soluble and ultimately improving their photodynamic effect.
- Full Text:
- Date Issued: 2020
Photophysicochemical and photodynamic antimicrobial chemotherapeutic studies of novel phthalocyanines conjugated to silver nanoparticles
- Authors: Rapulenyane, Nomasonto
- Date: 2013 , 2013-06-10
- Subjects: Phthalocyanines , Photochemistry , Photochemotherapy , Cancer -- Photochemotherapy , Anti-infective agents , Escherichia coli , Nanoparticles , Silver , Zinc
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4291 , http://hdl.handle.net/10962/d1003912 , Phthalocyanines , Photochemistry , Photochemotherapy , Cancer -- Photochemotherapy , Anti-infective agents , Escherichia coli , Nanoparticles , Silver , Zinc
- Description: This work reports on the synthesis, characterization and the physicochemical properties of novel unsymmetrically substituted zinc phthalocyanines: namely tris{11,19, 27-(1,2- diethylaminoethylthiol)-2-(captopril) phthalocyanine Zn ((ZnMCapPc (1.5)), hexakis{8,11,16,19,42,27-(octylthio)-1-(4-phenoxycarboxy) phthalocyanine} Zn (ZnMPCPc(1.7)) and Tris {11, 19, 27-(1,2-diethylaminoethylthiol)-1,2(caffeic acid) phthalocyanine} Zn ((ZnMCafPc (1.3)). Symmetrically substituted counterparts (tetrakis(diethylamino)zinc phthalocyaninato (3.8), octakis(octylthio)zinc phthalocyaninato (3.9) and tetrakis (carboxyphenoxy)zinc phthalocyaninato (3.10) complexes) were also synthesized for comparison of the photophysicochemical properties and to investigate the effect of the substituents on the low symmetry Pcs. The complexes were successfully characterized by IR, NMR, mass spectral and elemental analyses. All the complexes showed the ability to produce singlet oxygen, while the highest triplet quantum yields were obtained for 1.7, 1.5 and 3.9 (0.80, 0.65 and 0.62 respectively and the lowest were obtained for 1.3 and 3.10 (0.57 and 0.47 respectively). High triplet lifetimes (109-286 μs) were also obtained for all complexes, with 1.7 being the highest (286 μs) which also corresponds to its triplet and singlet quantum yields (0.80 and 0.77 respectively). The photosensitizing properties of low symmetry derivatives, ZnMCapPc and ZnMCafPc were investigated by conjugating glutathione (GSH) capped silver nanoparticles (AgNP). The formation of the amide bond was confirmed by IR and UV-Vis spectroscopies. The photophysicochemical behaviour of the novel phthalocyanine-GSH-AgNP conjugates and the simple mixture of the Ag NPs with low the symmetry phthalocyanines were investigated. It was observed that upon conjugation of the phthalocyanines to the GSH-AgNPs, a blue shift in the Q band was induced. The triplet lifetimes and quantum yields improved upon conjugation as compared to the phthalocyanines (Pc) alone. Complex 1.5 triplet lifetimes increased from 109 to 148 and triplet quantum yield from 0.65 to 0.86 upon conjugation. Fluorescence lifetimes and quantum yields decreased for the conjugates compared to the phthalocyanines alone, due to the quenching caused by the Ag NPs. The antimicrobial activity of the zinc phthalocyanines (complexes 1.3 and 1.5) and their conjugates against Escherichia coli was investigated. Only 1.3 and 1.5 complexes were investigated because of the availability of the sample. In general phthalocyanines showed increase in antibacterial activity with the increase in phthalocyanines concentration in the presence and absence of light. The Pc complexes and their Ag NP conjugates showed an increase in antibacterial activity, due to the synergistic effect afforded by Ag NP and Pcs. Improved antibacterial properties were obtained upon irradiation. 1.5-AgNPs had the highest antibacterial activity compared to 1.3-AgNPs conjugate; these results are in agreement with the photophysical behaviour. This work demonstrates improved photophysicochemical properties of low symm
- Full Text:
- Date Issued: 2013
- Authors: Rapulenyane, Nomasonto
- Date: 2013 , 2013-06-10
- Subjects: Phthalocyanines , Photochemistry , Photochemotherapy , Cancer -- Photochemotherapy , Anti-infective agents , Escherichia coli , Nanoparticles , Silver , Zinc
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4291 , http://hdl.handle.net/10962/d1003912 , Phthalocyanines , Photochemistry , Photochemotherapy , Cancer -- Photochemotherapy , Anti-infective agents , Escherichia coli , Nanoparticles , Silver , Zinc
- Description: This work reports on the synthesis, characterization and the physicochemical properties of novel unsymmetrically substituted zinc phthalocyanines: namely tris{11,19, 27-(1,2- diethylaminoethylthiol)-2-(captopril) phthalocyanine Zn ((ZnMCapPc (1.5)), hexakis{8,11,16,19,42,27-(octylthio)-1-(4-phenoxycarboxy) phthalocyanine} Zn (ZnMPCPc(1.7)) and Tris {11, 19, 27-(1,2-diethylaminoethylthiol)-1,2(caffeic acid) phthalocyanine} Zn ((ZnMCafPc (1.3)). Symmetrically substituted counterparts (tetrakis(diethylamino)zinc phthalocyaninato (3.8), octakis(octylthio)zinc phthalocyaninato (3.9) and tetrakis (carboxyphenoxy)zinc phthalocyaninato (3.10) complexes) were also synthesized for comparison of the photophysicochemical properties and to investigate the effect of the substituents on the low symmetry Pcs. The complexes were successfully characterized by IR, NMR, mass spectral and elemental analyses. All the complexes showed the ability to produce singlet oxygen, while the highest triplet quantum yields were obtained for 1.7, 1.5 and 3.9 (0.80, 0.65 and 0.62 respectively and the lowest were obtained for 1.3 and 3.10 (0.57 and 0.47 respectively). High triplet lifetimes (109-286 μs) were also obtained for all complexes, with 1.7 being the highest (286 μs) which also corresponds to its triplet and singlet quantum yields (0.80 and 0.77 respectively). The photosensitizing properties of low symmetry derivatives, ZnMCapPc and ZnMCafPc were investigated by conjugating glutathione (GSH) capped silver nanoparticles (AgNP). The formation of the amide bond was confirmed by IR and UV-Vis spectroscopies. The photophysicochemical behaviour of the novel phthalocyanine-GSH-AgNP conjugates and the simple mixture of the Ag NPs with low the symmetry phthalocyanines were investigated. It was observed that upon conjugation of the phthalocyanines to the GSH-AgNPs, a blue shift in the Q band was induced. The triplet lifetimes and quantum yields improved upon conjugation as compared to the phthalocyanines (Pc) alone. Complex 1.5 triplet lifetimes increased from 109 to 148 and triplet quantum yield from 0.65 to 0.86 upon conjugation. Fluorescence lifetimes and quantum yields decreased for the conjugates compared to the phthalocyanines alone, due to the quenching caused by the Ag NPs. The antimicrobial activity of the zinc phthalocyanines (complexes 1.3 and 1.5) and their conjugates against Escherichia coli was investigated. Only 1.3 and 1.5 complexes were investigated because of the availability of the sample. In general phthalocyanines showed increase in antibacterial activity with the increase in phthalocyanines concentration in the presence and absence of light. The Pc complexes and their Ag NP conjugates showed an increase in antibacterial activity, due to the synergistic effect afforded by Ag NP and Pcs. Improved antibacterial properties were obtained upon irradiation. 1.5-AgNPs had the highest antibacterial activity compared to 1.3-AgNPs conjugate; these results are in agreement with the photophysical behaviour. This work demonstrates improved photophysicochemical properties of low symm
- Full Text:
- Date Issued: 2013
Photophysical studies of zinc and indium tetraaminophthalocyanines in the presence of CdTe quantum dots
- Authors: Britton, Jonathan
- Date: 2010
- Subjects: Indium , Zinc , Quantum dots , Phthalocyanines , Photochemotherapy , Nonlinear optics , Nanocrystals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4332 , http://hdl.handle.net/10962/d1004993 , Indium , Zinc , Quantum dots , Phthalocyanines , Photochemotherapy , Nonlinear optics , Nanocrystals
- Description: CdTe QDs capped with mercaptopropionic acid (MPA) and thioglycolic acid (TGA) were covalently linked to zinc and indium tetraaminophthalocyanines (TAPcs) using N-ethyl-N(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS) as the coupling agents. The results presented give evidence in favour of formation of an amide bond between the MTAPc and CdTe QDs. Both the linked ZnTAPc–QD complexes and the mixture of QDs and ZnTAPc (without chemical linking) showed Förster resonance energy transfer (FRET), though the linked showed less FRET, whereas the QD interactions with InTAPc yielded no evidence of FRET. Both MTAPcs quenched the QDs emission, with quenching constants of the order of 103–104M−1, binding constants of the order of 108-1010M-1 and the number of binding sites for the MTAPc upon the QD being 2. High energy transfer efficiencies were obtained (in some cases as high as 93%), due to the low donor to acceptor distances. Lastly, both MTAPc were shown to be poor optical limiters because their imaginary third-order susceptibility (Im[χ(3)]) was of the order of 10-17-10-16 (optimal range is 10-9-10-11), the hyperpolarizability (γ) of the order of 10-37-10-36 (optimal range is 10-29-10-34) and the k values were above one but below ten.
- Full Text:
- Date Issued: 2010
- Authors: Britton, Jonathan
- Date: 2010
- Subjects: Indium , Zinc , Quantum dots , Phthalocyanines , Photochemotherapy , Nonlinear optics , Nanocrystals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4332 , http://hdl.handle.net/10962/d1004993 , Indium , Zinc , Quantum dots , Phthalocyanines , Photochemotherapy , Nonlinear optics , Nanocrystals
- Description: CdTe QDs capped with mercaptopropionic acid (MPA) and thioglycolic acid (TGA) were covalently linked to zinc and indium tetraaminophthalocyanines (TAPcs) using N-ethyl-N(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS) as the coupling agents. The results presented give evidence in favour of formation of an amide bond between the MTAPc and CdTe QDs. Both the linked ZnTAPc–QD complexes and the mixture of QDs and ZnTAPc (without chemical linking) showed Förster resonance energy transfer (FRET), though the linked showed less FRET, whereas the QD interactions with InTAPc yielded no evidence of FRET. Both MTAPcs quenched the QDs emission, with quenching constants of the order of 103–104M−1, binding constants of the order of 108-1010M-1 and the number of binding sites for the MTAPc upon the QD being 2. High energy transfer efficiencies were obtained (in some cases as high as 93%), due to the low donor to acceptor distances. Lastly, both MTAPc were shown to be poor optical limiters because their imaginary third-order susceptibility (Im[χ(3)]) was of the order of 10-17-10-16 (optimal range is 10-9-10-11), the hyperpolarizability (γ) of the order of 10-37-10-36 (optimal range is 10-29-10-34) and the k values were above one but below ten.
- Full Text:
- Date Issued: 2010
Synthesis, photochemical and photophysical properties of phthalocyanine derivatives
- Authors: Maqanda, Weziwe Theorine
- Date: 2005 , 2013-06-18
- Subjects: Photochemotherapy , Phthalocyanines , Zinc , Magnesium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4436 , http://hdl.handle.net/10962/d1007472 , Photochemotherapy , Phthalocyanines , Zinc , Magnesium
- Description: Substituted zinc and magnesium phthalocyanine and porphyrazine derivatives were synthesized according to the reported procedures. The magnesium and zinc phthalocyanine and porphyrazine derivatives were synthesized by ring enlargement of subphthalocyanine and statistical condensation of the two phthalonitrile derivatives. Characterization of the complexes involved the use of infrared spectroscopy, nuclear magnetic resonance spectroscopy, ultraviolet and visible spectroscopy, and Maldi-TOF spectroscopy (for selected compounds) and elemental analysis. Photochemical and photophysical properties of the complexes in non-aqueous solution was then investigated. Photobleaching quantum yields are in order of 10⁻⁵ indicating their relative photostability. Complexes containing more electron-donating substituents were more easily oxidized. For complexes 66 and 69 (as these complexes have the same number of substituents but differ in the metal center) photobleaching quantum yield for the ZincPc complex 69 was slightly less than that of the MgPc complex 66. Singlet oxygen quantum yields of the various complexes in DMSO using diphenylisobenzofuran (DPBF) as a quencher in organic solvents were determined. Singlet oxygen quantum yields of the complexes range from 0.23 to 0.67. High values of Φ[subscript]Δ ZnPc complexes was observed compared to the corresponding MgPc, complexes. This was evidenced by complexes 66 and 69 with Φ[subscript]Δ values of Φ[subscript]Δ = 0.26 and 0.40, respectively. Varying number of phenoxy substituents, complex 71 gave significantly large value of Φ[subscript]Δ compared to 70 (that is, the presence of more electron-donating substituted group, gave higher singlet oxygen quantum yields (0 .67 and 0.25 for 71 and 70 repectively). The triplet quantum yields and triplet lifetimes were determined by laser flash photolysis for selected compounds. The triplet quantum yields increase as the number of substituents increases e.g 68 > 67 > 66. Comparing porphyrazine complexes (63, 64 and 65), 63 with benzene attached to the ring, has higher triplet state lifetime (420 μs) compared to 64 and 65 containing long alkyl chain and tertbutyl substituents, 350 and 360 μs,respectively). The observed Φ[subscript]f values for 68 and 63 were quiet suprising, since low values are observed compared to the rest of the complexes (e.g 0.03 and 0.02 respectively). Although these values seem so low, they are sufficient for fluorescence imaging applications. The Φ[subscript]f values for the complexes under study are within the range reported for complexes currently used for PDT. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2005
- Authors: Maqanda, Weziwe Theorine
- Date: 2005 , 2013-06-18
- Subjects: Photochemotherapy , Phthalocyanines , Zinc , Magnesium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4436 , http://hdl.handle.net/10962/d1007472 , Photochemotherapy , Phthalocyanines , Zinc , Magnesium
- Description: Substituted zinc and magnesium phthalocyanine and porphyrazine derivatives were synthesized according to the reported procedures. The magnesium and zinc phthalocyanine and porphyrazine derivatives were synthesized by ring enlargement of subphthalocyanine and statistical condensation of the two phthalonitrile derivatives. Characterization of the complexes involved the use of infrared spectroscopy, nuclear magnetic resonance spectroscopy, ultraviolet and visible spectroscopy, and Maldi-TOF spectroscopy (for selected compounds) and elemental analysis. Photochemical and photophysical properties of the complexes in non-aqueous solution was then investigated. Photobleaching quantum yields are in order of 10⁻⁵ indicating their relative photostability. Complexes containing more electron-donating substituents were more easily oxidized. For complexes 66 and 69 (as these complexes have the same number of substituents but differ in the metal center) photobleaching quantum yield for the ZincPc complex 69 was slightly less than that of the MgPc complex 66. Singlet oxygen quantum yields of the various complexes in DMSO using diphenylisobenzofuran (DPBF) as a quencher in organic solvents were determined. Singlet oxygen quantum yields of the complexes range from 0.23 to 0.67. High values of Φ[subscript]Δ ZnPc complexes was observed compared to the corresponding MgPc, complexes. This was evidenced by complexes 66 and 69 with Φ[subscript]Δ values of Φ[subscript]Δ = 0.26 and 0.40, respectively. Varying number of phenoxy substituents, complex 71 gave significantly large value of Φ[subscript]Δ compared to 70 (that is, the presence of more electron-donating substituted group, gave higher singlet oxygen quantum yields (0 .67 and 0.25 for 71 and 70 repectively). The triplet quantum yields and triplet lifetimes were determined by laser flash photolysis for selected compounds. The triplet quantum yields increase as the number of substituents increases e.g 68 > 67 > 66. Comparing porphyrazine complexes (63, 64 and 65), 63 with benzene attached to the ring, has higher triplet state lifetime (420 μs) compared to 64 and 65 containing long alkyl chain and tertbutyl substituents, 350 and 360 μs,respectively). The observed Φ[subscript]f values for 68 and 63 were quiet suprising, since low values are observed compared to the rest of the complexes (e.g 0.03 and 0.02 respectively). Although these values seem so low, they are sufficient for fluorescence imaging applications. The Φ[subscript]f values for the complexes under study are within the range reported for complexes currently used for PDT. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2005
Synthesis of zinc phthalocyanine derivatives for possible use in photodynamic therapy
- Authors: Matlaba, Pulane Maseleka
- Date: 2003
- Subjects: Photochemotherapy , Electrochemistry , Phthalocyanines , Zinc
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4374 , http://hdl.handle.net/10962/d1005039 , Photochemotherapy , Electrochemistry , Phthalocyanines , Zinc
- Description: The synthesis of symmetrically and unsymmetrically substituted zinc phthalocyanines (ZnPc) derivatives is done according to reported procedures. The unsymmetrical ZnPc derivatives are synthesized by ring expansion of sub-phthalocyanine complexes. Ring substitution is effected with tert-butyl phenol, naphthol, and hydroxybenzoic acid. Comparison of the redox potentials for the complexes substituted with varying numbers of tert-butyl phenol: 1, 2, 3, 6 and 8 show that the complex with the highest number of substituents are more difficult to oxidize and easier to reduce. Water soluble sulphonated ZnPc (ZnPcSn) was prepared. The possibility of using axial ligation to increase the solubility and the photochemical activity of sulphotnated ZnPc in aqueous solutions was investigated. Pyridine, aminopyridyl and bipyridyl were used as axial ligands. When bipyridyl was used as the axial ligand, solubility of the ZnPcSn increased, shown by the increase in the Q-band of the monomer species in solution and the singlet oxygen quantum yields was relatively higher than that of the unligated ZnPcSn. The singlet oxygen quantum yields by the various complexes in DMF using diphenylisobenzofuran as a chemical quencher for organic solvent were determined. Singlet oxygen quantum yields for the unsymmetrically ring substituted complexes range from 0.22 to 0.68. Photobleaching quantum yields are in the order of 10-5, which means that the complexes are relatively photostable.
- Full Text:
- Date Issued: 2003
- Authors: Matlaba, Pulane Maseleka
- Date: 2003
- Subjects: Photochemotherapy , Electrochemistry , Phthalocyanines , Zinc
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4374 , http://hdl.handle.net/10962/d1005039 , Photochemotherapy , Electrochemistry , Phthalocyanines , Zinc
- Description: The synthesis of symmetrically and unsymmetrically substituted zinc phthalocyanines (ZnPc) derivatives is done according to reported procedures. The unsymmetrical ZnPc derivatives are synthesized by ring expansion of sub-phthalocyanine complexes. Ring substitution is effected with tert-butyl phenol, naphthol, and hydroxybenzoic acid. Comparison of the redox potentials for the complexes substituted with varying numbers of tert-butyl phenol: 1, 2, 3, 6 and 8 show that the complex with the highest number of substituents are more difficult to oxidize and easier to reduce. Water soluble sulphonated ZnPc (ZnPcSn) was prepared. The possibility of using axial ligation to increase the solubility and the photochemical activity of sulphotnated ZnPc in aqueous solutions was investigated. Pyridine, aminopyridyl and bipyridyl were used as axial ligands. When bipyridyl was used as the axial ligand, solubility of the ZnPcSn increased, shown by the increase in the Q-band of the monomer species in solution and the singlet oxygen quantum yields was relatively higher than that of the unligated ZnPcSn. The singlet oxygen quantum yields by the various complexes in DMF using diphenylisobenzofuran as a chemical quencher for organic solvent were determined. Singlet oxygen quantum yields for the unsymmetrically ring substituted complexes range from 0.22 to 0.68. Photobleaching quantum yields are in the order of 10-5, which means that the complexes are relatively photostable.
- Full Text:
- Date Issued: 2003
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