Synthesis of a near infrared-actuated phthalocyanine-lipid vesicle system for augmented photodynamic therapy
- Nwahara, Namdi, Managa, Muthumuni, Stoffels, Mihlali, Britton, Jonathan, Prinsloo, Earl, Nyokong, Tebello
- Authors: Nwahara, Namdi , Managa, Muthumuni , Stoffels, Mihlali , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185395 , vital:44383 , xlink:href="https://doi.org/10.1016/j.synthmet.2021.116811"
- Description: The efficacy of photodynamic therapy (PDT) is often limited by the poor bio-distributive properties of conventional photosensitizers and the local hypoxic microenvironment that characterises most solid tumours. Herein, a novel in situ oxygenic lipid formulation for photodynamic therapy (PDT) is reported. Such a hybrid was synthesized by adsorbing bimetallic nanozyme, MnO2@PtNPs (NPs = nanoparticles) onto graphene quantum dots (GQDs) – zinc (II) phthalocyanine conjugates, followed by liposomal encapsulation, affording it enhanced water solubility. The MnO2@PtNPs, which are is shown to possess excellent catalase-like properties surpassing that of MnO2 or PtNPs alone, serves to catalyze H2O2 to O2, while the zinc (II) phthalocyanine (1) serves to transform the formed oxygen to generate cytotoxic singlet oxygen immediately. We show that by combining each function of the respective building blocks, the as-synthesized 1-GQDs-MnO2@PtNPs-liposomes not only maintains the properties of oxygen supplementation through H2O2 catalysis but also displays cooperative properties for enhanced singlet oxygen production. Consequently, a remarkably improved PDT efficacy was observed for 1-GQDs-MnO2@PtNPs-liposomes in both normoxia and hypoxia. These results demonstrate the potential applicability of such nanozyme constituted 1-GQDs-MnO2@PtNPs-liposomes for achieving tumour treatment in hypoxic conditions by PDT.
- Full Text:
- Date Issued: 2021
- Authors: Nwahara, Namdi , Managa, Muthumuni , Stoffels, Mihlali , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185395 , vital:44383 , xlink:href="https://doi.org/10.1016/j.synthmet.2021.116811"
- Description: The efficacy of photodynamic therapy (PDT) is often limited by the poor bio-distributive properties of conventional photosensitizers and the local hypoxic microenvironment that characterises most solid tumours. Herein, a novel in situ oxygenic lipid formulation for photodynamic therapy (PDT) is reported. Such a hybrid was synthesized by adsorbing bimetallic nanozyme, MnO2@PtNPs (NPs = nanoparticles) onto graphene quantum dots (GQDs) – zinc (II) phthalocyanine conjugates, followed by liposomal encapsulation, affording it enhanced water solubility. The MnO2@PtNPs, which are is shown to possess excellent catalase-like properties surpassing that of MnO2 or PtNPs alone, serves to catalyze H2O2 to O2, while the zinc (II) phthalocyanine (1) serves to transform the formed oxygen to generate cytotoxic singlet oxygen immediately. We show that by combining each function of the respective building blocks, the as-synthesized 1-GQDs-MnO2@PtNPs-liposomes not only maintains the properties of oxygen supplementation through H2O2 catalysis but also displays cooperative properties for enhanced singlet oxygen production. Consequently, a remarkably improved PDT efficacy was observed for 1-GQDs-MnO2@PtNPs-liposomes in both normoxia and hypoxia. These results demonstrate the potential applicability of such nanozyme constituted 1-GQDs-MnO2@PtNPs-liposomes for achieving tumour treatment in hypoxic conditions by PDT.
- Full Text:
- Date Issued: 2021
Effects of Pluronic F127 micelles as delivering agents on the vitro dark toxicity and photodynamic therapy activity of carboxy and pyrene substituted porphyrins
- Managa, Muthumuni, Britton, Jonathan, Prinsloo, Earl, Nyokong, Tebello
- Authors: Managa, Muthumuni , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234439 , vital:50196 , xlink:href="https://doi.org/10.1016/j.poly.2018.06.031"
- Description: Metal free, Zn and ClGa containing carboxyphenoxy and phenoxy groups (complexes 1) and pyrene groups (complexes 2) were synthesized and embedded into Pluronic F127 micelles (represented as F127). Dark toxicity and photodynamic therapy activities of the embedded porphyrins were successfully studied on MCF-7 breast cancer cells. Dark toxicity showed more than 80% cell viability for all complexes. It was found that 1-Zn + F127 showed better photodynamic therapy activity compared to 1-H2 + F127, and 1-ClGa + F127, corresponding to the high partition coefficient for the Zn porphyrin derivatives. The same applies to 2-Zn + F127 compared to 2-H2 + F127, 2-ClGa + F127. 1-ClGa and 1-Zn were also linked to Pluronic F127 silica nanoparticles. PDT activities for embedded 1-ClGa + F127 and 1-Zn + F127 were much higher than when linked to Pluronic silica nanoparticles (PluS NPs), showing the importance of loading of porphyrins into Pluronic F127 as a drug delivering agent rather than linking. PDT studies at the highest concentration of 60 µg/ml showed decrease in cell viability down to 15.9% for 2-Zn + F127. The Kp was determined in biphasic octanol and water system.
- Full Text:
- Date Issued: 2018
- Authors: Managa, Muthumuni , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234439 , vital:50196 , xlink:href="https://doi.org/10.1016/j.poly.2018.06.031"
- Description: Metal free, Zn and ClGa containing carboxyphenoxy and phenoxy groups (complexes 1) and pyrene groups (complexes 2) were synthesized and embedded into Pluronic F127 micelles (represented as F127). Dark toxicity and photodynamic therapy activities of the embedded porphyrins were successfully studied on MCF-7 breast cancer cells. Dark toxicity showed more than 80% cell viability for all complexes. It was found that 1-Zn + F127 showed better photodynamic therapy activity compared to 1-H2 + F127, and 1-ClGa + F127, corresponding to the high partition coefficient for the Zn porphyrin derivatives. The same applies to 2-Zn + F127 compared to 2-H2 + F127, 2-ClGa + F127. 1-ClGa and 1-Zn were also linked to Pluronic F127 silica nanoparticles. PDT activities for embedded 1-ClGa + F127 and 1-Zn + F127 were much higher than when linked to Pluronic silica nanoparticles (PluS NPs), showing the importance of loading of porphyrins into Pluronic F127 as a drug delivering agent rather than linking. PDT studies at the highest concentration of 60 µg/ml showed decrease in cell viability down to 15.9% for 2-Zn + F127. The Kp was determined in biphasic octanol and water system.
- Full Text:
- Date Issued: 2018
Photophysics and NLO properties of Ga (III) and In (III) phthalocyaninates bearing diethyleneglycol chains
- Managa, Muthumuni, Khene, Samson M, Britton, Jonathan, Martynov, Alexander G, Gorbunova, Yulia G, Tsivadze, Aslan Y, Nyokong, Tebello
- Authors: Managa, Muthumuni , Khene, Samson M , Britton, Jonathan , Martynov, Alexander G , Gorbunova, Yulia G , Tsivadze, Aslan Y , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/237822 , vital:50556 , xlink:href="https://doi.org/10.1142/S1088424618500128"
- Description: This work reports on synthesis and characterizations of Ga(III) and In(III) complexes, formed by 2,3-bis[2′′-(2′′′′-hydroxyethoxy)ethoxy]-9,10,16,17,23,24-hexa-nn-butoxy phthalocyanine (1H2) coordinating acetatoindium(III) (1InOAc) and hydroxogallium(III) (1GaOH) Photophysical properties of hydroxogallium(III) phthalocyaninate 1GaOH and acetatoindium(III) phthalocyaninate 1InOAc were studied by UV-vis, fluorescence spectroscopy and time-resolved methods. The nonlinear absorption of the complexes was studied using the Z-scan technique at 532 nm and 10 ns pulse in DMSO and in thin films formed by composite with poly(bisphenol A carbonate) — PBC. The magnitude of absorption coefficients and other nonlinear optical parameters estimated in this work showed that complex 1InOAc exhibited the strongest nonlinear optical behavior in comparison with 1GaOH in solution and a reverse tendency when embedded in PBC thin films. DFT calculations were used to rationalize these results.
- Full Text:
- Date Issued: 2018
- Authors: Managa, Muthumuni , Khene, Samson M , Britton, Jonathan , Martynov, Alexander G , Gorbunova, Yulia G , Tsivadze, Aslan Y , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/237822 , vital:50556 , xlink:href="https://doi.org/10.1142/S1088424618500128"
- Description: This work reports on synthesis and characterizations of Ga(III) and In(III) complexes, formed by 2,3-bis[2′′-(2′′′′-hydroxyethoxy)ethoxy]-9,10,16,17,23,24-hexa-nn-butoxy phthalocyanine (1H2) coordinating acetatoindium(III) (1InOAc) and hydroxogallium(III) (1GaOH) Photophysical properties of hydroxogallium(III) phthalocyaninate 1GaOH and acetatoindium(III) phthalocyaninate 1InOAc were studied by UV-vis, fluorescence spectroscopy and time-resolved methods. The nonlinear absorption of the complexes was studied using the Z-scan technique at 532 nm and 10 ns pulse in DMSO and in thin films formed by composite with poly(bisphenol A carbonate) — PBC. The magnitude of absorption coefficients and other nonlinear optical parameters estimated in this work showed that complex 1InOAc exhibited the strongest nonlinear optical behavior in comparison with 1GaOH in solution and a reverse tendency when embedded in PBC thin films. DFT calculations were used to rationalize these results.
- Full Text:
- Date Issued: 2018
Photophysical properties of GaCl 5, 10, 15, 20-tetra (1-pyrenyl) porphyrinato incorporated into Pluronic F127 micelle
- Managa, Muthumuni, Britton, Jonathan, Amuhaya, Edith K, Nyokong, Tebello
- Authors: Managa, Muthumuni , Britton, Jonathan , Amuhaya, Edith K , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233101 , vital:50056 , xlink:href="https://doi.org/10.1016/j.jlumin.2016.12.043"
- Description: GaCl 5,10,15,20-Tetra(1-pyrenyl)porphyrin (GaClTPyP) was successfully synthesised and encapsulated into Pluronic F127. The unmetallated 5,10,15,20-tetra(1-pyrenyl)porphyrin (H2TPyP) precursor was also encapsulated into Pluronic F127. The fluorescence quantum yield for GaClTPyP at 0.045 was lower than that of H2TPyP at 0.13 due to the heavy atom effect of Ga in the former which encourages intersystem crossing to the triplet state, lowering the fluorescence. Fluorescence quantum yield values increased when GaClTPyP or H2TPyP were encapsulated in Pluronic F127. GaClTPyP/Pluronic F127 showed higher values of the binding constant (Kb) as well as Stern-Volmer constant (Ksv) when compared to H2ClTPyP/Pluronic F127. It was determined from fluorescence quenching studies for GaClTPyP was located more in the inner core (hydrophobic) of Pluronic F127 and H2TPyP more on the outer region. Single oxygen quantum yields (Ф△) were determined to be 0.32 and 0.53 for GaClTPyP and GaClTPyP/Pluronic F127 respectively, an increase for the latter compared to the former.
- Full Text:
- Date Issued: 2017
- Authors: Managa, Muthumuni , Britton, Jonathan , Amuhaya, Edith K , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233101 , vital:50056 , xlink:href="https://doi.org/10.1016/j.jlumin.2016.12.043"
- Description: GaCl 5,10,15,20-Tetra(1-pyrenyl)porphyrin (GaClTPyP) was successfully synthesised and encapsulated into Pluronic F127. The unmetallated 5,10,15,20-tetra(1-pyrenyl)porphyrin (H2TPyP) precursor was also encapsulated into Pluronic F127. The fluorescence quantum yield for GaClTPyP at 0.045 was lower than that of H2TPyP at 0.13 due to the heavy atom effect of Ga in the former which encourages intersystem crossing to the triplet state, lowering the fluorescence. Fluorescence quantum yield values increased when GaClTPyP or H2TPyP were encapsulated in Pluronic F127. GaClTPyP/Pluronic F127 showed higher values of the binding constant (Kb) as well as Stern-Volmer constant (Ksv) when compared to H2ClTPyP/Pluronic F127. It was determined from fluorescence quenching studies for GaClTPyP was located more in the inner core (hydrophobic) of Pluronic F127 and H2TPyP more on the outer region. Single oxygen quantum yields (Ф△) were determined to be 0.32 and 0.53 for GaClTPyP and GaClTPyP/Pluronic F127 respectively, an increase for the latter compared to the former.
- Full Text:
- Date Issued: 2017
Photophysical studies of meso-tetrakis (4-nitrophenyl) and meso-tetrakis (4-sulfophenyl) gallium porphyrins loaded into Pluronic F127 polymeric micelles
- Managa, Muthumuni, Ngoy, Bokolombe P, Mafukidze, Donovan M, Britton, Jonathan, Nyokong, Tebello
- Authors: Managa, Muthumuni , Ngoy, Bokolombe P , Mafukidze, Donovan M , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233132 , vital:50060 , xlink:href="https://doi.org/10.1016/j.jphotochem.2017.08.033"
- Description: 5,10,15,20-Tetra(4-nitrophenyl) porphyrinato gallium chloride (ClGaTNPP) and 5,10,15,20-tetra(4-sulfophenyl) porphyrinato gallium chloride (ClGaTSPP) and their metal free derivatives were successfully synthesised and were added to Pluronic F127 polymeric micelles to form ClGaTNPP-F127 (or H2TNPP-F127) and ClGaTSPP-F127 (or H2TSPP-F127), respectively. The fluorescence and singlet oxygen generating behaviour of the porphyrins were investigated following incorporation. The fluorescence lifetimes were short-lived upon incorporation into the polymer, compared to the porphyrin alone; suggesting the quenching of the lifetimes of the porphyrin by the polymers. Singlet oxygen quantum yields were determined to be 0.55 and 0.59 for ClGaTSPP and ClGaTSPP-F127, respectively. Thus there is an increase in singlet oxygen quantum yields in the presence of Pluronic F127 compared to the porphyrin alone. ClGaTSPP-F127 (or H2TSPP-F127) showed higher values of the binding constant (Kb) as well as high values of the Stern-Volmer constant (Ksv) compared to ClGaTNPP-F127 (or H2TNPP-F127).
- Full Text:
- Date Issued: 2017
- Authors: Managa, Muthumuni , Ngoy, Bokolombe P , Mafukidze, Donovan M , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233132 , vital:50060 , xlink:href="https://doi.org/10.1016/j.jphotochem.2017.08.033"
- Description: 5,10,15,20-Tetra(4-nitrophenyl) porphyrinato gallium chloride (ClGaTNPP) and 5,10,15,20-tetra(4-sulfophenyl) porphyrinato gallium chloride (ClGaTSPP) and their metal free derivatives were successfully synthesised and were added to Pluronic F127 polymeric micelles to form ClGaTNPP-F127 (or H2TNPP-F127) and ClGaTSPP-F127 (or H2TSPP-F127), respectively. The fluorescence and singlet oxygen generating behaviour of the porphyrins were investigated following incorporation. The fluorescence lifetimes were short-lived upon incorporation into the polymer, compared to the porphyrin alone; suggesting the quenching of the lifetimes of the porphyrin by the polymers. Singlet oxygen quantum yields were determined to be 0.55 and 0.59 for ClGaTSPP and ClGaTSPP-F127, respectively. Thus there is an increase in singlet oxygen quantum yields in the presence of Pluronic F127 compared to the porphyrin alone. ClGaTSPP-F127 (or H2TSPP-F127) showed higher values of the binding constant (Kb) as well as high values of the Stern-Volmer constant (Ksv) compared to ClGaTNPP-F127 (or H2TNPP-F127).
- Full Text:
- Date Issued: 2017
Effects of pluronic silica nanoparticles on the photophysical and photodynamic therapy behavior of triphenyl-p-phenoxy benzoic acid metalloporphyrins
- Managa, Muthumuni, Britton, Jonathan, Prinsloo, Earl, Nyokong, Tebello
- Authors: Managa, Muthumuni , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239698 , vital:50756 , xlink:href="https://doi.org/10.1080/00958972.2016.1236372"
- Description: 5, 10, 15, Triphenyl-20-p-phenoxy benzoic acid porphyrins (P) containing Zn (ZnP), Ga (GaP), and Si (SiP) were synthesized and conjugated to pluronic-silica (PluS) nanoparticles (NPs) where the fluorescence and singlet oxygen generating behavior of the porphyrins were investigated. The highest singlet oxygen quantum yield (ΦΔ) was obtained for ZnP. When the porphyrins were conjugated to the PluS NPs, the ΦΔ was quenched and fluorescence was enhanced. The pore size of the NPs upon conjugation decreased from 18.9 nm for PluS NPs to 2.4 nm (for ZnP as an example) as determined by applying the Brunauer–Emmett–Teller method. The porphyrin complexes and their conjugates were tested for their photodynamic therapy (PDT) activity on MCF-7 breast cancer cells. It was found that ZnP and its conjugate showed the highest PDT activity. The p > 0.05 indicated that ZnP is significantly different than GaP and SiP.
- Full Text:
- Date Issued: 2016
- Authors: Managa, Muthumuni , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239698 , vital:50756 , xlink:href="https://doi.org/10.1080/00958972.2016.1236372"
- Description: 5, 10, 15, Triphenyl-20-p-phenoxy benzoic acid porphyrins (P) containing Zn (ZnP), Ga (GaP), and Si (SiP) were synthesized and conjugated to pluronic-silica (PluS) nanoparticles (NPs) where the fluorescence and singlet oxygen generating behavior of the porphyrins were investigated. The highest singlet oxygen quantum yield (ΦΔ) was obtained for ZnP. When the porphyrins were conjugated to the PluS NPs, the ΦΔ was quenched and fluorescence was enhanced. The pore size of the NPs upon conjugation decreased from 18.9 nm for PluS NPs to 2.4 nm (for ZnP as an example) as determined by applying the Brunauer–Emmett–Teller method. The porphyrin complexes and their conjugates were tested for their photodynamic therapy (PDT) activity on MCF-7 breast cancer cells. It was found that ZnP and its conjugate showed the highest PDT activity. The p > 0.05 indicated that ZnP is significantly different than GaP and SiP.
- Full Text:
- Date Issued: 2016
Synthesis and dark toxicity of 5-(4-carboxyphenyl)-10, 15, 20-tris (phenyl)-porphyrinato chlorido gallium (III) when conjugated to δ-aminolevulinic acid
- Managa, Muthumuni, Mkhize, Scebi, Britton, Jonathan, Prinsloo, Earl, Nyokong, Tebello
- Authors: Managa, Muthumuni , Mkhize, Scebi , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240014 , vital:50789 , xlink:href="https://doi.org/10.1080/00958972.2016.1223292"
- Description: 5-(4-Carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato chlorido gallium(III) (2) was synthesized and then linked to ethyl ester δ-aminolevulinic acid to form 3. There was no shift in Soret band following conjugation. The fluorescence and singlet oxygen generating behavior of the porphyrins were also investigated. The highest singlet oxygen quantum yield (ΦΔ) obtained was that of 3. Complexes 2 and 3 as well as metal free 5-(4-carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato showed no dark toxicity on MCF-7 breast cancer cells.
- Full Text:
- Date Issued: 2016
- Authors: Managa, Muthumuni , Mkhize, Scebi , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240014 , vital:50789 , xlink:href="https://doi.org/10.1080/00958972.2016.1223292"
- Description: 5-(4-Carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato chlorido gallium(III) (2) was synthesized and then linked to ethyl ester δ-aminolevulinic acid to form 3. There was no shift in Soret band following conjugation. The fluorescence and singlet oxygen generating behavior of the porphyrins were also investigated. The highest singlet oxygen quantum yield (ΦΔ) obtained was that of 3. Complexes 2 and 3 as well as metal free 5-(4-carboxyphenyl)-10,15,20-tris(phenyl)-porphyrinato showed no dark toxicity on MCF-7 breast cancer cells.
- Full Text:
- Date Issued: 2016
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