Acetophenone substituted phthalocyanines and their graphene quantum dots conjugates as photosensitizers for photodynamic antimicrobial chemotherapy against Staphylococcus aureus
- Openda, Yolande I, Sen, Pinar, Managa, Muthumuni, Nyokong, Tebello
- Authors: Openda, Yolande I , Sen, Pinar , Managa, Muthumuni , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186507 , vital:44506 , xlink:href="https://doi.org/10.1016/j.pdpdt.2019.101607"
- Description: This work reports on the synthesis and characterization of novel acetophenone substituted phthalocyanines along with the self-assembled nanoconjugates formed via π-π stacking interaction between the synthesized unmetalated (2), zinc (3) and indium (4) phthalocyanines and graphene quantum dots (GQDs) to form 2@GQDs, 3@GQDs and 4@GQDs. The complexes and conjugates exhibited high singlet oxygen ranging from 0.20 to 0.79 in DMSO for Pcs and nanoconjugates where in all cases, the indium complexes showed the highest singlet oxygen quantum yields. The photodynamic antimicrobial chemotherapy activity of both phthalocyanines and nanoconjugates were tested against Staphylococcus aureus. 4@GQDs was found to be highly effective causing a 9.68 log reduction of the bacteria at 10 μM (based on Pc) when compared to 3.77 log reduction of 3@GQDs.
- Full Text:
- Date Issued: 2020
- Authors: Openda, Yolande I , Sen, Pinar , Managa, Muthumuni , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186507 , vital:44506 , xlink:href="https://doi.org/10.1016/j.pdpdt.2019.101607"
- Description: This work reports on the synthesis and characterization of novel acetophenone substituted phthalocyanines along with the self-assembled nanoconjugates formed via π-π stacking interaction between the synthesized unmetalated (2), zinc (3) and indium (4) phthalocyanines and graphene quantum dots (GQDs) to form 2@GQDs, 3@GQDs and 4@GQDs. The complexes and conjugates exhibited high singlet oxygen ranging from 0.20 to 0.79 in DMSO for Pcs and nanoconjugates where in all cases, the indium complexes showed the highest singlet oxygen quantum yields. The photodynamic antimicrobial chemotherapy activity of both phthalocyanines and nanoconjugates were tested against Staphylococcus aureus. 4@GQDs was found to be highly effective causing a 9.68 log reduction of the bacteria at 10 μM (based on Pc) when compared to 3.77 log reduction of 3@GQDs.
- Full Text:
- Date Issued: 2020
Asymmetrical zinc (II) phthalocyanines conjugated to metal tungstate nanoparticles for photoinactivation of Staphylococcus aureus
- Mgidlana, Sithi, Managa, Muthumuni, Nyokong, Tebello
- Authors: Mgidlana, Sithi , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295718 , vital:57372 , xlink:href="https://doi.org/10.1080/00958972.2022.2090837"
- Description: In this study, we report for the first time on the photodynamic antimicrobial chemotherapy (PACT) of asymmetrical zinc(II) phthalocyanines and their conjugates with nickel tungstate (NiWO4), cobalt tungstate (CoWO4) and bismuth tungstate (Bi2WO6) nanoparticles. CoWO4, NiWO4 and Bi2WO6 were capped with glutathione and covalently linked to three asymmetrical zinc(II) phthalocyanines for PACT. The plate count method was used to investigate the effect of covalently linking asymmetrical zinc(II) phthalocyanines to nanoparticles under light (for PACT against Staphylococcus aureus) and in the dark. Both Pc complexes and the conjugates indicated minimum dark-toxicity. The conjugates showed greater antimicrobial activity against a gram-positive and drug resistant bacteria, Staphylococcus aureus, than Pc complexes alone.
- Full Text:
- Date Issued: 2022
- Authors: Mgidlana, Sithi , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295718 , vital:57372 , xlink:href="https://doi.org/10.1080/00958972.2022.2090837"
- Description: In this study, we report for the first time on the photodynamic antimicrobial chemotherapy (PACT) of asymmetrical zinc(II) phthalocyanines and their conjugates with nickel tungstate (NiWO4), cobalt tungstate (CoWO4) and bismuth tungstate (Bi2WO6) nanoparticles. CoWO4, NiWO4 and Bi2WO6 were capped with glutathione and covalently linked to three asymmetrical zinc(II) phthalocyanines for PACT. The plate count method was used to investigate the effect of covalently linking asymmetrical zinc(II) phthalocyanines to nanoparticles under light (for PACT against Staphylococcus aureus) and in the dark. Both Pc complexes and the conjugates indicated minimum dark-toxicity. The conjugates showed greater antimicrobial activity against a gram-positive and drug resistant bacteria, Staphylococcus aureus, than Pc complexes alone.
- Full Text:
- Date Issued: 2022
Conjugates of platinum nanoparticles with gallium tetra–(4-Carboxyphenyl) porphyrin and their use in photodynamic antimicrobial chemotherapy when in solution or embedded in electrospun fiber
- Managa, Muthumuni, Antunes, Edith M, Nyokong, Tebello
- Authors: Managa, Muthumuni , Antunes, Edith M , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193791 , vital:45396 , xlink:href="https://doi.org/10.1016/j.poly.2014.03.050"
- Description: The conjugation of Pt nanoparticles with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (ClGaTCPP) showed greater antimicrobial activity against a gram positive and drug resistant bacteria Staphylococcus aureus, than when the porphyrin was used alone. ClGaTCPP and its conjugate with platinum nanoparticle was successfully electrospun into a polystyrene polymer where the diameter ranged from 10 to 22 μm. The conjugates within the fiber still showed activity towards S. aureus.
- Full Text:
- Date Issued: 2014
- Authors: Managa, Muthumuni , Antunes, Edith M , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193791 , vital:45396 , xlink:href="https://doi.org/10.1016/j.poly.2014.03.050"
- Description: The conjugation of Pt nanoparticles with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (ClGaTCPP) showed greater antimicrobial activity against a gram positive and drug resistant bacteria Staphylococcus aureus, than when the porphyrin was used alone. ClGaTCPP and its conjugate with platinum nanoparticle was successfully electrospun into a polystyrene polymer where the diameter ranged from 10 to 22 μm. The conjugates within the fiber still showed activity towards S. aureus.
- Full Text:
- Date Issued: 2014
Effect of symmetry and metal nanoparticles on the photophysicochemical and photodynamic therapy properties of cinnamic acid zinc phthalocyanine
- Matlou, Gauta G, Managa, Muthumuni, Nyokong, Tebello
- Authors: Matlou, Gauta G , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187026 , vital:44557 , xlink:href="https://doi.org/10.1016/j.saa.2019.02.005"
- Description: In this study, a novel asymmetric cinnamic acid zinc phthalocyanine (ZnPc, 1) containing three tert-butyl substituents is reported. The asymmetric ZnPc (1) is further linked to amino functionalized magnetic nanoparticles (AMNPs) (1-AMNPs) and to cysteine functionalized silver nanoparticles (cys-AgNPs) (1-cys-AgNPs) through an amide bond. 1-AMNPs and 1-cys-AgNPs improved the triplet and singlet oxygen quantum yields of complex 1, this was also observed with the previously reported 2-AMNPs when compared to 2 while 3-AMNPs yielded an unexpected decrease in triplet quantum yield as compared to 3. The silver nanoparticles (1-cys-AgNPs) had a better effect on improving the singlet oxygen quantum yield of complex 1 than the magnetic nanoparticles (1- AMNPs). The Pcs and conjugates recorded low cell cytotoxicity in the dark and high photocytotoxicity against MCF-7 cells in-vitro. MCF-7 cell viabilities of less than 50% were recorded at 80 μg/mL making the Pcs and conjugates under study potential candidates for use as photosensitizers in cancer therapy.
- Full Text:
- Date Issued: 2019
- Authors: Matlou, Gauta G , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187026 , vital:44557 , xlink:href="https://doi.org/10.1016/j.saa.2019.02.005"
- Description: In this study, a novel asymmetric cinnamic acid zinc phthalocyanine (ZnPc, 1) containing three tert-butyl substituents is reported. The asymmetric ZnPc (1) is further linked to amino functionalized magnetic nanoparticles (AMNPs) (1-AMNPs) and to cysteine functionalized silver nanoparticles (cys-AgNPs) (1-cys-AgNPs) through an amide bond. 1-AMNPs and 1-cys-AgNPs improved the triplet and singlet oxygen quantum yields of complex 1, this was also observed with the previously reported 2-AMNPs when compared to 2 while 3-AMNPs yielded an unexpected decrease in triplet quantum yield as compared to 3. The silver nanoparticles (1-cys-AgNPs) had a better effect on improving the singlet oxygen quantum yield of complex 1 than the magnetic nanoparticles (1- AMNPs). The Pcs and conjugates recorded low cell cytotoxicity in the dark and high photocytotoxicity against MCF-7 cells in-vitro. MCF-7 cell viabilities of less than 50% were recorded at 80 μg/mL making the Pcs and conjugates under study potential candidates for use as photosensitizers in cancer therapy.
- Full Text:
- Date Issued: 2019
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
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
Enhancement of photodynamic antimicrobialtherapy through the use of cationic indium porphyrin conjugated to Ag/CuFe2O4 nanoparticles
- Makola, Collen L, Managa, Muthumuni, Nyokong, Tebello
- Authors: Makola, Collen L , Managa, Muthumuni , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186233 , vital:44475 , xlink:href="https://doi.org/10.1016/j.pdpdt.2020.101736"
- Description: Photodynamic antimicrobial chemotherapy (PACT) is being actively researched as a possible alternative for antimicrobial agents. This study focuses on the application of neutral indium 5-p-carboxyphenyl-10-15-20-(tri-4-pyridyl)porphyrin and cationic indium 5-p-carboxyphenyl-10-15-20-(tris-4-methylpyridyl)-porphyrin triiodide conjugated to 6-mercapo-1-hexanol functionalized Ag/CuFe2O4 magnetic nanoparticles for photo-inactivation of S. aureus bacteria. Comparative studies were done on quaternized and unquaternized indium porphyrin complexes conjugated to Ag/CuFe2O4, where log reduction of 9.27 was obtained for quaternized conjugate and 0.83 for unquaternized conjugate.
- Full Text:
- Date Issued: 2020
- Authors: Makola, Collen L , Managa, Muthumuni , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186233 , vital:44475 , xlink:href="https://doi.org/10.1016/j.pdpdt.2020.101736"
- Description: Photodynamic antimicrobial chemotherapy (PACT) is being actively researched as a possible alternative for antimicrobial agents. This study focuses on the application of neutral indium 5-p-carboxyphenyl-10-15-20-(tri-4-pyridyl)porphyrin and cationic indium 5-p-carboxyphenyl-10-15-20-(tris-4-methylpyridyl)-porphyrin triiodide conjugated to 6-mercapo-1-hexanol functionalized Ag/CuFe2O4 magnetic nanoparticles for photo-inactivation of S. aureus bacteria. Comparative studies were done on quaternized and unquaternized indium porphyrin complexes conjugated to Ag/CuFe2O4, where log reduction of 9.27 was obtained for quaternized conjugate and 0.83 for unquaternized conjugate.
- Full Text:
- Date Issued: 2020
Fluorescence behaviour of supramolecular hybrids containing graphene quantum dots and pyrene-derivatized phthalocyanines and porphyrins
- Achadu, Ojodomo John, Managa, Muthumuni, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Managa, Muthumuni , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188953 , vital:44801 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.10.029"
- Description: Novel pyrene-derivatized zinc and cobalt phthalocyanines (Pcs) and porphyrins (Ps) were immobilized on graphene quantum dots (GQDs) to form GQDs-Pcs and GQDs-Ps supramolecular hybrids via the π–π stacking interaction method. Spectroscopic evidence shows that the resultant hybrids were stable owing to the strong π–π stacking interaction between the GQDs and the respective Pcs and Ps, thus leading to the fabrication of interesting and functional supramolecular hybrids by taking advantage of the delocalized π electron systems of GQDs and the macrocycles. The conjugates showed increased fluorescence quantum yields for the Pcs/Ps, but decreased values for the GQDs in the conjugates. These novel hybrid materials could potentially be deployed for studies in both fundamental and applied perspectives due to the synergistic contributions resulting from the combination of their excellent electronic and optical properties.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Managa, Muthumuni , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188953 , vital:44801 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.10.029"
- Description: Novel pyrene-derivatized zinc and cobalt phthalocyanines (Pcs) and porphyrins (Ps) were immobilized on graphene quantum dots (GQDs) to form GQDs-Pcs and GQDs-Ps supramolecular hybrids via the π–π stacking interaction method. Spectroscopic evidence shows that the resultant hybrids were stable owing to the strong π–π stacking interaction between the GQDs and the respective Pcs and Ps, thus leading to the fabrication of interesting and functional supramolecular hybrids by taking advantage of the delocalized π electron systems of GQDs and the macrocycles. The conjugates showed increased fluorescence quantum yields for the Pcs/Ps, but decreased values for the GQDs in the conjugates. These novel hybrid materials could potentially be deployed for studies in both fundamental and applied perspectives due to the synergistic contributions resulting from the combination of their excellent electronic and optical properties.
- Full Text:
- Date Issued: 2017
Incorporation of metal free and Ga 5, 10, 15, 20-tetrakis (4-bromophenyl) porphyrin into Pluronic F127-folic acid micelles
- Managa, Muthumuni, Ngoy, Bucolome P, Mafukidze, Donovan M, Nyokong, Tebello
- Authors: Managa, Muthumuni , Ngoy, Bucolome P , Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233256 , vital:50073 , xlink:href="https://doi.org/10.1016/j.jlumin.2017.09.045"
- Description: ClGa 5,10,15,20-Tetrakis (4-bromophenyl) porphyrinato (ClGaTBrPP) and its metal free derivative were successfully synthesized and incorporated into Pluronic F127 polymeric micelles that has been conjugated to folic acid (FA) to form ClGaTBrPP-F127-FA (or H2TBrPP-F127-FA). For comparison, ClGaTBrPP-F127 and H2TBrPP-F127 (without FA) were also formed. The singlet oxygen quantum yield for ClGaTBrPP-F127-FA was higher (ΦΔ = 0.44) than that of H2TBrPP-F127-FA (ΦΔ = 0.37), due to the heavy atom effect of Ga in the former which encourages intersystem crossing to the triplet state. The same applies to ClGaTBrPP-F127 (ΦΔ = 0.47) and H2TBrPP-F127 (ΦΔ = 0.41). Thus, ΦΔ values decreased in the presence of FA, but still high enough for practical application of the nanodrug system. The binding constants Kb were determined to be 1.08 × 104 M−1, 2.51 × 105 M−1, 1.52 × 103 and 2.68 × 103 for H2TBrPP+F127-FA, ClGaTBrPP+F127-FA, ClGaTBrPP-F127 and H2TBrPP-F127, respectively. The Kp values were determined in biphasic octanol and water system.
- Full Text:
- Date Issued: 2018
- Authors: Managa, Muthumuni , Ngoy, Bucolome P , Mafukidze, Donovan M , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233256 , vital:50073 , xlink:href="https://doi.org/10.1016/j.jlumin.2017.09.045"
- Description: ClGa 5,10,15,20-Tetrakis (4-bromophenyl) porphyrinato (ClGaTBrPP) and its metal free derivative were successfully synthesized and incorporated into Pluronic F127 polymeric micelles that has been conjugated to folic acid (FA) to form ClGaTBrPP-F127-FA (or H2TBrPP-F127-FA). For comparison, ClGaTBrPP-F127 and H2TBrPP-F127 (without FA) were also formed. The singlet oxygen quantum yield for ClGaTBrPP-F127-FA was higher (ΦΔ = 0.44) than that of H2TBrPP-F127-FA (ΦΔ = 0.37), due to the heavy atom effect of Ga in the former which encourages intersystem crossing to the triplet state. The same applies to ClGaTBrPP-F127 (ΦΔ = 0.47) and H2TBrPP-F127 (ΦΔ = 0.41). Thus, ΦΔ values decreased in the presence of FA, but still high enough for practical application of the nanodrug system. The binding constants Kb were determined to be 1.08 × 104 M−1, 2.51 × 105 M−1, 1.52 × 103 and 2.68 × 103 for H2TBrPP+F127-FA, ClGaTBrPP+F127-FA, ClGaTBrPP-F127 and H2TBrPP-F127, respectively. The Kp values were determined in biphasic octanol and water system.
- Full Text:
- Date Issued: 2018
New type of metal-free and Zinc (II), In (III), Ga (III) phthalocyanines carrying biologically active substituents: Synthesis and photophysicochemical properties and photodynamic therapy activity
- Sen, Pinar, Managa, Muthumuni, Nyokong, Tebello
- Authors: Sen, Pinar , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186971 , vital:44552 , xlink:href="https://doi.org/10.1016/j.ica.2019.03.010"
- Description: This study reports on novel phthalocyanines having benzimidazole units which are known to have biological properties. 4-(4-(5-chloro-1H-benzo[d]imidazol-2-yl) substituted metal-free, Zn(II), In(III) and Ga(III) phthalocyanines were synthesized, these newly synthesized molecules that were substituted by oxygen bridges were fully characterized. For the purpose of determining their potency for photodynamic therapy, the photophysicochemical properties were investigated in DMSO. The H2Pc (4) showed higher fluorescence quantum yield and fluorescence lifetime as compared to metallated phthalocyanines derivatives. However, the highest singlet oxygen (ΦΔ) and triplet state quantum yields (ΦT) values were obtained with the In(III)Pc (5).
- Full Text:
- Date Issued: 2019
- Authors: Sen, Pinar , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186971 , vital:44552 , xlink:href="https://doi.org/10.1016/j.ica.2019.03.010"
- Description: This study reports on novel phthalocyanines having benzimidazole units which are known to have biological properties. 4-(4-(5-chloro-1H-benzo[d]imidazol-2-yl) substituted metal-free, Zn(II), In(III) and Ga(III) phthalocyanines were synthesized, these newly synthesized molecules that were substituted by oxygen bridges were fully characterized. For the purpose of determining their potency for photodynamic therapy, the photophysicochemical properties were investigated in DMSO. The H2Pc (4) showed higher fluorescence quantum yield and fluorescence lifetime as compared to metallated phthalocyanines derivatives. However, the highest singlet oxygen (ΦΔ) and triplet state quantum yields (ΦT) values were obtained with the In(III)Pc (5).
- Full Text:
- Date Issued: 2019
Optical limiting properties of indium 5, 10, 15, 20-tetrakis (4-aminophenyl) porphyrin covalently linked to semiconductor quantum dots
- Managa, Muthumuni, Mgidlana, Sithi, Khene, Samson M, Nyokong, Tebello
- Authors: Managa, Muthumuni , Mgidlana, Sithi , Khene, Samson M , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186101 , vital:44463 , xlink:href="https://doi.org/10.1016/j.ica.2020.119838"
- Description: 5,10,15,20-tetrakis(4-aminophenyl) porphyrin and it indium derivative were synthesised and characterized then covalently linked to CdTe/ZnSe/ZnO semiconductor quantum dots. The nonlinear absorption of the complexes was studied using the Z-scan technique at 532 nm and 10 ns pulse in dimethyl sulfoxide. Indium 5,10,15,20- tetrakis(4-aminophenyl) porphyrin (InTAPP) exhibited the strongest nonlinear optical behaviour in comparison with the metal free derivative. DFT calculations were carried out using SDD basis set at B3LYP level of theory. The nonlinear absorption coefficient (βeff) values were determined experimentally using Z-scan whereby the first static hyperpolarizability (βHRS) value were determined using DFT calcutions.
- Full Text:
- Date Issued: 2020
- Authors: Managa, Muthumuni , Mgidlana, Sithi , Khene, Samson M , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186101 , vital:44463 , xlink:href="https://doi.org/10.1016/j.ica.2020.119838"
- Description: 5,10,15,20-tetrakis(4-aminophenyl) porphyrin and it indium derivative were synthesised and characterized then covalently linked to CdTe/ZnSe/ZnO semiconductor quantum dots. The nonlinear absorption of the complexes was studied using the Z-scan technique at 532 nm and 10 ns pulse in dimethyl sulfoxide. Indium 5,10,15,20- tetrakis(4-aminophenyl) porphyrin (InTAPP) exhibited the strongest nonlinear optical behaviour in comparison with the metal free derivative. DFT calculations were carried out using SDD basis set at B3LYP level of theory. The nonlinear absorption coefficient (βeff) values were determined experimentally using Z-scan whereby the first static hyperpolarizability (βHRS) value were determined using DFT calcutions.
- Full Text:
- Date Issued: 2020
Photo-physicochemical properties and in vitro photodynamic therapy activity of morpholine-substituted Zinc (II)-Phthalocyanines π-π stacked on biotinylated graphene quantum dots
- Nene, Lindokuhle, Managa, Muthumuni, Nyokong, Tebello
- Authors: Nene, Lindokuhle , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186993 , vital:44554 , xlink:href="https://doi.org/10.1016/j.dyepig.2019.03.002"
- Description: Two morpholine-substituted Zn(II) phthalocyanines, complex 4 and the cationic 5, were synthesized and conjugated to graphene quantum dots (GQDs) and biotinylated GQDs (GQDs-biotin) by non-covalent π-π interactions. The GQDs-biotin are prepared as potential nanoparticle-based Pc delivery vector combined with a receptor-mediated transport system using biotin. The photo-physicochemical properties of the Pc complexes and their corresponding conjugates were studied. Upon conjugation, the fluorescence quantum yields decrease for 4 and 5, however, the triplet quantum yields were increased for the conjugates. All samples demonstrated singlet oxygen generation. For conjugated complexes, the singlet quantum yields decreased due to the screening effect in some cases. An increase in the photodynamic therapy activities upon quaternization was observed for the conjugates, with the cell viability decreasing from 66.2% to 51.2% after treatment for 4-GQDs and 5-GQDs, respectively. A relatively better performance was also observed for the cationic complex in combination with the biotin functionalized GQDs, 5-GQDs-biotin, where the cell viability was 34.9% after treatment. Moreover, the cellular uptake of 5-GQDs-biotin over 24 h was relatively higher compared to Pc complex alone and other PcsGQDs conjugates.
- Full Text:
- Date Issued: 2019
- Authors: Nene, Lindokuhle , Managa, Muthumuni , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186993 , vital:44554 , xlink:href="https://doi.org/10.1016/j.dyepig.2019.03.002"
- Description: Two morpholine-substituted Zn(II) phthalocyanines, complex 4 and the cationic 5, were synthesized and conjugated to graphene quantum dots (GQDs) and biotinylated GQDs (GQDs-biotin) by non-covalent π-π interactions. The GQDs-biotin are prepared as potential nanoparticle-based Pc delivery vector combined with a receptor-mediated transport system using biotin. The photo-physicochemical properties of the Pc complexes and their corresponding conjugates were studied. Upon conjugation, the fluorescence quantum yields decrease for 4 and 5, however, the triplet quantum yields were increased for the conjugates. All samples demonstrated singlet oxygen generation. For conjugated complexes, the singlet quantum yields decreased due to the screening effect in some cases. An increase in the photodynamic therapy activities upon quaternization was observed for the conjugates, with the cell viability decreasing from 66.2% to 51.2% after treatment for 4-GQDs and 5-GQDs, respectively. A relatively better performance was also observed for the cationic complex in combination with the biotin functionalized GQDs, 5-GQDs-biotin, where the cell viability was 34.9% after treatment. Moreover, the cellular uptake of 5-GQDs-biotin over 24 h was relatively higher compared to Pc complex alone and other PcsGQDs conjugates.
- Full Text:
- Date Issued: 2019
Photodegradation of ibuprofen using 5-10-15-20-tetrakis (4-bromophenyl) porphyrin conjugated to graphene quantum dots
- Magaela, N Bridged, Ndlovu, Knowledge S, Tshangana, Charmaine S, Muleia, Adoph A, Mamba, Bhekie B, Nyokong, Tebello, Managa, Muthumuni
- Authors: Magaela, N Bridged , Ndlovu, Knowledge S , Tshangana, Charmaine S , Muleia, Adoph A , Mamba, Bhekie B , Nyokong, Tebello , Managa, Muthumuni
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304819 , vital:58493 , xlink:href="https://doi.org/10.1016/j.optmat.2022.113147"
- Description: Ibuprofen (IBU) is a common anti-inflammatory drug that is consumed by many individuals in the world. As such, analytical studies have detected high concentrations of the drug in many waterbodies, which poses a risk of harmful effects on the environment and public health. The hydroxyl radical technologies, a collective of techniques also known as advanced oxidation processes (AOPs), can be utilized to degrade this emerging pollutant. In this study, the photodegradation of ibuprofen using 5,10,15,20-tetrakis(4-bromophenyl) porphyrin conjugated to graphene quantum dots was investigated using a custom-built photoreactor. Three different concentrations of IBU (200, 300 and 500 μM) were utilized as initial concentrations. The pH of the IBU was varied between acidic (pH 3.0), natural (pH 5.0) and alkaline (pH 9.0) to note the effect on IBU degradation as a function of time. The Highest ФΔ was obtained for InTBrP- GDQs (ФΔ = 0.80), followed by InTBrP (ФΔ = 0.74). The photodegradation efficiency of the TBrP-GQDs and InTBrP-GQDs were determined to be 43.2 and 76.1% respectively.
- Full Text:
- Date Issued: 2022
- Authors: Magaela, N Bridged , Ndlovu, Knowledge S , Tshangana, Charmaine S , Muleia, Adoph A , Mamba, Bhekie B , Nyokong, Tebello , Managa, Muthumuni
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304819 , vital:58493 , xlink:href="https://doi.org/10.1016/j.optmat.2022.113147"
- Description: Ibuprofen (IBU) is a common anti-inflammatory drug that is consumed by many individuals in the world. As such, analytical studies have detected high concentrations of the drug in many waterbodies, which poses a risk of harmful effects on the environment and public health. The hydroxyl radical technologies, a collective of techniques also known as advanced oxidation processes (AOPs), can be utilized to degrade this emerging pollutant. In this study, the photodegradation of ibuprofen using 5,10,15,20-tetrakis(4-bromophenyl) porphyrin conjugated to graphene quantum dots was investigated using a custom-built photoreactor. Three different concentrations of IBU (200, 300 and 500 μM) were utilized as initial concentrations. The pH of the IBU was varied between acidic (pH 3.0), natural (pH 5.0) and alkaline (pH 9.0) to note the effect on IBU degradation as a function of time. The Highest ФΔ was obtained for InTBrP- GDQs (ФΔ = 0.80), followed by InTBrP (ФΔ = 0.74). The photodegradation efficiency of the TBrP-GQDs and InTBrP-GQDs were determined to be 43.2 and 76.1% respectively.
- Full Text:
- Date Issued: 2022
Photodynamic activity of novel cationic porphyrins conjugated to graphene quantum dots against Staphylococcus aureus
- Magaela, N Bridged, Makola, Lekgowa C, Managa, Muthumuni, Nyokong, Tebello
- Authors: Magaela, N Bridged , Makola, Lekgowa C , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295797 , vital:57379 , xlink:href="https://doi.org/10.1142/S1088424622500316"
- Description: Novel 5-(pyridyl)-10-15-20-tris(4-bromophenyl) porphyrin (complex 1), indium metal derivative (complex 2), and quaternized derivative (complex 3) were synthesized and conjugated to graphene quantum dots (GQDs). The conjugation of the porphyrins to GQDs was through ππ-ππ stacking. Herein, the ππ-ππ stacking approach was used to avoid covalent conjugation which might compromise the intrinsic chemical and physical properties. The photodynamic activities of the proposed nanomaterials were assessed towards Staphylococcus aureus cell obliteration. The photophysical properties of the prepared complexes were also studied prior to the application. Moreover, a decrease in fluorescence lifetimes was observed upon metalation of complex 1. As anticipated, singlet oxygen quantum yield (ΦΔ)ΦΔ) increased notably upon heavy metal (indium) insertion and upon composite formation. Antimicrobial photodynamic therapy comparative studies were done on quaternized and unquaternized indium porphyrins conjugated to GQDs. Complex 3-GQDs exhibited the highest antibacterial activities compared to other complexes, and this was attributed to the high ΦΔΦΔ which plays an imperative role in photodynamic therapy applications.
- Full Text:
- Date Issued: 2022
- Authors: Magaela, N Bridged , Makola, Lekgowa C , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295797 , vital:57379 , xlink:href="https://doi.org/10.1142/S1088424622500316"
- Description: Novel 5-(pyridyl)-10-15-20-tris(4-bromophenyl) porphyrin (complex 1), indium metal derivative (complex 2), and quaternized derivative (complex 3) were synthesized and conjugated to graphene quantum dots (GQDs). The conjugation of the porphyrins to GQDs was through ππ-ππ stacking. Herein, the ππ-ππ stacking approach was used to avoid covalent conjugation which might compromise the intrinsic chemical and physical properties. The photodynamic activities of the proposed nanomaterials were assessed towards Staphylococcus aureus cell obliteration. The photophysical properties of the prepared complexes were also studied prior to the application. Moreover, a decrease in fluorescence lifetimes was observed upon metalation of complex 1. As anticipated, singlet oxygen quantum yield (ΦΔ)ΦΔ) increased notably upon heavy metal (indium) insertion and upon composite formation. Antimicrobial photodynamic therapy comparative studies were done on quaternized and unquaternized indium porphyrins conjugated to GQDs. Complex 3-GQDs exhibited the highest antibacterial activities compared to other complexes, and this was attributed to the high ΦΔΦΔ which plays an imperative role in photodynamic therapy applications.
- Full Text:
- Date Issued: 2022
Photodynamic antimicrobial chemotherapy activity of (5, 10, 15, 20-tetrakis (4-(4-carboxyphenycarbonoimidoyl) phenyl) porphyrinato) chloro gallium (III)
- Managa, Muthumuni, Amuhaya, Edith K, Nyokong, Tebello
- Authors: Managa, Muthumuni , Amuhaya, Edith K , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189043 , vital:44811 , xlink:href="https://doi.org/10.1016/j.saa.2015.06.088"
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone.
- Full Text:
- Date Issued: 2015
- Authors: Managa, Muthumuni , Amuhaya, Edith K , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189043 , vital:44811 , xlink:href="https://doi.org/10.1016/j.saa.2015.06.088"
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone.
- Full Text:
- Date Issued: 2015
Photodynamic antimicrobial chemotherapy activity of (5,10,15,20-tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III)
- Managa, Muthumuni, Amuhaya, Edith K, Nyokong, Tebello
- Authors: Managa, Muthumuni , Amuhaya, Edith K , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Date Issued: 2015
- Authors: Managa, Muthumuni , Amuhaya, Edith K , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Date Issued: 2015
Photodynamic antimicrobial chemotherapy activity of gallium tetra-(4-carboxyphenyl) porphyrin when conjugated to differently shaped platinum nanoparticles
- Managa, Muthumuni, Nyokong, Tebello
- Authors: Managa, Muthumuni , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189088 , vital:44815 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.06.077"
- Description: This work reports on the conjugation of differently shaped Pt nanoparticles (PtNPs) with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (ClGaTCPP). The resulting conjugates were used for photodynamic antimicrobial chemotherapy against Staphylococcus aureus. The degree of photoinactivation is dependent on concentration of the conjugates, light dose (fluence) and illumination time. The log reduction obtained for ClGaTCPP when conjugated to cubic PtNPs was 4.64 log (which indicate 99.99% of the bacteria have been killed), which is much higher than 3.94 log unit for ClGaTCPPHexagonal PtNPs and 3.31 log units for ClGaTCPP-Unshaped PtNPs. ClGaTCPP alone gave a log unit reduction of less than 3, showing the importance of conjugation to PtNPs.
- Full Text:
- Date Issued: 2015
- Authors: Managa, Muthumuni , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189088 , vital:44815 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.06.077"
- Description: This work reports on the conjugation of differently shaped Pt nanoparticles (PtNPs) with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (ClGaTCPP). The resulting conjugates were used for photodynamic antimicrobial chemotherapy against Staphylococcus aureus. The degree of photoinactivation is dependent on concentration of the conjugates, light dose (fluence) and illumination time. The log reduction obtained for ClGaTCPP when conjugated to cubic PtNPs was 4.64 log (which indicate 99.99% of the bacteria have been killed), which is much higher than 3.94 log unit for ClGaTCPPHexagonal PtNPs and 3.31 log units for ClGaTCPP-Unshaped PtNPs. ClGaTCPP alone gave a log unit reduction of less than 3, showing the importance of conjugation to PtNPs.
- Full Text:
- Date Issued: 2015
Photodynamic antimicrobial chemotherapy activity of gallium tetra-(4-carboxyphenyl) porphyrin when conjugated to differently shaped platinum nanoparticles
- Managa, Muthumuni, Nyokong, Tebello
- Authors: Managa, Muthumuni , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7297 , http://hdl.handle.net/10962/d1020360
- Description: This work reports on the conjugation of differently shaped Pt nanoparticles (PtNPs) with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (ClGaTCPP). The resulting conjugates were used for photodynamic antimicrobial chemotherapy against Staphylococcus aureus. The degree of photo-inactivation is dependent on concentration of the conjugates, light dose (fluence) and illumination time. The log reduction obtained for ClGaTCPP when conjugated to cubic PtNPs was 4.64 log (which indicate 99.99% of the bacteria have been killed), which is much higher than 3.94 log unit for ClGaTCPP-Hexagonal PtNPs and 3.31 log units for ClGaTCPP-Unshaped PtNPs. ClGaTCPP alone gave a log unit reduction of less than 3, showing the importance of conjugation to PtNPs. , Original publication is available at http://dx.doi.org/10.1016/j.molstruc.2015.06.077
- Full Text: false
- Authors: Managa, Muthumuni , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7297 , http://hdl.handle.net/10962/d1020360
- Description: This work reports on the conjugation of differently shaped Pt nanoparticles (PtNPs) with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (ClGaTCPP). The resulting conjugates were used for photodynamic antimicrobial chemotherapy against Staphylococcus aureus. The degree of photo-inactivation is dependent on concentration of the conjugates, light dose (fluence) and illumination time. The log reduction obtained for ClGaTCPP when conjugated to cubic PtNPs was 4.64 log (which indicate 99.99% of the bacteria have been killed), which is much higher than 3.94 log unit for ClGaTCPP-Hexagonal PtNPs and 3.31 log units for ClGaTCPP-Unshaped PtNPs. ClGaTCPP alone gave a log unit reduction of less than 3, showing the importance of conjugation to PtNPs. , Original publication is available at http://dx.doi.org/10.1016/j.molstruc.2015.06.077
- Full Text: false
Photodynamic antimicrobial chemotherapy of asymmetric porphyrin-silver conjugates towards photoinactivation of Staphylococcus aureus
- Shabangu, Samuel M, Babu, Balaji, Soy, Rodah C, Managa, Muthumuni, Sekhosana, Kutloano E, Nyokong, Tebello
- Authors: Shabangu, Samuel M , Babu, Balaji , Soy, Rodah C , Managa, Muthumuni , Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186536 , vital:44509 , xlink:href="https://doi.org/10.1080/00958972.2020.1739273"
- Description: Asymmetric mono-carboxy-porphyrins, (5-(4-carboxyphenyl)10,15, 20-tris(pentafluorophenyl)porphyrinato zinc(II) (1), 5-(4- carboxyphenyl)10,15,20-triphenylporphyrinato zinc(II) (2) and 5-(4- carboxyphenyl)10,15,20-tris(2-thienyl)porphyrinato zinc(II) (3), were linked to Ag nanoparticles (AgNPs) through amide bonds and selfassembly (the latter only for 3). The porphyrins and conjugates were used for photodynamic antimicrobial chemotherapy (PACT) against Staphylococcus aureus. PACT uses singlet oxygen for antimicrobial activity. Complex 3 and its conjugates had higher singlet oxygen quantum yields and higher log reduction when compared with the rest of the porphyrins and corresponding conjugates. These high log reductions for 3 and its conjugate were attributed to the presence of sulfur groups whereby there was more interaction with the bacterial membrane.
- Full Text:
- Date Issued: 2020
- Authors: Shabangu, Samuel M , Babu, Balaji , Soy, Rodah C , Managa, Muthumuni , Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186536 , vital:44509 , xlink:href="https://doi.org/10.1080/00958972.2020.1739273"
- Description: Asymmetric mono-carboxy-porphyrins, (5-(4-carboxyphenyl)10,15, 20-tris(pentafluorophenyl)porphyrinato zinc(II) (1), 5-(4- carboxyphenyl)10,15,20-triphenylporphyrinato zinc(II) (2) and 5-(4- carboxyphenyl)10,15,20-tris(2-thienyl)porphyrinato zinc(II) (3), were linked to Ag nanoparticles (AgNPs) through amide bonds and selfassembly (the latter only for 3). The porphyrins and conjugates were used for photodynamic antimicrobial chemotherapy (PACT) against Staphylococcus aureus. PACT uses singlet oxygen for antimicrobial activity. Complex 3 and its conjugates had higher singlet oxygen quantum yields and higher log reduction when compared with the rest of the porphyrins and corresponding conjugates. These high log reductions for 3 and its conjugate were attributed to the presence of sulfur groups whereby there was more interaction with the bacterial membrane.
- Full Text:
- Date Issued: 2020
Photodynamic therapy activity of 5, 10, 15-tris (5-bromo-2-thienyl), 20 (phenylcarboxy) porphyrin conjugated to graphene quantum dot against MCF-7 breast cancer cells
- Makola, Lekgowa Collen, Nwahahra, Nnamdi, Managa, Muthumuni, Nyokong, Tebello
- Authors: Makola, Lekgowa Collen , Nwahahra, Nnamdi , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300244 , vital:57909 , xlink:href="https://doi.org/10.1080/00958972.2022.2087515"
- Description: A novel 5,10,15-tris(5-bromo-2-thienyl),20(phenylcarboxy)porphyrin and its gallium derivative have been synthesized and fully characterized by various spectroscopic techniques and their respective photophysical and photochemical properties, such as the singlet oxygen quantum yield (ΦΔ), fluorescence quantum yield (ΦF) and triplet lifetime (τT) were determined. The complexes were conjugated to PEI_GQDs resulting is stable conjugates, owing to strong π–π stacking interaction between the PEI_GQDs and the porphyrins. PDT studies were carried out on these nanoconjugates and results obtained indicated they are suitable candidates for further in-depth PDT studies.
- Full Text:
- Date Issued: 2022
- Authors: Makola, Lekgowa Collen , Nwahahra, Nnamdi , Managa, Muthumuni , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300244 , vital:57909 , xlink:href="https://doi.org/10.1080/00958972.2022.2087515"
- Description: A novel 5,10,15-tris(5-bromo-2-thienyl),20(phenylcarboxy)porphyrin and its gallium derivative have been synthesized and fully characterized by various spectroscopic techniques and their respective photophysical and photochemical properties, such as the singlet oxygen quantum yield (ΦΔ), fluorescence quantum yield (ΦF) and triplet lifetime (τT) were determined. The complexes were conjugated to PEI_GQDs resulting is stable conjugates, owing to strong π–π stacking interaction between the PEI_GQDs and the porphyrins. PDT studies were carried out on these nanoconjugates and results obtained indicated they are suitable candidates for further in-depth PDT studies.
- Full Text:
- Date Issued: 2022