Photophysicochemical properties and in vitro cytotoxicity of zinc tetracarboxyphenoxy phthalocyanine–quantum dot nanocomposites
- Oluwole, David O, Tilbury, Chelsea M, Prinsloo, Earl, Limson, Janice L, Nyokong, Tebello
- Authors: Oluwole, David O , Tilbury, Chelsea M , Prinsloo, Earl , Limson, Janice L , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240846 , vital:50878 , xlink:href="https://doi.org/10.1016/j.poly.2015.12.060"
- Description: Cadmium based quantum dots (QDs) capped with two different ligands (thioglycolic acid, TGA, and glutathione, GSH) were synthesized. The QDs are: CdTe, CdTe/ZnO, CdTeSe, CdTeSe/ZnO and CdSe/ZnS (the last one for TGA only). Cytotoxicity of the QDs against MCF-7 epithelial breast cancer was evaluated. The TGA capped core QDs were found to be highly cytotoxic to the cell lines when compared to GSH capped ones. The glutathione capped QDs were covalently linked to zinc tetracarboxyphenoxy phthalocyanine (ZnTCPPc). Cytotoxicity and photophysicochemical properties of the conjugates were investigated. The toxicity of the core QDs was reduced in the presence of ZnTCPPc. Enhanced triplet quantum yields and long triplet lifetimes were obtained for ZnTCPPc in the presence of all QDs.
- Full Text:
- Date Issued: 2015
- Authors: Oluwole, David O , Tilbury, Chelsea M , Prinsloo, Earl , Limson, Janice L , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240846 , vital:50878 , xlink:href="https://doi.org/10.1016/j.poly.2015.12.060"
- Description: Cadmium based quantum dots (QDs) capped with two different ligands (thioglycolic acid, TGA, and glutathione, GSH) were synthesized. The QDs are: CdTe, CdTe/ZnO, CdTeSe, CdTeSe/ZnO and CdSe/ZnS (the last one for TGA only). Cytotoxicity of the QDs against MCF-7 epithelial breast cancer was evaluated. The TGA capped core QDs were found to be highly cytotoxic to the cell lines when compared to GSH capped ones. The glutathione capped QDs were covalently linked to zinc tetracarboxyphenoxy phthalocyanine (ZnTCPPc). Cytotoxicity and photophysicochemical properties of the conjugates were investigated. The toxicity of the core QDs was reduced in the presence of ZnTCPPc. Enhanced triplet quantum yields and long triplet lifetimes were obtained for ZnTCPPc in the presence of all QDs.
- Full Text:
- Date Issued: 2015
Photophysicochemical properties and photodynamic therapy activity of highly water-soluble Zn (II) phthalocyanines
- Oluwole, David O, Sari, Fatma Aslihan, Prinsloo, Earl, Dube, Edith, Yuzer, Abdulcelil, Nyokong, Tebello, Ince, Mine
- Authors: Oluwole, David O , Sari, Fatma Aslihan , Prinsloo, Earl , Dube, Edith , Yuzer, Abdulcelil , Nyokong, Tebello , Ince, Mine
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234507 , vital:50203 , xlink:href="https://doi.org/10.1016/j.saa.2018.05.090"
- Description: The syntheses of two zinc(II) phthalocyanines (ZnPcs) having either imidazole (ZnPc 1) or pyridiloxy (ZnPc 2) moieties as their macrocycle substituents are reported. Quaternization of the ZnPcs with methyl iodide afforded water soluble cationic phthalocyanines. The photophysical, photochemical properties and photodynamic therapy (PDT) activity of the ZnPcs were studied in solution. The fluorescence quantum yield and lifetime of ZnPc 1 were higher as compared to ZnPc 2. ZnPc 2 afforded higher triplet state (ΦT) and singlet oxygen quantum yields (ΦΔ) in comparison to ZnPc 1. The PDT activity of ZnPcs was investigated against human breast adenocarcinoma cells (MCF–7). The two compounds afforded a very minimal in vitro dark cytotoxicity with 85% viable cells at concentration ≤80 μM. On irradiation of the cells having the ZnPcs, ≥50% cell death was recorded for ZnPc 1 which was also evidenced by the cells photo–micrograph.
- Full Text:
- Date Issued: 2018
- Authors: Oluwole, David O , Sari, Fatma Aslihan , Prinsloo, Earl , Dube, Edith , Yuzer, Abdulcelil , Nyokong, Tebello , Ince, Mine
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234507 , vital:50203 , xlink:href="https://doi.org/10.1016/j.saa.2018.05.090"
- Description: The syntheses of two zinc(II) phthalocyanines (ZnPcs) having either imidazole (ZnPc 1) or pyridiloxy (ZnPc 2) moieties as their macrocycle substituents are reported. Quaternization of the ZnPcs with methyl iodide afforded water soluble cationic phthalocyanines. The photophysical, photochemical properties and photodynamic therapy (PDT) activity of the ZnPcs were studied in solution. The fluorescence quantum yield and lifetime of ZnPc 1 were higher as compared to ZnPc 2. ZnPc 2 afforded higher triplet state (ΦT) and singlet oxygen quantum yields (ΦΔ) in comparison to ZnPc 1. The PDT activity of ZnPcs was investigated against human breast adenocarcinoma cells (MCF–7). The two compounds afforded a very minimal in vitro dark cytotoxicity with 85% viable cells at concentration ≤80 μM. On irradiation of the cells having the ZnPcs, ≥50% cell death was recorded for ZnPc 1 which was also evidenced by the cells photo–micrograph.
- Full Text:
- Date Issued: 2018
Photophysicochemical properties of nanoconjugates of zinc (II) 2 (3)-mono-2-(4-oxy) phenoxy) acetic acid phthalocyanine with cysteamine capped silver and silver–gold nanoparticles
- Oluwole, David O, Prinsloo, Earl, Nyokong, Tebello
- Authors: Oluwole, David O , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188552 , vital:44764 , xlink:href="https://doi.org/10.1016/j.poly.2016.09.034"
- Description: A novel asymmetrical zinc(II) 2(3)-mono-2-(4-oxy)phenoxy)acetic acid phthalocyanine (complex 1) was synthesized and subsequently linked to cysteamine capped silver (AgNPs) and silver–gold (AgAuNPs) nanoparticles (NPs) via amide bonds. The photophysicochemical properties and in vitro photodynamic therapy activity of complex 1 and its nanoconjugates were investigated. The nanoconjugates showed improved photophysical properties compared to complex 1 alone. The fluorescence, triplet and singlet quantum yields of complex 1 were found to be 20%, 48%, and 43% respectively. Complex 1 showed in vitro dark cytotoxicity, but the dark toxicity was reduced for the combination of complex 1 with AgAuNPs, this combination also gave the best photodynamic therapy activity when compared to complex 1 and its conjugate with AgNPs without AuNPs.
- Full Text:
- Date Issued: 2016
- Authors: Oluwole, David O , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188552 , vital:44764 , xlink:href="https://doi.org/10.1016/j.poly.2016.09.034"
- Description: A novel asymmetrical zinc(II) 2(3)-mono-2-(4-oxy)phenoxy)acetic acid phthalocyanine (complex 1) was synthesized and subsequently linked to cysteamine capped silver (AgNPs) and silver–gold (AgAuNPs) nanoparticles (NPs) via amide bonds. The photophysicochemical properties and in vitro photodynamic therapy activity of complex 1 and its nanoconjugates were investigated. The nanoconjugates showed improved photophysical properties compared to complex 1 alone. The fluorescence, triplet and singlet quantum yields of complex 1 were found to be 20%, 48%, and 43% respectively. Complex 1 showed in vitro dark cytotoxicity, but the dark toxicity was reduced for the combination of complex 1 with AgAuNPs, this combination also gave the best photodynamic therapy activity when compared to complex 1 and its conjugate with AgNPs without AuNPs.
- Full Text:
- Date Issued: 2016
Plasmodium falciparum Hop (PfHop) interacts with the Hsp70 chaperone in a nucleotide-dependent fashion and exhibits ligand selectivity
- Zininga, Tawanda, Makumire, Stanley, Gitau, Grace W, Njunge, James M, Pooe, Ofentse J, Klimek, Hanna, Scheurr, Robina, Raifer, Hartmann, Prinsloo, Earl, Przyborski, Jude M, Hoppe, Heinrich C, Shonhai, Addmore
- Authors: Zininga, Tawanda , Makumire, Stanley , Gitau, Grace W , Njunge, James M , Pooe, Ofentse J , Klimek, Hanna , Scheurr, Robina , Raifer, Hartmann , Prinsloo, Earl , Przyborski, Jude M , Hoppe, Heinrich C , Shonhai, Addmore
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431752 , vital:72801 , xlink:href=" https://doi.org/10.1371/journal.pone.0135326"
- Description: Heat shock proteins (Hsps) play an important role in the development and pathogenicity of malaria parasites. One of the most prominent functions of Hsps is to facilitate the folding of other proteins. Hsps are thought to play a crucial role when malaria parasites invade their host cells and during their subsequent development in hepatocytes and red blood cells. It is thought that Hsps maintain proteostasis under the unfavourable conditions that malaria parasites encounter in the host environment. Although heat shock protein 70 (Hsp70) is capable of independent folding of some proteins, its functional cooperation with heat shock protein 90 (Hsp90) facilitates folding of some proteins such as kinases and steroid hormone receptors into their fully functional forms. The cooperation of Hsp70 and Hsp90 occurs through an adaptor protein called Hsp70-Hsp90 organising protein (Hop). We previously characterised the Hop protein from Plasmodium falciparum (PfHop). We observed that the protein co-localised with the cytosol-localised chaperones, PfHsp70-1 and PfHsp90 at the blood stages of the malaria parasite. In the current study, we demonstrated that PfHop is a stress-inducible protein. We further explored the direct interaction between PfHop and PfHsp70-1 using far Western and surface plasmon resonance (SPR) analyses.
- Full Text:
- Date Issued: 2015
- Authors: Zininga, Tawanda , Makumire, Stanley , Gitau, Grace W , Njunge, James M , Pooe, Ofentse J , Klimek, Hanna , Scheurr, Robina , Raifer, Hartmann , Prinsloo, Earl , Przyborski, Jude M , Hoppe, Heinrich C , Shonhai, Addmore
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431752 , vital:72801 , xlink:href=" https://doi.org/10.1371/journal.pone.0135326"
- Description: Heat shock proteins (Hsps) play an important role in the development and pathogenicity of malaria parasites. One of the most prominent functions of Hsps is to facilitate the folding of other proteins. Hsps are thought to play a crucial role when malaria parasites invade their host cells and during their subsequent development in hepatocytes and red blood cells. It is thought that Hsps maintain proteostasis under the unfavourable conditions that malaria parasites encounter in the host environment. Although heat shock protein 70 (Hsp70) is capable of independent folding of some proteins, its functional cooperation with heat shock protein 90 (Hsp90) facilitates folding of some proteins such as kinases and steroid hormone receptors into their fully functional forms. The cooperation of Hsp70 and Hsp90 occurs through an adaptor protein called Hsp70-Hsp90 organising protein (Hop). We previously characterised the Hop protein from Plasmodium falciparum (PfHop). We observed that the protein co-localised with the cytosol-localised chaperones, PfHsp70-1 and PfHsp90 at the blood stages of the malaria parasite. In the current study, we demonstrated that PfHop is a stress-inducible protein. We further explored the direct interaction between PfHop and PfHsp70-1 using far Western and surface plasmon resonance (SPR) analyses.
- Full Text:
- Date Issued: 2015
Plasmodium falciparum Hsp70-z, an Hsp110 homologue, exhibits independent chaperone activity and interacts with Hsp70-1 in a nucleotide-dependent fashion
- Ziningwa, Tawanda, Achilonu, Ikechukwu, Hoppe, Heinrich C, Prinsloo, Earl, Dirr, Heinrich W, Shonhai, Addmore
- Authors: Ziningwa, Tawanda , Achilonu, Ikechukwu , Hoppe, Heinrich C , Prinsloo, Earl , Dirr, Heinrich W , Shonhai, Addmore
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431765 , vital:72802 , xlink:href="https://doi.org/10.1007/s12192-016-0678-4"
- Description: The role of molecular chaperones, among them heat shock proteins (Hsps), in the development of malaria parasites has been well documented. Hsp70s are molecular chaperones that facilitate protein folding. Hsp70 proteins are composed of an N-terminal nucleotide binding domain (NBD), which confers them with ATPase activity and a Cterminal substrate binding domain (SBD). In the ADPbound state, Hsp70 possesses high affinity for substrate and releases the folded substrate when it is bound to ATP. The two domains are connected by a conserved linker segment. Hsp110 proteins possess an extended lid segment, a feature that distinguishes them from canonical Hsp70s.
- Full Text:
- Date Issued: 2016
- Authors: Ziningwa, Tawanda , Achilonu, Ikechukwu , Hoppe, Heinrich C , Prinsloo, Earl , Dirr, Heinrich W , Shonhai, Addmore
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431765 , vital:72802 , xlink:href="https://doi.org/10.1007/s12192-016-0678-4"
- Description: The role of molecular chaperones, among them heat shock proteins (Hsps), in the development of malaria parasites has been well documented. Hsp70s are molecular chaperones that facilitate protein folding. Hsp70 proteins are composed of an N-terminal nucleotide binding domain (NBD), which confers them with ATPase activity and a Cterminal substrate binding domain (SBD). In the ADPbound state, Hsp70 possesses high affinity for substrate and releases the folded substrate when it is bound to ATP. The two domains are connected by a conserved linker segment. Hsp110 proteins possess an extended lid segment, a feature that distinguishes them from canonical Hsp70s.
- Full Text:
- Date Issued: 2016
Preparation of NIR absorbing axial substituted tin (iv) porphyrins and their photocytotoxic properties
- Babu, Balaji, Amuhaya, Edith K, Oluwole, David O, Prinsloo, Earl, Mack, John, Nyokong, Tebello
- Authors: Babu, Balaji , Amuhaya, Edith K , Oluwole, David O , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234592 , vital:50211 , xlink:href="https://doi.org/10.1039/C8MD00373D"
- Description: Sn(IV) porphyrins ([Sn(IV)TTP(3PyO)2] (5) and [Sn(IV)TPP(3PyO)2] (6) [tetrathienylporphyrin (TTP), tetraphenylporphyrin (TPP), and pyridyloxy (PyO)]) were prepared and characterized and their photocytotoxicity upon irradiation with 625 nm light has been studied. The presence of the 3PyO axial ligands was found to limit the aggregation and enhance the solubility of 5 and 6 in DMF/H2O (1 : 1). The photophysical properties and photodynamic therapy (PDT) activity of the meso-2-thienyl and meso-phenyl-substituted Sn(IV) porphyrins are compared. 5 and 6 were found to be photocytotoxic in MCF-7 cancer cells when irradiated with a Thorlabs M625L3 LED at 625 nm but remained nontoxic in the dark. The PDT activity of Sn(IV) meso-tetra-2-thienylporphyrin 5 was found to be significantly enhanced relative to its analogous tetraphenylporphyrin 6. There is a marked red-shift of the Q00 band of 5 into the therapeutic window due to the meso-2-thienyl rings, and 5 has an unusually high singlet oxygen quantum yield value of 0.83 in DMF. The results demonstrate that readily synthesized axially ligated Sn(IV) meso-arylporphyrins are potentially suitable for use as singlet oxygen photosensitizers in biomedical applications and merit further in depth investigation in this context.
- Full Text:
- Date Issued: 2019
- Authors: Babu, Balaji , Amuhaya, Edith K , Oluwole, David O , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234592 , vital:50211 , xlink:href="https://doi.org/10.1039/C8MD00373D"
- Description: Sn(IV) porphyrins ([Sn(IV)TTP(3PyO)2] (5) and [Sn(IV)TPP(3PyO)2] (6) [tetrathienylporphyrin (TTP), tetraphenylporphyrin (TPP), and pyridyloxy (PyO)]) were prepared and characterized and their photocytotoxicity upon irradiation with 625 nm light has been studied. The presence of the 3PyO axial ligands was found to limit the aggregation and enhance the solubility of 5 and 6 in DMF/H2O (1 : 1). The photophysical properties and photodynamic therapy (PDT) activity of the meso-2-thienyl and meso-phenyl-substituted Sn(IV) porphyrins are compared. 5 and 6 were found to be photocytotoxic in MCF-7 cancer cells when irradiated with a Thorlabs M625L3 LED at 625 nm but remained nontoxic in the dark. The PDT activity of Sn(IV) meso-tetra-2-thienylporphyrin 5 was found to be significantly enhanced relative to its analogous tetraphenylporphyrin 6. There is a marked red-shift of the Q00 band of 5 into the therapeutic window due to the meso-2-thienyl rings, and 5 has an unusually high singlet oxygen quantum yield value of 0.83 in DMF. The results demonstrate that readily synthesized axially ligated Sn(IV) meso-arylporphyrins are potentially suitable for use as singlet oxygen photosensitizers in biomedical applications and merit further in depth investigation in this context.
- Full Text:
- Date Issued: 2019
Real-time monitoring of 3T3-L1 preadipocyte differentiation using a commercially available electric cell-substrate impedance sensor system
- Kramer, Adam H, Joos-Vandewalle, Julia, Edkins, Adrienne L, Frost, Carminita L, Prinsloo, Earl
- Authors: Kramer, Adam H , Joos-Vandewalle, Julia , Edkins, Adrienne L , Frost, Carminita L , Prinsloo, Earl
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431171 , vital:72751 , xlink:href="https://doi.org/10.1016/j.bbrc.2013.12.123"
- Description: Real-time analysis offers multiple benefits over traditional end point assays. Here, we present a method of monitoring the optimisation of the growth and differentiation of murine 3T3-L1 preadipocytes to adipocytes using the commercially available ACEA xCELLigence Real-Time Cell Analyser Single Plate (RTCA SP) system. Our findings indicate that the ACEA xCELLigence RTCA SP can reproducibly monitor the primary morphological changes in pre- and post-confluent 3T3-L1 fibroblasts induced to differentiate using insulin, dexamethasone, 3-isobutyl-1-methylxanthine and rosiglitazone; and may be a viable primary method of screening compounds for adipogenic factors.
- Full Text:
- Date Issued: 2014
- Authors: Kramer, Adam H , Joos-Vandewalle, Julia , Edkins, Adrienne L , Frost, Carminita L , Prinsloo, Earl
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431171 , vital:72751 , xlink:href="https://doi.org/10.1016/j.bbrc.2013.12.123"
- Description: Real-time analysis offers multiple benefits over traditional end point assays. Here, we present a method of monitoring the optimisation of the growth and differentiation of murine 3T3-L1 preadipocytes to adipocytes using the commercially available ACEA xCELLigence Real-Time Cell Analyser Single Plate (RTCA SP) system. Our findings indicate that the ACEA xCELLigence RTCA SP can reproducibly monitor the primary morphological changes in pre- and post-confluent 3T3-L1 fibroblasts induced to differentiate using insulin, dexamethasone, 3-isobutyl-1-methylxanthine and rosiglitazone; and may be a viable primary method of screening compounds for adipogenic factors.
- Full Text:
- Date Issued: 2014
Real-time monitoring of 3T3-L1 preadipocyte differentiation using a commercially available electric cell-substrate impedance sensor system:
- Kramer, Adam H, Joos-Vandewalle, Julia, Edkins, Adrienne L, Frost, Carminita L, Prinsloo, Earl
- Authors: Kramer, Adam H , Joos-Vandewalle, Julia , Edkins, Adrienne L , Frost, Carminita L , Prinsloo, Earl
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164830 , vital:41176 , DOI: 10.1016/j.bbrc.2013.12.123
- Description: Real-time analysis offers multiple benefits over traditional end point assays. Here, we present a method of monitoring the optimisation of the growth and differentiation of murine 3T3-L1 preadipocytes to adipocytes using the commercially available ACEA xCELLigence Real-Time Cell Analyser Single Plate (RTCA SP) system. Our findings indicate that the ACEA xCELLigence RTCA SP can reproducibly monitor the primary morphological changes in pre- and post-confluent 3T3-L1 fibroblasts induced to differentiate using insulin, dexamethasone, 3-isobutyl-1-methylxanthine and rosiglitazone; and may be a viable primary method of screening compounds for adipogenic factors.
- Full Text:
- Date Issued: 2014
- Authors: Kramer, Adam H , Joos-Vandewalle, Julia , Edkins, Adrienne L , Frost, Carminita L , Prinsloo, Earl
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164830 , vital:41176 , DOI: 10.1016/j.bbrc.2013.12.123
- Description: Real-time analysis offers multiple benefits over traditional end point assays. Here, we present a method of monitoring the optimisation of the growth and differentiation of murine 3T3-L1 preadipocytes to adipocytes using the commercially available ACEA xCELLigence Real-Time Cell Analyser Single Plate (RTCA SP) system. Our findings indicate that the ACEA xCELLigence RTCA SP can reproducibly monitor the primary morphological changes in pre- and post-confluent 3T3-L1 fibroblasts induced to differentiate using insulin, dexamethasone, 3-isobutyl-1-methylxanthine and rosiglitazone; and may be a viable primary method of screening compounds for adipogenic factors.
- Full Text:
- Date Issued: 2014
Sn (IV) porphyrin-biotin decorated nitrogen doped graphene quantum dots nanohybrids for photodynamic therapy
- Magaela, N Bridged, Matshitse, Refilwe, Balaji, Babu, Managa, Muthumuni, Prinsloo, Earl, Nyokong, Tebello
- Authors: Magaela, N Bridged , Matshitse, Refilwe , Balaji, Babu , Managa, Muthumuni , Prinsloo, Earl , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230018 , vital:49733 , xlink:href="https://doi.org/10.1016/j.poly.2021.115624"
- Description: Photodynamic therapy (PDT) is a minimally invasive therapeutic procedure for cancer treatment. This study focuses on the synthesis, photophysicochemical properties, and PDT activity of Sn (IV) porphyrin (2), when linked to biotin decorated nitrogen doped graphene quantum dots (B-NGQDs). The porphyrin complex 2 was conjugated through an ester bond to B-NGQDs to form 2-B-NGQDs. Singlet oxygen quantum yield increased for 2 when linked to B-NGQDs to form 2-B-NQGDs. The dark toxicity and photodynamic therapy studies were conducted for 2, NGQDs and their conjugates using MCF-7 breast cancer cells. The cell viability for dark toxicity of all the compounds was above 90%, and 2-B-NGQDs showed high PDT activity at a concentration of 40 µg/mL with cell viability of 22%.
- Full Text:
- Date Issued: 2022
- Authors: Magaela, N Bridged , Matshitse, Refilwe , Balaji, Babu , Managa, Muthumuni , Prinsloo, Earl , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/230018 , vital:49733 , xlink:href="https://doi.org/10.1016/j.poly.2021.115624"
- Description: Photodynamic therapy (PDT) is a minimally invasive therapeutic procedure for cancer treatment. This study focuses on the synthesis, photophysicochemical properties, and PDT activity of Sn (IV) porphyrin (2), when linked to biotin decorated nitrogen doped graphene quantum dots (B-NGQDs). The porphyrin complex 2 was conjugated through an ester bond to B-NGQDs to form 2-B-NGQDs. Singlet oxygen quantum yield increased for 2 when linked to B-NGQDs to form 2-B-NQGDs. The dark toxicity and photodynamic therapy studies were conducted for 2, NGQDs and their conjugates using MCF-7 breast cancer cells. The cell viability for dark toxicity of all the compounds was above 90%, and 2-B-NGQDs showed high PDT activity at a concentration of 40 µg/mL with cell viability of 22%.
- Full Text:
- Date Issued: 2022
STAT3 interacts directly with Hsp90:
- Prinsloo, Earl, Kramer, Adam H, Edkins, Adrienne L, Blatch, Gregory L
- Authors: Prinsloo, Earl , Kramer, Adam H , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165142 , vital:41212 , DOI: 10.1002/iub.607
- Description: Heat shock protein 90 (Hsp90) functionally modulates signal transduction. The signal transducer and activator of transcription 3 (STAT3) mediates interleukin‐6 family cytokine signaling. Aberrant activation and mutation of STAT3 is associated with oncogenesis and immune disorders, respectively. Hsp90 and STAT3 have previously been shown to colocalize and coimmunoprecipitate in common complexes.
- Full Text:
- Date Issued: 2012
- Authors: Prinsloo, Earl , Kramer, Adam H , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165142 , vital:41212 , DOI: 10.1002/iub.607
- Description: Heat shock protein 90 (Hsp90) functionally modulates signal transduction. The signal transducer and activator of transcription 3 (STAT3) mediates interleukin‐6 family cytokine signaling. Aberrant activation and mutation of STAT3 is associated with oncogenesis and immune disorders, respectively. Hsp90 and STAT3 have previously been shown to colocalize and coimmunoprecipitate in common complexes.
- Full Text:
- Date Issued: 2012
Supplementary Material Synthesis and biological evaluation of (E)-cinnamic acid,(E)-2-styrylthiazole and (E)-2-[2-(naphthalen-1-yl) vinyl] thiazole derivatives
- Olawode, Emmanuel O, Tandlich, Roman, Prinsloo, Earl, Isaacs, Michelle, Hoppe, Heinrich C, Seldon, Ronnett, Warner, Digby F, Steenkamp, Vanessa, Kaye, Perry T
- Authors: Olawode, Emmanuel O , Tandlich, Roman , Prinsloo, Earl , Isaacs, Michelle , Hoppe, Heinrich C , Seldon, Ronnett , Warner, Digby F , Steenkamp, Vanessa , Kaye, Perry T
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431778 , vital:72803 , xlink:href=" https://www.arkat-usa.org/get-file/59868/"
- Description: The screening was conducted using multi-well plates which are suited for HeLa cells in the log phase of growth with final cell density > 10 cells/cm. Each experiment normally includes a blank control, containing medium without the cells.28,45 Non-contaminated HeLa cells (6.57 x 105 cells per well) in media were allowed to grow in the incubator under an atmosphere of 5% CO2 at 37 0C for 24 h. To each well was dispensed 200 µL of HeLa culture, containing 6.57 x 105 cells under LabEAir laminar flow hood (Vivid Air, South Africa); 20 µL of resazurin dye (Sigma TOX-8) and test compound (50 µL) were added, which were then incubated in the presence of 5% CO2 at 37 0C for 24 hours in a shaker, to enhance the distribution of the dye. The absorbance of each well was measured with Bio-tek Power Wave X fluorometer (Beijing, China), and increases in fluorescence was monitored at a wavelength of 590 nm, using an excitation wavelength of 560 nm.
- Full Text:
- Date Issued: 2016
- Authors: Olawode, Emmanuel O , Tandlich, Roman , Prinsloo, Earl , Isaacs, Michelle , Hoppe, Heinrich C , Seldon, Ronnett , Warner, Digby F , Steenkamp, Vanessa , Kaye, Perry T
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431778 , vital:72803 , xlink:href=" https://www.arkat-usa.org/get-file/59868/"
- Description: The screening was conducted using multi-well plates which are suited for HeLa cells in the log phase of growth with final cell density > 10 cells/cm. Each experiment normally includes a blank control, containing medium without the cells.28,45 Non-contaminated HeLa cells (6.57 x 105 cells per well) in media were allowed to grow in the incubator under an atmosphere of 5% CO2 at 37 0C for 24 h. To each well was dispensed 200 µL of HeLa culture, containing 6.57 x 105 cells under LabEAir laminar flow hood (Vivid Air, South Africa); 20 µL of resazurin dye (Sigma TOX-8) and test compound (50 µL) were added, which were then incubated in the presence of 5% CO2 at 37 0C for 24 hours in a shaker, to enhance the distribution of the dye. The absorbance of each well was measured with Bio-tek Power Wave X fluorometer (Beijing, China), and increases in fluorescence was monitored at a wavelength of 590 nm, using an excitation wavelength of 560 nm.
- 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
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
Synthesis, characterization and photodynamic activity of Sn (iv) triarylcorroles with red-shifted Q bands
- Babu, Balaji, Prinsloo, Earl, Mack, John, Nyokong, Tebello
- Authors: Babu, Balaji , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187521 , vital:44668 , xlink:href="https://doi.org/10.1039/C9NJ03391B"
- Description: Two Sn(IV) triarylcorroles were synthesised and characterized. The absorption spectrum of a meso-thien-2-yl substituted tin(IV)corrole (1-Sn) is red shifted compared to its phenyl analogue (2-Sn) and shows no sign of aggregation in solution. 1-Sn and 2-Sn exhibited singlet oxygen quantum yields of 0.87 and 0.54 in DMF, and have a triplet lifetime of 31 and 50 μs, respectively. Time dependent cellular uptake in MCF-7 cells for 1-Sn reached a peak at 24 h, and 1-Sn was found to be more lipophilic than 2-Sn. 1-Sn showed good photo-cytotoxicity on exposure to a Thorlabs 625 nm LED with an IC50 value of 3.2 μM and remained inactive in the dark.
- Full Text:
- Date Issued: 2019
- Authors: Babu, Balaji , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187521 , vital:44668 , xlink:href="https://doi.org/10.1039/C9NJ03391B"
- Description: Two Sn(IV) triarylcorroles were synthesised and characterized. The absorption spectrum of a meso-thien-2-yl substituted tin(IV)corrole (1-Sn) is red shifted compared to its phenyl analogue (2-Sn) and shows no sign of aggregation in solution. 1-Sn and 2-Sn exhibited singlet oxygen quantum yields of 0.87 and 0.54 in DMF, and have a triplet lifetime of 31 and 50 μs, respectively. Time dependent cellular uptake in MCF-7 cells for 1-Sn reached a peak at 24 h, and 1-Sn was found to be more lipophilic than 2-Sn. 1-Sn showed good photo-cytotoxicity on exposure to a Thorlabs 625 nm LED with an IC50 value of 3.2 μM and remained inactive in the dark.
- Full Text:
- Date Issued: 2019
The effects of silica based nanoparticles on the photophysicochemical properties, in vitro dark viability and photodynamic therapy study of zinc monocarboxyphenoxy phthalocyanine
- Oluwole, David O, Uddin, Imran, Prinsloo, Earl, Nyokong, Tebello
- Authors: Oluwole, David O , Uddin, Imran , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240371 , vital:50828 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.07.002"
- Description: Aminopropyl triethoxysilane functionalized core SiO2 and core/shell ZnO/SiO2 nanoparticles (NP) were covalently linked to zinc monocarboxyphenoxy phthalocyanine (ZnMCPPc, complex 1) via amide bond formation. The photophysicochemical behavior, in vitro dark viability and photodynamic therapy (PDT) activity against human breast adenocarcinoma cell line (MCF-7 cells) of the conjugates were studied. The nanoconjugates showed enhanced photophysicochemical behavior as compared to complex 1 alone. Complex 1 showed higher dark toxicity against MCF-7 cells when compared to the conjugates. In the dark, complex 1 accounted for less than 50% viable cells at 28.6 μg/mL and 57.1 μg/mL compared to the conjugates which accounted for more than 50% cell viability at these concentrations. The in vitro dark viability and PDT activity of complex 1 was reduced in the presence of these nanoparticles.
- Full Text:
- Date Issued: 2016
- Authors: Oluwole, David O , Uddin, Imran , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240371 , vital:50828 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.07.002"
- Description: Aminopropyl triethoxysilane functionalized core SiO2 and core/shell ZnO/SiO2 nanoparticles (NP) were covalently linked to zinc monocarboxyphenoxy phthalocyanine (ZnMCPPc, complex 1) via amide bond formation. The photophysicochemical behavior, in vitro dark viability and photodynamic therapy (PDT) activity against human breast adenocarcinoma cell line (MCF-7 cells) of the conjugates were studied. The nanoconjugates showed enhanced photophysicochemical behavior as compared to complex 1 alone. Complex 1 showed higher dark toxicity against MCF-7 cells when compared to the conjugates. In the dark, complex 1 accounted for less than 50% viable cells at 28.6 μg/mL and 57.1 μg/mL compared to the conjugates which accounted for more than 50% cell viability at these concentrations. The in vitro dark viability and PDT activity of complex 1 was reduced in the presence of these nanoparticles.
- Full Text:
- Date Issued: 2016
The in vitro photo-sonodynamic combinatorial therapy activity of cationic and zwitterionic phthalocyanines on MCF-7 and HeLa cancer cell lines
- Nene, Lindokuhle Cindy, Buthelezi, Khanyisile, Prinsloo, Earl, Nyokong, Tebello
- Authors: Nene, Lindokuhle Cindy , Buthelezi, Khanyisile , Prinsloo, Earl , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295891 , vital:57387 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114116"
- Description: The syntheses and characterization studies of zwitterionic 2,9,16,23-tetrakis-(N-propane sultone-morpholino) zinc(II) (4) and 2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-propane sultone-morpholinomethyl))-phenoxy zinc(II) (6) phthalocyanines are reported in this work. The photophysical properties, reactive oxygen species (ROS) generation and in vitro anticancer photodynamic (PDT), sonodynamic (SDT), and photo-sonodynamic combination (PSDT) therapy activities of the Pcs were studied and compared to their cationic counterparts: (2,9,16,23-tetrakis-(N-methyl-morpholino) Zn(II)Pc, 3), (2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-methylmorpholine)-phenoxy) Zn(II)Pc, 5). The cationic Pcs maintained higher anticancer activity for all treatment types and had higher ROS generation compared to the zwitterionic Pcs. Singlet oxygen and hydroxyl radicals were generated during ultrasound and combination irradiations of the Pcs. The zwitterionic Pcs also generated carbon radicals under ultrasound and combination irradiations. The ability of the Pcs to generate ROS is essential for PDT, SDT and PSDT, thus making these Pcs potential anticancer probes for these treatment types. Furthermore, the Pcs demonstrated the ability to bind to bovine serum albumin protein.
- Full Text:
- Date Issued: 2022
- Authors: Nene, Lindokuhle Cindy , Buthelezi, Khanyisile , Prinsloo, Earl , Nyokong, Tebello
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295891 , vital:57387 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114116"
- Description: The syntheses and characterization studies of zwitterionic 2,9,16,23-tetrakis-(N-propane sultone-morpholino) zinc(II) (4) and 2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-propane sultone-morpholinomethyl))-phenoxy zinc(II) (6) phthalocyanines are reported in this work. The photophysical properties, reactive oxygen species (ROS) generation and in vitro anticancer photodynamic (PDT), sonodynamic (SDT), and photo-sonodynamic combination (PSDT) therapy activities of the Pcs were studied and compared to their cationic counterparts: (2,9,16,23-tetrakis-(N-methyl-morpholino) Zn(II)Pc, 3), (2,9,16,23-tetrakis-(2,5-dimethyl-4-(N-methylmorpholine)-phenoxy) Zn(II)Pc, 5). The cationic Pcs maintained higher anticancer activity for all treatment types and had higher ROS generation compared to the zwitterionic Pcs. Singlet oxygen and hydroxyl radicals were generated during ultrasound and combination irradiations of the Pcs. The zwitterionic Pcs also generated carbon radicals under ultrasound and combination irradiations. The ability of the Pcs to generate ROS is essential for PDT, SDT and PSDT, thus making these Pcs potential anticancer probes for these treatment types. Furthermore, the Pcs demonstrated the ability to bind to bovine serum albumin protein.
- Full Text:
- Date Issued: 2022
The investigation of in vitro dark cytotoxicity and photodynamic therapy effect of a 2, 6-dibromo-3, 5-distyryl BODIPY dye encapsulated in Pluronic® F-127 micelles
- Molupe, Nthabeleng, Babu, Balaji, Oluwole, David O, Prinsloo, Earl, Mack, John, Nyokong, Tebello
- Authors: Molupe, Nthabeleng , Babu, Balaji , Oluwole, David O , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187862 , vital:44704 , xlink:href="https://doi.org/10.1080/00958972.2018.1522536"
- Description: A 2,6-dibrominated 3,5-distyryl boron-dipyrromethene (BODIPY) dye with a moderately high singlet oxygen quantum yield was encapsulated in Pluronic® F-127 micelles, and its dark cytotoxicity and photodynamic activity were investigated on the human breast adenocarcinoma MCF-7 cell line. The BODIPY dye exhibited very low dark toxicity and a significant PDT effect when added in drug formulations consisting of 5.0% (v/v) DMSO in supplemented Dulbecco’s modified Eagle’s medium (DMEM) and as Pluronic® F-127 micelle encapsulation complexes in supplemented DMEM alone. An IC50 value of 4 ± 2 μM was obtained when the BODIPY dye was encapsulated in Pluronic® F-127 micelles during in vitro photodynamic activity studies in MCF-7 cancer cells with a 660 nm light emitting diode.
- Full Text:
- Date Issued: 2018
- Authors: Molupe, Nthabeleng , Babu, Balaji , Oluwole, David O , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187862 , vital:44704 , xlink:href="https://doi.org/10.1080/00958972.2018.1522536"
- Description: A 2,6-dibrominated 3,5-distyryl boron-dipyrromethene (BODIPY) dye with a moderately high singlet oxygen quantum yield was encapsulated in Pluronic® F-127 micelles, and its dark cytotoxicity and photodynamic activity were investigated on the human breast adenocarcinoma MCF-7 cell line. The BODIPY dye exhibited very low dark toxicity and a significant PDT effect when added in drug formulations consisting of 5.0% (v/v) DMSO in supplemented Dulbecco’s modified Eagle’s medium (DMEM) and as Pluronic® F-127 micelle encapsulation complexes in supplemented DMEM alone. An IC50 value of 4 ± 2 μM was obtained when the BODIPY dye was encapsulated in Pluronic® F-127 micelles during in vitro photodynamic activity studies in MCF-7 cancer cells with a 660 nm light emitting diode.
- Full Text:
- Date Issued: 2018
The Malarial Exported PFA0660w Is an Hsp40 Co-Chaperone of PfHsp70-x
- Daniyan, Michael O, Boshoff, Aileen, Prinsloo, Earl, Pesce, Eva-Rachele, Blatch, Gregory L
- Authors: Daniyan, Michael O , Boshoff, Aileen , Prinsloo, Earl , Pesce, Eva-Rachele , Blatch, Gregory L
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66098 , vital:28901 , https://doi.org/10.1371/journal.pone.0148517
- Description: publisher version , Plasmodium falciparum, the human pathogen responsible for the most dangerous malaria infection, survives and develops in mature erythrocytes through the export of proteins needed for remodelling of the host cell. Molecular chaperones of the heat shock protein (Hsp) family are prominent members of the exportome, including a number of Hsp40s and a Hsp70. PFA0660w, a type II Hsp40, has been shown to be exported and possibly form a complex with PfHsp70-x in the infected erythrocyte cytosol. However, the chaperone properties of PFA0660w and its interaction with human and parasite Hsp70s are yet to be investigated. Recombinant PFA0660w was found to exist as a monomer in solution, and was able to significantly stimulate the ATPase activity of PfHsp70-x but not that of a second plasmodial Hsp70 (PfHsp70-1) or a human Hsp70 (HSPA1A), indicating a potential specific functional partnership with PfHsp70-x. Protein binding studies in the presence and absence of ATP suggested that the interaction of PFA0660w with PfHsp70-x most likely represented a co-chaperone/chaperone interaction. Also, PFA0660w alone produced a concentration-dependent suppression of rhodanese aggregation, demonstrating its chaperone properties. Overall, we have provided the first biochemical evidence for the possible role of PFA0660w as a chaperone and as co-chaperone of PfHsp70-x. We propose that these chaperones boost the chaperone power of the infected erythrocyte, enabling successful protein trafficking and folding, and thereby making a fundamental contribution to the pathology of malaria. , This work was supported by grants from the National Research Foundation (NRF) and Medical Research Council (MRC) of South Africa. The ProteOn XPR36 IAS was purchased from a National Nanotechnology Equipment Programme grant from the Department of Science and Technology and the NRF of South Africa. Michael O. Daniyan was a recipient of the Education Trust Fund (ETF) Academic Staff Training and Development (AST and D) scholarship of Obafemi Awolowo University, Ile-Ife, Nigeria and a Rhodes University Council research bursary
- Full Text:
- Date Issued: 2016
- Authors: Daniyan, Michael O , Boshoff, Aileen , Prinsloo, Earl , Pesce, Eva-Rachele , Blatch, Gregory L
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66098 , vital:28901 , https://doi.org/10.1371/journal.pone.0148517
- Description: publisher version , Plasmodium falciparum, the human pathogen responsible for the most dangerous malaria infection, survives and develops in mature erythrocytes through the export of proteins needed for remodelling of the host cell. Molecular chaperones of the heat shock protein (Hsp) family are prominent members of the exportome, including a number of Hsp40s and a Hsp70. PFA0660w, a type II Hsp40, has been shown to be exported and possibly form a complex with PfHsp70-x in the infected erythrocyte cytosol. However, the chaperone properties of PFA0660w and its interaction with human and parasite Hsp70s are yet to be investigated. Recombinant PFA0660w was found to exist as a monomer in solution, and was able to significantly stimulate the ATPase activity of PfHsp70-x but not that of a second plasmodial Hsp70 (PfHsp70-1) or a human Hsp70 (HSPA1A), indicating a potential specific functional partnership with PfHsp70-x. Protein binding studies in the presence and absence of ATP suggested that the interaction of PFA0660w with PfHsp70-x most likely represented a co-chaperone/chaperone interaction. Also, PFA0660w alone produced a concentration-dependent suppression of rhodanese aggregation, demonstrating its chaperone properties. Overall, we have provided the first biochemical evidence for the possible role of PFA0660w as a chaperone and as co-chaperone of PfHsp70-x. We propose that these chaperones boost the chaperone power of the infected erythrocyte, enabling successful protein trafficking and folding, and thereby making a fundamental contribution to the pathology of malaria. , This work was supported by grants from the National Research Foundation (NRF) and Medical Research Council (MRC) of South Africa. The ProteOn XPR36 IAS was purchased from a National Nanotechnology Equipment Programme grant from the Department of Science and Technology and the NRF of South Africa. Michael O. Daniyan was a recipient of the Education Trust Fund (ETF) Academic Staff Training and Development (AST and D) scholarship of Obafemi Awolowo University, Ile-Ife, Nigeria and a Rhodes University Council research bursary
- Full Text:
- Date Issued: 2016
The photophysicochemical properties and photodynamic therapy activity of In and Zn phthalocyanines when incorporated into individual or mixed Pluronic® micelles
- Motloung, Banele M, Babu, Balaji, Prinsloo, Earl, Nyokong, Tebello
- Authors: Motloung, Banele M , Babu, Balaji , Prinsloo, Earl , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186124 , vital:44465 , xlink:href="https://doi.org/10.1016/j.poly.2020.114683"
- Description: The synthesis, photophysicochemical properties and photodynamic activity (PDT) of tetra-pyridyloxy (1,2) and benzothiazole (3, 4) substituted indium (III) (1,3) and zinc (2, 4) phthalocyanines (Pcs) and their incorporation into Pluronic® F127 and Pluronic L121/F127 mixed micelles (the latter for 3 and 4 only) are presented in this study. The InPcs exhibited higher singlet oxygen (ΦΔ) at 0.76 and 0.68 compared to the ZnPc’s at 0.47 and 0.44 in dimethyl sulfoxide. The ΦΔ values in the presence of Pluronic® F127 and in water, were 0.39 and 0.42 for InPcs and 0.23 and 0.37 for ZnPc. The ΦΔ values in the presence of Pluronic F127/L121 mixed micelles for complex 3 and 4 were 0.51 and 0.29 in water. The Kp was determined using the water and octanol system. InPcs had larger Kp values suggesting that they are more likely to be taken up by the cancer cells hence they showed better PDT activity
- Full Text:
- Date Issued: 2020
- Authors: Motloung, Banele M , Babu, Balaji , Prinsloo, Earl , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186124 , vital:44465 , xlink:href="https://doi.org/10.1016/j.poly.2020.114683"
- Description: The synthesis, photophysicochemical properties and photodynamic activity (PDT) of tetra-pyridyloxy (1,2) and benzothiazole (3, 4) substituted indium (III) (1,3) and zinc (2, 4) phthalocyanines (Pcs) and their incorporation into Pluronic® F127 and Pluronic L121/F127 mixed micelles (the latter for 3 and 4 only) are presented in this study. The InPcs exhibited higher singlet oxygen (ΦΔ) at 0.76 and 0.68 compared to the ZnPc’s at 0.47 and 0.44 in dimethyl sulfoxide. The ΦΔ values in the presence of Pluronic® F127 and in water, were 0.39 and 0.42 for InPcs and 0.23 and 0.37 for ZnPc. The ΦΔ values in the presence of Pluronic F127/L121 mixed micelles for complex 3 and 4 were 0.51 and 0.29 in water. The Kp was determined using the water and octanol system. InPcs had larger Kp values suggesting that they are more likely to be taken up by the cancer cells hence they showed better PDT activity
- Full Text:
- Date Issued: 2020
The photophysicochemical properties and photodynamic therapy activity of phenyldiazenyl phenoxy substituted phthalocyanines when incorporated into Pluronic® F127 micelles
- Motloung, Banele M, Sekhosana, Kutloano E, Managa, Muthumuni, Prinsloo, Earl, Nyokong, Tebello
- Authors: Motloung, Banele M , Sekhosana, Kutloano E , Managa, Muthumuni , Prinsloo, Earl , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186769 , vital:44532 , xlink:href="https://doi.org/10.1016/j.poly.2019.114157"
- Description: The synthesis, photophysicochemical properties and photodynamic activity (PDT) of 4(4-phenyldiazenyl) phenoxy substituted indium (III) (InPc) and zinc (ZnPc) phthalocyanines when alone or incorporated into Pluronic_ F127 micelles are presented in this study. The InPc exhibited higher singlet oxygen (UD) at 0.47 compared to the ZnPc at 0.20 in dimethylsulfoxide. The UD values in the presence of Pluronic_ F127 and in water, were 0.32 for InPc and 0.09 for ZnPc. The triplet quantum yields (UT) were 0.92 for InPc and 0.32 for ZnPc in DMSO. The PDT activity followed the same trend as the singlet oxygen quantum yields. At the highest concentration, InPc in Pluronic_ F127 gave 22% cell viability compared to 34% for complex ZnPc. The partition coefficient Kp values were determined using the water and octanol system. InPc had a larger Kp suggesting that it is more likely to be taken up by the cancer cells, hence it exhibited better PDT activity.
- Full Text:
- Date Issued: 2019
- Authors: Motloung, Banele M , Sekhosana, Kutloano E , Managa, Muthumuni , Prinsloo, Earl , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186769 , vital:44532 , xlink:href="https://doi.org/10.1016/j.poly.2019.114157"
- Description: The synthesis, photophysicochemical properties and photodynamic activity (PDT) of 4(4-phenyldiazenyl) phenoxy substituted indium (III) (InPc) and zinc (ZnPc) phthalocyanines when alone or incorporated into Pluronic_ F127 micelles are presented in this study. The InPc exhibited higher singlet oxygen (UD) at 0.47 compared to the ZnPc at 0.20 in dimethylsulfoxide. The UD values in the presence of Pluronic_ F127 and in water, were 0.32 for InPc and 0.09 for ZnPc. The triplet quantum yields (UT) were 0.92 for InPc and 0.32 for ZnPc in DMSO. The PDT activity followed the same trend as the singlet oxygen quantum yields. At the highest concentration, InPc in Pluronic_ F127 gave 22% cell viability compared to 34% for complex ZnPc. The partition coefficient Kp values were determined using the water and octanol system. InPc had a larger Kp suggesting that it is more likely to be taken up by the cancer cells, hence it exhibited better PDT activity.
- Full Text:
- Date Issued: 2019