Photo-physicochemical studies and photodynamic therapy activity of indium and gallium phthalocyanines
- Authors: Tshangana, Charmaine Sesethu
- Date: 2015
- Subjects: Quantum dots , Nanoparticles , Photochemotherapy , Phthalocyanines
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4548 , http://hdl.handle.net/10962/d1017928
- Description: The potential toxicity of seven different types of quantum dots without shell (L-cysteine-CdTe, TGA-CdTe, MPA-CdTe, TGA-CdSe) and with the shell (GSH-CdSe@ZnS, GSH-CdTe@ZnS,) with different capping agents were evaluated. The growth inhibitory effects of the various quantum dots on human pancreatic BON cancerous cells were determined. The least cytotoxic of the various quantum dots synthesized and the one displaying the lowest growth inhibitory potential and no embryotoxicity was determined to be the GSH-CdSe@ZnS quantum dots. The GSH-CdSe@ZnS quantum dots were then conjugated to gallium, aluminium and indium octacarboxy phthalocyanine and the photophysical behaviour of the conjugates studied for potential use in photodynamic therapy and imaging applications. The sizes, morphology, thermal stability and confirmation of successful conjugation was determined using X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR), respectively. The study was extended by conjugating amino functionalized magnetic nanoparticles (Fe₃O₄) to indium octacarboxy phthalocyanine to study the photophysical behaviour of the conjugate as a potential bi-functional anti-cancer agent (hyperthermia and photodynamic therapy applications). A three-in-one multifunctional nanocomposite comprising of the quantum dots, magnetic nanoparticles and indium octacarboxy phthalocyanine was developed with the aim of developing a multifunctional composite that is able detect, monitor and treat cancer. All conjugates showed improved and enhanced photophysical behaviour. Finally, GSH-CdSe@ZnS conjugated to aluminium octacarboxy phthalocyanine was applied in human pancreatic carcinoid BON cells. The conjugates induced cell death dose-dependently.
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Photodynamic antimicrobial chemotherapy activities of porphyrin- and phthalocyanine-platinum nanoparticle conjugates
- Authors: Managa, Muthumuni Elizabeth
- Date: 2015
- Subjects: Photochemotherapy , Anti-infective agents , Porphyrins , Phthalocyanines , Platinum , Nanoparticles , Bioconjugates , Electrospinning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4539 , http://hdl.handle.net/10962/d1017919
- Description: This work reports on the conjugation of differently shaped Pt nanoparticles (PtNPs) with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (1) as well as chloro - (5,10,15,20-tetrakis (4- (4- carboxy phenycarbonoimidoyl) phenyl) porphyrinato) gallium(III) (2) The work also reports on platination of dihydroxosilicon octacarboxyphthalocyanine (OH)₂SiOCPc (3) to give dihydroxosilicontris(diaquaplatinum)octacarboxyphthalocyanine (OH)₂SiOCPc(Pt)₃ (4). The resulting conjugates were used for photodynamic antimicrobial chemotherapy against S. aureus, E. coli and C. albicans. The degree of photo-inactivation is dependent on concentration of the conjugates, light dose (fluence) and illumination time. The log reduction obtained for 1 when conjugated to cubic PtNPs was 4.64 log (which indicate 99.99 percent of the bacteria have been killed), which is much higher than 3.94 log unit for 1-hexagonal PtNPs and 3.31 log units for 1-unshaped PtNPs. Complex 2 conjugated to hexagonal PtNPs showed 18 nm red shift in the Soret band when compared to 2 alone. Complex 2 and 2-hexagonal PtNPs as well showed promising photodynamic antimicrobial chemotherapy (PACT) activity against S. aureus, E. coli and C. albicans in solution where the log reduction obtained was 4.92, 3.76, and 3.95 respectively for 2-hexagonal PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 2-hexagonl PtNPs in DMF while that of 2 was 0.52 in the same solvent. This resulted in improved PACT activity for 2-hexagonal PtNPs compared to 2. Complex 4 showed slight blue shifting of the absorption spectrum when compared to complex 3 The antimicrobial activity of 4 were promising as the highest log reduction value was observed when compared to the porphyrin conjugates.
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