Effects of ZnO nanohexagons and nanorods on the fluorescence behavior of metallophthalocyanines

Photodynamic antimicrobial chemotherapy with asymmetrical cationic or neutral metallophthalocyanines conjugated to amino-functionalized zinc oxide nanoparticles (spherical or pyramidal) against planktonic and biofilm microbial cultures

The synthesis and characterization of neutral zinc and indium substituted mercaptobenzothiazole substituted phthalocyanines (Pcs) and their respective cationic derivatives are presented. The phthalocyanines were further covalently linked to two differently shaped amino-functionalized ZnO nanoparticles (ZnONPs): namely nanospheres (NH₂-ZnONSp), and nanopyramids (NH₂-ZnONPy), to form corresponding nanoconjugates. The photophysicochemical properties of each nanocomposite were determined, and the Pc-ZnONPs produced high singlet oxygen quantum yields. The photodynamic antimicrobial chemotherapy activity was determined using planktonic and biofilm cells of Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Candida albicans (C. albicans). The conjugates of the cationic Pc derivatives with ZnONPy produced the highest log reduction values (∼ 8 and above) with the complete elimination of all planktonic cells at 0.45 kJ/cm² for S. aureus and at 0.9 kJ/cm² for E. coli, and C. albicans. For biofilms log reduction values >3 for both S. aureus and E. coli were obtained. The conjugates of the cationic Pc derivatives with NH₂-ZnONPy showed great potential in eradicating mixed microbial biofilms.

The application of titanium dioxide, zinc oxide, fullerene, and graphene nanoparticles in photodynamic therapy

Nanoparticles (NPs) have been shown to have good ability to improve the targeting and delivery of therapeutics. In the field of photodynamic therapy (PDT), this targeting advantage of NPs could help ensure drug delivery at specific sites. Among the commonly reported NPs for PDT applications, NPs from zinc oxide, titanium dioxide, and fullerene are commonly reported. In addition, graphene has also been reported to be used as NPs albeit being relatively new to this field. In this context, the present review is organized by these different NPs and contains numerous research works related to PDT applications. The effectiveness of these NPs for PDT is discussed in detail by collecting all essential information described in the literature. The information thus assembled could be useful in designing new NPs specific for PDT and/or PTT applications in the future.

Synthesis, characterization and investigation of the photophysical and photochemical properties of highly soluble novel metal-free, zinc(ii), and indium(iii) phthalocyanines substituted with 2,3,6-trimethylphenoxy moieties

The synthesis, characterization and photophysicochemical properties of 2,3,6-trimethylphenoxy substituted metal-free, zinc(ii), and indium(iii)acetate phthalocyanines were described.