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The toxicity of heavy metals present in binary semiconductor nanoparticles also known as quantum dots (QDs) has hindered their wide applications hence the advent of non-toxic ternary quantum dots. These new group of quantum dots have been shown to possess some therapeutic action against cancer cell lines but not significant enough to be referred to as an ideal therapeutic agent. In this report, we address this problem by conjugating red emitting CuInS/ZnS QDs to a 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin -photosensitizer for improved bioactivities. The glutathione capped CuInS/ZnS QDs were synthesized in an aqueous medium using a kitchen pressure cooker at different Cu: In ratios (1:4 and 1:8) and at varied temperatures (95 °C, 190 °C and 235 °C). Optical properties show that the as-synthesized CuInS/ZnS QDs become red-shifted compared to the core (CuInS) after passivation with emission in the red region while the cytotoxicity study revealed excellent cell viability against normal kidney fibroblasts (BHK21). The highly fluorescent, water-soluble QDs were conjugated to 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin (mTHPP) via esterification reactions at room temperature. The resultant water-soluble conjugate was then used for the cytotoxicity, fluorescent imaging and gene expression study against human monocytic leukemia cells (THP-1). Our result showed that the conjugate possessed high cytotoxicity against THP-1 cells with enhanced localized cell uptake compared to the bare QDs. In addition, the gene expression study revealed that the conjugate induced inflammation compared to the QDs as NFKB gene was over-expressed upon cell inflammation while the singlet oxygen ( 1 O 2 ) study showed the conjugate possessed large amount of 1 O 2 , three times than the bare porphyrin. Thus, the as-synthesized conjugate looks promising as a therapeutic agent for cancer therapy.

Background:  Metal-free, water-soluble and highly stable meso-tetra-(4-sulfonatophenyl) porphyrin (TPPS 4 ) has been studied for their singlet oxygen quantum yield. However, TPPS 4  suffers from inherent shortcomings. To address these, TPPS 4  was conjugated to ternary copper indium sulphide/ zinc sulphide (CuInS 2 /ZnS) quantum dots (QDs)., Purpose:  We herein report for the first time the synthesis of TPPS 4 -CuInS/ZnS QDs conjugate as an improved photosensitizer., Methods:  Water-soluble TPPS 4  was synthesized from tetraphenylporphyrin (TPPH 2 ) after silica-gel purification. The CuInS/ZnS QDs were synthesized by hydrothermal method at a Cu:In ratio of 1:4. The porphyrin-QDs conjugate was formed via the daggling sulfonyl bond of the porphyrin and amine bond of the QDs. The effect of pH on the optical properties of TPPS 4  was evaluated. The effect of Zn:Cu + In ratio on the ZnS shell passivation was examined to reduce structural defects on the as-synthesized QDs., Results: Various spectroscopic techniques were used to confirm the successful conversion of the organic TPPH 2  to water-soluble TPPS 4 . The singlet oxygen generation evaluation shows an improved singlet oxygen quantum yield from 0.19 for the porphyrin (TPPS 4 ) alone to 0.69 after conjugation (CuInS/ZnS-TPPS 4 ) with an increase in the reaction rate constant (k (s-1))., Competing Interests: Ms Vuyelwa Ncapayi reports grants from National Research Council, during the conduct of the study. The authors report no other conflicts of interest in this work.

Antibiotics are commonly used to control, treat, or prevent bacterial infections, however bacterial resistance to all known classes of traditional antibiotics has greatly increased in the past years especially in hospitals rendering certain therapies ineffective. To limit this emerging public health problem, there is a need to develop non-incursive, non-toxic, and new antimicrobial techniques that act more effectively and quicker than the current antibiotics. One of these effective techniques is antibacterial photodynamic therapy (aPDT). This review focuses on the application of porphyrins in the photo-inactivation of bacteria. Mechanisms of bacterial resistance and some of the current 'greener' methods of synthesis of meso-phenyl porphyrins are discussed. In addition, significance and limitations of aPDT are also discussed. Furthermore, we also elaborate on the current clinical applications and the future perspectives and directions of this non-antibiotic therapeutic strategy in combating infectious diseases.

Cancer and bacterial diseases have been the most incidental diseases to date. According to the World Health Report 2018, at least every family is affected by cancer around the world. In 2012, 14.1 million people were affected by cancer, and that figure is bound to increase to 21.6 million in 2030. Medicine therefore sorts out ways of treatment using conventional methods which have been proven to have many side effects. Researchers developed photothermal and photodynamic methods to treat both cancer and bacterial diseases. These methods pose fewer effects on the biological systems but still no perfect method has been synthesized. The review serves to explore porphyrin and gold nanorods to be used in the treatment of cancer and bacterial diseases: porphyrins as photosensitizers and gold nanorods as delivery agents. In addition, the review delves into ways of incorporating photothermal and photodynamic therapy aimed at producing a less toxic, more efficacious, and specific compound for the treatment. [ABSTRACT FROM AUTHOR]

Singlet oxygen is a dominant reactive oxygen species that determine the fate of photodynamic therapy efficacy. We herein report the singlet oxygen generation potential of a newly synthesized superparamagnetic iron oxide nanoparticles-gold core-shell porphyrin conjugate prepared for the purpose of achieving magnetically-driven porphyrin structure. Successful conjugation was achieved via encapsulation within thiolated methoxy polyethylene glycol matrix following solvent evaporation approach. The magnetic PEGylated porphyrin nano-construct was characterized using optical absorption, transmission electron microscopy (TEM) and zeta potential techniques. The as-synthesized porphyrin conjugate emits red and near-infrared light at various excitations from ultraviolet to visible, shows strong attraction towards external magnetic field and exhibits high singlet oxygen generation potential. [ABSTRACT FROM AUTHOR]