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Unique diagnostic and therapeutic roles of porphyrins and phthalocyanines in photodynamic therapy, imaging and theranostics.

Josefsen LB, Boyle RW - Theranostics (2012)

Bottom Line: Porphyrinic molecules have a unique theranostic role in disease therapy; they have been used to image, detect and treat different forms of diseased tissue including age-related macular degeneration and a number of different cancer types.Current focus is on the clinical imaging of tumour tissue; targeted delivery of photosensitisers and the potential of photosensitisers in multimodal biomedical theranostic nanoplatforms.The roles of porphyrinic molecules in imaging and pdt, along with research into improving their selective uptake in diseased tissue and their utility in theranostic applications are highlighted in this Review.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, The University Of Hull, Kingston-Upon-Hull, HU6 7RX, U.K.

ABSTRACT
Porphyrinic molecules have a unique theranostic role in disease therapy; they have been used to image, detect and treat different forms of diseased tissue including age-related macular degeneration and a number of different cancer types. Current focus is on the clinical imaging of tumour tissue; targeted delivery of photosensitisers and the potential of photosensitisers in multimodal biomedical theranostic nanoplatforms. The roles of porphyrinic molecules in imaging and pdt, along with research into improving their selective uptake in diseased tissue and their utility in theranostic applications are highlighted in this Review.

No MeSH data available.


Related in: MedlinePlus

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Figure 10: Eosin.

Mentions: The first reported use of pdt in the treatment of solid tumours came in the early 20th Century by von Tappeiner's group in Munich, Germany - patients with skin carcinomas where successfully treated with the fluorescein-based dye eosin (figure 10) 3, 25, 29, 32, 63. Shortly after, fellow German physician Meyer-Betz reported the major stumbling block of pdt - acute cutaneous photosensitisation. After injecting himself with the photosensitiser haematoporphyrin (Hp) Meyer-Betz swiftly experienced a general skin sensitivity upon exposure to sunlight; a problem that still exists 3, 14, 24, 25, 27. Further research into Hp and the purified derivative (HpD) in tumours resulted in the first clinically-approved photosensitiser, Photofrin® (figure 11). Photofrin® was approved by the Canadian Health Agency in 1993 for use against bladder cancer and later in Japan, America and parts of Europe for use against certain cancers of the oesophagus and non-small cell lung cancer 4, 5, 13, 14, 24, 25, 27, 28, 32-34. However, Photofrin® has well-documented problems - in addition to patients exhibiting prolonged photosensitivity, the drug itself has a weak long-wavelength absorption (630nm) 14, 25, 28, 33. Research into improved photosensitisers saw the development of second-generation photosensitisers, including Verteporfin® (Visudyne®) and third-generation photosensitisers focused on targeting strategies, such as antibody-directed photosensitisers and photosensitiser-loaded nanocarriers 4, 14, 24, 26, 32, 64, 65. Combined diagnostic and therapeutic modalities gave begun to emerge creating theranostic tools for use in identifying (imaging) and treating diseased states: are these the next generation of pdt agents 28, 66-69? The ability to “switch on” a cytotoxic effect, and combine photosensitisers with imaging modalities such as magnetic resonance imaging (MRI) and radioimaging, makes pdt particularly attractive as the therapeutic partner in theranostic agents. The use of single agents/entities has the added benefit of ruling out variability in localisation; uptake; pharmacokinetic; and pharmacodynamic patterns of the agent (present when separate entities are used) at any stage during the theranostic treatment; stress on the body's clearance system is also minimised when a single agent rather than multiple agents are administered. A further advantage of using small molecule multimodal agents is their clearance by the renal system -avoiding toxicity associated with long-term liver retention 70.


Unique diagnostic and therapeutic roles of porphyrins and phthalocyanines in photodynamic therapy, imaging and theranostics.

Josefsen LB, Boyle RW - Theranostics (2012)

Eosin.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3475217&req=5

Figure 10: Eosin.
Mentions: The first reported use of pdt in the treatment of solid tumours came in the early 20th Century by von Tappeiner's group in Munich, Germany - patients with skin carcinomas where successfully treated with the fluorescein-based dye eosin (figure 10) 3, 25, 29, 32, 63. Shortly after, fellow German physician Meyer-Betz reported the major stumbling block of pdt - acute cutaneous photosensitisation. After injecting himself with the photosensitiser haematoporphyrin (Hp) Meyer-Betz swiftly experienced a general skin sensitivity upon exposure to sunlight; a problem that still exists 3, 14, 24, 25, 27. Further research into Hp and the purified derivative (HpD) in tumours resulted in the first clinically-approved photosensitiser, Photofrin® (figure 11). Photofrin® was approved by the Canadian Health Agency in 1993 for use against bladder cancer and later in Japan, America and parts of Europe for use against certain cancers of the oesophagus and non-small cell lung cancer 4, 5, 13, 14, 24, 25, 27, 28, 32-34. However, Photofrin® has well-documented problems - in addition to patients exhibiting prolonged photosensitivity, the drug itself has a weak long-wavelength absorption (630nm) 14, 25, 28, 33. Research into improved photosensitisers saw the development of second-generation photosensitisers, including Verteporfin® (Visudyne®) and third-generation photosensitisers focused on targeting strategies, such as antibody-directed photosensitisers and photosensitiser-loaded nanocarriers 4, 14, 24, 26, 32, 64, 65. Combined diagnostic and therapeutic modalities gave begun to emerge creating theranostic tools for use in identifying (imaging) and treating diseased states: are these the next generation of pdt agents 28, 66-69? The ability to “switch on” a cytotoxic effect, and combine photosensitisers with imaging modalities such as magnetic resonance imaging (MRI) and radioimaging, makes pdt particularly attractive as the therapeutic partner in theranostic agents. The use of single agents/entities has the added benefit of ruling out variability in localisation; uptake; pharmacokinetic; and pharmacodynamic patterns of the agent (present when separate entities are used) at any stage during the theranostic treatment; stress on the body's clearance system is also minimised when a single agent rather than multiple agents are administered. A further advantage of using small molecule multimodal agents is their clearance by the renal system -avoiding toxicity associated with long-term liver retention 70.

Bottom Line: Porphyrinic molecules have a unique theranostic role in disease therapy; they have been used to image, detect and treat different forms of diseased tissue including age-related macular degeneration and a number of different cancer types.Current focus is on the clinical imaging of tumour tissue; targeted delivery of photosensitisers and the potential of photosensitisers in multimodal biomedical theranostic nanoplatforms.The roles of porphyrinic molecules in imaging and pdt, along with research into improving their selective uptake in diseased tissue and their utility in theranostic applications are highlighted in this Review.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, The University Of Hull, Kingston-Upon-Hull, HU6 7RX, U.K.

ABSTRACT
Porphyrinic molecules have a unique theranostic role in disease therapy; they have been used to image, detect and treat different forms of diseased tissue including age-related macular degeneration and a number of different cancer types. Current focus is on the clinical imaging of tumour tissue; targeted delivery of photosensitisers and the potential of photosensitisers in multimodal biomedical theranostic nanoplatforms. The roles of porphyrinic molecules in imaging and pdt, along with research into improving their selective uptake in diseased tissue and their utility in theranostic applications are highlighted in this Review.

No MeSH data available.


Related in: MedlinePlus