Dynamic fluorescence changes during photodynamic therapy in vivo and in vitro of hydrophilic A1 (III) phthalocyanine tetrasulphonate and lipophilic ZN(II) phthalocyanine administered in liposomes

Rück, Angelika; Beck, Gerd C.; Bachor, R.; Akgün, Nermin; Gschwend, Michael H.; Steiner, Rudolf

doi:10.1016/s1011-1344(96)07359-9

Cited by 48 publications

(31 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These systems show higher intracellular accumulation of the drug and higher photocytotoxicity in comparison to free PpIX [55]. Similar results were reported for phthalocyanines [96,97]. Protoporphyrin IX has also been encapsulated into silica nanoparticles [98].…”

Section: Nano Pdt Passive Nanoparticlessupporting

confidence: 73%

Nanodrug applications in photodynamic therapy

Paszko

Ehrhardt

Senge

et al. 2011

Photodiagnosis and Photodynamic Therapy

326

215

View full text Add to dashboard Cite

SummaryPhotodynamic therapy (PDT) has developed over last century and is now becoming a more widely used medical tool having gained regulatory approval for the treatment of various diseases such as cancer and macular degeneration. It is a two-step technique in which delivery of a photosensitizing drug is followed by irradiation of light. Activated photosensitizers transfer energy to molecular oxygen which results in generation of reactive oxygen species which in turn cause cells apoptosis or necrosis. Although this modality has significantly improved quality of life and survival time for many cancer patients it still offers significant potential for further improvement. In addition to the development of new PDT drugs, the use of nanosized carriers for photosensitizers is a promising approach which might improve the efficiency of photodynamic activity and which can overcome many side effects associated with classic photodynamic therapy. This review aims at highlighting the different types of nanomedical approaches currently used in PDT and outlines future trends and limitations of nanodelivery of photosensitizers. PDT -photodynamic therapy; PGA -poly(glycolic acid); PGLA -poly(D,L-lactide-coglycolide); PLA -poly(lactic acid); PS -photosensitizer; PEG -polyethylene glycol; ALA  aminolevulinic acid; m-THPC  5,10,15,20-tetra-(m-hydroxyphenyl)chlorine; m-THPP  meso-tetra(p-hydroxyphenyl); PpIX  protoporphyrin; Hp  hematoporphyrin; Pc4  silicon phthalocyanine; Ig  immunoglobulin; Tf  transferrin; TfR  transferrin receptor; VEGF  vascular endothelial growth factor; EPR  enhanced permeability and retention effect; FRET  fluorescence resonance energy transfer; MRI  magnetic resonance imaging; RES  reticuloendothelial system; ROS  reactive oxygen species; NP  nanoparticle; ND -nanodiamonds; SNP  silica nanoparticle; AMD  age-related macular degeneration; CNV  choroidal neovascularization; PTT  photothermal therapy;

show abstract

Section: Nano Pdt Passive Nanoparticlessupporting

confidence: 73%

Nanodrug applications in photodynamic therapy

Paszko

Ehrhardt

Senge

et al. 2011

Photodiagnosis and Photodynamic Therapy

326

215

View full text Add to dashboard Cite

show abstract

“…In vivo redistribution of Al(III) phthalocyanine tetrasulfonate, but not zinc phthalocyanine, has been observed in RR1022 rat bladder tumour cells, correlating with in vitro results. 60 It should be pointed out, however, that for many PS there is no clear correlation between the ability to bind to particular serum proteins and in vivo PDT efficiency.…”

Section: Subcellular Distribution Of Photosensitizers Administered Inmentioning

confidence: 99%

Targeted intracellular delivery of photosensitizers to enhance photodynamic efficiency

Jans²,

2000

View full text Add to dashboard Cite

IntroductionPhotodynamic therapy (PDT) is a relatively new cytotoxic treatment, predominantly used in anticancer approaches, that depends on the retention of photosensitizers (PS) in tumour cells and their activation within the tumour through irradiation with light of the appropriate wavelength. Photoactivated PS generate reactive oxygen species (singlet oxygen, 1 O 2 , and free radicals, such as ·OH, HO· 2 and ·O 2 -) which are able to damage cellular structures, meaning that PDT is particularly attractive as an alternative means to kill drug-and radioresistant tumour cells.1,2 Normal cells, however, are also able to accumulate PS and be damaged by them, so that prolonged skin photosensitization, light-sensitivity of the eye and other side-effects have proved to be severe limitations of PDT. When photoactivated, PS inflict damage on many types of biomolecules without any specificity, their action being mediated largely via the reactive oxygen species mentioned, none of which travel more than several tens of nanometers before reacting with a biomolecule. Keeping in mind that cell dimensions are of the order of micrometres or tens of micrometres, it is clear that the intracellular action of PS is restricted to the site of their subcellular location and the surrounding radius of not more than 40 nm.3-5 That uneven intracellular distribution of PS can lead to differences in toxicity has been shown using laser microbeam irradiation. 6In contrast to cell membranes and other cytoplasmic organelles, the cell nucleus 7-9 is known to be a very sensitive target for reactive oxygen species. In order to reduce the dose of PS administered to patients and hence minimize the harmful side-effects of PDT, new approaches have been devised to increase the effectiveness of tumour-cell killing through targeted delivery of PS to hypersensitive subcellular sites. These approaches are the focus of the present review. Subcellular distribution of photosensitizersInsomuch as most mammalian cells span tens of micrometres, it is clear that PS efficiency will depend not only on the relative distribution of PS between the tumour and surrounding tissues and between malignant and normal cells, but also on the intracellular distribution of the PS. Furthermore, membranes divide the interior of the eucaryotic cell into compartments that differ markedly in their sensitivity to reactions induced by PS-generated reactive oxygen species, in the ability of damaged molecules to be replaced/recycled and in the extent to which such damage affects cell viability and/or the capability of the cell to divide. It is noteworthy that preferential PS accumulation in tumours is itself not a guarantee of selective photoinduced tumour damage and successful PDT. In experiments on rats with gliosarcoma 9L, 10 for example, it has been found that despite a 13-fold higher accumulation of the PS Photofrin in the tumour compared with Summary Photodynamic therapy (PDT) is a novel treatment, used mainly for anticancer therapy, that depends on the retention of photosensitizer...

show abstract

“…1) on cultured cells is a well-known feature that results in cell death by apoptotic or necrotic mechanisms (Villanueva et al 1999, Fabris et al 2001, Galaz et al 2005. Different localization sites for ZnPc in living cells have been reported including lysosomelike granules and diffuse cytoplasm (Rü ck et al 1996), plasma membrane (Valduga et al 1998), Golgi apparatus and mitochondria (Rodal et al 1998, Fabris et al 2001, mitochondria (Alexandratou et al 2005), and Golgi region (Cristó bal et al 2006, Rello-Varona et al 2008. Accounting for these differences, the aim of the study reported here was to analyze the subcellular localization of ZnPc more precisely using a co-localization procedure with NBD C 6 -ceramide ( Fig.…”

mentioning

confidence: 99%

Improving images of fluorescent cell labeling by background signal subtraction

Stockert

Villanueva

Cristóbal

et al. 2009

Biotechnic & Histochemistry

View full text Add to dashboard Cite

The uptake and selective accumulation of fluorescent labels and drugs into organelles of cultured cells currently are widely investigated in biomedical research. In such studies, co-localization procedures are frequently used to identify the accumulation sites of compounds with biological activity. A drawback with fluorescent labeling is the autofluorescence of some cell organelles, which can hinder the precise assessment of co-localization. We report here labeling of the Golgi apparatus of A-549 cells using the photosensitizer zinc(II)-phthalocyanine (ZnPc) and co-localization with the Golgi probe NBD C6-ceramide. The blue autofluorescence signal of mitochondria can be subtracted easily from the original picture by image processing, after which the co-localization of the isolated red ZnPc signal with the green signal from the Golgi probe is considerably improved.

show abstract

Dynamic fluorescence changes during photodynamic therapy in vivo and in vitro of hydrophilic A1 (III) phthalocyanine tetrasulphonate and lipophilic ZN(II) phthalocyanine administered in liposomes

Cited by 48 publications

References 23 publications

Nanodrug applications in photodynamic therapy

Nanodrug applications in photodynamic therapy

Targeted intracellular delivery of photosensitizers to enhance photodynamic efficiency

Improving images of fluorescent cell labeling by background signal subtraction

Contact Info

Product

Resources

About