Physical and chemical studies related to the development of m-THPC (FOSCAN<sup>®</sup>) for the photodynamic therapy (PDT) of tumours

Bonnett, Raymond; Djelal, Birgul D.; Nguyen, Angelina

doi:10.1002/jpp.377

Cited by 61 publications

(10 citation statements)

References 31 publications

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“…A broadening of Q band (widening of the half maximum bandwidths; Δν), from 259 cm −1 to 368 cm −1 and further to 581 cm −1 for m ‐THPBC in methanol, incubated HSA–PBS and freshly prepared HSA–PBS, respectively was also observed. The bathochromic shift together with an hypochromic effect and a widening of the half maximum bandwidths are indicative of an aggregation of the photosensitizer in HSA–PBS solutions 16–18. Presence of proteins results in monomerization of chlorin‐type photosensitizers 19.…”

Section: Resultssupporting

confidence: 94%

MALDI‐TOF mass spectrometric analysis for the characterization of the 5,10,15,20‐tetrakis‐ (m‐hydroxyphenyl)bacteriochlorin (m‐THPBC) photoproducts in biological environment

Lassalle¹,

Lourette²,

Maunit³

et al. 2005

J. Mass Spectrom.

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Photoproducts formation upon irradiation (739 nm) of 5,10,15,20-tetrakis(m-hydroxyphenyl)bacteriochlorin (m-THPBC) in phosphate buffer saline (PBS) supplemented with human serum albumin (HSA) were studied by means of absorption spectroscopy and MALDI-TOF mass spectrometry. The experiments were performed with a freshly prepared PBS-HSA solution of m-THPBC and with a PBS-HSA m-THPBC solution incubated for 6 h at 37 degrees C. The incubation of m-THPBC solution leads to the dye monomerisation, whereas in the freshly prepared solution, m-THPBC is under an aggregated form. Regardless of the incubation condition, photobleaching experiments carried out by absorption spectroscopy demonstrate the degradation of the photosensitizer and its phototransformation in m-THPC. Moreover, m-THPC was the sole photoproduct detected using absorption spectroscopy. Together with a degradation of m-THPBC and formation of m-THPC, MALDI-TOF mass spectrometry evidenced several other photoinduced modifications. Photoproducts such as dihydroxy m-THPBC and dihydroxy m-THPC were detected in both conditions; however, the formation of hydroxylated photoproducts was significantly greater in incubated solution. In addition, small molecules arising from the degradation of the photosensitizer and identified as dipyrin derivatives and dipyrrolic synthon were observed.

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Section: Resultssupporting

confidence: 94%

MALDI‐TOF mass spectrometric analysis for the characterization of the 5,10,15,20‐tetrakis‐ (m‐hydroxyphenyl)bacteriochlorin (m‐THPBC) photoproducts in biological environment

Lassalle¹,

Lourette²,

Maunit³

et al. 2005

J. Mass Spectrom.

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“…Only relatively small drug and light doses are required to achieve treatment response. However, in aqueous media the hydrophobic mTHPC molecules form aggregates, leading to limitations in sensitizer transportation within biological media, tumor selectivity and PDT efficacy (3,4).…”

Section: Introductionmentioning

confidence: 99%

Unusual Photoinduced Response of mTHPC Liposomal Formulation (Foslip)

Kachatkou

Sasnouski

Zorin

et al. 2009

Photochem & Photobiology

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Liposomal formulations of meso-tetra(hydroxyphenyl)chlorin (mTHPC) have already been proposed with the aim to optimize photodynamic therapy. Spectral modifications of these compounds upon irradiation have not yet been investigated. The objective of this study was to evaluate photobleaching properties of mTHPC encapsulated into dipalmitoylphosphatidylcholine (DPPC) liposomes, Foslip. Fluorescence measurements in DPPC liposomes with different DPPC:mTHPC ratios demonstrated a dramatic decrease in fluorescence anisotropy with increasing local mTHPC concentration, thus suggesting strong interactions between mTHPC molecules in lipid bulk medium. Exposure of Foslip suspensions to small light doses (<50 mJ/cm(2)) resulted in a substantial drop in fluorescence, which, however, was restored after addition to the sample of a non-ionic surfactant Triton X-100. We attributed this behavior to photoinduced fluorescence quenching. This effect depended strongly on the molar DPPC:mTHPC ratio and was revealed only for high local mTHPC concentrations. The results were interpreted supposing energy migration between closely located mTHPC molecules with its subsequent dissipation by the molecules of photoproduct acting as excitation energy traps. We further assessed the effect of photoinduced quenching in plasma protein solution. Relatively slow kinetics of photoinduced Foslip response during incubation in the presence of proteins was attributed to mTHPC redistribution from liposomal formulations to proteins. Therefore, changes in mTHPC distribution pattern in biological systems would be consistent with changes in photoinduced quenching and would provide valuable information on mTHPC interactions with a biological environment.

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“…Preformed photosensitizers have been developed that offer advantages over ALA‐induced PpIX. For example, compared with porphyrins, such as PpIX, the absorption spectrum of phthalocyanines is shifted to longer wavelengths, typically around 700 nm (34). Light fluence through tissue is known to reduce exponentially with thickness.…”

Section: Discussionmentioning

confidence: 99%

Microneedle Arrays Permit Enhanced Intradermal Delivery of a Preformed Photosensitizer

Donnelly

Morrow

McCarron

et al. 2009

Photochem & Photobiology

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Silicon microneedle (MN) arrays were used to puncture excised murine and porcine skin in vitro and transdermal and intradermal delivery of meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP) investigated using topical application of a bioadhesive patch containing 19 mg TMP cm . Animal studies, using nude mice, were then conducted to investigate the in vivo performance of the bioadhesive patch following MN puncture of skin. MN puncture significantly enhanced both intradermal and transdermal delivery of TMP in vitro, though the total amounts of drug delivered (25.22% into porcine skin and 0.07% across murine skin) were still quite small in each case. Notwithstanding this, in vivo experiments showed that MN puncture was capable of permitting a prolonged increase in TMP fluorescence at the site of application. Importantly, fluorescence was negligible at distant sites, meaning systemic delivery of the drug was not sufficient to induce TMP accumulation other than at the application site. In this study we have conclusively demonstrated proof of principle; MN puncture allows true intradermal delivery of a preformed photosensitizer in animal skin models in vitro and in vivo. Importantly, transdermal delivery was much reduced in each case. Increasing MN density would allow increased amounts of photosensitizer to be delivered. However, as MNs create aqueous pores in the stratum corneum, a preformed photosensitizer must possess at least some degree of water solubility in order to permit enhanced intradermal delivery in this way. We believe that use of MN array technology in this way has the potential to significantly improve topical photodynamic therapy of skin tumors.

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Physical and chemical studies related to the development of m-THPC (FOSCAN^®) for the photodynamic therapy (PDT) of tumours

Cited by 61 publications

References 31 publications

MALDI‐TOF mass spectrometric analysis for the characterization of the 5,10,15,20‐tetrakis‐ (m‐hydroxyphenyl)bacteriochlorin (m‐THPBC) photoproducts in biological environment

MALDI‐TOF mass spectrometric analysis for the characterization of the 5,10,15,20‐tetrakis‐ (m‐hydroxyphenyl)bacteriochlorin (m‐THPBC) photoproducts in biological environment

Unusual Photoinduced Response of mTHPC Liposomal Formulation (Foslip)

Microneedle Arrays Permit Enhanced Intradermal Delivery of a Preformed Photosensitizer

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Physical and chemical studies related to the development of m-THPC (FOSCAN®) for the photodynamic therapy (PDT) of tumours

Cited by 61 publications

References 31 publications

MALDI‐TOF mass spectrometric analysis for the characterization of the 5,10,15,20‐tetrakis‐ (m‐hydroxyphenyl)bacteriochlorin (m‐THPBC) photoproducts in biological environment

MALDI‐TOF mass spectrometric analysis for the characterization of the 5,10,15,20‐tetrakis‐ (m‐hydroxyphenyl)bacteriochlorin (m‐THPBC) photoproducts in biological environment

Unusual Photoinduced Response of mTHPC Liposomal Formulation (Foslip)

Microneedle Arrays Permit Enhanced Intradermal Delivery of a Preformed Photosensitizer

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Product

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Physical and chemical studies related to the development of m-THPC (FOSCAN^®) for the photodynamic therapy (PDT) of tumours