Polymeric micelles are emerging as attractive drug delivery systems. Hydrophobic drugs including photosensitizers for photodynamic therapy can be covalently bound or physically entrapped in the core of the micelles and thus be systemically delivered to, for example, tumors using passive or active targeting strategies. Polymers used for photosensitizer encapsulation include pluronics, poly(ethyl...

Novel biomaterials based on hydrophilic polycaprolactone and polyurethane (Tecophilic®) nanofibers with an encapsulated 5,10,5,20-tetraphenylporphyrin photosensitizer were prepared by electrospinning. The doped nanofiber textiles efficiently photo-generate O(2)((1)Δ(g)), which oxidize external chemical and biological substrates/targets. Strong photo-virucidal effects toward non-enveloped polyom...

Protons from water are reduced by a catalytic system composed of a heteroleptic iridium(III) photosensitizer [Ir(ppy)2(bpy)]+, platinum catalyst, and sacrificial reductant. The hydrogen quantum yield reaches 0.26 in this study, which proceeds via reductive quenching of the excited photosensitizer by triethanolamine. This simplified approach allows the characterization of degradation products th...

Sulfonated Zn phthalocyanine, as a prospective photosensitizer in the photodynamic therapy of tumors, is investigated by means of Raman, infrared, and fluorescence spectroscopies. Conventional and surface-enhanced spectra from this photosensitizer are obtained and compared. Gold nano-islands attached to silica cores (Au-SiO2) are proposed as nanostructures providing plasmonically enhanced signa...

Photodynamic therapy (PDT) and bio-nanotechnology (NT) show striking similarities in clinical design and mechanistics. The PDT paradigm of photosensitizer application, light activation and singlet oxygen generation does in fact occur on the nanoscale level as does the resultant outcomes. NT has the ability to explain as well as modify each of the critical steps of PDT particularly photosensitiz...

A polymeric photosensitizer, poly(NIPAM-co-RB), consisting of N-isopropylacrylamide and rose bengal units, demonstrates a temperature-controlled changeable oxygenation selectivity by singlet oxygen in water.

The uptake and biological activity of porphyrins and phthalocyanines in tumours were correlated with the geometrical features of the photosensitizer molecules. The data suggest that a critical distance of approximately 1.2 nm between oxygen atoms (originating in SO3-, COO- or OH substituents) characterizes a biologically active photosensitizer for photodynamic therapy. We propose that tubulin, ...

The use of in vivo contrast-enhanced magnetic resonance (MR) imaging as a surrogate for photosensitizer (verteporfin) dosimetry in photodynamic therapy of pancreas cancer is demonstrated by correlating MR contrast uptake to ex vivo fluorescence images on excised tissue. An orthotopic pancreatic xenograft mouse model was used for the study. A strong correlation (r = 0.57) was found for bulk inte...

The translation of photodynamic therapy (PDT) to the clinic has mostly been limited to superficial diseases where traditional light delivery is noninvasive. To overcome this limitation, a variety of mechanisms have been suggested to noninvasively deliver light to deep tissues. This work explores the minimum amount of light required by these methods to produce a meaningful PDT effect in the in v...

Reversible noninvasive control over the generation of singlet oxygen is demonstrated in a bicomponent system comprising a diarylethene photochromic switch and a porphyrin photosensitizer by selective irradiation at distinct wavelengths. The efficient generation of singlet oxygen by the photosensitizer is observed when the diarylethene unit is in the colorless open form. Singlet oxygen generatio...