Photo-induced processes in collagen-hypericin system revealed by fluorescence spectroscopy and multiphoton microscopy

Hovhannisyan, Vladimir A.; Guo, Han; Hovhannisyan, A.; Ghukasyan, Vladimir; Buryakina, Tatyana; Chen, Y. F.; Chen, Dong

doi:10.1364/boe.5.001355

Cited by 9 publications

(6 citation statements)

References 28 publications

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“…HYP has recently received increasing attention due to its high phototoxicity against viruses and malignant cells. [28][29][30] In addition, it has been shown that HYP is an effective sensitizer for selective light-controlled collagen modification in connective tissues, 31,32 which is important for therapy of collagen-related disorders and tissue engineering. However, HYP molecules aggregate in water or blood, form nonsoluble, nonfluorescent complexes, and lose photosensitizing, antitumor properties.…”

Section: Discussionmentioning

confidence: 99%

Natural zeolite for adsorbing and release of functional materials

et al. 2018

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Using multiphoton microscopy (MPM), we demonstrated that effective inducing of two-photon excited luminescence and second-harmonic generation signals in nano/microparticles of clinoptilolite type of zeolite (CZ) by femtosecond near-infrared laser excitation can be successfully utilized in multiphoton imaging of the drug adsorption processes. Adsorption of photodynamic active dyes (hypericin, chlorin e6, methylene blue, and fluorescein) and their release from CZ pores in the presence of biomolecules, such as collagen from bovine Achilles tendon, albumin, and hemoglobin, were investigated by absorption and fluorescence spectrometry. To quantify the experimental results on hypericin release, here we use a kinetic curves fitting approach and calculate hypericin release rates in different environments. This approach allows to compare various mathematical models and uses more parameters to better characterize drug release profiles. In addition, magnetic CZ particles were fabricated and proposed as a promising material for drug delivery and controlled release in biological systems. Optical spectrometry and MPM are effective approaches that may reveal potential of natural zeolites in controlled drug delivery and biomedical imaging.

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Section: Discussionmentioning

confidence: 99%

Natural zeolite for adsorbing and release of functional materials

et al. 2018

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“…Take the case of tumors, for example, some PSes compromise tumor cells mainly in an indirect way, damaging the tumor vasculature and blocking the supply of molecular oxygen and essential nutrients. This effect is associated to binding of the hydrophilic/water soluble PSes to serum albumin, since it mediates PS accumulation in vascular stroma, or to binding to vascular structures/constituents, such as collagen [ 170 , 171 , 172 ]. On the other hand, there is evidence that highly hydrophobic PSes act in tumors mostly by direct interactions, since they are usually transported inside the body by association to low density lipoproteins (LDL), which can deliver them to intracellular sites [ 172 , 173 , 174 ].…”

Section: Parameters Determining Photosensitizer (Ps) Efficiencymentioning

confidence: 99%

Photodynamic Efficiency: From Molecular Photochemistry to Cell Death

Bacellar

Tsubone

Pavani

et al. 2015

IJMS

333

267

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Photodynamic therapy (PDT) is a clinical modality used to treat cancer and infectious diseases. The main agent is the photosensitizer (PS), which is excited by light and converted to a triplet excited state. This latter species leads to the formation of singlet oxygen and radicals that oxidize biomolecules. The main motivation for this review is to suggest alternatives for achieving high-efficiency PDT protocols, by taking advantage of knowledge on the chemical and biological processes taking place during and after photosensitization. We defend that in order to obtain specific mechanisms of cell death and maximize PDT efficiency, PSes should oxidize specific molecular targets. We consider the role of subcellular localization, how PS photochemistry and photophysics can change according to its nanoenvironment, and how can all these trigger specific cell death mechanisms. We propose that in order to develop PSes that will cause a breakthrough enhancement in the efficiency of PDT, researchers should first consider tissue and intracellular localization, instead of trying to maximize singlet oxygen quantum yields in in vitro tests. In addition to this, we also indicate many open questions and challenges remaining in this field, hoping to encourage future research.

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“…Hyp has recently received increasing attention due to its high phototoxicity against viruses and anti-tumour photoreactivity 30 41 42 43 . In addition, it is shown that Hyp is an effective mediator for light-controlled selective modification of collagen in connective tissues, and may be used in biomedical engineering and therapy of collagen-related disorders 44 45 . However, Hyp in PBS and pure water tends to aggregate and form non-soluble and non-fluorescent complex thereby losing its tumour-selective properties 46 .…”

Section: Discussionmentioning

confidence: 99%

Photodynamic dye adsorption and release performance of natural zeolite

Hovhannisyan

Dong

Chen

2017

Sci Rep

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Clinoptilolite type of zeolite (CZ) is a promising material for biomedicine and pharmaceutics due to its non-toxicity, thermal stability, expanded surface area, and exceptional ability to adsorb various atoms and organic molecules into micropores. Using multiphoton microscopy, we demonstrated that individual CZ particles produce two-photon excited luminescence and second harmonic generation signal at femtosecond laser excitation, and adsorb photo-dynamically active dyes such as hypericin and methylene blue. Furthermore, the release of hypericin from CZ pores in the presence of biomolecules is shown, and CZ can be considered as an effective material for drug delivery and controlled release in biological systems. The results may open new perspectives in application of CZ in biomedical imaging, and introducing of the optical approaches into the clinical environment.

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Photo-induced processes in collagen-hypericin system revealed by fluorescence spectroscopy and multiphoton microscopy

Cited by 9 publications

References 28 publications

Natural zeolite for adsorbing and release of functional materials

Natural zeolite for adsorbing and release of functional materials

Photodynamic Efficiency: From Molecular Photochemistry to Cell Death

Photodynamic dye adsorption and release performance of natural zeolite

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