scholarly journals Can Cerenkov Light Really Induce an Effective Photodynamic Therapy?

Radiation ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 5-17
Author(s):  
Joël Daouk ◽  
Batoul Dhaini ◽  
Jérôme Petit ◽  
Céline Frochot ◽  
Muriel Barberi-Heyob ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Therapeutic Effect ◽  
Radioactive Isotopes ◽  
Major Drawback ◽  
Equation Resolution ◽  
Original Works ◽  
Uv Photons ◽  
Cerenkov Light

Photodynamic therapy (PDT) is a promising therapeutic strategy for cancers where surgery and radiotherapy cannot be effective. PDT relies on the photoactivation of photosensitizers, most of the time by lasers to produced reactive oxygen species and notably singlet oxygen. The major drawback of this strategy is the weak light penetration in the tissues. To overcome this issue, recent studies proposed to generate visible light in situ with radioactive isotopes emitting charged particles able to produce Cerenkov radiation. In vitro and preclinical results are appealing, but the existence of a true, lethal phototherapeutic effect is still controversial. In this article, we have reviewed previous original works dealing with Cerenkov-induced PDT (CR-PDT). Moreover, we propose a simple analytical equation resolution to demonstrate that Cerenkov light can potentially generate a photo-therapeutic effect, although most of the Cerenkov photons are emitted in the UV-B and UV-C domains. We suggest that CR-PDT and direct UV-tissue interaction act synergistically to yield the therapeutic effect observed in the literature. Moreover, adding a nanoscintillator in the photosensitizer vicinity would increase the PDT efficacy, as it will convert Cerenkov UV photons to light absorbed by the photosensitizer.

DEVELOPMENT OF A PHOTOSENSITIZER DELIVERY SYSTEM FOR THERAPY AND DIAGNOSTICS IN ONCOLOGY

2020 ◽  
pp. 124-125
Author(s):  
A.Semkina Semkina ◽  
M.Abakumov Abakumov ◽  
P.Ostroverkhov Ostroverkhov ◽  
M. Grin
Keyword(s):  
Photodynamic Therapy ◽  
Physicochemical Properties ◽  
Tumor Cells ◽  
Therapeutic Effect ◽  
Delivery System ◽  
Biological Studies ◽  
Kinetics Of ◽  
Ct26 Tumor

In this work, the MNP-HSA-PEG-PS@4 complex was obtained and its physicochemical properties were studied. Biological studies have also been conducted. Namely, the ability of the drug to accumulate in CT26 tumor cells in vitro and the kinetics of drug accumulation in the tumor in vivo were studied. Then, the effectiveness of photodynamic therapy was studied under different conditions. The maximum therapeutic effect was achieved with irradiation at 1 hour after injection of the drug.

scholarly journals In-situ oxygen-generation nanoplatform with dual amplification effect for combined chemo-photodynamic therapy

2021 ◽  
Author(s):  
Qingcheng Song ◽  
Xiangtian Deng ◽  
Wenbo Yang ◽  
Yiran Zhang ◽  
Junyong Li ◽  
...  
Keyword(s):  
Dna Damage ◽  
Photodynamic Therapy ◽  
Tumor Cells ◽  
Therapeutic Effect ◽  
Mesoporous Silica Nanoparticles ◽  
Drug Loading ◽  
Repair Process ◽  
Amplification Effect ◽  
Dual Amplification

Abstract Background Photodynamic therapy (PDT) is a promising method for cancer treatment because of its advantages such as easy operation, good targeting, minimal side effects, low systemic toxicity and less invasiveness. However, the hypoxic microenvironment within the tumor significantly inhibited the therapeutic effect of PDT. The development of targeted nanoplatform for regulating hypoxia microenvironment is an important method to give full play to the therapeutic effect of PDT. Methods In this study, we designed and prepared a novel chemo-photodynamic therapy nanoplatform, which can continuously catalyze the decomposition of H2O2 in tumors to generate oxygen (O2) to enhance the therapeutic effect of PDT, resulting in DNA damage, while releasing MTH1 inhibitors in tumor cells to inhibit the repair process of DNA damage caused by PDT. Results In our work, a simple one-step reduction approach was applied to enable platinum nanoparticles (Pt NPs) growth in situ in the nanochannels of mesoporous silica nanoparticles (MSNs). After physical encapsulation of photosensitizer chlorin e6 (Ce6) and MTH1 inhibitor TH588, the drug loading nanoplatform was modified with an arginine-glycine-aspartic acid (RGD) functionalized liposome shell, resulting in the fabrication of multifunctional nanoplatform MSN-Pt@Ce6/TH588@Liposome-RGD (MPCT@Li-R) with dual amplification effect and achieve the purpose of chemo-photodynamic therapy. Conclusions Our study provides a new strategy for PDT to ablation tumor cells by damaging the DNA of tumor nucleus and mitochondria, meanwhile inhibiting the repair process after the damage.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

In Situ Localization of PPAR Gamma and Uncoupling Protein in Mouse Embryo Sections Using Digoxigenin-Labeled Riboprobes

1996 ◽  
Vol 54 ◽  
pp. 32-33
Author(s):  
C. Jennermann ◽  
S. A. Kliewer ◽  
D. C. Morris
Keyword(s):  
Alkaline Phosphatase ◽  
Room Temperature ◽  
Uncoupling Protein ◽  
Ppar Gamma ◽  
Nuclear Hormone Receptor ◽  
Full Length ◽  
Northern Analysis ◽  
Peroxisome Proliferator

Peroxisome proliferator-activated receptor gamma (PPARg) is a member of the nuclear hormone receptor superfamily and has been shown in vitro to regulate genes involved in lipid metabolism and adipocyte differentiation. By Northern analysis, we and other researchers have shown that expression of this receptor predominates in adipose tissue in adult mice, and appears first in whole-embryo mRNA at 13.5 days postconception. In situ hybridization was used to find out in which developing tissues PPARg is specifically expressed.Digoxigenin-labeled riboprobes were generated using the Genius™ 4 RNA Labeling Kit from Boehringer Mannheim. Full length PPAR gamma, obtained by PCR from mouse liver cDNA, was inserted into pBluescript SK and used as template for the transcription reaction. Probes of average size 200 base pairs were made by partial alkaline hydrolysis of the full length transcripts. The in situ hybridization assays were performed as described previously with some modifications. Frozen sections (10 μm thick) of day 18 mouse embryos were cut, fixed with 4% paraformaldehyde and acetylated with 0.25% acetic anhydride in 1.0M triethanolamine buffer. The sections were incubated for 2 hours at room temperature in pre-hybridization buffer, and were then hybridized with a probe concentration of 200μg per ml at 70° C, overnight in a humidified chamber. Following stringent washes in SSC buffers, the immunological detection steps were performed at room temperature. The alkaline phosphatase labeled, anti-digoxigenin antibody and detection buffers were purchased from Boehringer Mannheim. The sections were treated with a blocking buffer for one hour and incubated with antibody solution at a 1:5000 dilution for 2 hours, both at room temperature. Colored precipitate was formed by exposure to the alkaline phosphatase substrate nitrobluetetrazoliumchloride/ bromo-chloroindlylphosphate.

CONSERVATION OF RARE SPECIES PLANTS AND LICHENS IN SITU WITH PLANNED ANTHROPOGENIC ACTIVITIES: BASIC APPROACHES AND IMPLEMENTATION PRINCIPLES

2018 ◽  
Vol 12 (7-8) ◽  
pp. 38-45
Author(s):  
A. N. EFREMOV ◽  
N. V. PLIKINA ◽  
T. ABELI
Keyword(s):  
Rare Species ◽  
Technology Implementation ◽  
Technology Development ◽  
Anthropogenic Activities ◽  
Natural Habitat ◽  
Local Population ◽  
Main Stage ◽  
Social Risks

Rare species are most vulnerable to man-made impacts, due to their biological characteristics or natural resource management. As a rule, the economic impact is associated with the destruction and damage of individual organisms, the destruction or alienation of habitats. Unfortunately, the conservation of habitat integrity is an important protection strategy, which is not always achievable in the implementation of industrial and infrastructural projects. The aim of the publication is to summarize the experience in the field of protection of rare species in the natural habitat (in situ), to evaluate and analyze the possibility of using existing methods in design and survey activities. In this regard, the main methodological approaches to the protection of rare species in the natural habitat (in situ) during the proposed economic activity were reflected. The algorithm suggested by the authors for implementing the in situ project should include a preparatory stage (initial data collection, preliminary risk assessments, technology development, obtaining permitting documentation), the main stage, the content of which is determined by the selected technology and a long monitoring stage, which makes it possible to assess the effectiveness of the taken measures. Among the main risks of in situ technology implementation, the following can be noted: the limited resources of the population that do not allow for the implementation of the procedure without prior reproduction of individuals in situ (in vitro); limited knowledge of the biology of the species; the possibility of invasion; the possibility of crossing for closely related species that сo-exist in the same habitat; social risks and consequences, target species or population may be important for the local population; financial risks during the recovery of the population. The available experience makes it possible to consider the approach to the conservation of rare species in situ as the best available technology that contributes to reducing negative environmental risks.

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