Selective release of a potent anticancer agent from a supramolecular hydrogel using green light

This contribution reports the design, preparation, photophysical and photochemical characterization, as well as a preliminary biological evaluation of mesoporous silica nanoparticles (MSNs) covalently integrating a nitric oxide (NO) photodonor (NOPD) and a singlet oxygen (1O2) photosensitizer (PS) and encapsulating the anticancer doxorubicin (DOX) in a noncovalent fashion. These MSNs bind the NOPD mainly in their inner part and the PS in their outer part in order to judiciously exploit the different diffusion radius of the cytotoxic NO and 1O2. Furthermore this silica nanoconstruct has been devised in such a way to permit the selective excitation of the NOPD and the PS with light sources of different energy in the visible window. We demonstrate that the individual photochemical performances of the photoactive components of the MSNs are not mutually affected, and remain unaltered even in the presence of DOX. As a result, the complete nanoconstruct is able to deliver NO and 1O2 under blue and green light, respectively, and to release DOX under physiological conditions. Preliminary biological results performed using A375 cancer cells show a good tolerability of the functionalized MSNs in the dark and a potentiated activity of DOX upon irradiation, due to the effect of the NO photoreleased.

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Synthesis and characterization of bis(4-amino-2-bromo-6-methoxy)azobenzene derivatives

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.15.296 ◽

2019 ◽

Vol 15 ◽

pp. 3000-3008

Author(s):

David Martínez-López ◽

Amirhossein Babalhavaeji ◽

Diego Sampedro ◽

G Andrew Woolley

Keyword(s):

Double Bond ◽

Red Light ◽

Green Light ◽

Azo Compounds ◽

Synthesis And Characterization ◽

Physiological Conditions ◽

Acidic Conditions ◽

Azobenzene Derivatives

Aminoazobenzene derivatives with four ortho substituents with respect to the N–N double bond are a relatively unexplored class of azo compounds that show promise for use as photoswitches in biology. Tetra-ortho-methoxy-substituted aminoazobenzene compounds in particular can form azonium ions under physiological conditions and exhibit red-light photoswitching. Here, we report the synthesis and characterization of two bis(4-amino-2-bromo-6-methoxy)azobenzene derivatives. These compounds form red-light-absorbing azonium ions, but only under very acidic conditions (pH < 1). While the low pK a makes the azonium form unsuitable, the neutral versions of these compounds undergo trans-to-cis photoisomerization with blue-green light and exhibit slow (τ1/2 ≈ 10 min) thermal reversion and so may find applications under physiological conditions.

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Synthesis and characterization of ortho bromo-methoxy aminoazobenzene derivatives

10.3762/bxiv.2019.88.v1 ◽

2019 ◽

Author(s):

David Martínez-López ◽

Amir Babalhavaeji ◽

Diego Sampedro ◽

Andrew Woolley

Keyword(s):

Double Bond ◽

Red Light ◽

Green Light ◽

Azo Compounds ◽

Synthesis And Characterization ◽

Physiological Conditions ◽

Acidic Conditions

Aminoazobenzene derivatives with four ortho substituents with respect to the NN double bond are a relatively unexplored class of azo compounds that show promise for use as photoswitches in biology. Tetra-ortho methoxy aminoazobenzenes, in particular, can form azonium ions under physiological conditions and exhibit red-light photoswitching. Here, we report the synthesis and characterization of two ortho bromo-methoxy aminoazobenzene derivatives. These compounds form red light absorbing azonium ions but only under very acidic conditions (pH <1). While the low pKa makes the azonium form unsuitable, the neutral versions of these compounds undergo trans-to-cis photoisomerization with blue-green light and exhibit slow (τ½ ~10 min) thermal reversion and so may find applications under physiological conditions.

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In situ targeted activation of an anticancer agent using ultrasound-triggered release of composite droplets

European Journal of Medicinal Chemistry ◽

10.1016/j.ejmech.2017.03.057 ◽

2017 ◽

Vol 142 ◽

pp. 2-7 ◽

Cited By ~ 2

Author(s):

Marine Bezagu ◽

Jonathan Clarhaut ◽

Brigitte Renoux ◽

Fabrice Monti ◽

Mickael Tanter ◽

...

Keyword(s):

Anticancer Agent ◽

Triggered Release

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Cooling-Triggered Release from Mesoporous Poly(N-isopropylacrylamide) Microgels at Physiological Conditions

ACS Applied Materials & Interfaces ◽

10.1021/acsami.0c15370 ◽

2020 ◽

Vol 12 (51) ◽

pp. 57401-57409

Author(s):

Anna S. Vikulina ◽

Natalia A. Feoktistova ◽

Nadezhda G. Balabushevich ◽

Regine von Klitzing ◽

Dmitry Volodkin

Keyword(s):

Triggered Release ◽

Physiological Conditions

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Ultrastructure of Giant Mitochondria and Their Inclusions in Schwann Cells of Bovine Splenic Nerve

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050986 ◽

1974 ◽

Vol 32 ◽

pp. 194-195

Author(s):

Å. Thureson-Klein

Keyword(s):

Schwann Cells ◽

Cell Organelles ◽

Giant Mitochondria ◽

Matrix Density ◽

Physiological Conditions ◽

Unmyelinated Axons ◽

Internal Structures ◽

Structural Abnormalities ◽

Cytotoxic Compounds ◽

Cell Components

Giant mitochondria of various shapes and with different internal structures and matrix density have been observed in a great number of tissues including nerves. In most instances, the presence of giant mitochondria has been associated with a known disease or with abnormal physiological conditions such as anoxia or exposure to cytotoxic compounds. In these cases degenerative changes occurred in other cell organelles and, therefore the giant mitochondria also were believed to be induced structural abnormalities.Schwann cells ensheating unmyelinated axons of bovine splenic nerve regularly contain giant mitochondria in addition to the conventional smaller type (Fig. 1). These nerves come from healthy inspected animals presumed not to have been exposed to noxious agents. As there are no drastic changes in the small mitochondria and because other cell components also appear reasonably well preserved, it is believed that the giant mitochondria are normally present jin vivo and have not formed as a post-mortem artifact.

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Freeze-fracture observations on changes in the distribution of Filipin-sterol complexes during epididymal maturation and capacitation of boar spermatozoa

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157991 ◽

1990 ◽

Vol 48 (3) ◽

pp. 90-91

Author(s):

N. Seki ◽

Y. Toyama ◽

T. Nagano

Keyword(s):

Plasma Membrane ◽

Essential Role ◽

Freeze Fracture ◽

Final Concentration ◽

Freeze Fracturing ◽

Physiological Conditions ◽

Epididymal Maturation ◽

Cacodylate Buffer ◽

Sperm Membrane ◽

Boar Spermatozoa

It is believed that i ntramembra.nous sterols play an essential role in membrane stability and permeability. To investigate the distribution changes of sterols in sperm membrane during epididymal maturation and capacitation, filipin has been used as a cytochemical probe for the detection for membrane sterols. Using this technique in combination with freeze fracturing, we examined the boar spermatozoa under various physiological conditions.The spermatozoa were collected from: 1) caput, corpus and cauda epididymides, 2) sperm rich fraction of ejaculates, and 3)the uterus 2hr after natural coition. They were fixed with 2.5% glutaraldehyde in 0.05M cacodylate buffer (pH 7.4), and treated with the filipin solution (final concentration : 0.02.0.05%) for 24hr at 4°C with constant agitation. After the filipin treatment, replicas were made by conventional freeze-fracture technique. The density of filipin-sterol complexes (FSCs) was determined in the E face of the plasma membrane of head regions.

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