DEVICE FOR PHOTOACTIVATED PRODUCTION OF SINGLET OXYGEN AND METHOD FOR THE PRODUCTION OF THE DEVICE

DISPOSITIF PERMETTANT DE PRODUIRE PAR PHOTOACTIVATION DE L'OXYGENE SINGULET ET PROCEDE DE FABRICATION ASSOCIE

English Abstract

The invention pertains to a device for the production of singlet oxygen. At
least one photosensitizer is mixed with at least one polymeric or monomeric
material. Subsequently, a shaped body that may be used in the production of
singlet oxygen is produced from said mixture.

French Abstract

L'invention concerne un dispositif qui permet de produire de l'oxygène singulet. On mélange au moins un agent photosensibilisant avec au moins un matériau polymère ou monomère, puis on produit à partir dudit mélange un corps moulé que l'on peut utiliser pour produire de l'oxygène singulet.

Claims

1
Claims
1. Formed body for photoactivated production of singlet oxygen,
characterised in that the formed body is obtained by means of pressing
and subsequent sintering, injection moulding, extrusion, curing or
polymerisation from a mixture made of at least one photosensitiser and
polymer,
the photosensitiser being embedded in a polymer matrix.
2. Formed body according to claim 1, characterised in that the proportion of
photosensitiser of the formed body is less than 50% by weight.
3. Formed body according to claim 1 or 2, characterised in that the
photosensitiser is chosen from porphyrines, phthalocyanines, chlorins,
tetraphenylporphyrines, benzoporphyrine derivatives, purpurines,
pheophorbides and their metal complexes.
4. Formed body according to one of the claims 1 to 3, characterised in that
the photosensitiser is chosen from copper(II)phthalocyanine, rose bengal
and 5-aminolevulinic acid.
5. Formed body according to one of the claims 1 to 4, characterised in that
the matrix is transparent.
6. Formed body according to one of the claims 1 to 5, characterised in that
the formed body is porous and/or has a rough surface.
7. Formed body according to one of the claims 1 to 6, characterised in that
the formed body is a foil.
8. Method for manufacture of a formed body for photoactivated production
of singlet oxygen, characterised in that at least one photosensitiser is
mixed with at least one polymer or monomer material and the formed
body is manufactured from the mixture by means of pressing and

2
subsequent, sintering, injection moulding, extrusion, curing or
polymerisation.
9. Method according to claim 8,
characterised in that a granulate is manufactured from the mixture,
which granulate is used for the manufactures of the formed body.
10. Method according to claim 8 or 9,
characterised in that the formed body is subjected at least in regions to a
surface treatment.
11. Method according to one of the claims 8 to 10,
characterised in that the mixture has in addition a substance added
which is washed out again. after the manufacture of the formed body.
12. Method according to one of the claims 8 to 11,
characterised in that the photosensitiser is mixed with polymer
granulate, monomers and/ or resins.
13. Method according to one of the claims 8 to 12,
characterised in that the photosensitiser is mixed with fluorinated
hydrocarbons.
14. Method according to one of the claims 8 to 13,
characterised in that the photosensitiser is mixed with PTFE granulate.
15. Method according to claim 14,
characterised in that the sintering is carried out at temperatures of over
300 °C.
16. Use of a formed body according to claim 7 in order to cover surfaces.
17. Use according to claim 16,
characterised in that floors, bodies of water or skin surfaces are covered.

Description

CA 02339271 2001-02-O1
1
Device for photoactivated production of ringlet oxygen and method for
manufacture of the det~tce
The invention concerns a device for production of ringlet oxygen anal a method
for manufacture of the device.
Oxygen exists in the normal state as a triplet molecule and can be converted,
by supplying energy, into the activated ringlet state. Activated ringlet
oxygen is
particularly reactive and is used for example in chemical process engineering,
i_n. medicine and in water treatment.
Up till now, ringlet oxygen has been produced either by means of chemical
reactions or by means of irradiation of a photosensitive layer, which is
situated
in contact with air or pure oxygen. By quenching the fluorescence, the triplet
oxygen molecules are transferred into the acaivated ringlet state via a
radiatioxzless transition. Since ringlet oxygen has oxzly a very short life-
span in
solution, it it generally brought to the place of use in the gaseous state.
When producing ringlet oxygen with the aid of photosensitisers it is
disadvantageous that a series of photosensitisers are unsuitable as coating
matex-ial.. One of these photosensitisers which is unsuitable as coating
material
is for example copper(II~phthalocyanine. This dyestuff is insoluble in. water
and
hence difficult for the body to absorb. Therefore this dyestuff is
particularly
suitable for medicinal applications such as for example in inhalation
apparatus
for ringlet oxygen. Up till now, copper(II)phthaloc,yanine and a series of
further
photosensitisers have however hardly been used for the photoactivated
production of ringlet oxygen for reasons of their costly processing.
Proceeding from these problems, the object of tlse invention is to indicate a
device which permits the photoactivated production of ringlet oxygen without
requiring to fall back upon a coating method for the preparation of the
photosensitiser. Fu,rtb.ermore, the object is to indicate a method for the
manufacture of such a device.

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This object is achieved by a device according to claim. 1 and a method
according to claim 8. The sub-clams concern preferred and advantageous
embodiments of the invention.
According to the invention, it is proposed to mix one or more photosensitxsers
with one or more polymer or monomer materials ~u~.d to manufacture a formed
body of arbitrary geometry from the mixture. The i:ormed body then contains at
least one photosensitises embedded in a polymer matrix which comprises the
polymer material. or the polymerised monomer material. Triplet oxygen is able
to come into contact with the photosensitises on 2ua. exterior or interior
surface
of the formed body and, by means of photoactivation, be activated to singlet
oxygen.
In this m~mner, photosensitisers which cannot, or only with difficulty, be
applied with the coating method can also be immobilised and used for the
photoactivated production of ringlet oxygen. The device according to the
invention is however not restricted to photosens:itisers of the type which are
unsuitable as a coating material.. Rather, any ph~otosensitisers can be used
in
this manner for the production of ringlet oxygen.
In. many cases it is advantageous to subject at least one part of a surface of
the
formed body to a mechanical or chemical surface; treatment. In this way, the
portion of the photosensitises which is exposed on the formed body surfaces
can be increased. In. addition, the photosensitises can be exposed in this
manner if first only matrix material. is disposed on the formed body surfaces
due to the mutual wetting behaviour of the photosensitises and matrix material
after the manufacture of the formed body. In. every case, the surface
treatment
(for example roughening by means of grinding, sand blasting, cutting, etching,
dissolving etc.) effects an increase in the production of ringlet oxygen.
A further increase in production of ringlet oxygen can be achieved if polymer
materials which have a high oxygen permeation are used as matrix.

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Advantageously, there can be added to the mixture a substance which can be
washed out again after the manufacture of the formed body. Because of the
interior surfaces in the form of pores which arise by means of the crashing-
out,
the active surface can furthermore be increased and/ or a porous formed body
can be manufactured, which permits the through-~Low of fluid or gaseous
media.
The formed body surfaces according to the invention have a high chemical
resistance, which permits the use of the device according to the invention in
medical technology (for example in endoscopy), in water treatment and in
chemical process engineering. Use of the device in fluids is possible.
Further details and advantages of the invention are apparent from the
subsequent description of embodiments, given by «ay of example.
According to a first embodiment, a photosensitiser such as
copper(II)phthalocyanin.e can be embedded in a matrix made of fluorinated
hydrocarbons. To this is mixed the photosensitiser with PTFE granulate and
the mixture is then pressed. The proportion of the photosensitiser in the
formed body is preferably less than 50% by weight and particularly preferred
less than 10% by weight. Subsequent to the pressing, a temperature-
controlled sinter process is carried out in order to manufacture a formed body
which can be mechanically processed. In. the scope of the sinter process, the
pressed mixture is slowly heated over a few days to temperatures of over 300
°C and preferably to a peak temperature of 380 °C. Thereafter,
the sintered
formed body is again left to slowly cool. Finally, the formed body is
subjected
to a mechanical surface processing.
Surprisingly, it was found that formed bodies produced in this way and
containing copper(II)phthalocyanin.e for the production of singlet oxygen have
an extremely high thermal stability up to 300 °C, without the onset of
a
thermal degradation of the photosensitiser.

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According to a further embodiment, a photosensitiser (for example chosen from
porphyrines, phthalocyanines, chlorins, tetraphenylporpbyr~n.es,
~benzoporphyrine derivatives, purpurines, pheophorbides and their metal
complexes, copper(II)phthalocyan:in.e, rose bengal anal 5-aminolevulinic acid)
is
mixed with a polymer granulate, monomers (for ex<~mple acrylate monomers) or
resins (for example polyester resins). The mixture can then be further
processed into a granulate. By means of injection moulding, extrusion, curing
or polymerisation, a formed body can be manufactured from the mixture or
from the granulate, which body can be mechanically processed. Since the
maximum occurring temperatures during these manufacturing methods are
substantially less than those temperatures arising during sintering according
to the brst embodiment, photosensitisers, which are less temperature-stable,
can also be used in the scope of the second embodiment.
The use of a transparent matrix is preferred. This makes possible the
activation of the photosensitiser by illumination also from the rear side by
means of artificial light or sunlight. The embodiment of the formed body as a
transparent foil can be used as covering over floors in order to improve the
floor
quality by means of direct influence of singlet oxygen and by means of
selective
activation of the growth of aerobic bacteria. As a~ covering for bodies of
water
(aquaria, ponds, lakes), the water quality is improved by means of the singlet
oxygen. In the field of dermatology and of plastic ;surgery, transparent foils
can
be used in order to promote healing processes.
A thin, flat formed body which contains a transparent matrix can be applied
for
example to windows or function as windows and, by using sunlight or artificial
light, be used for the production of singiet oxygen in order to improve air
quality in rooms.