BE1028762B1 - PROCEDURE FOR VENTILATING A ROOM OR REGULATING THE AIR QUALITY IN A ROOM - Google Patents

Abstract

The present invention relates to a method for ventilating a room or regulating the air quality in a room, wherein clean air is supplied or air is circulated through a ventilation system, wherein the air is brought into contact with sulfated polysaccharides. In addition, the invention relates to a carrier provided with sulfated polysaccharides, and an air ventilation duct provided with such a carrier or provided with a nebulizer comprising a suspension of sulfated polysaccharides to be nebulized. The invention also relates to a use of a suspension or aerosol comprising sulfated polysaccharides or use of such carrier for regulating the air quality in a room, whereby virus particles present in the air are captured and inactivated.

Description

PROCEDURE FOR VENTILATING A ROOM OR REGULATING OF THE AIR QUALITY IN A SPACE

TECHNICAL DOMAIN The invention relates to a method and means for ventilating a room or regulating the air quality in a room.

BACKGROUND ART Ventilation or air exchange is the replacement of the air in a room, which for whatever reason is polluted or polluted, with clean air. Through ventilation, carbon dioxide, moisture and pollution are removed and fresh air is supplied. The air pollution can be of different nature, such as dust, bacteria, mold spores and viruses, chemical substances or fragrances. Air conditioning (air conditioning), climate control, air treatment or air control is the regulation of the air in indoor spaces, for example the regulation of temperature and humidity. The air can also be purified by applying a filter system. HVAC (heating, ventilation, air conditioning or heating, ventilation and air conditioning) installations in buildings, including non-residential buildings such as offices, restaurants, hotels, shopping centers, retirement homes, schools and hospitals are often provided with (partial) air recirculation. Also in airplanes, (cruise) ships, metros, etc., air is also recirculated instead of refreshed, often with a view to energy and cost savings. If the HVAC installation is not properly maintained and/or operated, it can contribute to the transfer of polluting components. Such an installation itself can then recirculate this polluted air and thus spread the pollution further, possibly to other rooms connected to the same ventilation system. Such ventilation systems may include filters, however these are often sized for the removal of particles larger than 1 µm, and thus not efficient for the removal of smaller particles such as viruses. Viruses have a diameter between 20 and 300 nm, and cannot reproduce outside the body of a host. Viruses need a host cell to reproduce. A virus does this by infecting a bacterial, plant or animal cell. Once inside the host's cell, the virus uses the copying mechanisms present to copy its own genetic material. Viruses that cannot infect a host (cell) cannot survive. In fact, once outside the host, the viability of the virus will gradually decrease over time.

However, a virus can be passed from one person to another. Possible ways of virus transmission are: direct person-to-person transmission by released droplets (coughing, sneezing, talking) over a short distance; the indirect transmission through contact of the hands with surfaces and objects previously contaminated (by these droplets), followed by contact of the hands with the face; airborne transmission, after evaporation of the droplets, over longer distances and for longer durations; and the indirect faecal transmission through the airborne spread of virus particles from the feces of an infected person.

When virus transmission continues through the air, these viruses can then be spread more quickly via ventilation systems to other rooms that are linked to the same ventilation systems. In addition, such ventilation systems can also create indoor conditions that support the survival of viruses, such as an ideal humidity and temperature. An example of the spread of viruses through ventilation systems is the pandemic spread of SARS-CoV-2, or COVID-19, which has been shown to be mediated, among other things, through the air and through ventilation systems.

Filters that can remove these smaller particles such as viruses are HEPA (high-efficient particulate air) filters and are used in specific environments such as hospitals, operating theaters and certain labs. According to current standards, a HEPA air filter must remove at least 99.95% (European standard) or 99.97% (US standard) of the particles whose diameter is equal to 0.3 µm; with higher filtration efficiency for particle diameters both less and more than 0.3 µm.

Extensive air filtration such as HEPA is more energy-intensive, which means that this technology is not used in offices, for example. Moreover, existing ventilation systems are not dimensioned to simply replace classic air filters with HEPA filter systems.

A problem with the known ventilation systems is that they either do not stop virus particles or, in the case of HEPA filter systems, they are energy-intensive, so that this technology is not widely used.

There is a need for an improved method of ventilating a room or regulating the air quality in a room. The present invention aims to provide a solution to the above problem.

SUMMARY OF THE INVENTION The invention relates to a method according to claim 1. In particular, the invention relates to a method for ventilating a room or regulating the air quality in a room, wherein clean air is supplied or air is circulated by means of a ventilation system, wherein the air of the present invention is contacted with sulfated polysaccharides. Preferred embodiments of the method are set forth in claims 2-13. In an embodiment according to claim 2, the sulfated polysaccharides are provided on a support. These may be embedded in a matrix, preferably an oil-based matrix according to the embodiment of claim 3. In an embodiment according to claim 7, oil-based aerosols are introduced into the air. These aerosols can capture virus particles present in the air. According to an embodiment of claim 9, these aerosols may contain sulfated polysaccharides. In another embodiment according to claim 10, a suspension of sulfated polysaccharides is atomized into an aerosol, preferably in the room or in an air ventilation duct. In a preferred embodiment according to claim 12, these sulfated polysaccharides inhibit, inactivate and/or eliminate virus particles present in the air. In a particularly preferred embodiment according to claim 13, the virus particles are of viruses selected from the family of influenza viruses, coronaviruses, herpes viruses such as herpes simplex virus or cytomegalovirus, and paramoxyviruses such as measles virus, preferably SARS-Cov-2. Preferably, the sulfated polysaccharides are supported on a support, preferably a polyurethane support. These sulfated polysaccharides preferably do not come into direct contact with humans and/or animals that breathe treated air. In a second aspect, the invention relates to a support provided with a porous surface, wherein the porous surface of the support is provided with sulfated polysaccharides, according to claim 14. Embodiments of the support are set forth in claims 15-16.

In a third aspect, the invention relates to an air ventilation duct according to claim

17. In particular, it concerns an air ventilation duct provided with a carrier provided with sulfated polysaccharides, or provided with a nebulization installation comprising a suspension of sulfated polysaccharides to be nebulized. In a fourth aspect, the invention relates to a use according to claim 18. In particular, the invention relates to a use of a suspension or aerosol comprising sulfated polysaccharides or a carrier as previously discussed for regulating the air quality in a room. The advantage of this is that virus particles present in the air are captured and inactivated.

DETAILED DESCRIPTION The invention relates to a method for ventilating a room or regulating the air quality in a room by means of sulphated polysaccharides, a carrier provided with sulphated polysaccharides, an air ventilation duct provided with a carrier or with a misting installation, and a use of a suspension or aerosol comprising sulfated polysaccharides or a carrier comprising sulfated polysaccharides for regulating the air quality in a room. Polysaccharides are carbohydrates made up of ten or more monosaccharide units. These may be sulfated. Non-limiting examples of these sulfated polysaccharides are heparin, heparan sulfates, fucoidan, glycosaminoglycans, carrageenans, agar and ulvan. It has been found that all of the above sulfated polysaccharides or mixtures thereof are capable of inhibiting, inactivating or eliminating virus particles as they circulate in the air and the air comes into contact with these polysaccharides. In other words, these sulfated polysaccharides have an antiviral effect. The inhibitory or inactivating effect of the sulfated polysaccharides can therefore reduce the number of viruses in the air that have come into contact with these polysaccharides, and will positively regulate air quality. These polysaccharides may preferably be present on a carrier. In addition, they may be embedded in a matrix applied to the support. In addition, oil-based aerosols can be released into the air. These can capture virus particles in the air. These aerosols may themselves also contain sulfated polysaccharides. These aerosols that have captured virus particles can

> BE2020/5772 then inhibit these particles itself, by means of the polysaccharides present, or subsequently come into contact with the carrier on which the polysaccharides have been applied, where the virus particles are inhibited, inactivated and/or eliminated. Unless otherwise defined, all terms used in the description of the invention, including technical and scientific terms, have the meaning as generally understood by those skilled in the art of the invention. For a better assessment of the description of the invention, the following terms are explicitly explained. “A”, “the” and “the” in this document refer to both the singular and the plural unless the context clearly dictates otherwise. For example, “a segment” means one or more than one segment.

The terms “comprise”, “comprising”, “consist of”, “consisting of”, “include”, “contain”, “containing”, “include”, “include”, “contain”, “include” are synonyms and are inclusive or open terms designating the presence of the following, and which do not exclude or preclude the presence of other components, features, elements, members, steps known from or described in the art.

In a first aspect, the invention relates to a method for ventilating a room or regulating the air quality in a room, wherein clean air is supplied or air is circulated by means of a ventilation system, characterized in that the air is brought into contact with sulphated polysaccharides. “Air quality” indicates the degree of absence of air pollution, and is dependent on the presence of substances that are harmful to human and animal health. In a room, or indoors, these pollutants can include: chemicals such as volatile organic compounds (VOCs) from perfumes, insecticides, paint and formaldehyde from fiberboards; biological substances such as allergens from pets, dust mites or plants, as well as bacteria, fungi and viruses. In addition, certain gases such as carbon monoxide are also harmful substances.

“Ventilation” or “air exchange” is the replacement of the air in a room, which for whatever reason is polluted or polluted, with clean air and thus also significantly improves the air quality.

“Exopolysaccharides”, also abbreviated to EPS, are high molecular weight polymers composed of sugar residues, such as (sulphated) polysaccharides,

are produced by microorganisms and sometimes released into the surrounding environment.

In one embodiment, said sulfated polysaccharides are provided on a support through which or over which air to be treated is passed. Due to the contact of the air with the carrier containing sulphated polysaccharides, the air quality is positively regulated. Preferably, the support has been treated to provide the sulfated polysaccharides directly on the support, or they can be provided on the support by spraying a suspension comprising these sulfated polysaccharides onto the support. The nebulization of the suspension comprising these sulfated polysaccharides on the carrier can be done by means of a nebulization installation comprising a nebulizer. Sun nebulizer(s) can be installed or provided in an air ventilation duct of an air ventilation system. Preferably, the atomized suspension droplets have a diameter between 1 and 100 µm, preferably between 2.5 and 50 µm. Preferably the suspension contains between 0.1 and 100 g/L, i.e. between 0.01 and 10%, more preferably between 1 and 50 g/L (0.1-5%) of sulfated polysaccharides. In one embodiment, the suspension contains 0.01 - 10% sulfated polysaccharides, more preferably 0.05 - 10%, more preferably 0.1 - 10%, more preferably

0.5 - 10 %, more preferably 1 - 10 %, more preferably 1.5 - 10 %, more preferably 2 - 10 %, more preferably 2.5 - 10 %, more preferably 3 - 10 %, more preferably 3.5 - 10%, more preferably 4-10%, more preferably 4.5-10%, more preferably 5-10%, more preferably 5.5-10%, more preferably 6-10%, more preferably 6.5-10% more preferably 7-10%, more preferably 7.5-10%, more preferably 8-10%, more preferably 8.5-10%, more preferably 9-10%, more preferably 9.5-10%. In one embodiment, the suspension contains 0.1 - 5% sulfated polysaccharides, more preferably 0.5 - 5%, more preferably 1 - 5%, more preferably 1.5 - 5%, more preferably 2 - 5%, more preferably 2.5 - 5%, more preferably 3 - 5%, more preferably 3.5 - 5%, more preferably 4 - 5%, more preferably 4.5 -5%. In one embodiment, the suspension contains between 0.01 and 2%, or between 2 and 4%, or between 4 and 6%, or between 6 and 8%, or between 8 and 10% sulfated polysaccharides.

If a nebulizer is installed in an air ventilation duct, this will preferably be a carrier before (incoming air) and not after (outgoing air). This carrier may be an air filter. If this nebulizer is set up in front of a carrier/air filter, the carrier/air filter will be provided with sulfated polysaccharides on the surface as a result. In another or further embodiment, said sulfated polysaccharides are embedded in a matrix. Preferably, airborne viruses are captured by this matrix on contact with the matrix. This matrix can be any kind of matrix known to a person skilled in the art. Preferably, this matrix does not release harmful substances into the air that could possibly cause damage to humans, animals and/or the environment, or where released harmful substances are only released in an amount lower than the legally permissible limit. In addition, this matrix is preferably not harmful in contact with the skin, in contact with the digestive system and/or in contact with the respiratory system.

In a preferred embodiment, this matrix is an oil-based matrix. A non-limiting example of such an oil-based matrix is a matrix based on paraffin oil.

In another or further embodiment, this matrix is a hydrophobic matrix. In another or further embodiment, this matrix is a sticky substance.

An advantage of using an oil-based matrix and/or other sticky substance as matrix is that viruses can be easily captured in the matrix. Subsequently, the embedded sulfated polysaccharides can inhibit, inactivate and/or eliminate the virus particles.

Preferably the matrix contains between 0.1 and 100 g/L, i.e. between 0.01 and 10%, more preferably between 1 and 50 g/L (0.1-5%) of sulfated polysaccharides.

In one embodiment, the matrix contains 0.01 - 10% sulfated polysaccharides, more preferably 0.05 - 10%, more preferably 0.1 - 10%, more preferably 0.5 - 10%, more preferably 1 - 10%, more preferably 1.5 - 10%, more preferably 2-10%, more preferably 2.5-10%, more preferably 3-10%, more preferably 3.5-10%, more preferably 4-10%, more preferably 4.5-10% more preferably 5-10%, more preferably 5.5-10%, more preferably 6-10%, more preferably 6.5-10%, more preferably 7-10%, more preferred

7.5-10%, more preferably 8-10%, more preferably 8.5-10%, more preferably 9-10%, more preferably 9.5-10%.

In one embodiment, the matrix contains 0.1 - 5% sulfated polysaccharides, more preferably 0.5 - 5%, more preferably 1 - 5%, more preferably 1.5 -5%, more preferably 2 - 5%, more preferably 2.5 - 5%, more preferably 3 - 5%, more preferably 3.5 - 5%, more preferably 4 - 5%, more preferably 4.5 -5%. In one embodiment, the matrix contains between 0.01 and 2%, or between 2 and 4%, or between 4 and 6%, or between 6 and 8%, or between 8 and 10% sulfated polysaccharides. In another or further embodiment, the carrier is placed in or on a ventilation channel. As a result, the treated air that comes into contact with the carrier, which preferably contains the polysaccharides, if any, embedded on the surface will be dispersed by means of the ventilation system.

In one embodiment, an oil-based matrix is sprayed over the support to prevent drying. Preferably, this is a paraffin oil-based matrix or a matrix such as that already provided on the support.

Preferably, the support will have a porous surface to allow air to migrate through the support. “Porosity” in the current context means that there are (small) openings (pores) present. Porous materials have a large specific surface. The “specific surface area” is a property of a solid that represents the total surface area per unit mass or volume of this material. The larger this surface area, the more sulfated polysaccharides can be provided on the support, and the more efficiently they can be brought into contact with the air.

In a preferred embodiment, the carrier is an air filter. Air filters can consist of various materials such as, but not limited to, paper, foam, cotton, spun (glass) fiber components, woven or non-woven synthetic material, woven metal wire. The air filter may additionally include an activated carbon component that can remove odors from the air.

Air filters are porous, allowing air to pass through them, and depending on the type of filter, trap certain harmful substances, improving air quality.

A specific example of air filters are HEPA (high-efficient particulate air) filters, which are frequently used, for example, in hospital operating rooms. A HEPA air filter removes at least 99.95% (European standard) of particles with a diameter equal to 0.3 µm from the air, with a higher filtration efficiency for particle diameters both less and more than 0.3 µm . HEPA filters are composed of a matrix of randomly arranged fibers, mostly glass fibres. As mentioned before, HEPA filters can stop most virus particles. Also in the context of these HEPA filters, the polysaccharides can be provided on the filter or atomized in an air ventilation duct in front of the filter. These sulfated polysaccharides may be embedded in a matrix, for example an oil-based matrix. Sulfated polysaccharides can be used here to inhibit, inactivate and/or eliminate the virus particles that were retained by the (HEPA) filter. The few particles that can migrate through the filter will be inhibited, inactivated and/or eliminated by the sulfated polysaccharides. In a further or different embodiment, the support is a polyurethane support. In another or further embodiment of the invention, oil-based aerosols are introduced into the air. Preferably, these are released into the air by atomizing an oil base in an air ventilation duct. The effect of this is that these aerosols can capture virus particles in the air. In a further embodiment, these oil-based aerosols are paraffin oil-based aerosols. In another or further embodiment, the aerosols introduced into the air are a sticky substance. Preferably, the aerosols have a diameter between 1 and 100 µm, preferably between

2.5 and 50 µm. Preferably, the oil-based and oil-based aerosols do not release harmful substances into the air that could potentially cause damage to humans, animals and/or the environment, or where released harmful substances are only released in an amount lower than the legally permissible limit. In addition, these oil-based and oil-based aerosols are preferably not harmful in contact with the skin, in contact with the digestive system and/or in contact with the respiratory system. In one embodiment, the oil-based aerosols contain sulfated polysaccharides. When these captured virus particles in these oil-based aerosols come into contact with sulfated polysaccharides, these particles will be inhibited, inactivated and/or eliminated as mentioned above.

When these captured virus particles in the oil-based aerosols come into contact with a carrier as discussed above in any of the embodiments, such as an air filter provided with sulfated polysaccharides, these aerosols will land on the carrier, and be (partially) retained by the carrier. Preferably, they will even stick to the support to a certain extent. The sulfated polysaccharides from the carrier and/or from the oil-based aerosols will then inhibit, inactivate and/or eliminate the virus particles. In another or further embodiment, the oil-based aerosols themselves will be enriched with sulfated polysaccharides as described in any of the embodiments described above or below. Preferably, these sulfated polysaccharides are carrageenans.

It will be clear to a person skilled in the art that the present invention also relates to such a support as already described above, provided with a porous surface, wherein the porous surface of the support is provided with sulfated polysaccharides. These sulfated polysaccharides may be embedded in a matrix, preferably an oil-based matrix as already described above. Preferably, the carrier is an air filter.

It will also be understood that the present invention also relates to an air ventilation duct provided with a carrier as described above, or provided with a nebulizer comprising a nebulized suspension of sulfated polysaccharides capable of atomizing this suspension onto a carrier.

By providing the carrier or misting installation with an air ventilation duct, the air quality of air that is moved through this installation can be efficiently regulated by means of the sulfated polysaccharides.

Preferably, an air ventilation duct is used to limit the number of viruses in the air and thus reduce the spread of viruses through ventilation systems and ventilation ducts.

It will be apparent to a person skilled in the art that the present invention also relates to a use of a carrier as described above comprising sulfated polysaccharides for regulating the air quality in a room. Virus particles present in the air can be captured and inactivated as a result.

In addition to providing sulfated polysaccharides on a carrier, it is also possible to atomize a suspension comprising these polysaccharides to form an aerosol. Preferably, this suspension is atomized into an aerosol in the room or in an air ventilation duct. The suspension may be an oil-based suspension. A non-limiting example is a paraffin oil-based suspension.

Preferably, the aerosols with sulfated polysaccharides have a diameter between 1 and 100 µm, preferably between 2.5 and 50 µm. Preferably the suspension contains between 0.1 and 100 g/L, i.e. between 0.01 and 10%, more preferably between 1 and 50 g/L (0.1-5%) of sulfated polysaccharides. In one embodiment, the suspension contains 0.01 - 10% sulfated polysaccharides, more preferably 0.05 - 10%, more preferably 0.1 - 10%, more preferably

0.5 - 10 %, more preferably 1 - 10 %, more preferably 1.5 - 10 %, more preferably 2 - 10 %, more preferably 2.5 - 10 %, more preferably 3 - 10 %, more preferably 3.5 - 10%, more preferably 4-10%, more preferably 4.5-10%, more preferably 5-10%, more preferably 5.5-10%, more preferably 6-10%, more preferably 6.5-10% more preferably 7-10%, more preferably 7.5-10%, more preferably 8-10%, more preferably 8.5-10%, more preferably 9-10%, more preferably 9.5-10%. In one embodiment, the suspension contains 0.1 - 5% sulfated polysaccharides, more preferably 0.5 - 5%, more preferably 1 - 5%, more preferably 1.5 - 5%, more preferably 2 - 5%, more preferably 2.5 - 5%, more preferably 3 - 5%, more preferably 3.5 - 5%, more preferably 4 - 5%, more preferably 4.5 -5%. In one embodiment, the suspension contains between 0.01 and 2%, or between 2 and 4%, or between 4 and 6%, or between 6 and 8%, or between 8 and 10% sulfated polysaccharides. Preferably, this atomized suspension does not comprise any substances which are harmful to humans and/or animals. More preferably, this suspension is not harmful in contact with the skin, in contact with the digestive system and/or in contact with the respiratory system. A suspension can be nebulized into aerosol by means of a nebulizer installation comprising a nebulizer. Such a nebulizer(s) may be arranged in the room where, when this suspension is nebulized, aerosols comprising sulfated polysaccharides are released into the air. A nebulizer can also be arranged or provided in an air ventilation duct of an air ventilation system, whereby the diffusion of the aerosols with sulphated polysaccharides is improved and/or accelerated by means of an air ventilation system.

If a nebulizer is installed in an air ventilation duct, this can be an air filter before (incoming air) or after (outgoing air) as mentioned earlier. If this is after an air filter, other air pollution or harmful substances, such as dust, allergens, etc., are first stopped by the filter, so that the aerosols are dispersed into more purified air. This allows the sulfated polysaccharides to make better contact with (harmful substances such as the viruses in) the clean or circulated air in the room. It will be apparent to a person skilled in the art that the present invention also relates to a use of a suspension or aerosol comprising sulfated polysaccharides for regulating the air quality in a room. Preferably the suspension contains between 0.1 and 100 g/L, i.e. between 0.01 and 10%, more preferably between 1 and 50 g/L (0.1-5%) sulfated polysaccharides. This invention also relates to a suspension or aerosol comprising sulfated polysaccharides for inhibiting and/or eliminating airborne virus particles. Preferably, the suspension contains between 0.1 and 100 g/L, i.e. between 0.01 and 10.%, more preferably between 1 and 50 g/L (0.1-5%) % sulfated polysaccharides. In one embodiment, the suspension contains 0.01 - 10% sulfated polysaccharides, more preferably 0.05 - 10%, more preferably 0.1 - 10%, more preferably

0.5 - 10 %, more preferably 1 - 10 %, more preferably 1.5 - 10 %, more preferably 2 - 10 %, more preferably 2.5 - 10 %, more preferably 3 - 10 %, more preferably 3.5 - 10%, more preferably 4-10%, more preferably 4.5-10%, more preferably 5-10%, more preferably 5.5-10%, more preferably 6-10%, more preferably 6.5-10% more preferably 7-10%, more preferably 7.5-10%, more preferably 8-10%, more preferably 8.5-10%, more preferably 9-10%, more preferably 9.5-10%. In one embodiment, the suspension contains 0.1 - 5% sulfated polysaccharides, more preferably 0.5 - 5%, more preferably 1 - 5%, more preferably 1.5 -5%, more preferably 2 - 5%, more preferably 2.5 - 5%, more preferably 3 - 5%, more preferably 3.5 - 5%, more preferably 4 - 5%, more preferably 4.5 -5%. In one embodiment, the suspension contains between 0.01 and 2%, or between 2 and 4%, or between 4 and 6%, or between 6 and 8%, or between 8 and 10% sulfated polysaccharides.

In one embodiment of the invention, said sulfated polysaccharides are selected from the group of heparin, heparan sulfates, fucoidan, glycosaminoglycans, carrageenans, agar, ulvans and combinations thereof.

Heparin, also known as unfractionated heparin (UFH), is a naturally occurring glycosaminoglycan, and is used as a medicine, specifically as an anticoagulant.

It also exhibits direct antiviral activity against many enveloped viruses and has anti-inflammatory activity.

In addition, other glysocaminoglycans and heparansulfates also show antiviral activity.

Fucoidan is mainly found in various types of brown algae and brown algae such as mozuku, kombu, bladderwrack, wakame and hijiki.

In addition, variants of fucoidan have also been found in animal species, including the sea cucumber.

Fucoidins are believed to have antioxidant, cognitive protective, anti-inflammatory, anti-angiogenic, anti-cancer, anti-viral and anti-hyperglycemic activity.

Agar is a polymer made up of subunits of the sugar galactose, and is a mixture of two components: the linear polysaccharide agarose, and a heterogeneous mixture of smaller molecules called agaropectin.

It forms the support structure in the cell walls of certain algae species and is released during cooking processes.

These algae are known as agarophytes, and belong to the Rhodophyta (red algae) phylum.

Agar can be used as a laxative, appetite suppressant, vegetarian gelatin substitute, thickener for soups, in fruit preserves, ice cream and other desserts, as a fining agent in brewing, and for stiffening paper and fabrics.

Ulvan is a sulfated polysaccharide present in U/va spp. such as U. conglobate, U. lactuca and U. rigida, whose cell walls contain up to 29% ulvan on a dry weight basis.

Ulvan has an antioxidant effect depending on its molecular weight.

Ulvan van U. conglobate has significant anticoagulant activity.

Alvan also has antiviral and immunomodulatory activities, has potential to treat gastric ulcers and is used for targeted drug delivery.

Carrageenan is a generic name for a family of gel-forming and viscosifying polysaccharides, which are obtained by extraction from certain species of red algae or Rhodophyceae.

Examples include Chondrus, Gigartina and various Eucheuma species.

They are often used in the food industry for their gelling, thickening and stabilizing properties, and as a vegetarian and vegan alternative to gelatin.

In addition, these compounds have also been shown to possess antiviral activity and to inhibit viral infections.

It has been found that all of the above sulfated polysaccharides or mixtures thereof are capable of inhibiting, inactivating and/or eliminating virus particles as they circulate in the air and the air comes into contact with these polysaccharides.

In a preferred embodiment of the invention, said sulfated polysaccharides are selected from carrageenans such as, but not limited to, iota-carrageenan, kappa-carrageenan and lambda-carrageenan.

Carrageenans, or carrageenan, are classified into different types such as À (lambda), k (kappa), 1 (jota), € (epsilon), u (Mu) type carrageenans, all of which contain 22 to 35% sulfate groups. These names do not reflect fixed chemical structures, but general differences in the composition and degree of sulphation at specific sites in the polymer.

In a preferred embodiment, the sulfated polysaccharides inhibit, inactivate and/or eliminate virus particles present in the air.

As mentioned above, several sulfated polysaccharides have already been shown to exhibit antiviral activity. This antiviral action is either an “indirect antiviral action”, in which the initial infection process is disrupted, e.g. inhibition of replication in the cell, interference of virus adsorption and binding to the cell and uncoating; or a “direct antiviral action” in which virus-polysaccharide complexes are formed, which prevent the virus from attaching to the host cell and thus not being able to infect it.

The antiviral activity of carrageenan is discussed further below. Among other things, carrageenan is a selective inhibitor of several enveloped viruses, including human or animal pathogens such as human immunodeficiency virus, herpes simplex virus (HSV), human cytomegalovirus, denge virus, enterovirus, influenza virus, papilloma virus, and human rhinovirus. Carrageenan primarily works by preventing the binding or entry of viruses into cells. This finding is consistent with the fact that carrageenan resembles heparan sulfate, a viral cell binding factor.

Research with such viruses suggests that carrageenan has both a direct and indirect antiviral effect. In the indirect action, the initial infection process is disrupted, for example inhibition of replication in the cell, interference of virus adsorption and binding to the cell and uncoating. The antiviral activities of carrageenan are associated with the molecular weight and the sulfated fraction as the antiviral activity only applies if carrageenan can penetrate the tissue to protect the host cells against the infecting virus. Direct virucidal effects attributed to carrageenan are primarily directed against enveloped viruses, where the negatively charged carrageenan binds to viruses such as Herpes simplex virus and forms virus-carrageenan complexes rendering the envelope unavailable for attachment to the host cell. The antiviral effect of carrageenan thus depends on the type of carrageenan (incl. molecular weight and sulphation), the type of virus and the type of host cell.

In the present process, as already described above, the air will be contacted with sulfated polysaccharides. These polysaccharides have an antiviral effect and will therefore be able to inhibit, inactivate and/or eliminate at least some of the airborne viruses that are brought into contact with these sulfated polysaccharides. The sulfated polysaccharides may be embedded in a matrix, which facilitates the capture of the viruses, after which the sulfated polysaccharides may inhibit and/or eliminate the virus particles. The inhibitory/inactivating effect of the sulfated polysaccharides will reduce the number of viruses in the air that have been brought into contact with these polysaccharides, in other words will provide positive regulation of air quality. It will be clear to a person skilled in the art that the present invention also relates to a method for reducing or limiting viruses in air in a room, by ventilating a room or regulating the air quality in a room, wherein air to be treated comes into contact with is carried out with sulfated polysaccharides. These sulfated polysaccharides can be any type of sulfated polysaccharides known to those skilled in the art. Preferably, the sulfated polysaccharides have an antiviral activity. It will also be apparent to a person skilled in the art that viruses on surfaces in contact with the air in which these sulfated polysaccharides are present, after atomization in an air ventilation duct or directly in the room, will also be inhibited and/or eliminated. More specifically, this means that viruses that are not present in the air, but are present in the room where this air comes into contact with sulphated polysaccharides, will also be inhibited and/or eliminated.

In addition, it will also be clear to a person skilled in the art that the present invention also relates to a method for reducing or limiting the spread of viruses by means of a ventilation system, wherein air which (re)circulates through a ventilation system is brought into contact with sulfated polysaccharides.

These sulfated polysaccharides may be any type of sulfated polysaccharides known to those skilled in the art.

Preferably, the sulfated polysaccharides have an antiviral activity.

In a further embodiment, the virus particles of a virus are selected from the family of influenza viruses, coronaviruses, herpes viruses such as herpes simplex virus or cytomegalovirus, and paramoxyviruses.

In a further embodiment, the virus particles of a virus are selected from herpes simplex virus, cytomegalovirus, measles virus, influenza virus A, group 1 (H1N1), group 2 (H2N2), group 3 (H3N2), group 5 (H5N1, H5N2, H5N8 ) or group 7 (H7N7, H7N9); influenza B; influenza C; SARS-CoV-1; MERS-CoV; or SARS-CoV-2 (causative agent of COVID-19 or coronavirus disease 2019). In a preferred embodiment, this virus is SARS-CoV-2. In another or further embodiment, the virus particles of a virus are selected from the enveloped viruses.

These are viruses that comprise a virus envelope or virus envelope.

Non-limiting examples of enveloped viruses are viruses of the family of herpesviruses, poxviruses, hepadnaviruses, asfaviruses, flaviviruses, alphaviruses, togaviruses, coronaviruses, hepatitis delta virus, orthomoxyviruses including influenza viruses, paramyxoviruses, rhabdoviruses and retroviruses, bunoviruses.

In another or further embodiment, the virus particles of a virus are selected from the family of flaviviruses such as dengue virus, enteroviruses, picornaviruses such as rhinoviruses and papillomaviruses such as human papillomavirus.

In an embodiment of the present invention, at least one of said sulfated polysaccharides is recovered from seaweed or microbiologically produced.

In one embodiment, these sulfated polysaccharides are recovered from seaweed or are produced microbiologically.

The recovery of sulfated polysaccharides from seaweed usually involves extraction of these saccharides.

Various extraction methods for sulfated polysaccharides are known to those skilled in the art.

In general, these methods involve pre-treatment of the seaweed tissue with an organic solvent to remove as much lipids and pigments as possible, followed by proteolytic digestion and acid and/or alkaline extraction. An example of a method for extracting sulfated polysaccharides from red seaweed involves the use of NaOH, sonication followed by proteolysis.

Sulfated polysaccharides can also be produced microbiologically, for example by culturing microorganisms such as bacteria, known to produce sulfated polysaccharides, in one or more bioreactors. In one embodiment of the present invention, the air contacted with the sulfated polysaccharides may also be contacted with these sulfated polysaccharides through contact with microorganisms expressing these sulfated polysaccharides. These micro-organisms preferably have a Generally Recognized as Safe or GRAS status, and are thus generally recognized as safe.

Microorganisms suitable for microbiologically producing sulfated polysaccharides include sulfate-reducing microorganisms and sulfide-oxidizing microorganisms, and/or combinations thereof. Examples include Desulfovibrio sp. such as but not limited to Desulfovibrio vulgaris (Marburg, Madison or Hildenborough), Desulfovibrio G11, Desulfovibrio desulfuricans (Essex 6); Desulfotomaculum orientis; Desulfobacterium autotrophicum; Desulfobulbus sp.; Desulfotomaculum sp.; Desulfosporomusa sp.; Desulphosporosinus sp.; Thermodesulfovibrio sp.; Geobacter sp.; Archaeoglobus sp.; Thermocladium sp.; Thermodesulphobium sp.; Thiobacillus sp.; Thiothrix sp.; Halothiobacillus sp.; Acidithiobacillus sp.; Thioalkali vibrio sp.; Thiomicrospira sp.; Thermothrix sp.; Chlorobaculum sp. and Beggiatoa sp.

It will be clear that also combinations of different micro-organisms can be used for the production of these sulfated polysaccharides, and/or a consortium and/or a mixture of micro-organisms. Preferably, it contains at least one sulfate-reduced and at least one sulfide-oxidizing microorganism. These microorganisms may be naturally occurring or genetically modified, for example by mutagenesis or by the introduction of foreign plasmids, genes or gene fragments.

In one embodiment, said sulfated polysaccharides are produced microbiologically by a multi-step method. In one step, sulfur compounds are converted to hydrogen sulfide by sulfate-reducing microorganisms under anaerobic conditions.

Examples of sulfate-reducing microorganisms include sulfate-reducing bacteria such as, but not limited to, Desulfovibrio sp, Desulfotomaculum sp., Desulfobaterium sp., Desulfobulbus sp., Desulfotomaculum Sp., Desulfosporomusa sp., Desulfosporosinus spovibriodes. sp. and Geobacter sp.; and sulfate-reducing archaea such as, but not limited to, Archaeoglobus sp., Thermocladium sp. and, Thermodesulfobium sp. In a next step, the hydrogen sulfides obtained will be converted into biomass and biomass derivatives by means of sulfide-oxidizing bacteria under aerobic conditions.

Examples of sulfide-oxidizing bacteria are, for example, Thiobacillus sp., Thiothrix sp., Halothiobacillus sp., Acidithiobacillus sp., Thioalkalivibrio sp. Thiomicrospira sp.; Thermothrix sp., Chlorobaculum sp. and Beggiatoa sp..

Preferably, these conversions are mediated by energy-rich gases. “Energy rich gases” are gases rich in chemical energy such as hydrogen, CO, H:S, PH3, CH4, volatile organic compounds, mixtures of such gases, gases produced by fermentation such as H2 and biogas, or by physical/chemical gasification processes such as syngas made from fossil or renewable resources or waste. Such energy-rich gases can serve as electron donors and through biochemical conversions in which these electrons are transferred to good electron acceptor compounds, value-added microbial products can be generated.

Preferably, said multi-step conversions take place in one or more bioreactors. These biomass and biomass derivatives produced by the multi-step process contain various cell wall components, including exopolysaccharides, especially the sulfated polysaccharides used in the present invention.

The biomass can thus be used in the method of the present invention, wherein the sulfated polysaccharides, preferably from the cell wall of the microorganisms, are brought into contact with the air. As described earlier, this can be done by means of nebulization by means of a nebulizer installation and nebulizer in a space and/or an air ventilation duct, or by providing these micro-organisms on a carrier such as an air filter, preferably in a ventilation duct.

The sulfated polysaccharides can also be purified from the resulting biomass. For this purpose, the harvested biomass is preferably first treated. One step in this post-treatment process is to kill the micro-organisms without reducing the quality of their polysaccharides. This can be done in one of the ways mentioned in the non-exclusive list of pasteurization, steam treatment, irradiation, chemical methods or mechanical stress. During this step or thereafter, the biomass may be subjected to drying or extrusion while preserving the qualitative properties of the derivatives in or on the biomass. Subsequently, the biomass derivatives, in this case the sulfated polysaccharides, can be purified. These purified sulfated polysaccharides can then be used in the method of the present invention as already discussed above. In a preferred embodiment, the present invention relates to a method of ventilating a room or regulating the air quality in a room, wherein clean air is supplied or air is recirculated through a ventilation system, wherein the air is contacted with sulfated polysaccharides provided on a support, preferably made of polyurethane, over or through which air to be treated is passed, wherein the sulfated polysaccharides inhibit, inactivate and/or eliminate virus particles present in the air. It will be appreciated that the present invention also contemplates a use of a suspension or aerosol as described above in an embodiment comprising sulfated polysaccharides or a carrier as described above in an embodiment for regulating the air quality in a room, wherein virus particles present in the air captured and inactivated. In what follows, the invention is described by reference to: non-limiting examples illustrating the invention, and which are not intended or should be construed to limit the scope of the invention.

EXAMPLES Example 1: Sulfated Polysaccharides Provided on Air Filter A porous support, in particular an air filter, is placed in an air ventilation system. This support is provided with sulfated polysaccharides, in particular carrageenans, which are embedded in a paraffin oil-based matrix. This matrix contains approximately 0.9% sulfated polysaccharides. Different rooms are ventilated by means of the same ventilation system in which this carrier/air filter is placed.

The air is recirculated and is passed through the various rooms by means of the ventilation system.

The sulphated polysaccharides provided on the air filter come into contact with the air of the rooms being ventilated when it is passed through the air filter.

Aerosols of a paraffin oil are introduced into the air by means of a misting installation.

Viruses, including influenza viruses, coronaviruses such as SARS-Cov-2, herpes viruses and paramoxyviruses present in this air, are captured by these aerosols and are carried through the air up to the air filter.

There they come into contact with the carrageenans on the air filter that inhibit these viruses.

Viruses that cannot infect a host due to this inhibition will ultimately not survive.

The number of viruses in the air, as well as the spread of these viruses through the ventilation system, is limited in this way.

A reduction in the number of viruses in the air also means a positive regulation of the air quality in the room.

Example 2: sulfated polysaccharides atomized on a support A 4% solution of sulfated polysaccharides, more specifically a solution of carrageenans, is atomized on a porous support, preferably an air filter, placed in an air ventilation duct.

Different spaces are ventilated by means of the same ventilation system comprising this air ventilation duct in which this carrier is placed.

The air is recirculated and is passed through the various rooms by means of the ventilation system.

The carrageenans provided on the air filter come into contact with the air of the rooms ventilated when they are passed through the air filter.

Aerosols of a paraffin oil with a diameter varying between 2.5 and 50 µm are introduced into the air by means of a misting installation.

Viruses, including influenza viruses, coronaviruses such as SARS-Cov-2, herpes viruses and paramoxyviruses present in this air, are captured by these aerosols and are carried through the air up to the air filter.

There they come into contact with these carrageenans on the air filter that inhibit these viruses.

Viruses that cannot infect a host due to this inhibition will ultimately not survive.

The number of viruses in the air, as well as the spread of these viruses through the ventilation system, is limited in this way.

A reduction in the number of viruses in the air also means a positive regulation of the air quality in the room.

Example 3: Nebulization of micro-organisms via an air ventilation duct in a room A suspension of 3% micro-organisms, in particular micro-organisms with a GRAS (Generally Recognized As Safe) status, which are generally recognized as safe sulfated polysaccharides, in particular those expressing carrageenans, is envisioned.

This suspension is atomized into aerosols with a diameter varying between 1 and 100 µm in an air ventilation duct.

Different spaces are ventilated by means of the same ventilation system comprising this air ventilation duct in which this suspension is atomized by means of a misting installation.

The air is recirculated and is passed through the various rooms by means of the ventilation system.

The micro-organisms expressing these carrageenans, which have been atomized via the suspension in the air ventilation duct, come into contact with the air in the rooms being ventilated.

Viruses, including influenza viruses, coronaviruses such as SARS-Cov-2, herpes viruses, and paramoxyviruses that are in the air or on surfaces that come into contact with this air, come into contact with these carrageenans which inhibit these viruses.

Viruses that cannot infect a host due to this inhibition will ultimately not survive.

The number of viruses in the air, as well as the spread of these viruses through the ventilation system, is limited in this way.

A reduction in the number of viruses in the air also means a positive regulation of the air quality in the room.

Example 4: Nebulization of Sulfated Polysaccharides in a Chamber. A suspension comprising 1.5% sulfated polysaccharides, in particular carrageenans, in a paraffin oil is provided.

This suspension is atomized into aerosols in a room by means of a misting installation.

Various rooms, including the room in which this suspension is atomized, are ventilated by means of the same ventilation system.

The air is recirculated and is passed through the various rooms by means of the ventilation system.

The carrageenans, which have been atomized into the room via the suspension, come into contact with the air in the rooms that are ventilated.

Viruses, including influenza viruses, coronaviruses such as SARS-Cov, herpes viruses, and paramoxyviruses, that are in the air or on surfaces that come into contact with this air come into contact with these carrageenans which inhibit these viruses.

Viruses that cannot infect a host due to this inhibition will ultimately not survive.

The number of viruses in the air, as well as the spread of these viruses through the ventilation system, is limited in this way. A reduction in the number of viruses in the air also means a positive regulation of the air quality in the room.

It is believed that the present invention is not limited to the embodiments described above and that some modifications or changes may be added to the described examples without revising the appended claims.

Claims (18)

CONCLUSIONS A method of ventilating a room or regulating the air quality in a room, wherein clean air is supplied or air is circulated through a ventilation system, wherein the air is contacted with sulfated polysaccharides, characterized in that said sulfated polysaccharides carrageenans, preferably selected from the group of iota-carrageenan, kappa-carrageenan and lambda-carrageenan. Process according to claim 1, wherein said sulfated polysaccharides are provided on a support over or through which air to be treated is passed. A method according to claim 2, wherein said sulfated polysaccharides are embedded in a matrix, preferably an oil-based matrix. A method according to claim 2-3, wherein the carrier is placed in or on a ventilation duct. A method according to any one of claims 2-4, wherein the support has a porous surface. A method according to any one of claims 2-5, wherein the carrier is an air filter. A method according to any one of the preceding claims, wherein oil-based aerosols are introduced into the air, preferably by atomizing an oil base in an air ventilation duct. The method of claim 7, wherein the oil-based aerosols are paraffin oil-based aerosols. The method of claims 7-8 wherein the oil-based aerosols contain sulfated polysaccharides. A method according to claim 1, wherein a suspension of sulfated polysaccharides is atomized into an aerosol, preferably in the room or in an air ventilation duct. A method according to any one of the preceding claims, wherein at least one of said sulfated polysaccharides is recovered from seaweed or microbiologically produced. A method according to any one of the preceding claims, wherein the sulfated polysaccharides inhibit, inactivate and/or eliminate virus particles present in the air. The method of claim 12, wherein the virus particles of a virus are selected from the family of influenza viruses, coronaviruses, herpes viruses such as herpes simplex virus or cytomegalovirus, and paramoxyviruses such as measles virus, preferably SARS-Cov-2. Support provided with a porous surface, characterized in that the porous surface of the support is provided with sulfated polysaccharides, the sulfated polysaccharides being carrageenans, preferably selected from the group consisting of iota-carrageenan, kappa-carrageenan and lambda-carrageenan. carrageenan. A carrier according to claim 14, wherein said sulfated polysaccharides are embedded in a matrix, preferably an oil-based matrix. The carrier of claims 14 or 15, wherein the carrier is an air filter. An air ventilation duct provided with a support according to any one of claims 14-16, or provided with a nebulization installation comprising a suspension of sulfated polysaccharides to be atomized, wherein the sulfated polysaccharides are carrageenans, preferably selected from the group of iota-carrageenan, kappa-carrageenan. and lambda carrageenan. Use of a suspension or aerosol comprising sulfated polysaccharides, wherein the sulfated polysaccharides are carrageenans, preferably selected from the group of iota-carrageenan, kappa-carrageenan and lambda-carrageenan, or a carrier according to any one of claims 14 or 16 for the regulating the air quality in a room, whereby virus particles present in the air are captured and inactivated.