Aerosol-generating articles suitable for use in aerosol-generating devices

Abstract

An aerosol-generating article includes an aerosol-generating substrate and at least one element comprising at least one polyhydroxyalkanoic acid (PHA), the at least one element being positioned downstream of the aerosol-generating substrate. According to a preferred embodiment, the aerosol-generating article includes the aerosol-generating substrate, a support element positioned immediately downstream of the aerosol-generating substrate, an aerosol-cooling element positioned downstream of the support element, and an outer wrapper surrounding the aerosol-generating substrate, the support element, and the aerosol-cooling element, the aerosol-cooling element comprising at least one PHA. The at least one element comprising at least one polyhydroxyalkanoic acid (PHA) is capable of suppressing reactive oxygen species (ROS) inevitably present in volatile substances generated by heating the aerosol-generating substrate.

Description

[Technical field]

[0001] The present invention relates to an aerosol-generating article suitable for use in an aerosol-generating device, more particularly, to an aerosol-generating article comprising at least one component comprising at least one polyhydroxyalkanoic acid (PHA) suitable for use in an aerosol-generating device to suppress reactive oxygen species (ROS) in an aerosol generated by the aerosol-generating article. [Background technology]

[0002] Conventional smoking articles, such as cigarettes, usually have a substantially cylindrical rod-like structure and include a roll of smokable material, such as tobacco, surrounded by a paper wrapper, thereby forming a so-called "smokable rod". Typically, cigarettes have a cylindrical filter element aligned end-to-end on the smokable rod. Typically, the filter element includes a bundle of cellulose acetate fibers surrounded by a paper material, and the filter element is attached to one end of the smokable rod using a surrounding wrapping material known as "tipping material". Conventional cellulose acetate fibers (manufactured in the form of a bundle, also known as a "tow") are bonded with a suitable plasticizer, usually glyceryl triacetate (triacetin), which allows the short fibers to be bonded together to create a relatively stiff and rigid structure that does not soften or disintegrate during smoking.

[0003] In addition to traditional cigarettes, which are smoked by burning tobacco at high temperatures, alternative smoking systems, conventionally known as "heated tobacco systems," such as the IQOS® kit by Philip Morris, have recently been on the market in which aerosols containing nicotine and other chemicals are generated by simply heating a tobacco rod rather than burning it. Typically, in such heated smoking articles, the aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating substrate or material that may be located within, around, or downstream of the heat source. During smoking, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and are mixed into the air drawn through the smoking article. When the released compounds cool, they condense to form an aerosol, which is inhaled by the user.

[0004] Aerosol-generating articles are described, for example, in U.S. Pat. No. 5,399,633 and U.S. Pat. No. 5,499,466. Such an aerosol-generating article includes, in a linear continuous arrangement, an aerosol-generating substrate, a support element disposed immediately downstream of the aerosol-generating substrate, a transfer section disposed downstream of the support element where the aerosol is cooled, and an outer wrapper surrounding the aerosol-generating substrate, the support element, and the transfer section. The aerosol-generating article is used in an aerosol-generating system including an electrically heated aerosol-generating device including an internal heating element. The aerosol-generating substrate is penetrable by the heating element of the aerosol-generating device. The transfer section may be constituted by a hollow tubular element, as described in U.S. Pat. No. 5,499,633. Alternatively, the transfer section is more effectively manufactured as an aerosol cooling element by using a sheet of a suitable material that is crimped, pleated, gathered, or folded to define a plurality of longitudinally extending channels, wrapped with a wrapper material, as disclosed in U.S. Pat. No. 5,499,466. The sheet may be manufactured from a variety of materials, such as metal foil, polymeric material, substantially non-porous paper or cardboard, etc. More specifically, the aerosol cooling element may comprise a gathered sheet of a material selected from polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminum foil. More preferably, the aerosol cooling element comprises a gathered sheet of a compostable material such as non-porous paper, or a biodegradable polymeric material such as polylactic acid or Mater-Bi® (a family of commercially available starch-based copolyesters). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2013 / 098405 Brochure [Patent Document 2] International Publication No. 2013 / 098410 Brochure [Patent Document 3] International Publication No. 1999 / 023146 Brochure [Patent Document 4] International Publication No. 2011 / 045625 Brochure [Patent Document 5] International Publication No. 2015 / 015395 Brochure [Patent Document 6] US Patent No. 8956835 (B2) [Non-patent literature]

[0006] [Non-Patent Document 1] Jiayuan Zhao & Philip K. Hopke, "Concentration of Reactive Oxygen Species (ROS) in Mainstream and Sidestream Cigarette Smoke", Aerosol Science and Technology, 46:191-197, 2012 Summary of the Invention [Problem to be solved by the invention]

[0007] While aerosol-generating articles are capable of reducing the presence in inhaled aerosols of harmful smoke constituents that are typically produced by the combustion and pyrolysis of tobacco in conventional cigarettes, Applicants faced the problem of further improving this capability in order to make current aerosol-generating articles more attractive to consumers wishing to reduce the health risks associated with tobacco smoking.

[0008] The applicant has surprisingly found that at least one element comprising at least one polyhydroxyalkanoic acid (PHA) arranged downstream relative to the aerosol-generating substrate can suppress reactive oxygen species (ROS) inevitably present in the volatile substances generated by heating the aerosol-generating substrate. ROS are known to be toxic to cells and cause oxidative stress. More than 100 diseases are associated with ROS, such as diabetes, inflammatory immune damage, systemic autoimmune diseases, tissue damage due to blood loss and cancer. At least one element comprising at least one PHA is arranged downstream relative to the aerosol-generating substrate such that the volatile substances generated therefrom come into contact with the PHA when the heating element heats the aerosol-generating substrate. In a preferred embodiment, the element comprising the PHA is an aerosol cooling element having a plurality of longitudinally extending tubes. Such an aerosol cooling element may be formed by a pleated sheet of a polymer composition comprising at least one PHA. [Means for solving the problem]

[0009] Thus, according to a first aspect, the present invention relates to an aerosol-generating article comprising an aerosol-generating substrate and at least one element comprising at least one polyhydroxyalkanoic acid (PHA), said at least one element being positioned downstream relative to the aerosol-generating substrate.

[0010] According to a preferred embodiment, the aerosol-generating article comprises: an aerosol-generating substrate; a support element disposed immediately downstream of the aerosol-generating substrate; an aerosol cooling element disposed downstream of the support element; an outer wrapper surrounding the aerosol-generating substrate, the support element, and the aerosol-cooling element; and the aerosol cooling element comprises at least one PHA.

[0011] According to a preferred embodiment, the aerosol cooling element is formed by a sheet of a polymeric composition pleated to define a plurality of longitudinally extending channels, the polymeric composition including at least one PHA.

[0012] According to another preferred embodiment, the aerosol cooling element is formed by a sheet of a polymeric composition pleated to define a plurality of longitudinally extending channels, the sheet being coated with at least one PHA.

[0013] According to another aspect, the present invention relates to a method for suppressing reactive oxygen species (ROS) in an aerosol generated by an aerosol-generating article comprising an aerosol-generating substrate, the method comprising providing the aerosol-generating article with at least one element comprising at least one polyhydroxyalkanoic acid (PHA), the at least one element being positioned downstream relative to the aerosol-generating substrate.

[0014] According to another aspect, the present invention relates to the use of at least one polyhydroxyalkanoate (PHA)-containing element in an aerosol-generating article comprising an aerosol-generating substrate to suppress reactive oxygen species (ROS) in an aerosol generated by the aerosol-generating article, wherein the at least one element is positioned downstream relative to the aerosol-generating substrate.

[0015] As used herein, the term "aerosol-generating substrate" refers to a substrate from which volatile compounds capable of forming an aerosol can be released by heating. The aerosol generated from the aerosol-generating substrate can be visible or invisible and can include vapor, gas and / or condensed vapor droplets.

[0016] As used herein, the terms "upstream" and "downstream" are meant to define the relative position of an element or portion of an element of an aerosol-generating article with respect to the direction in which a user draws on the aerosol-generating article when the article is in use.

[0017] The aerosol-generating article includes two ends, a proximal end through which aerosol is expelled from the aerosol-generating article and delivered to a user, and a distal end, In use, a user can suck on the proximal end to inhale the aerosol generated by the aerosol-generating article.

[0018] As used herein, the term "aerosol cooling element" refers to an element having a large surface area and low draw resistance. In use, the aerosol formed by the volatile compounds released from the aerosol-generating substrate passes through and is cooled by the aerosol cooling element before being inhaled by the user. In contrast to the high resistance of draw filters and other mouthpieces, the aerosol cooling element has a low draw resistance. Chambers and cavities within the aerosol-generating article are also not considered aerosol cooling elements.

[0019] As used herein, the term "aerosol-generating device" refers to a device that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol. Preferably, the aerosol-generating device is a smoking device that interacts with an aerosol-generating substrate of an aerosol-generating article to generate an aerosol that is inhalable directly through the user's mouth into the user's lungs.

[0020] For purposes of this specification and the claims that follow, unless otherwise indicated, all numbers expressing totals, amounts, percentages, and the like, are to be understood in all instances to be modified by the term "about." Moreover, all ranges include any combination of the maximum and minimum points disclosed, and include any intermediate ranges therein, which may or may not be specifically recited herein.

[0021] According to a preferred embodiment, the support element is a hollow tubular element. Preferably, the hollow tubular element is made of fibers bonded together to form the filter element, said fibers comprising at least one PHA. More preferably, said fibers comprise cellulose acetate fibers bonded by at least one PHA surrounding the cellulose acetate fibers.

[0022] According to a preferred embodiment, the aerosol-generating article includes a mouthpiece filter disposed at the most downstream end of the aerosol-generating article. Preferably, the mouthpiece filter is made from fibers bonded to form a filter element, said fibers comprising at least one PHA. Preferably, the mouthpiece filter is made from fibers bonded to form a filter element, said fibers comprising cellulose acetate fibers bonded with at least one PHA surrounding the cellulose acetate fibers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] With respect to the aerosol-forming substrate, the aerosol-forming substrate preferably comprises tobacco, more preferably a gathered sheet of crimped homogenized tobacco material surrounded by a wrapper. Preferably, the crimped sheet of homogenized tobacco material comprises glycerin as an aerosol-forming agent.

[0024] With respect to the PHA used in the present invention, the PHA preferably has formula (I): -O-CHR1-(CH2) n -CO- (I) A polymer comprising the repeat unit Here, R1 is C1-C 12 Alkyl, C4-C 16 Cycloalkyl, C2-C 12 alkenyl, optionally substituted with at least one group selected from halogen (F, Cl, Br), -CN, -OH, -OOH, -OR, -COOR (R = C1-C4 alkyl, benzyl); n is zero or an integer of 1 to 6, and is preferably 1 or 2.

[0025] Preferably, R1 is methyl or ethyl and n is 1 or 2.

[0026] PHAs can be either homopolymers, copolymers or terpolymers. In the case of copolymers or terpolymers, they can consist of at least one repeating unit of formula (I) in combination with different repeating units of formula (I) or at least one repeating unit derived from a comonomer capable of copolymerizing with the hydroxyalkanoic acid, such as a lactone or lactam. In the latter case, the repeating units of formula (I) are present in an amount equal to at least 10% in moles relative to the total number of moles of repeating units.

[0027] Particularly preferred repeat units of formula (I) are those derived from 3-hydroxybutyrate, 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxyundec-10-enoate, 4-hydroxyvalerate.

[0028] Particularly preferred PHAs are polyhydroxybutyrate (PHB), poly-3-hydroxyvalerate (PHV), poly-3-hydroxyhexanoate (PHH), poly-3-hydroxyoctanoate (PHO), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxyoctanoate-co-3-hydroxyundecen-10-enoate) (PHOU), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-4-hydroxyvalerate) (PHBVV), polyhydroxybutyrate-hydroxyvalerate copolymer, or mixtures thereof.

[0029] For purposes of the present invention, particularly preferred PHAs are polyhydroxybutyrate (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV).

[0030] Preferably, the PHA has a weight average molecular weight (M) in the range of 10,000 to 1,000,000 Da. w ).

[0031] For the production of PHA, this is preferably achieved by microbial fermentation of organic substrates (e.g. carbohydrates or other fermentable substrates such as glycerol) via microbial strains capable of producing PHA, and subsequent recovery of PHA from the cell mass. For details, see, for example, US Pat. No. 5,399,633, US Pat. No. 5,499,462 and US Pat. No. 5,499,471. Substrates suitable for the production of PHA by fermentation can be obtained in particular from vegetable processing, for example juices, molasses, pulp, etc. obtained from sugar beet, sugar cane processing. These substrates generally contain, in addition to sucrose and other carbohydrates, organic growth factors, nitrogen, phosphorus, and / or other minerals useful as nutrients for cell growth. An alternative is glycerol, a low-cost organic carbon source that is a by-product of biodiesel production, which can be used, optionally in a mixture with levulinic acid (see, for example, US Pat. No. 5,499,471).

[0032] As noted above, the PHA is preferably included in the aerosol cooling element. This can be accomplished according to two different embodiments.

[0033] In a first embodiment, the aerosol cooling element is formed by a sheet of a polymeric composition pleated to define a plurality of longitudinally extending channels, the polymeric composition including at least one PHA.

[0034] The polymeric composition comprising at least one PHA can be formulated according to known techniques and can comprise 100% by weight of PHA as the polymer base, or preferably a mixture of 60% to 90% by weight of PHA and 10% to 40% by weight of at least one different biodegradable / compostable polymer, such as polylactide (PLA), poly(butylene-co-adipate-co-terephthalate) (PBAT), poly(butylene-co-succinate) (PBS), poly(butylene-co-succinate-co-adipate) (PBSA), polycaprolactone (PCL), and mixtures thereof, the percentages being expressed relative to the total weight of the polymer base.

[0035] The polymer composition may further comprise at least one plasticizer, typically in an amount of 2-15% by weight, based on the total weight of the polymer base. Preferably, the plasticizer may be selected from natural or bio-based plasticizers, such as natural oils (e.g., linseed oil, castor oil, palm oil, flax oil and coconut oil, their hydrogenated and non-hydrogenated derivatives, glycerol and citrate esters, and mixtures thereof).

[0036] Other possible additives of the polymer composition may be, for example, processing aids, fillers (such as kaolin, talc, chalk, silica, montmorillonite and mixtures thereof), primary or secondary antioxidants.

[0037] The sheets can be manufactured according to known techniques, for example, by extruding the polymer composition through a die to form a sheet, followed by collection and winding by a chill roll, which is then pleated and cut to the desired length according to known techniques to form the aerosol cooling elements.

[0038] FIG. 1 shows an image of the pleated sheet taken under an optical microscope.

[0039] In a second embodiment, the aerosol cooling element is formed by a sheet of polymeric material pleated to define a plurality of longitudinally extending channels, the sheet being coated with at least one PHA. In this case, the sheet may be manufactured from any suitable polymer composition, preferably from biodegradable / compostable polymers such as polylactide (PLA), poly(butylene-co-adipate-co-terephthalate) (PBAT), poly(butylene-co-succinate) (PBS), poly(butylene-co-succinate-co-adipate) (PBSA), polycaprolactone (PCL), and mixtures thereof. The pleated sheet is then coated with the PHA. The coating can be carried out by known techniques. Preferably, the coating is carried out by spraying an aqueous suspension of the PHA onto the pleated sheet. The spraying can be carried out on only one side of the pleated sheet, or on both sides. After spraying, the coated pleated sheet is dried, for example, at room temperature or in an oven at a temperature not exceeding 80° C. (eg, 40° C. for 1 hour).

[0040] An image of the surface of a pleated sheet coated with PHB taken with a SEM electron microscope is shown in Figure 2. The white spots and particles in the image are formed by the PHB adhering to the sheet material.

[0041] FIG. 3 is a schematic cross-sectional view of one embodiment of an aerosol-generating article according to the present invention suitable for use with an aerosol generating device.

[0042] In Figure 3, the aerosol-generating article (10) includes four coaxially aligned elements: an aerosol-generating substrate (20), a support element (30), an aerosol cooling element (40), and a mouthpiece filter (50). These four elements are sequentially arranged and surrounded by an outer wrapper (60) to form the aerosol-generating article (10). The aerosol-generating article (10) has a proximal or mouth end (70) that is inserted into the mouth of a user during use, and a distal end (80) that is disposed at the opposite end of the aerosol-generating article (10) relative to the mouth end (70).

[0043] In use, air is drawn by a user through the aerosol-generating article from the distal end (80) to the mouth end (70).

[0044] The aerosol-generating substrate (20) is located at the distal or upstream end of the aerosol-generating article (10). The support element (30) is located immediately downstream of and adjacent to the aerosol-generating substrate (20). In the embodiment shown in FIG. 3, the support element (30) is a hollow tube of cellulose acetate fiber. The support element (30) positions the aerosol-generating substrate (20) at the distal end (80) of the aerosol-generating article (10) and allows it to be penetrated by the heating element of the aerosol-generating device. The support element (30) acts to prevent the aerosol-generating substrate (20) from being pushed downstream within the aerosol-generating article (10) towards the aerosol cooling element (40) when the heating element of the aerosol-generating device is inserted into the aerosol-generating substrate (20). The support element (30) also functions as a spacer to space the aerosol cooling element (40) of the aerosol-generating article 10 from the aerosol-generating substrate (20).

[0045] The aerosol cooling element (40) is disposed immediately downstream of and adjacent to the support element (30). In use, volatile material released from the aerosol-generating substrate (20) passes along the aerosol cooling element (40) toward the mouth end (70) of the aerosol-generating article (10). The volatile material can be cooled within the aerosol cooling element (40) to form an aerosol that is inhaled by a user. In the embodiment shown in FIG. 3, the aerosol cooling element includes a pleated sheet surrounded by a wrapper (90). The pleated sheet defines a plurality of longitudinal channels that extend along the length of the aerosol cooling element (40). The mouthpiece filter (50) is disposed immediately downstream of and adjacent to the aerosol cooling element (40).

[0046] To assemble the aerosol-generating article (10), the four above elements are aligned and tightly wrapped within an outer wrapper (60), which may be conventional cigarette paper.

[0047] As disclosed above, at least one element of the aerosol-generating article (10) arranged downstream relative to the aerosol-generating substrate comprises at least one PHA. With reference to Figure 3, such an element may be the aerosol cooling element (40). Alternatively, it may be the support element (30) and / or the mouthpiece filter (50). Advantageously, the PHA may be included in both the aerosol cooling element (40) and at least one element selected from the support element (30) and the mouthpiece filter (50).

[0048] Further details regarding the construction, manufacture and use of the above-mentioned aerosol-generating articles are reported in US Pat. No. 5,399,623 and US Pat. No. 5,499,633.

[0049] Applicant wishes to emphasize that since PHAs are well known to be biodegradable materials produced from renewable resources, the use of at least one PHA to manufacture at least one element of an aerosol-generating article improves the biodegradability and environmental sustainability of the article.

[0050] With respect to the embodiment in which the PHA is used as a binder for the cellulose acetate fibers to form the filter element, the applicant has found that at least one PHA can be advantageously used as a binder for the cellulose acetate fibers instead of triacetin or other binders commonly used in the art. The PHA can bond the cellulose acetate fibers when applied to the fiber surface, causing the formation of random connection points to maintain the space between the fibers suitable for the proper pressure drop during smoking and to impart the appropriate hardness to the filter element. Furthermore, since the PHA has a relatively high melting point and is substantially insoluble in water, it does not soften or melt when exposed to the warm, moist smoke generated during smoking, preventing the filter element from softening or collapsing during smoking.

[0051] The above filter elements are: immersing a bundle of cellulose acetate fibers in an aqueous suspension of at least one PHA to obtain a wet bundle of cellulose acetate fibers covered with a PHA suspension; forming the wetted bundle into a continuous elongated element; heating the continuous elongated element to a temperature of 140°C to 180°C for a time sufficient to dissolve the PHA and evaporate the water; cooling the heated continuous elongated element to obtain crystals of the PHA; cutting the continuous elongated element thus obtained into segments of predetermined length; The composition can be produced by a process including:

[0052] The following examples are provided to further illustrate the present invention.

[0053] [Example 1] A polymer composition was prepared having the following components: PHB (polyhydroxybutyrate) 60.70% by weight PLA (polylactide) 30.00% by weight Plasticizer 6.00% by weight Processing aids 2.40% by weight Antioxidant 0.90% by weight

[0054] The Mw of PHB was approximately 500 KDa.

[0055] The compositions were prepared in a LabTech LMX5-VS high speed mixer applying speeds ranging from 100 rpm to 900 rpm.

[0056] The composition thus obtained in powder form was extruded in a twin screw extruder (LabTech LTE 16-40) equipped with a metered hopper feeder. The extruded material was formed into a sheet by a chill roll unit (LabTech LBCR-150) connected to the extruder head. The thickness of the sheet was about 150 μm.

[0057] The sheet was cut into strips 11 mm long and 1.8 mm high, each weighing approximately 0.260-0.360 g.

[0058] The strip was pleated by a mechanical tool and subsequently folded and rolled to obtain an aerosol cooling element having the same dimensions as those found in HEETs® cigarettes for I-QOS® (Philip Morris). Such a cigarette (or, more precisely, the aerosol-generating article) has a structure as shown in Figure 3. The aerosol cooling element of the HEETs® cigarette is made from PLA (polylactide).

[0059] [Examples 2 to 3] Aerosol cooling elements found in HEETs® cigarettes made from PLA (polylactide) were extracted, deployed and then sprayed with an aqueous suspension of PHB (Mw: 443 KDa) (Example 2) or poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) (Mw: 700 KDa) (Example 3). The concentration of PHB and PHBV in the aqueous suspension was 10% w / v. The suspension was sprayed onto only one side or both sides of pleated strips of PLA. The sprayed strips were then dried in an oven at 40° C. for 1 hour.

[0060] [Example 4] Determination of ROS (a) Sampling system A computer-controlled Single Cigarette Smoking Machine (SCSM, CH Technologies) was used to generate mainstream smoke under standard smoking conditions (cigarettes were burned for 5 min with a 2-s puff duration, 2-s puff interval, and 65-mL puff volume). An I-QOS (2.4 Plus) "heat-not-burn" device was used to generate e-cigarette vapor. Three impingers were filled with 20 mL of 2´,7´-dichlorofluorescein-horseradish peroxidase (DCFH-HRP) solution and used to collect gas-phase ROS from mainstream smoke.

[0061] The experimental system is shown diagrammatically in Figure 4. Commercially available HEETS® Marlboro® (gold) cigarettes were used to collect ROS from mainstream smoke. In Figure 4, an SCSM (1) is connected to three impingers (2) containing DCFH-HRP solutions, which receive smoke generated by cigarettes (3) connected to the impingers by filter holders (4). Exhaust smoke leaves the SCSM through a pipe (5). The SCSM is connected to a laptop (6) to control the puff duration and puff interval of the cigarette smoking.

[0062] (b) Sample preparation and analysis Preparation of fluorescent probes and standards for ROS in cigarette smoke. The fluorescent probe used to determine ROS in this study was DCFH. A 1 mM stock solution was prepared by dissolving 2´,7´-dichlorofluorescein diacetate (DCFH-DA; Calbiochem, USA) in ethyl alcohol (ACS grade, Pharmo, USA). 10 mL of the solution was mixed with 40 mL of 0.01 M sodium hydroxide (NaOH) and left for 30 min at room temperature in the dark to hydrolyze. Then, 200 mL of phosphate buffer, obtained by mixing disodium hydrogen phosphate (Na2HPO4, Sigma Aldrich, MO, USA) with anhydrous disodium hydrogen phosphate (NaH2PO4, Fluka, Germany) to achieve a pH of 7.2, was added to the solution. Horseradish peroxidase (HRP, Sigma Aldrich, USA) was used as a catalyst at a concentration of 0.5 units / mL. The final DCFH concentration in this working solution was 5 μM.

[0063] Equivalent H2O2 concentrations were used to express ROS concentrations by converting the fluorescence intensity using a standard H2O2 calibration curve. ROS concentrations of 1.0, 2.0, 3.0, and 4.0x10 were obtained by mixing 0.1 mL of hydrogen peroxide (ACS grade, Sigma Aldrich, USA) with 3 mL of DCFH-HRP working solution. -7 Four H2O2 standard samples with concentrations in nmol were prepared. Standard blanks were obtained by mixing 0.1 mL of deionized Milli-Q water (resistivity >18.2 MΩ) with the probe. The standard samples were placed in cuvettes and incubated in a water bath at 37 °C. The formation of 2,7-dichlorofluorescein was monitored by measuring fluorescence (excitation wavelength: 504 nm; emission wavelength: 524 nm) using a Shimadzu spectrophotometer (model: RF-5301 PC, Japan).

[0064] (c) Analysis of reactive oxygen species (ROS) After sampling, 3 mL of reagent solution was removed from each impinger (each containing 20 mL), placed in a cuvette, and incubated in a 37 °C water bath for 15 min. Generally, the fluorescence intensity of the solutions in the impingers was within the standard range. The amount of solution was used to obtain the amount of ROS in each impinger, and then the contents of all three impingers were combined. An aliquot of the solution was removed and the fluorescence intensity was measured. A sampling blank was obtained by operating the smoking system without burning a cigarette and analyzed in the same way. The sampling blank values ​​were subtracted from the sample results.

[0065] Total ROS were also measured from the smoke produced by the commercial cigarettes, as reported in Table 1 .

[0066] For further details regarding ROS analysis, see non-patent literature 1.

[0067] The results are shown in Table 1. Data are averages measured on 12 samples for each type of aerosol cooling element.

[0068] [Table 1]

[0069] The amount of PHA is the amount in each aerosol cooling element according to the present invention.

[0070] The above data demonstrates the significant effect of ROS suppression in aerosols generated by aerosol-generating articles according to the present invention that include PHA.

[0071] Without being bound by any theory, the positive effect of contacting the generated aerosol with PHA in suppressing ROS is mainly due to the monomer unit -O-CHR1-(CH2) nThis is believed to be due to the -CO- structure. Hydrogen attached to the tertiary carbon atom -CHR1- specifically reacts with the formation of hydrogen radicals that inhibit ROS by inactivating them via radical reactions.

Claims

1. an aerosol-generating substrate; a support element disposed immediately downstream of the aerosol-generating substrate; an aerosol cooling element disposed downstream of the support element; an outer wrapper surrounding the aerosol-generating substrate, the support element, and the aerosol-cooling element; the aerosol cooling element is formed by a sheet of a polymeric composition pleated to define a plurality of longitudinally extending channels; The aerosol-generating article, wherein the sheet is coated with at least one polyhydroxyalkanoic acid (PHA).

2. 2. The aerosol-generating article of claim 1, wherein the support element is a hollow tubular element made from fibers bonded together to form a filter element.

3. The aerosol-generating article of claim 2 , wherein the fibers comprise at least one PHA.

4. 3. The aerosol-generating article of claim 2, wherein the fibers comprise cellulose acetate fibers bonded by at least one PHA that surrounds the cellulose acetate fibers.

5. 2. The aerosol-generating article of claim 1, comprising a mouthpiece filter disposed at a downstream-most end of the aerosol-generating article, the mouthpiece filter being made from fibers bonded together to form a filter element, the fibers comprising at least one PHA.

6. 2. The aerosol-generating article of claim 1, comprising a mouthpiece filter disposed at a downstream-most end of the aerosol-generating article, the mouthpiece filter being made from fibers bonded together to form a filter element, the fibers being cellulose acetate fibers bonded together by at least one PHA that surrounds the cellulose acetate fibers.

7. 10. The aerosol-generating article of claim 1, wherein the aerosol-generating substrate comprises a gathered sheet of crimped and homogenized tobacco material surrounded by a wrapper.

8. The aerosol-generating article of claim 7, wherein the tobacco material contains glycerin as an aerosol forming agent.

9. The PHA has the formula (I): -O-CHR １ -(CH ２ ) ｎ -CO- (I) Here, R １ is C １ -C １２ Alkyl, C ４ -C １６ Cycloalkyl, C ２ -C １２ alkenyl, 2. An aerosol-generating article according to claim 1, which is a polymer comprising repeat units of formula (I), where n is zero or an integer from 1 to 6, preferably 1 or 2.

10. The aerosol-generating article of claim 9, wherein in formula (I), R 1 is substituted with at least one group selected from halogen (F, Cl, Br), -CN, -OH, -OOH, -OR, -COOR (R=C 1 -C 4 alkyl, benzyl).

11. 10. The aerosol-generating article of claim 9, wherein the PHA is selected from polyhydroxybutyrate (PHB), poly-3-hydroxyvalerate (PHV), poly-3-hydroxyhexanoate (PHH), poly-3-hydroxyoctanoate (PHO), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxyoctanoate-co-3-hydroxyundecen-10-enoate) (PHOU), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-4-hydroxyvalerate) (PHBVV), polyhydroxybutyrate-hydroxyvalerate copolymers, or mixtures thereof.

12. The PHA has a weight average molecular weight (M ｗ 2. The aerosol-generating article of claim 1, comprising:

13. A method for suppressing reactive oxygen species (ROS) in an aerosol generated by an aerosol-generating article comprising an aerosol-generating substrate, a support element positioned immediately downstream of the aerosol-generating substrate, the aerosol cooling element positioned downstream of the support element, and an outer wrapper surrounding the aerosol-generating substrate, the support element and the aerosol cooling element, using an aerosol cooling element formed by a sheet of a polymeric composition pleated to define a plurality of longitudinally extending channels, the method comprising providing on the aerosol-generating article at least one element comprising at least one polyhydroxyalkanoic acid (PHA), the at least one element being positioned downstream relative to the aerosol-generating substrate, the sheet being coated with the at least one PHA.

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