Use of polylysine dendrimers in the prevention and management of acne-prone and acneic skin - Patent Application 20070233633

Abstract

The present invention relates to the use of polylysine dendrimers or salts thereof for managing breakouts or acne-prone skin, or for treating or preventing acne vulgaris. The polylysine dendrimers are used as active agents for restoring or rebalancing the skin's microflora. The polylysine dendrimers are also used as active agents for improving or restoring the appearance and feel of the treated skin.

Description

[Technical field]

[0001] Acne vulgaris, also known simply as acne, is a common chronic inflammatory disease of the sebum-producing glands (sebaceous follicles). Acne results in the formation of inflamed bumps (papules, pustules, nodules and cysts), comedones (blackheads and whiteheads), and scarring of the skin. Acne is one of the most common disorders treated by dermatologists and other health care professionals. Over 90% of the world's population suffers from acne at some point in their lives. The pathogenesis of acne is multifactorial and includes four key factors with interrelated mechanisms: increased sebum production, hyperkeratosis, skin inflammation, and proliferation of Cutibacterium acnes. Cutibacterium acnes (formerly Propionibacterium acnes) is omnipresent in human sebaceous follicles of the skin, mostly on the face and back. C. acnes is a widespread member of the normal skin microbiota and plays an important role in maintaining the normal skin microbiota by inhibiting the development of some pathogenic bacteria, such as Staphylococcus aureus, and by maintaining an acidic pH in the pilosebaceous follicles. Although C. acnes is commensal, it is generally believed to be involved in the pathogenesis of acne by promoting inflammation. Indeed, several studies have shown that in the skin, C. acnes activates innate immunity through Toll-like receptors expressed by monocytes and keratinocytes, increasing the secretion of interleukins. Additionally, C. acnes has been shown to be associated with opportunistic infections, especially in the context of indwelling medical devices. Its dual role in the balance of the skin microbiota, acne inflammatory conditions and opportunistic infections has led to the hypothesis that certain strains of C. acnes are characterized by enhanced pathogenic and inflammatory potential.

[0002] Phylogenetic studies have provided valuable insights into the genetic population structure of C. acnes. It has been shown that C. acnes has an overall clonal structure and that its isolates can be divided into several statistically significant clades or phylogroups, designated types IA1, IA2, IB, IC, II and III. These phylogroups have been shown to show differences in their association with specific types of infection and vary in their production of putative virulence determinants, inflammatory potential, antibiotic resistance, invasive properties and morphological characteristics. C. acnes phylotypes IA1, IA2, IB, IC have been identified as acne strains, while phylotypes II and III have been classified as non-acne strains. Phylotype IA1 has been shown to be the most abundant strain in acne strains, while phylotypes II and III are predominantly present in healthy non-acne skin.

[0003] Indeed, several independent epidemiological studies have shown a correlation between clonal complexes derived from the type IA1 phylogroup and moderate to severe acne (Scholz et al., PlosOne, 2014, e104199, Barnard et al. Journal of Clinical Microbiology, 2015, 53, 1149-1155). Recently, Dagnelie et al. (Acta Derm Venereol, 2018; 98:262-267) determined the various phylotypes, clonal complex (CC) and single locus sequence typing (SLST) types in patients with severe acne and compared them to healthy patients. Dagnelie et al. showed that healthy patients had phylotypes IA1 (39.1%) and II (43.4%), while the acne group had a much higher prevalence of IA1 (84.4%), especially on the back (95.6%). The IA1 SLST type was significantly associated with severe acne. Of note, Dagnelie et al. reported that severe inflammatory acne on both the face and back was associated with a significant loss of C. acnes diversity population. Since the microbiota modulates the innate immunity of the skin, it is conceivable that such a loss of diversity could trigger inflammation and promote inflammatory acne lesions. In a very recent publication, Dagnelie et al. presented evidence that loss of diversity of C. acnes subpopulations on the skin (sin) surface triggers activation of the innate immune system, i.e., the development of skin inflammation (Dagnelie et al., JEADV, 2019; 33:2340-2348).

[0004] At present, there are several treatment strategies to manage acne, depending on the severity of the acne. The treatments are essentially based on two types of active ingredients: topical retinoids, which exert anti-inflammatory effects, normalize skin desquamation, and exert a comedolytic action, and antibiotics and bactericides, such as benzoyl peroxide, which are used to reduce the overall abundance of C. acnes on the skin surface. Treatments for moderate and severe acne generally combine topical combination therapy with benzyl peroxide and retinoids or antibiotics. Oral treatments with antibiotics and isotretinoin can also be prescribed. In women, combination oral pills can also be prescribed. Unfortunately, these treatments also have some drawbacks, such as skin irritation, dermatitis, or photosensitivity. The use of antibiotics is also controversial due to antibiotic resistance problems and may lead to imbalance of the microflora. However, none of these treatments aim to rebalance the skin microbiota to favor non-acnegenic C. acnes strains over acnegenic C. acnes strains. Therefore, there is a need for alternative methods of managing acne-prone skin as well as acne-prone and breakout-prone skin. Summary of the Invention

[0005] The present invention relates to the cosmetic non-therapeutic use of polylysine dendrimers or salts thereof as active ingredients in the management of acne-prone and breakout-prone skin.The present invention also relates to the use of polylysine dendrimers or salts thereof as active ingredients for treating or preventing acne vulgaris. In some embodiments, polylysine dendrimer or its salt is used as an active ingredient for restoring or rebalancing skin microbiota, preferably for restoring the diversity of C. acnes in skin.For example, polylysine dendrimer or its salt can be used as an active ingredient for reducing the abundance of acnegenic C. acnes strains in skin, preferably C. acnes strains belonging to phylotypes IA1, IA2, IB and IC, more preferably phylotype IA1.Alternatively or additionally, polylysine dendrimer or its salt can be used for increasing the abundance of non-acnegenic C. acnes strains in skin, preferably C. acnes strains belonging to phylotypes II or III, preferably C. acnes strains belonging to phylotype II.

[0006] In some embodiments, the polylysine dendrimer or salt thereof is used as an active ingredient in acne-prone, acne-prone or breakout-prone skin, as follows: - Improve the appearance and feel of the skin, and / or - Restoring skin comfort, and / or - Preventing, improving or treating breakouts; and / or - Anti-inflammatory effect on the skin, and / or - Reducing or preventing skin redness or skin irritation, and / or - Decreased sebum production, and / or - Reduction in visible lesions such as comedones, pustules and papules, and / or - Improves skin desquamation Used for. In some embodiments, the polylysine dendrimer is a second generation non-conjugated poly-L-lysine dendrigraft with a DPn of 40-60, such as 48, preferably 46-50. In some other embodiments, the polylysine dendrimer is a poly-L-lysine dendrigraft having a linear poly-L-lysine core in which the ε-amino groups are substituted by poly-L-lysine moieties, e.g., the linear poly-L-lysine core contains 6 to 10, preferably 8, lysine residues in length and / or the poly-L-lysine moieties grafted onto the ε-amino groups have a length of 2 to 6, preferably 5, lysine residues.

[0007] In some further embodiments, the polylysine dendrimer is in the form of a polycationic dendrimer, in which the counter anion is an acetate anion. An example of such a dendrimer is provided in FIG. The polylysine dendrimers can be present as active ingredients in non-medical, cosmetic or dermocosmetic compositions. Examples of cosmetic compositions of interest include soothing creams, exfoliating products, daily cream or gel products, clarifying toners or lotions, purifying cleansers, breakout creams or sticks, and concealer sticks or creams. In some embodiments, the polylysine dendrimers can be used in combination with an active ingredient selected from vitamin A, retinoids (such as adapalene, tretinoin or tazarotene), bactericides (benzoyl peroxide and decanediol), azelaic acid, salicylic acid, anti-inflammatory agents (such as dapsone or Melaleuca alternifolia (tea tree) oil), anti-redness agents, anti-inflammatory agents and combinations thereof.

[0008] The present invention also relates to a topical composition for use in managing acne-prone, acne-prone or breakout-prone skin, comprising a polylysine dendrimer as an active ingredient and one or more excipients. - 0.1 to 100 ppm of a polylysine dendrimer, preferably as defined in any one of claims 7 to 10, - 0% to 20% of one or more additional active agents, and - 70% to 99.9999% of one or more excipients may include The percentages are expressed by weight relative to the total weight of the composition. A further object of the present invention is a method for treating or preventing acne in a subject, comprising topically administering to said subject an effective amount of a polylysine dendrimer or a composition thereof. The present invention also relates to a method for restoring or rebalancing the microbiota in acne-prone, breakout-prone or acne-prone skin, comprising topically administering to said subject an effective amount of a polylysine dendrimer or a composition thereof.

[0009] The present invention further relates to a method of improving the appearance and feel of skin, and / or restoring skin comfort, and / or preventing, ameliorating or treating breakouts and / or acne lesions, and / or soothing the skin, and / or reducing the appearance of pores (and thus smoothing the skin), and / or reducing or preventing redness and / or skin inflammation, and / or reducing sebum production, and / or making the skin less shiny and / or oily in appearance, and / or improving the skin in a subject having acne, breakout-prone or acne-prone skin, comprising the step of topically administering to said subject an effective amount of a polylysine dendrimer or a composition thereof. The present invention also relates to the use of a polylysine dendrimer, preferably a poly-L-lysine dendrimer, in the manufacture of a topical composition for managing or treating the above-mentioned acne-prone, breakout-prone or acne-prone skin. [Brief description of the drawings]

[0010] [Figure 1] Figure 1 shows the anti-inflammatory effect of the G2 dendrimer according to the invention in normal human dermal fibroblasts. The cells were treated with 0.0003ng / mL IL-α in the presence of hydrocortisone (0.05μg / mL) or G2 dendrimer (10-9M, 10-8M, 10-7M or 10-6M) and the amount of IL-8 produced was determined by IL-8 ELISA assay. *p<0.05, **p<0.01, ***p<0.001. [Diagram 2] FIG. 1 is a schematic diagram showing the schedule of product application in the ex vivo model of acne vulgaris used in Example 5. G2 dendrimer was applied at 2 ppm or 5 ppm on DO, D1, D4 and D6, followed by C. acnes (1 h). [Diagram 3] Figure 1 shows the effect of G2 dendrimer on TRL2 expression in human skin explants inoculated with C. acnes. Explants without treatment with C. acnes or G2 were used as controls. [Figure 4]1 shows the effect of G2 dendrimer on membrane fluidity of C. acnes strains (RT4 and RT5) and a non-acne strain of C. acnes (RT6). G2 dendrimer specifically and significantly increases membrane fluidity in acne strains. [Figure 5A] FIG. 5 shows the results of a clinical study aimed at evaluating the effect of treatment with a test cream containing G2 dendrimer (G2) compared to a placebo cream (Placebo) on the number of inflammatory lesions (i.e., pustules and papules) (FIG. 5A), retention lesions (i.e., blackheads and whiteheads) (FIG. 5B) and blackheads, as well as the sebum excretion rate (FIG. 5C) after 28 days of treatment. [Figure 5B] FIG. 5 shows the results of a clinical study aimed at evaluating the effect of treatment with a test cream containing G2 dendrimer (G2) compared to a placebo cream (Placebo) on the number of inflammatory lesions (i.e., pustules and papules) (FIG. 5A), retention lesions (i.e., blackheads and whiteheads) (FIG. 5B) and blackheads, as well as the sebum excretion rate (FIG. 5C) after 28 days of treatment. [Figure 5C] FIG. 5 shows the results of a clinical study aimed at evaluating the effect of treatment with a test cream containing G2 dendrimer (G2) compared to a placebo cream (Placebo) on the number of inflammatory lesions (i.e., pustules and papules) (FIG. 5A), retention lesions (i.e., blackheads and whiteheads) (FIG. 5B) and blackheads, as well as the sebum excretion rate (FIG. 5C) after 28 days of treatment. [Figure 5D] FIG. 5 shows the results of a clinical study aimed at evaluating the effect of treatment with a test cream containing G2 dendrimer (G2) compared to a placebo cream (Placebo) on the number of inflammatory lesions (i.e., pustules and papules) (FIG. 5A), retention lesions (i.e., blackheads and whiteheads) (FIG. 5B) and blackheads, as well as the sebum excretion rate (FIG. 5C) after 28 days of treatment. [Figure 5E] 1 shows the diversity of C. acnes strains after 28 days of treatment using the Simpson and Shannon indices, respectively. The clinical trial protocol and results are detailed in Example 8. [Figure 5F] 1 shows the diversity of C. acnes strains after 28 days of treatment using the Simpson and Shannon indices, respectively. The clinical trial protocol and results are detailed in Example 8. [Figure 6A] Figure 1 shows the effect of dendrimers of the present invention on biofilms formed by non-acne strain RT6 and from acne strain RT5. G2 dendrimer reduces the thickness of biofilms of both strains. It is noteworthy that G2 dendrimer significantly reduces the biomass density in biofilms formed by RT5 strain, while it has no significant effect on the biomass density of biofilms formed by RT6 strain. [Figure 6B] Figure 1 shows the effect of dendrimers of the present invention on biofilms formed by non-acne strain RT6 and from acne strain RT5. G2 dendrimer reduces the thickness of biofilms of both strains. It is noteworthy that G2 dendrimer significantly reduces the biomass density in biofilms formed by RT5 strain, while it has no significant effect on the biomass density of biofilms formed by RT6 strain. [Figure 7] FIG. 1 shows examples of polylysine dendrimers of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The applicant has shown that a "dendritic" polymer of lysine residues, referred to herein as "G2 dendrimer", exhibits antibacterial activity against acne-causing C. acnes strains belonging to phylotype IA1 with an MIC of 20 ppm. Furthermore, the G2 dendrimer modulates keratolysis and reduces immune and inflammatory cascades known to be associated with P. acnes colonization. The applicant has further shown that this poly-L-lysine dendrimer can specifically target acne strains of C. acnes. Of note, Example 6 shows that the G2 dendrimer significantly increases membrane fluidity in acne-causing ribotypes belonging to phylotype IA1 (RT4 and RT5), while having no significant effect on the non-acne-causing ribotype RT6 belonging to phylotype II. In other words, this result suggests that G2 dendrimer can specifically destabilize the cell membrane of acne strains, thus inhibiting the growth of acne strains without damaging non-acnegenic C. acnes strains.Otherwise, Example 7 shows that G2 dendrimer significantly reduces the biomass density in the biofilm formed by acne strain RT5, while it has no significant effect on the biomass density in the biofilm formed by non-acnegenic RT6 strain.Therefore, it is expected that polylysine dendrimer exerts selective and specific inhibitory effect on acne strains by destabilizing the biofilm of acne strains, and at the same time, reduces the inflammatory response triggered by C. acnes biofilm by reducing the thickness of biofilm, regardless of the strain.

[0012] The efficacy of the G2 dendrimer of the present invention for managing blemishes and lesions and improving the skin microbiome in acne-prone skin has been clinically confirmed. The applicant has shown that a 28-day treatment with a cream containing G2 dendrimer at a low concentration (2 ppm) significantly improves the appearance of the skin, especially by reducing the number of acne breakouts and lesions, such as papules, pustules, blackheads and retention lesions, when compared with treatment with a placebo cream. The G2-containing cream was further able to reduce the sebum secretion rate of the skin. Of note, genomic analysis performed on facial samples showed that the G2 dendrimer-containing composition improves the skin microbiome by increasing the diversity of C. acnes strains. The abundance of phylotype IA1 strains, identified in the literature as acne-promoting strains, was reduced, while the abundance of non-acne-prone phylotype II strains was increased in samples derived from skin treated with G2-containing composition. In other words, polylysine dendrimers have been shown to be agents capable of rebalancing the diversity of C. acnes in acneic skin.

[0013] Taken together, these results demonstrate that polylysine dendrimers are effective active agents for managing breakouts and restoring the skin microbiota in acne and acne-prone and breakout-prone skin. The present invention therefore relates to the use of polylysine dendrimers, preferably poly-L-lysine dendrimers, as active agents in the management of acne-prone, acne-prone and breakout-prone skin. The present invention also relates to the use of polylysine dendrimers as active agents in the prevention or treatment of acne vulgaris and / or in the management of breakouts and skin lesions associated with acne vulgaris.

[0014] The present invention also provides a method for treating acne vulgaris, comprising administering to a subject having a skin type selected from acne skin, acne-prone skin and pimple-acne skin, the method comprising administering to said subject a therapeutically effective amount of: - To improve the appearance and feel of the skin; and / or - to restore skin comfort and / or - To prevent, improve or treat acne breakouts; and / or - for preventing, ameliorating or treating acne lesions; and / or - for anti-inflammatory purposes on the skin and / or - To reduce the visibility of pores and / or - To reduce or prevent skin redness or skin irritation; and / or - to reduce sebum production and / or make the skin less shiny and / or oily in appearance; - To reduce visible lesions: blackheads, pustules and papules, and / or - To improve skin desquamation (e.g. by exerting a keratolytic effect) The present invention relates to the use of polylysine dendrimers, preferably poly-L-lysine dendrimers, as active agents.

[0015] The present invention also relates to the use of polylysine dendrimers, preferably poly-L-lysine dendrimers, to restore or rebalance the microbiota in acne skin, acne-prone skin or breakout-prone skin. More precisely, the polylysine dendrimers of the present invention are used as medicaments to reduce the abundance of acnegenic C. acnes strains in skin, preferably acne and acne-prone skin. In another or additional embodiment, the polylysine dendrimers of the present invention are for increasing the abundance of non-acnegenic C. acnes in skin, preferably acne or acne-prone skin. The present invention also relates to the use of polylysine dendrimers to prevent or reduce the colonization of skin by acnegenic C. acnes strains. The present invention further relates to the use of polylysine dendrimers to increase the diversity of C. acnes in acne or acne-prone skin, for example by reducing the abundance of C. acnes phylotype IA1, while allowing the abundance of C. acnes phylotype II or III to be increased.

[0016] In a more general aspect, the present invention relates to the use of polylysine dendrimers, preferably poly-L-lysine dendrimers, as active agents to restore the balance of the skin microflora, in particular in acne or acne-prone skin. In a further aspect, the present invention relates to the use of polylysine dendrimers, preferably poly-L-lysine dendrimers, to prevent or treat skin structural abnormalities associated with an imbalance in the C. acnes population. The present invention also relates to the use of polylysine dendrimers, preferably poly-L-lysine dendrimers, as active agents for maintaining or restoring skin microbiota homeostasis, especially in subjects with acne-prone, acne-prone or breakout-prone skin. A further aspect of the present invention relates to a method of managing a skin type selected from acne-prone skin, acne-prone skin and breakout-prone skin in a subject, comprising topically administering to said subject an effective amount of a polylysine dendrimer. Such a method can improve the appearance of the skin in a subject, for example, by treating, reducing and / or delaying the onset of skin breakouts and skin lesions in the subject.

[0017] The present invention also relates to a method for treating or preventing acne in a subject, comprising topically administering to said subject an effective amount of polylysine dendrimer. Another object of the present invention is a method for improving the appearance and feel of skin, and / or restoring skin comfort, and / or preventing, improving or treating acne and / or acne lesions, and / or soothing the skin, and / or reducing the appearance of pores (and thus smoothing the skin), and / or reducing or preventing skin redness and / or skin inflammation, and / or reducing sebum secretion, and / or making the skin less shiny and / or oily in appearance, and / or improving the skin, in a subject with acne, acne-prone skin or acne-prone skin, comprising topically administering to said subject an effective amount of polylysine dendrimer. The present invention further relates to a method for restoring or rebalancing the microbiota in acne skin or acne-prone skin, comprising topically administering to said subject an effective amount of polylysine dendrimer.

[0018] The present invention also relates to the use of a polylysine dendrimer, preferably a poly-L-lysine dendrimer, in the manufacture of a topical composition for managing or treating the above-mentioned acne-prone, breakout-prone or acne-prone skin. The present invention also provides topical compositions and methods for treating acne vulgaris, reducing inflammatory responses in the skin, and promoting desquamation of the skin using polylysine dendrimers, such as G2 dendrimers and / or salts thereof. For example, the present invention relates to a method for reducing inflammatory responses in the skin, comprising the step of applying a composition comprising a polylysine dendrimer, such as a non-conjugated poly-L-lysine dendrigraft, or a salt thereof, to the skin of a subject in need of treatment, thereby reducing an inflammatory response in the skin of the subject, the inflammatory response comprising IL-8 release or TLR2 overexpression in response to Cutibacterium acnes. The present invention further relates to a method for promoting desquamation of skin cells, comprising the step of applying a composition comprising a polylysine dendrimer, such as a non-conjugated poly-L-lysine dendrigraft, or a salt thereof, to the skin of a subject in need of treatment, thereby promoting desquamation of the skin cells of the subject.

[0019] The polylysine dendrimers according to the invention can be formulated as active ingredients in topical compositions, typically pharmaceutical, cosmetic or dermocosmetic compositions. Typically, the polylysine dendrimer is present in the topical composition at a concentration of 0.1 ppm to 100 ppm, preferably 0.1 ppm to 20 ppm, more preferably 0.5 to 7 ppm, such as 0.5 to 10 ppm, such as 0.5 to 6 ppm. The concentration of the polylysine dendrimer in the topical composition and the frequency of application of said topical composition may depend on the skin being treated and / or the stage of treatment. For example, to treat acne-prone skin, breakout-prone skin and skin with mild acne, a concentration of less than 4 ppm, such as 2 ppm, for once-a-day application may be sufficient. When treating skin with moderate or severe acne, higher concentrations of the polylysine dendrimer may be used (e.g., 4 to 10 ppm, such as 4 ppm or 6 ppm) for twice-a-day application during the initial treatment. The dosage and frequency of application can be reduced once acne-related skin lesions are under control and maintenance treatment can be performed for several weeks. Polylysine dendrimers are usually used by topical route, for example, applied to the skin area to be treated, for example, to the skin area affected by acne or the skin area with acne-prone or breakout-prone profile.Usually, the skin area to be treated may show one or some of the following skin breakouts and / or skin lesions and / or oily appearance (for example, due to excess sebum production).Target skin area includes, but is not limited to, face, neck, chest, shoulders and back.

[0020] The frequency of treatment can vary and depends on the type of skin of the subject and / or the severity of acne, if any.Generally, polylysine dendrimer is applied to the treated skin once a day or twice a day.Treatment with polylysine dendrimer can continue for several consecutive days, for example, 7-28 days, or for several months (at least 2, 3, 4, 6, 8 or 10 months). At least since the polylysine dendrimers promote a rebalance of the skin microbiota by specifically targeting acne strains of C. acnes, extended treatment with the polylysine dendrimers of the invention, especially at concentrations below 10 ppm, is expected to be well tolerated by patients with no significant side effects such as skin irritation. The benefit exerted by the dendrimers may be therapeutic, prophylactic and / or cosmetic, depending on the skin type and method of application. For example, the use of the polylysine dendrimers of the present invention may be of cosmetic, non-therapeutic use when applied to pimple-acne affected skin.

[0021] The subject can be either a subject suffering from acne or a subject having acne-prone or breakout-prone skin. In some embodiments, the subject is a teenager between the ages of 10-18, preferably between the ages of 12-16. In some embodiments, the subject suffers from acne and is greater than 23 years of age. In another embodiment, the subject is either a female or male over the age of 23. In some embodiments, the subject has acne-prone skin. In some further embodiments, the subject is suffering from mild acne, moderate acne or severe acne, preferably moderate or severe acne. In a further embodiment, the subject has breakout-prone skin. As used herein, "breakout-prone skin" refers to a skin type in which the skin has a tendency to develop some comedones and acne, e.g., blackheads and whiteheads, without any inflammatory lesions such as papules and pustules. "Pimple-prone skin" can be characterized by an oily and shiny appearance due to the sebaceous glands producing more sebum than other skin types. This increase in sebum production commonly occurs during puberty, when there is an increase in the production of hormone substances called androgens, which in turn stimulates the sebaceous glands to produce more sebum than necessary. Certain hormone treatments can also trigger the skin to produce too much sebum. This seborrhea, in itself, can also interfere with normal skin shedding, leading to skin breakouts. In some embodiments, subjects with acne-prone skin do not have a history of acne, especially severe or moderate acne.

[0022] As used herein, "acne-prone skin" refers to the type of skin that has a tendency to develop some comedones and pimples, and also some very slight inflammatory lesions (usually papules).In some embodiments, the subject with acne-prone skin refers to the subject with a personal history of acne, i.e., the subject who has already suffered at least one acne episode, or the subject with a family history of acne, i.e., the subject who has at least one family member (mother, father or sister / brother) who suffered from moderate or severe acne. "Acne-prone skin" or "breakout-prone skin" in the narrow sense does not refer to skin that is affected by a skin disorder but that may progress to acne if not properly managed.

[0023] As used herein, "acneous skin", also referred to herein as "acne skin", refers to skin affected by acne (also referred to as acne vulgaris). Acne is a non-contagious inflammatory skin disorder involving the pilosebaceous structures and is characterized by acne caused by inflammation and infection of the sebaceous glands. The disease is most common during adolescence, but symptoms can continue into adulthood, with some people, especially women, experiencing symptoms for the first time after age 25. Persistent or delayed-onset acne is known as acne tarda. Acne usually appears on the face, neck, shoulders, chest and back. Acne ranges in severity from mild acne (Acne Comedonica), through moderate acne (Acne Papulopustulosa), to severe acne (Acne Conglobata). Mild acne is characterized by the presence of multiple blackheads, whiteheads, and occasionally few papules. Moderate acne is characterized by the presence of comedones, papules, and pustules. The skin may appear red and inflamed. Finally, severe acne is a less common form of acne characterized by multiple inflamed breakouts, including papules and pustules that may cluster together to form nodules and cysts. The pathogenesis of acne is multifactorial and includes four key factors with interrelated mechanisms: increased sebum production, hyperkeratosis, skin inflammation, and proliferation of Cutibacterium acnes.

[0024] As used herein, "pimple" refers to a skin imperfection such as redness, pimples, or comedones, e.g., that may be observed in pimple-prone skin (or acne-prone skin), typically storage lesions such as blackheads, whiteheads, and other acne. As used herein, "acne lesions" refers to inflamed inflammatory lesions associated with acne, such as papules, pustules, cysts and nodules, observed in moderate and severe acne. As used herein, acne strains refer to C. acnes strains that are statistically more abundant in acneic skin than in healthy skin. C. acnes is subclassified into six major phylotypes, namely IA1, IA2, 1B, IC, II and III (Dagnelie et al., 2018, supra). In skin, bacteria belonging to phylotype IA1, such as RT4 and RT5 ribotypes, predominate in acneic skin. Acne strains encompass phylotypes IA1, 1A2, 1B and IC, preferably IA1 and IA2, more preferably IA1, such as ribotype I (RT1), ribotype 4 (RT4) and ribotype 5 (RT5).

[0025] Non-acne strains refer to C. acnes strains that are statistically more abundant in healthy skin than in acneic skin. Such strains include phylotypes II and III, such as ribotype RT6. For further details regarding the C. acnes phylotype, clonal complex and single locus sequences, see Dagnelie et al. (supra) and Scholz et al., 2016. In some embodiments, treatment with the polylysine dendrimers of the invention reduces the abundance of C. acnes phylotype I strains in the total population of C. acnes present on the skin surface of a subject, hi some other embodiments, treatment with the polylysine dendrimers of the invention increases the abundance of C. acnes phylotype II or III strains, preferably phylotype II, in the total population of C. acnes present on the skin surface of a subject. As used herein, the term "skin microbiota", "skin microbiome" or "skin microbiota" refers to the microorganisms that reside on the skin, usually on the surface of human skin, and include bacterial, mycobacterial, fungal and parasitic bacteria. Most are found in the superficial layers of the epidermis and on top of hair follicles. Skin microbiota is usually non-pathogenic and either commensal or mutualistic. The benefits that such microorganisms may provide include preventing transient pathogenic organisms from colonizing the skin surface, either by competing for nutrients, secreting chemicals in response to nutrients, or stimulating the skin's immune system.

[0026] "Restoring or rebalancing" the skin microbiome means restoring microbial diversity to obtain a balanced microbial distribution that promotes skin health and / or corresponds to healthy skin. In the context of the present invention, "restoring or rebalancing the microbiome" or "restoring or rebalancing C. acnes distribution" in breakout-prone, acne-prone or acneic skin means reducing the abundance of acne-causing C. acnes strains on the skin surface. In some embodiments, it also encompasses promoting non-acne strains on the skin surface, for example, by increasing the abundance of non-acne strains. In some further embodiments, "restoring or rebalancing C. acnes distribution" means that the polylysine dendrimers of the present invention are capable of promoting C. acnes diversity while simultaneously regulating the biomass density of C. acnes on the surface of the treated skin area to obtain a C. acnes population of the microbiome of healthy skin, for example, a C. acnes population close to or similar to the C. acnes population of a healthy skin area in a subject. It can also be included that the applied composition or active ingredient does not exert a significant lethal effect on non-pathogenic commensal strains, particularly non-pathogenic commensal strains of C. acnes.

[0027] The term "reducing the abundance of acne strains" means reducing the amount / proportion of bacteria belonging to acne-causing C. acnes strains relative to the total amount of C. acnes bacteria present in a given area of ​​the subject's skin, e.g., on the subject's facial area. The phrase "increased abundance of non-acne strains" means an increase in the amount / proportion of bacteria belonging to non-acne causing C. acnes strains compared to the total amount of C. acnes bacteria present in a given area of ​​a subject's skin, e.g., on the subject's facial area. A significant increase / decrease in the abundance / proportion of a strain refers to a change of at least 0.1%, such as at least 1%, 2%, 3%, 5%, 10%, 15%, 20%, 25%, 30%, 35% or 45% of its abundance determined before treatment. The abundance of C. acnes strains can be determined by metagenomics performed on swabs from skin aera of interest, as shown in Example 8.

[0028] As used herein, "increasing microbiome diversity" means increasing the number of different strains present on the skin surface. More precisely, "increasing diversity with respect to C. acnes" means increasing the number and / or abundance of non-acnegenic strains on the skin surface. As used herein, "managing acne-prone or breakout-prone skin" means that the visual appearance of acne-prone or breakout-prone skin is improved, e.g., the skin has a less oily appearance and / or shows fewer or reduced breakouts and acne, and / or breakouts are less visible and / or the skin is less prone to showing breakouts due to treatment of the present invention. The expression "prevent" is intended to mean delaying or preventing the onset of the disorder of interest, such as a pimple, acne lesion or acne. The expression "treating a condition" is intended to mean reducing, reducing, relieving, correcting, or slowing the onset of the condition of interest, or its associated symptoms, such as acne and related breakouts or lesions.

[0029] As used herein, a "dendrimer" is a highly branched macromolecular compound formed by repeated sequential reactions starting from an initial core molecule with successive layers or steps added in successive "generations" to build a three-dimensional highly regular polymeric compound. The preparation of dendrimers has been described in the art (see, for example, US 4,289,872 and US 4,410,688, which describe dendrimers based on layers of lysine units). The dendrimers of the present invention are polylysine dendrimers, more preferably poly-L-lysine dendrimers such as poly-L-lysine dendrigrafts.

[0030] As with conventional dendrimers, the preparation of grafted dendrimers (also referred to herein as dendrigrafts) in a generation-based scheme can be achieved by a protecting group manipulation coupled with a polymerization step, i.e., a cycle of protection, monomer polymerization, and deprotection (the so-called "grafting from" method; Klok & Rodriguez Hernandez (2002) Macromolecules 35:8718-23), or a cycle of protection, condensation, and deprotection to form the AB nThis includes either by using preformed polymers instead of molecular compounds as building blocks (the so-called "grafting onto" method; Teertstra & Gauthier (2004) Prog. Polym. Sci. 29:277-327). Because G2 dendrimers are no longer monomolecular compounds, dendrigraft polymers do not have as controlled a structure as conventional dendrimers (e.g., as described in US 4,289,872), but they usually have a more ordered structure compared to hyperbranched polymers (e.g., as described in Rodriguez-Hernandez, et al. (2003) Biomacromolecules 4:249-258 and Klok, et al. (2002) Macromolecules 35:8718-8723). Nevertheless, due to the synthetic procedure, the molecular weight of the grafted dendrimer increases more rapidly than the molecular weight of the dendrimer for each generation.

[0031] In some embodiments, the polylysine dendrimers according to the invention are second generation (G2) grafted polylysine dendrimers, also referred to herein interchangeably as "G2 poly-L-lysine dendrigrafts", "G2 dendrimers", "grafted dendrimers", "grafted polylysine dendrimers" or "grafted homopolylysine dendrimers", "lysine dendrigrafts" or "DGLs". G2 dendrimers have been shown to be more effective than linear polylysine in inhibiting C. acnes growth and promoting anti-inflammatory effects. The G2 dendrimers used in the methods of the invention can be prepared as described herein (Example 1) or, for example, as described in US2008 / 0206183 or Collet, et al. (2010) Chem. Eur. J. 16:2309-16.

[0032] In certain embodiments, the polylysine dendrimer, e.g., the G2 dendrimer, is a homopolylysine dendrigraft consisting of 30-70 lysine residues, or more preferably 40-60 lysine residues, or most preferably 48 lysine residues. In certain embodiments, the polylysine dendrimer is a G2 dendrimer, said G2 dendrimer being a homopolylysine dendrigraft comprising, consisting of, or consisting essentially of 48 lysine residues. Preferably, as used herein, the number of lysine residues refers to the average degree of polymerization (DPn) of said dendrimer or dendrigraft. In certain embodiments of the present invention, the dendrimers of the present invention are not conjugated. An "unconjugated" polylysine dendrigraft or dendrimer generally refers to a polylysine dendrigraft or dendrimer that is not covalently bound to or associated with another substance, such as a pharmaceutical or agricultural substance, such as a therapeutic moiety. In other words, the dendrimers of the present invention may lack any therapeutic, pharmaceutical or cosmetic moiety other than lysine. In some embodiments, lysine residues are the only building block present in the polylysine dendrimers of the present invention.

[0033] In some embodiments, the polylysine dendrimer of the invention is a dendrigraft comprising a linear polylysine core, in which the side chain NH2 group (ε-amino group) of one or some (preferably all) of the lysine residues of said core is replaced by a polylysine moiety. For example, the polylysine dendrigraft of the invention may comprise a linear poly-L-lysine core (i.e. α-poly-L-lysine), in which the ε-NH2 group of each lysine residue is replaced by a poly-L-lysine moiety, preferably α-poly-L-lysine. The linear core may comprise 2-10, such as 6-10, such as 8 lysine residues in length, and the poly-L-lysine substituent may comprise 2-10, such as 3-8, such as 5, lysine residues in length.

[0034] For example, the polylysine dendrigraft of the present invention has the formula (I): [ka] (I) (wherein n is an integer from 2 to 10, for example, 2, 3, 4, 5, 6, 7, 8 or 9, preferably 6, 7, 8 or 9, more preferably 7).

[0035] [Lys] represents a lysine residue and n1 represents the number of lysine moieties linked together to form a polylysine moiety, preferably an α-polylysine moiety. Each n1 is an integer independently selected from 2 to 10, e.g., 2, 3, 4, 5, 6, 7 or 8, preferably 3, 4, 5, 6 or 7, and even more preferably 4, 5 or 6. In some embodiments, all n1 are the same, e.g., 5. The average degree of polymerization (DPn) of the dendrigrafts of the present invention is between 42 and 58, preferably between 46 and 50, more preferably about 48. As used herein, the average degree of polymerization (DPn) represents the number average of lysine monomers per dendrimer molecule in the polylysine dendrimer according to the present invention.

[0036] In some or further embodiments, the mass-average molar mass (M w ) is 7500-10000gmol -1 , preferably 8600 gmol -1 8400~8800gmol etc. -1 It is. Polylysine dendrimers, including the G2 dendrimers of the present invention, are polycationic polymers. The G2 dendrimers synthesized and exemplified herein contain trifluoroacetate (TFA) as a counter anion, but this anionic component can be exchanged for a variety of other counter anions, such as bicarbonate, dihydrogen phosphate, fluoride, chloride, bromide, iodide, citrate or acetate.

[0037] Thus, the present invention includes polylysine dendrimers, such as G2 dendrimers, and salts thereof. Suitable counter anions are acetate, trifluoroacetate, chloride, citrate, phosphate, carbonate and combinations thereof, preferably acetate, chloride, carbonate and combinations thereof, more preferably acetate. In certain embodiments, the counter anion of the dendrimer is acetate. Indeed, the applicant has shown that G2 dendrimers with acetate counter anion have improved anti-inflammatory activity in vitro compared to G2 dendrimers with chloride or carbonate counter anions: indeed, G2 dendrimers with acetate as counter anion achieve more efficient production of IL-8 in dermal fibroblasts in vitro after IL1-α stimulation.

[0038] Various methods are available to exchange the TFA counter anion for the acetate counter anion. One method involves the use of a steric exclusion support (G25) in a chromatographic mode with an ammonium bicarbonate elution buffer (0.1 M). After chromatography, the polymer is recovered in a bicarbonate buffer and dried on a rotary evaporator, which gives a polymer with a bicarbonate counter anion. This counter anion can then be exchanged for an acetate anion by neutralizing with acetic acid at pH 6.5. The product is then dried by lyophilization. Alternatively, the polymer solution is dialyzed in an ammonium acetate buffer to exchange the TFA counter anion. As a further alternative, the polymer is applied to an anion exchange resin preconditioned in acetate anion. The performance of the exchange is evaluated by: 19 This can be confirmed by F NMR, by centesimal analysis, or by looking for the TFA ion in LC / MS. When employed in the methods and uses of the present invention, the polylysine dendrimer, such as the G2 dendrimer and / or salts thereof, may be provided as a cosmetically active ingredient present in a cosmetic, pharmaceutical or dermocosmetic composition.

[0039] For example, cosmetic compositions include, but are not limited to, anti-acne products, urban care products, soothing creams, exfoliating products, daily protection products, clarifying toners or lotions, purifying cleansers, breakout-relieving creams or sticks, concealer sticks, etc. In some embodiments, the polylysine dendrimers are formulated into non-medical, cosmetic, or dermocosmetic compositions suitable for, for example, acne-prone or breakout-prone skin. Thus, in certain embodiments, polylysine dendrimer, such as G2 dendrimer, is a component of the composition or preparation that is applied topically or locally to skin.In certain embodiments, the composition is in the form of cleanser, toner, lotion, solution, gel, cream, ointment or foam.In this respect, the preparation or composition that contains polylysine dendrimer, such as G2 dendrimer, is suitable or adapted for topical or local application.

[0040] The composition containing the polylysine dendrimer according to the present invention, for example the G2 dendrimer, may be a thick or medium viscous fluid, or may be a less thick viscous fluid, such as may be used in a spray or aerosol. The composition may take the form of a solution, suspension or emulsion. The composition may take the form of a solid, such as a powder or granules, which may be designed to be added to a liquid (e.g. water) before use. In some embodiments, the formulation may be applied to a carrier, such as a sponge, swab, brush, pad, tissue, cloth, wipe, skin patch or dressing (including bandages, plasters, skin adhesives, or other materials designed to be applied to tissue surfaces), to facilitate its administration. The compositions according to the invention may be intended for pharmaceutical (which includes veterinary, but preferably human) use and / or for cosmetic, dermocosmetic or other non-medical care purposes (e.g. for cleansing the skin or improving the appearance, feel or smell of the skin). The compositions according to the invention may contain excipients and other additives known for use in topical formulations. Suitable excipients for use in formulations designed for topical or local application will be well known to those skilled in the art. Inclusions will depend on the intended mode and site of application of the formulation. With regard to formulations for topical application to the skin, examples can be found, for example, in Williams' Transdermal and Topical Drug Delivery (Pharmaceutical Press, 2003) and other similar reference books. See Date, et al. ((2006) Skin Pharmacol. Physiol. 19(1):2-16) for a review of topical delivery strategies, also see Skin Delivery Systems (2006) John J Wille, Ed, Blackwell Publishing.

[0041] The excipient used can be suitable for targeted or controlled release of the composition or the components of the composition at the intended site of administration, for example, to target the desired site and / or time of delivery.Such excipient can, for example, target the composition to the region of skin, for example, the stratum corneum or pilosebaceous follicle, or to the hair follicle.The excipient can delay or otherwise control the release of the composition over a certain period of time. When the composition is intended to be applied topically to the skin, examples of suitable additives, also called excipients, include diluents, fillers, carriers, emollients, moisturizers, fragrances, antioxidants, preservatives, stabilizers, gelling agents and surfactants; and / or other substances that are generally used in formulations in the cosmetic or pharmaceutical fields.Others can be found in Williams' Transdermal and Topical Drug Delivery (see above).However, for the treatment of acne, compositions that do not contain emollients may be preferred.

[0042] The polylysine dendrimers, such as G2 dendrimers and / or salts thereof, may be used individually or together, or in combination with one or more additional active ingredients, such as antimicrobial (especially antibacterial) agents or anti-inflammatory agents. The additional active ingredients may be combined with the polylysine dendrimer in one single composition, or may be administered separately, including by different routes (e.g., by the oral route). In some embodiments, the additional active ingredient and the polylysine dendrimer are combined in the same composition. For example, the formulations may contain one or more agents selected from anti-acne agents, keratolytic agents such as lactic acid, comedolytics, agents capable of normalizing keratinocyte and / or sebaceous cell function, anti-inflammatory agents such as Licochalcone A and Glycyrrhiza Inflata extract, anti-proliferative agents, antibiotics, anti-androgens, sebum reducers / suppressants (also known as sebum regulators) (e.g., natural extract of Lemon Myrtle (Backhousia citriodora)), anti-itch agents, immunomodulators, anti-irritants or anti-inflammatory agents (e.g., extract of Epilobium angustifolium), agents promoting wound healing, sunscreens, skin lightening agents, anti-aging substances and mixtures thereof.

[0043] For example, anti-acne agents include, but are not limited to, vitamin A, retinoids (such as adapalene, tretinoin, or tazarotene), bactericides (such as benzoyl peroxide and decanediol), antibiotics (such as clindamycin or erythromycin), azelaic acid, salicylic acid, anti-inflammatory agents (such as dapsone or Melaleuca alternifolia (tea tree) oil), and combinations thereof. As examples of sebum regulators, mention may be made of flax lignans, rice flour, zinc gluconate, sarcosine, Cinnamon (Cinnamomum zeylanicum) bark extract, avocado extract, extract derived from Australian lemon myrtle (Backhousia citriodora) leaves, Trifolium Pratense (clover) flower extract, and combinations thereof. By anti-redness agents there may be mentioned saponins, flavonoids, ruscogenins, esculosides and extracts containing them, such as extracts of ruscus, but also certain essential oils, for example of lavender or rosemary.

[0044] Examples of anti-inflammatory agents include allantoin, aloe, calendula (Calendula officinalis), birch (e.g., Betula alba), willow herb (Epilobium angustifolium), Tasmania pepper (e.g., Tasmania Lanceolata), chestnut (e.g., Castenea sativa), cornflower (e.g., Centaurea cyanus), centella (e.g., Centella asiatica), horsetail (e.g., Equisetum arvense), fennel (e.g., Foeniculum vulgare), common witch hazel (e.g., Hamamelis virginiana), ivy (e.g., Hedera helix), and the like. helix), roselle (Habiscus sabdariffa), lilies (e.g. Lilium candidum), mallow (e.g. Malva sylvestris), lemon balm (e.g. Melissa officinalis), skullcap (e.g. Scutellaria baicalensis), mimosa (e.g. Mimosa tenuiflora), cinquefoil (e.g. Potentilla erecta), extracts of exopolysaccharides derived from extremophilic microorganisms (e.g. Alteromonas ferment), oligosaccharides or oligosaccharides, such as flax extracts, peptides (such as palmitoyl tripeptide-8), and combinations thereof may be mentioned.

[0045] For example, polylysine dendrimers may be present in the composition. The cosmetic composition may contain one or more excipients and may contain one or more additional active agents having a cosmetic or pharmaceutical action. In some embodiments, the additional active agent present in the composition is a cosmetic active ingredient. The expression "cosmetic active agent" refers to a compound capable of exerting at least one cosmetic action on the skin surface. The term "cosmetic action" is intended to mean any non-therapeutic action aimed at modifying and / or improving the appearance or feel of the skin, protecting it from external aggressions (sun, wind, moisture, dryness, chemical products) or preventing and / or correcting phenomena associated with aging or puberty. Typically, the composition comprises: - 0.1 to 100 ppm of the polylysine dendrimer of the present invention - 0% to 20% of one or more additional active agents, and - 70% to 99.9999% of one or more excipients Including, The percentages are expressed by weight relative to the total weight of the composition.

[0046] Preferably, said composition is a cosmetic or dermocosmetic composition. In some embodiments, polylysine dendrimers, such as G2 dendrimers, are used in synergistic combination with antimicrobial and / or anti-inflammatory agents, allowing for lower dosages of one or both of the agents to achieve similar or improved effects, potentially allowing for the use of lower doses and therefore reducing the potential incidence of toxicity and the cost of expensive antimicrobial agents. In this context, the additional antimicrobial agent may be selected from biocides, disinfectants, antiseptics, antibiotics, bacteriophages, enzymes, anti-adhesins, immunoglobulins, antimicrobially active antioxidants, and mixtures thereof. It may be particularly active as a microbicide against the genus Propionibacterium. In certain embodiments, the antimicrobial agent is an antibiotic, such as a penicillin, a cephalosporin, a carbacephem cephamycin, a carbapenem, a monobactam, an aminoglycoside, a glycopeptide, a quinolone, a tetracycline, a macrolide, or a fluoroquinolone.Specific examples of antibiotics include, but are not limited to, penicillin G, methicillin, nafcillin, oxacillin, cloxacillin, dicloxacillin, ampicillin, amoxicillin, ticarcillin, carbenicillin, mezlocillin, azlocillin, piperacillin, imipenem, aztreonam, cephalothin, cefazolin, cefaclor, cefamandole sodium formate, cefoxitin, cefuroxime, cefotaxime ... Nisid, cefinetazole, cefotetan, cefprozil, loracarbef, cefetamet, cefoperazone, cefotaxime, cefrizoxime, ceftriaxone, ceftazidime, cefepime, cefixime, cefpodoxime, cefsulodin, fleroxacin, nalidixic acid, norfloxacin, ciprofloxacin, ofloxacin, enoxacin, lomefloxacin, cinoxacin, doxycycline, minocycline Examples of such antibacterial agents include cyclosporine, tetracycline, amikacin, gentamicin, kanamycin, netilmicin, tobramycin, streptomycin, azithromycin, clarithromycin, erythromycin, erythromycin estolate, erythromycin ethyl succinate, erythromycin glucoheptonate, erythromycin lactobionate, erythromycin stearate, vancomycin, teicoplanin, chloramphenicol, clindamycin, trimethoprim, sulfamethoxazole, nitrofurantoin, rifampin, mupirocin, metronidazole, cephalexin, roxithromycin, co-amoxiclavuanate, combinations of piperacillin and tazobactam, and various salts, acids, bases and other derivatives thereof, and combinations thereof.

[0047] Polylysine dendrimers, such as G2 dendrimers and / or salts thereof, may also be used in combination with antifungal agents. Exemplary antifungal agents include, but are not limited to, terbinafine hydrochloride, nystatin, amphotericin B, griseofulvin, ketoconazole, miconazole nitrate, flucytosine, fluconazole, itraconazole, clotrimazole, benzoic acid, salicylic acid and selenium sulfide. Polylysine dendrimers, such as G2 dendrimers and / or salts thereof, may also be used in combination with antiviral agents. Exemplary antiviral agents include, but are not limited to, amantadine hydrochloride, rimantadine, acyclovir, famciclovir, foscarnet, ganciclovir sodium, idoxuridine, ribavirin, sorivudine, trifluridine, valacyclovir, vidarabine, didanosine, stavudine, zalcitabine, zidovudine, interferon alpha and edoxudine.

[0048] Polylysine dendrimers, such as G2 dendrimers and / or salts thereof, may also be used in combination with antiparasitic agents. Exemplary antiparasitic agents include, but are not limited to, pyrethrin / piperonyl butoxide, permethrin, iodoquinol, metronidazole, diethylcarbamazine citrate, piperazine, pyrantel pamoate, mebendazole, thiabendazole, praziquantel, albendazole, proguanil, quinidine gluconate injection, quinine sulfate, chloroquine phosphate, mefloquine hydrochloride, primaquine phosphate, atovaquone, cotrimoxazole (sulfamethoxazole / trimethoprim) and pentamidine isethionate.

[0049] As stated above, polylysine dendrimers, such as G2 dendrimers and / or their salts, may be used in synergistic combination with other known anti-inflammatory agents. Anti-inflammatory agents include, but are not limited to, corticosteroids (e.g., hydrocortisone, triamcinolone), nonsteroidal anti-inflammatory drugs (NSAIDs) (e.g., nabumetone, indomethicin, naproxen, ibuprofen), anti-inflammatory cytokines (e.g., IL-4, IL-10, IL-13), cytokine antagonists (e.g., IL-1 receptor antagonists, TNF-α monoclonal antibodies, soluble TNF receptors, platelet factor 4), and the like.See, for example, US6,190,691; US5,776,892; US4,816,449; and US RE37,263.

[0050] The preparations used in the method of the present invention can be incorporated into cosmetics; skin care preparations (such as skin cleansers, toners or moisturizers), deodorants or antiperspirants; cleansing preparations (such as facial washes); pharmaceutical preparations (including veterinary preparations); cosmeceutical preparations; toiletry products (such as bath or shower additives or soaps) and therefore can be applied in these forms.The preparations can be or be incorporated into skin cleansers or rinse-off skin treatment products, such as leave-on skin treatment products in particular. As described herein, polylysine dendrimers, such as G2 dendrimers and / or salts thereof, exhibit antimicrobial activity and reduce adhesion of certain strains of C. acnes to skin cells. Thus, one aspect of the present invention is a method of treating acne vulgaris by applying to the skin of a subject in need of treatment an antimicrobially effective amount of a composition containing unconjugated poly-L-lysine dendrigrafts and / or salts thereof.

[0051] As used herein, "antimicrobial active" refers to an active agent capable of preventing or reducing the growth and proliferation of C. acnes, preferably acnegenic C. acnes strains. As mentioned above, "acne" or "acne vulgaris" is a multifactorial disease of the pilosebaceous follicles of face and upper trunk, characterized by various inflammatory and non-inflammatory lesions, such as papules, pustules, nodules, and open and closed comedones.Therefore, the treatment can include the treatment of any of these symptoms (this treatment includes prevention or alleviation), and therefore can be interpreted as referring to use as an anti-acne agent.In particular, the treatment of acne includes the treatment (including prevention) of lesions related to acne.The treatment also includes the inhibition of the activity of Propidobacteria that may cause or otherwise be related to acne or its symptoms.In the context of the present invention, the treatment can be particularly the treatment of inflamed acne lesions. Treatment of acne includes both therapeutic and preventive treatment, either in humans or animals, but particularly in humans. Treatment can include complete or partial eradication of the condition, removal or amelioration of associated symptoms of the condition, inhibition of subsequent development of the condition, and / or prevention or reduction of the risk of subsequent occurrence of the condition. Treatment specifically includes the use of unconjugated G2 dendrimers and / or salts thereof as described herein. In certain embodiments, the method includes treatment of acne vulgaris associated with C. acnes present on facial skin.

[0052] Another aspect of the present invention is directed to a method of reducing an inflammatory response by applying a composition containing unconjugated poly-L-lysine dendrigrafts and / or salts thereof to the skin of a subject in need of treatment. In certain embodiments, the inflammatory response comprises IL-8 release or TLR2 overexpression in response to P. acnes. A measurable reduction in IL-8 release or TLR2 overexpression can be assessed using any of the conventional techniques or the techniques exemplified herein. Preferably, the polylysine dendrimer, e.g., unconjugated poly-L-lysine dendrigrafts and / or salts thereof, achieves at least a 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or 80% reduction in IL-8 protein production and / or TLR2 overexpression compared to skin not contacted with unconjugated poly-L-lysine dendrigrafts and / or salts thereof. A further aspect of the present invention is a method for promoting desquamation of skin cells by applying a composition containing a polylysine dendrimer, such as a non-conjugated poly-L-lysine dendrigraft and / or a salt thereof, to the skin of a subject in need of treatment. Desquamation is a natural phenomenon associated with the constant renewal of the epidermis, which constitutes the upper layer of the skin. During the normal process of desquamation, the uppermost layer of keratinocytes is detached from the surface of the epidermis. According to this method, application of a polylysine dendrimer, such as a non-conjugated poly-L-lysine dendrigraft, to the surface of the skin promotes desquamation and / or stimulates the epidermal renewal process.

[0053] "Applying" a composition containing a polylysine dendrimer, such as the unconjugated G2 dendrimer and / or a salt thereof, to the skin of a subject, its "application" to the skin of a subject, its "administration" to the skin of a subject or its "administration" to the skin of a subject includes local or topical skin treatment with the composition. In certain embodiments, the polylysine dendrimer, such as the G2 dendrimer and / or a salt thereof, is applied to the facial skin of a subject. A subject in need of treatment with a composition containing a polylysine dendrimer, such as a G2 dendrimer and / or a salt thereof, refers to any subject at risk of having, susceptible to, or having a condition for which the G2 dendrimer and / or a salt thereof provides a benefit, such as anti-acne activity, anti-inflammatory activity, or keratolytic activity. In some embodiments, the method of the present invention is particularly useful for reducing acne problems in teenagers, reducing skin inflammation, and improving the appearance or feel of adult skin.

[0054] An effective amount of a composition containing a polylysine dendrimer, such as a non-conjugated G2 dendrimer and / or a salt thereof, can refer to an amount that causes a measurable inhibition, whether complete or partial, of bacterial growth of one or more acne-causing C. acnes strains; a measurable reduction in an inflammatory response, such as IL-8 release or TLR2 overexpression in response to C. acnes; and / or a measurable desquamation of skin cells. An effective amount also refers to an amount that can improve or treat breakouts in acne-prone or acne-prone skin. An effective amount of a composition containing a polylysine dendrimer, such as a non-conjugated G2 dendrimer and / or a salt thereof, comprises between about 0.01 ppm and about 100 ppm, or more preferably between about 0.1 ppm and 50 ppm, or most preferably between about 1 ppm and 10 ppm, of a polylysine dendrimer, such as a non-conjugated G2 dendrimer and / or a salt thereof. In certain embodiments, the use of the compositions of the present invention is for non-therapeutic purposes. According to this embodiment, the compositions are used for non-therapeutic purposes, for example, for cosmetic purposes, such as to improve the appearance or feel of the skin, especially the skin of the face, as anti-acne / anti-inflammatory, or especially skin care agents. EXAMPLES

[0055] The invention is described in greater detail by the following non-limiting examples. Example 1: Synthesis of DGL G2 The first generation synthesis of poly(L-lysine) was carried out via a three-step sequence (Scheme 1). [ka]

[0056] N-carbamoylation of Ne-trifluoroacetyl-L-lysine gave C-Lys(Tfa). NO-mediated nitration of C-Lys(Tfa) in acetonitrile gave monomeric Lys(Tfa)-NCA, which was then reacted in aqueous sodium bicarbonate (pH 6.5) to give Ne-protected oligo(L-lysine) G1P. Both the nitrosation and polycondensation steps were carried out in one pot without isolation of the NCA intermediate, and the resulting polymeric G1P spontaneously precipitated from the reaction medium. The G1P polymer was isolated by filtration, and the ε-amino group was deprotected by alkaline treatment of G1P with ammonia in methanol / water. Deprotection afforded oligo(L-lysine) G1 with a DPn of about 8 in 50-60% overall yield from C-Lys(Tfa). Dendrimeric materials were subsequently prepared in multigenerational order by carrying out the above reaction sequence (Scheme 1). Upon reaction of crude Lys(Tfa)-NCA in the presence of poly(L-lysine) G1 (30% w / w; 0.36 equivalents in monomer units) in aqueous NaHCO3, polymer G2P spontaneously precipitated from the reaction medium, which after isolation underwent alkaline Ne-deprotection to give poly(L-lysine) G2 in 36% overall yield from about 48 DPn and C-Lys(Tfa). Subsequent ion exchange was performed to convert the trifluoroacetate to acetate.

[0057] Example 2: Inhibition of C. acnes by G2 dendrimers The effectiveness of the G2 dendrimer in inhibiting the growth of C. acnes in culture was evaluated. The G2 dendrimer was -2 M~10 -5 M. Experiments were performed using C. acnes strain IP53117T (see French Patent Application Publication No. 2844715), a strain known to cause acne. This strain belongs to ribotype 1 (RT1) derived from phylotype 1A1 and is therefore an acne strain. Bacteria (10 8The MIC (minimal inhibitory concentration) was visually defined as the lowest concentration resulting in no visible growth after 24–48 h of incubation at 37°C. This analysis was based on the results of two separate experiments, and showed that the MIC of the G2 dendrimer against C. acnes strain IP53117T ranged from 1.6–2.3 × 10 -5 M (10-20 ppm). Thus, the G2 dendrimer significantly inhibited growth against the acneogenic C. acnes strains tested, and thus exhibited bactericidal activity at high doses (20 ppm).

[0058] Example 3: Effect of G2 dendrimer on C. acnes adhesion in keratinocyte cultures An early stage of acne vulgaris is bacterial colonization of the skin surface. Colonization depends on bacterial adhesion. Therefore, it was determined whether G2 dendrimers could inhibit adhesion of acne-causing C. acnes strains to keratinocytes in culture. Keratinocytes were isolated from the human epithelial cell line NCTC2544 (Neufahrt, et al. (1978) Arch. Dermaol. Res. 256(3):255-60). Cultures were maintained at 37°C with 5% CO2 and 95% humidity in Dulbecco's modified Eagle's medium (DMEM) containing 10% fetal bovine serum, 1% antibiotics (penicillin / streptomycin) and 1% L-glutamine. To monitor bacterial adhesion, adenines of the IP53117T strain (belonging to acneiform phylotype IA1) were labeled with tritium and bacterial adhesion to the surface of keratinocytes was determined by counting the radioactivity.

[0059] Method 1. Labeled bacteria (2x10 8 Microorganisms / mL) were cultured with various amounts of G2 dendrimer (10 -5 M~6.25×10 -6M final concentration) and deposited on the surface of the keratinocyte monolayer. After incubation for 2 h (37° C., 5% CO2), the cells were washed with phosphate buffered saline (PBS) to remove non-adherent cells. Method 2. Keratinocytes were pretreated with G2 dendrimers for 24 hours. Then, labeled bacteria (2x10 8 (microorganisms / mL) was added to the cell monolayer for 2 h. The results of this assay showed that after 2 hours, the dendrimers reduced adhesion of C. acnes by 10% compared to that in the absence of G2 dendrimer. -5 M, 5×0 -6 M and 2.5×10 -6 The results showed that the G2 dendrimer inhibited the adhesion of C. acnes to the keratinocyte surface by 50%, 40% and 29%, respectively, at 100 M, 100 M, 100 M, and 100 M, respectively. After 24 h of pretreatment, the G2 dendrimer inhibited the adhesion of C. acnes to the keratinocyte surface by 10% compared to the adhesion in the absence of the G2 dendrimer. -5 M, 5×10 -6 M and 2.5×10 -6 In M, G2 dendrimer inhibited adhesion of C. acnes to keratinocyte surfaces by 50%, 51% and 35%, respectively. Based on the results of these two assays (simultaneous or pretreatment), G2 dendrimer was shown to exhibit strong anti-adhesion activity. Thus, G2 dendrimer is useful for blocking the early stages of acne vulgaris, i.e., by preventing excessive bacterial adhesion or colonization by acne strains.

[0060] Example 4: Effect of G2 dendrimer on inflammation in normal human dermal fibroblasts There is evidence that C. acnes is involved in inducing inflammatory responses. In particular, it has been shown that stimulation of Toll-like receptor 2 (TLR2) by C. acnes results in increased concentrations of interleukins 8 and 12 (IL-8 and IL-12) (Kim, et al. (2002) J. Immunol. 169(3):1535-41). Therefore, the effect of G2 dendrimers on inflammation in normal human dermal fibroblasts (NHDFs) was evaluated. NHDFs were isolated from human dermis and maintained at 37°C under 5% CO2 and 95% humidity in DMEM containing 10% fetal bovine serum, 1% antibiotics (penicillin / streptomycin) and 1% L-glutamine. IL-8 mediates inflammatory responses in the skin by recruiting neutrophils and other immune cells to enter damaged or inflamed tissue. IL-8 secretion can be induced in cultured human dermal fibroblasts after activation with the proinflammatory cytokine IL-1α (Larsen, et al. (1989) Immunology 68(1):31-6). Therefore, non-confluent NHDF cells were cultured with G2 dendrimers (10 -9 M, 10 -8 M, 10 -7 M or 10 -6 Fibroblasts were treated with IL1-α (0.1 ng / mL) as an inducer of IL-8 production, or with hydrocortisone (0.05 μg / mL) as a positive anti-inflammatory control, in the presence or absence of IL-1α (0.1 ng / mL). The amount of IL-8 released from fibroblasts was determined by enzyme-linked immunosorbent assay (ELISA). The results of this analysis (Figure 1) show that hydrocortisone reduced IL-8 production by 83%. G2 dendrimer, under the same experimental conditions, reduced IL1-α-induced IL-8 production by 66-81%. Thus, G2 dendrimer is able to attenuate the inflammatory cascade in human dermal fibroblasts known to be associated with C. acnes colonization.

[0061] Example 5: Anti-acne and keratolytic activity of G2 dendrimers in human skin explants To demonstrate the antiacne and keratolytic activity of G2 dendrimers, human skin explants were exposed to lyophilized P. acnes (C. acnes strain IP53117T-RT1-phylotype IA1) to stimulate in vivo acne ex vivo. Skin treatment. Fifteen human skin specimens were obtained from patients undergoing cosmetic surgery (Caucasian female, 26 years old). Skin explants were maintained in culture for 8 days. One hour treatment with G2 dendrimer (2 ppm and 5 ppm) was performed simultaneously with the application of lyophilized C. acnes (30 μL) on days 0, 1, 4 and 6 (Figure 2). On day 8, explants were fixed and embedded in paraffin. 5 μm thick sections were stained with Masson's trichrome stain or anti-TLR2 antibody.

[0062] Evaluation of keratolytic activity. The general geometry of the explants and the stratum corneum in particular were analyzed. Images were taken with a Leica Orthoplan microscope equipped with a digital camera (tri-CCD) driven by the acquisition and archiving software Leica IM1000. Immunostaining for TLR2. TLR2 is known to mediate the inflammatory response of skin to acne (Kim, et al. (2002) J. Immunol. 169(3):1535-41; McInturff & Kim (2005) Semin. Cutan. Med. Surg. 24(2):73-8). Therefore, TLR2 protein in frozen sections was assessed with anti-TLR2 (clone TL2.1; Santa Cruz). Sections were incubated with a 1:25 dilution of anti-TLR2 antibody overnight at 4° C., and antibody binding was subsequently detected with a biotin / streptavidin-FITC conjugate. Nuclei were stained with propidium iodide. Quantification of IL1-α cytokine. The concentration of IL1-α in the culture medium was determined using an ELISA assay kit (Cayman, Ann Arbor, MI). Absorbance was measured using a microplate reader Tecan Infinite M200 Pro combined with Magellan software.

[0063] Results: Topical application of 2 ppm G2 dendrimer induced moderate separation of the upper layers of the stratum corneum, while the lower layers remained more stacked. In comparison, application of 5 ppm G2 dendrimer induced less desquamation. In view of its keratolytic activity, G2 dendrimer is useful for promoting skin desquamation. With regard to TLR2 expression, topical application of 2 ppm and 5 ppm of G2 dendrimer resulted in complete inhibition of C. acnes-induced TLR2 overexpression. To evaluate the inflammatory response, IL1-α production was quantified (Figure 3). At day 1 (D1), C. acnes did not induce a significant increase in IL1-α production compared to the control condition (i.e., explants without treatment). Furthermore, G2 dendrimer significantly reduced IL1-α production at 2 ppm and 5 ppm, respectively, at day 1 compared to treatment with C. acnes by 49% and 42%. After 4 days of survival (D4), IL1-α release was significantly reduced by 53% in the control condition. Furthermore, G2 dendrimer at 2 ppm and 5 ppm led to a reduced IL1-α production at day 4 (28% and 27%, respectively) compared to treatment with C. acnes. Thus, G2 dendrimer reduces C. acnes growth and attenuates immune and inflammatory cascades for optimal skin protection, resulting in keratolytic action.

[0064] Example 6: G2 dendrimer selectively increases membrane fluidity in C. acnes strains belonging to C. acnes phylotype IA1. The effect of G2 dendrimers on membrane fluidity of three strains of C. acnes was tested. Two of the tested C. acnes strains are "acnegenic" strains belonging to phylotype IA1 (RT4 and RT5), while the last one is a non-acnegenic strain (RT6) belonging to phylotype II. Several colonies of RT4, RT5 and RT6 (C. acnes strains) were broken and placed in enriched clostridial medium (RMC medium). The tubes were vortexed for a few seconds to homogenize and then completely filled with RMC to generate anaerobic conditions. The tubes were then incubated at 37°C for at least 48 hours. Bacterial cultures were harvested and OD was measured at 580 nm. After inoculation, bacteria were transferred to microplates and treated or not with G2 dendrimer. After 2 hours in the anaerobic chamber, the plates were transferred to a microplate reader for 72 hours (OD580 nm was measured every 30 minutes).

[0065] The bacterial production time was then analyzed for each C. acnes strain. G2 dendrimer was tested at the following concentrations: 6.10 -6 M and 6.10 -7 M. - results These results are shown in Figure 4. After 72 hours of incubation, the G2 dendrimer (6.10 -6 M) significantly reduced the membrane stiffness of acne strains RT4 and RT5 compared to the control. Notably, the G2 dendrimer at 6.10 -6 In contrast, G2 dendrimer does not show any significant effect on the RT6 strain in M. In other words, G2 dendrimer shows a differential effect on membrane fluidity in acne strains RT4 and RT5 compared to the non-acne strain (RT6). Such an increase in membrane fluidity is expected to destabilize the bacterial membrane of acne strains of acne phylotype IA1, thus limiting the growth of said strains while at the same time maintaining and even promoting non-acne phylotype strains of phylotype II.

[0066] Example 7: Effect of G2 dendrimer on biofilm formation of acne strains - Protocol Bacterial strains and bacterial cultures C. acnes strain ribotype 5 (RT5) HL043PA2 / HM-514 and C. acnes non-strain ribotype 6 (RT6) HL110PA3 / HM-554 were obtained from the BEI Resources American Type Culture Collection (Virginia, USA). These two strains belong to phylotypes IA1 and II, respectively (McDowell, 2017). Bacteria stored at -80°C were first plated onto brain heart infusion (BHI, BD) agar plates for RT6 strains and onto enriched clostridial medium (RCM) agar plates for RT5 strains and incubated under anaerobic conditions at 37°C using a BD GasPack™ system. Colonies were transferred to a sterile 15 mL conical tube (Falcon) containing 12 ml of RCM and after vortexing to homogenize, the falcon tube was filled completely with RCM medium and incubated at 37° C. for 72 hours.

[0067] Biofilm formation on glass slides To evaluate the formation of C. acnes biofilms during exposure to G2 dendrimers, 24-well culture plates with flat glass bottom were used (Sensoplate, Greiner bio-one, Germany). 72 h bacterial cultures (see paragraph above) were centrifuged at 7,500 g for 10 min at room temperature. The bacterial pellet was resuspended in 5 ml of sterile physiological water (SPW). Finally, 300 μl of bacterial inoculum (OD 580nm =0.8) was placed in the eight central wells of a 24-well culture plate. The plates were incubated for 3 hours in anaerobic conditions to favor primary bacterial adhesion. After this incubation period, the saline was carefully removed in each well and 1 ml of bacterial culture medium (RCM) supplemented or not with G2 dendrimer was added. The plates were incubated for 72 hours at 37°C in an anaerobic Whitley A85 Workstation. After 72 h (biofilm formation), the RCM medium was carefully removed in each well to remove planktonic cells. Then, 300 μl of SYTO9 green fluorescent nucleic acid stain (Thermofisher) was added to each well and incubated for 20 min in dark conditions. Afterwards, the SYTO9 stain was removed and 300 μl of SPW was added to each well. CLSM observations were immediately performed with a Zeiss LSM710 (Carl Zeiss Microscopy, Oberkochen, Germany) using a 63× oil immersion objective. Syto9 was excited at 488 nm and fluorescence emission was detected at 500–550 nm. Images were taken every micrometer throughout the entire depth of the biofilm. For visualization and processing of three-dimensional (3D) images, Zen2.1 SP1 software (Carl Zeiss Microscopy, Oberkochen, Germany) was used. Quantitative analysis of image stacks was performed using the COMSTAT software (http: / / www.imageanalysis.dk / ) (Heydorn et al., 2000). Maximum and mean values ​​of biofilm thickness (μm) and their biomass volume (μm) were calculated. 3 / μm 2 ) was determined. Each study was repeated at least three times.

[0068] - results G2 dendrimer was shown to reduce biofilm thickness for both RT5 (-48%) and RT6 (-32%) strains. Notably, the reduction in biofilm thickness was significantly more significant for acne strain RT5 than for non-acne strain RT6. Furthermore, as shown in Figure 6, G2 dendrimer significantly reduced biofilm biomass density for RT5 (-50%) but had no effect on biofilm biomass density for RT6. In conclusion, polylysine dendrimers are expected to exert a selective and specific inhibitory effect against acne strains by destabilizing C. acnes biofilms and at the same time reduce the inflammatory response triggered by C. acnes biofilms, whatever the strain, by decreasing the biofilm thickness. This destabilizing effect was not observed in the case of the non-acne strain RT6, since the biomass density remained unchanged. Of note, such results are consistent with Example 6, which shows that polylysine dendrimers increase membrane fluidity in the acnegenic RT5 strain, but not in the non-acnegenic RT6 strain.

[0069] Example 8: Clinical study Twenty Caucasian subjects with oily, acne-prone facial skin (50% of subjects were between 14-25 years of age and 50% were between 26-40 years of age) applied a cream containing 2 ppm G2 dendrimer (test cream) or a placebo cream twice daily to half of their face for 28 days. The test formulation (G2 dendrimer formulation) was as follows: [Table 1] The G2 dendrimer significantly improved the appearance of acneic skin by reducing acneic lesions and regulating the rate of sebum excretion.

[0070] The placebo formulation was similar to that of the test formulation, except that the G2 dendrimer was replaced by water. After 28 days of use, the comedogenic potential and anti-inflammatories activity were evaluated, compared to the number of lesions on the face before application (D0). - Clinical study: After 28 days of use, the comedogenic potential and anti-inflammatory effect of the test cream against placebo was evaluated by comparing the number of lesions on the face before application (D0). On D0 and D28, a dermatologist examined the skin and counted the total inflammatory lesions, as well as the papules and pustules, on each half of the face of each enrolled subject. The dermatologist also determined the total number of retention lesions and blackheads on each half of the face of each patient. These results are shown in Figures 5A, 5B and 5C. - Measurement of sebum levels: The amount of sebum secreted on the skin surface was quantitatively assessed using a COURAGE and KHAZAKA SM 810 PC Sebumeter® on day 28. The results are shown in Figure 5D.

[0071] result: As illustrated in Figures 5A-5C, the test cream containing G2 dendrimer significantly reduced the number of blackheads, retention lesions and inflammatory lesions after 28 days of treatment compared to the placebo cream. Furthermore, the test cream also significantly reduced the rate of sebum excretion by acneic skin compared to the placebo cream (Figure 5D). Taken together, these data demonstrate that G2 dendrimer is an effective agent for managing acne disorders. * G2 dendrimers improve the microbiota of acne-prone skin. After 28 days of treatment, skin sampling (swabs) was performed on each half of the face of each enrolled volunteer to quantify C. acnes strains by metagenomic analysis and determine the effect of the test cream on C. acnes diversity compared to a placebo cream. The principle of this metagenomics study is to amplify a region of Cutibacterium acnes and sequence the amplicon. The amplicon sequence is compared to the SLST reference database (http: / / medbac.dk / slst / pacnes), which links the amplicon sequence to SLST types and clades, as well as phylotypes. The method is based on the publication of Scholtz et al. (Scholz, 2014, supra) with modifications. The abundance and diversity of SLST types, clades and phylotypes were calculated for each sample and compared to evaluate the treatment effect between the groups of volunteers treated with active and placebo preparations.

[0072] protocol Swabs were frozen and stored at -80°C until DNA extraction. DNA extraction and purification was performed using the Qiagen DNeasy PowerSoil kit (cat. no. 12888). Briefly, cells were lysed by a combination of mechanical (bead beating) and chemical (detergent) treatments. Extracted DNA was then purified on a silica membrane. The original Cutibacterium acnes SLST method (Scholz, 2014, supra) amplifies a region of 612 base pairs, too large to sequence using Illumina technology. Novel primers were designed to amplify one region or 497 base pairs, with the forward primer located 74 nucleotides downstream and the reverse located 26 nucleotides upstream from the original. This modification does not allow for differentiation between SLST types A1 and A6, or between SLST types E3 and E7. In both cases, these variants belong to the same clade and phylotype. DNA sequencing was performed on an Illumina Miseq using paired-end technology. Sequencing processing was performed using the QIIME2 suite (https: / / qiime2.org / ). After quality filtering, read pairs were fused by overlap and clustered to remove chimeric sequences. SLST types were assigned to sequences against the Cutibacterium acnes SLST reference database (http: / / medbac.dk / slst / pacnes) using a 99% homology threshold.

[0073] Data analysis. Input data Raw data were normalized using the Total Sum Scaling (TSS) procedure, i.e., for a given sample, each SLST abundance is divided by the sum of the abundances of all taxa. Before statistical comparison between groups, abundance data were further filtered by removing SLST types that were observed in only one sample. Dilution The rarefaction curves (f(sequence number) = SLST number) were drawn with Past 3.20 software (https: / / palaeo-electronica.org / 2001_1 / past / issue1_01.htm). These curves allow a graphical assessment of whether the sequencing depth is sufficient (when the curve reaches a plateau) or not.

[0074] Alpha (α)-Diversity. Shannon and Simpson diversity indices were calculated using Past3.20 software. These two alpha-diversity measures were used to characterize the taxonomic diversity of each sample: Shannon, entropy-like diversity and Simpson (1-D) diversity. The value of both indices depends on the richness (number of different taxa) and the fairness of the population, with the Simpson index being less affected by less abundant taxa. In both cases, the index improves with diversity. The number of SLSTs (high abundance) is shown, which can also be considered as a diversity metric index, with a bias that high and low abundant SLSTs are given the same weight. In all cases, abundance data normalized to SLST type were used for calculations.

[0075] Comparison of abundance. The abundance of strain types at each level was compared using paired parametric Student's T-test, and non-parametric Wilcoxon and sign tests. Normalized SLST type and filtered abundance data were used for calculations. result This study led to the identification of 32 SLST types among the samples tested, all related to phylotypes described in the literature.

[0076] Phylotype IA1 was the most representative, followed by SLST type A1 as the main one, followed by phylotypes II, IB, IA2, IC and III. This reassignment was the same for samples treated with test cream or placebo cream. Phylotype reassignment varied according to the individual (age, sex) and sampling area. Phylotype IA1 was more abundant in the majority of back samples compared to face samples. Our findings were consistent with the study of Dagnelie et al. (Dagnelie, 2018, supra), who further showed that phylotype IA1 was more abundant in acne skin than in healthy skin, while phylotype II was not as abundant in acneic skin as in healthy skin.

[0077] As shown in Figure 5E and 5F, after 28 days of treatment, treatment with test cream increases the diversity of strains compared to placebo cream.The inventors further observed that treatment with test composition reduces the abundance of acne IA1 phylotype and increases non-acne phylotype II compared to placebo cream, especially in male subjects and subjects at least 23 years old.Therefore, G2 dendrimer exerts a beneficial effect on C. acnes population in acne skin by promoting non-acne strains while restricting acne strains.In other words, G2 dendrimer can be used to rebalance C. acnes population in acne skin and acne-prone skin. Yet another aspect of the present invention may be as follows. [1] Cosmetic and non-therapeutic use of a polylysine dendrimer or a salt thereof as an active ingredient in the management of acne-prone and pimple-prone skin. [2] A polylysine dendrimer or a salt thereof for use as an active ingredient for treating acne vulgaris. [3] A polylysine dendrimer or a salt thereof for the cosmetic use according to [1] or the use according to [2], wherein the polylysine dendrimer or a salt thereof is used as an active ingredient for restoring or rebalancing the skin microbiota, preferably for restoring the diversity of C. acnes on the skin surface. [4] The cosmetic use according to [1] or [3] above, or a polylysine dendrimer or a salt thereof for use according to [2] or [3] above, wherein the polylysine dendrimer or a salt thereof is used as an active ingredient for reducing the abundance of acnegenic C. acnes strains, preferably C. acnes strains belonging to phylotypes IA1, IA2, IB and IC, more preferably phylotype IA1, in the skin. [5] The cosmetic use according to any one of [1] and [3] to [4] above, or the polylysine dendrimer or a salt thereof for use according to any one of [2] to [4] above, wherein the polylysine dendrimer or a salt thereof is used to increase the abundance of a non-acnegenic C. acnes strain, preferably a C. acnes strain belonging to phylotype II or III, preferably phylotype II, in the skin. [6] The polylysine dendrimer or a salt thereof is selected from the following: - Improve the appearance and feel of the skin, and / or - Restoring skin comfort, and / or - Preventing, improving or treating breakouts; and / or - Anti-inflammatory effect on the skin, and / or - Reducing or preventing skin redness or skin irritation, and / or. - Decreased sebum production, and / or - Reduction in visible lesions such as comedones, pustules and papules, and / or - Improves skin desquamation The polylysine dendrimer or a salt thereof for the cosmetic use according to any one of [1] and [3] to [5] above, or for the use according to any one of [2] to [5] above, which is used as an active ingredient for the purpose of the cosmetic use according to any one of [1] and [3] to [5] above. [7] The cosmetic use according to any one of [1] and [3] to [6] above, or the polylysine dendrimer or its salt for use according to any one of [2] to [6] above, wherein the polylysine dendrimer is a second generation non-conjugated poly-L-lysine dendrigraft having a DPn of 40 to 60, such as 48, preferably 46 to 50. [8] A polylysine dendrimer or a salt thereof for cosmetic use according to any one of [1] and [3] to [7] above, or for use according to any one of [2] to [7] above, wherein the polylysine dendrimer is a poly-L-lysine dendrigraft having a linear poly-L-lysine core, each of the ε-amino groups being substituted by a poly-L-lysine moiety. [9] The cosmetic use according to [8] above, or a polylysine dendrimer or a salt thereof for the use according to [8] above, wherein the linear poly-L-lysine core contains 6 to 10, preferably 8, lysine residues in length and / or the poly-L-lysine moiety grafted onto the ε-amino group has a length of 2 to 6, preferably 5, lysine residues.

[10] A polylysine dendrimer or a salt thereof for cosmetic use according to any one of [1] and [3] to [9] above, or for use according to any one of [2] to [9] above, wherein the polylysine dendrimer is in the form of a polycationic dendrimer whose counter anion is an acetate anion.

[11] A polylysine dendrimer or a salt thereof for the cosmetic use described in any one of [1] and [3] to

[10] above, or for the use described in any one of [2] to

[10] above, wherein the polylysine dendrimer is present in a non-medical composition, a cosmetic composition or a dermocosmetic composition.

[12] The cosmetic use according to any one of [1] and [3] to

[11] above, or the polylysine dendrimer or a salt thereof for use according to any one of [2] to

[11] above, wherein the polylysine dendrimer is present as an active ingredient in a cosmetic composition selected from the group consisting of a soothing cream, an exfoliating product, a daily cream or gel product, a clarifying toner or lotion, a purifying cleanser, an acne-reducing cream or stick, and a concealer stick or cream, and the cosmetic composition is used on acne-prone skin, acne-prone skin or acne-prone skin.

[13] The cosmetic use according to any one of [1] and [3] to

[12] above, or a polylysine dendrimer or a salt thereof for use according to any one of [2] to

[12] above, wherein the polylysine dendrimer is used in combination with an active ingredient selected from vitamin A, retinoids (such as adapalene, tretinoin or tazarotene), bactericides (benzoyl peroxide and decanediol), azelaic acid, salicylic acid, anti-inflammatory agents (such as dapsone or Melaleuca alternifolia (tea tree) oil), anti-redness agents, anti-inflammatory agents and combinations thereof.

[14] A topical composition for use in the management of acne-prone, acne-prone or breakout-prone skin, comprising a polylysine dendrimer as an active ingredient and one or more excipients. 〔15〕 - 0.1 to 100 ppm, preferably 0.1 to 10 ppm, of a polylysine dendrimer preferably according to any one of the above items [7] to

[10] ; - 0% to 20% of one or more additional active agents, and - 70% to 99.9999% of one or more excipients A topical composition for use according to claim 14, comprising: The percentages are expressed by weight based on the total weight of the composition. Topical compositions.

[16] A method for treating or preventing acne in a subject, comprising the step of topically administering to the subject an effective amount of a polylysine dendrimer or a composition thereof preferably described in any one of [7] to

[10] .

[17] A method for restoring or rebalancing the microbiota in acne-prone skin, pimple-prone skin or acne-prone skin, comprising the step of topically administering to the subject an effective amount of a polylysine dendrimer or a composition thereof preferably described in any one of [7] to

[10] above.

[18] A method for improving the appearance and feel of skin, and / or restoring comfort to the skin, and / or preventing, ameliorating or treating breakouts and / or acne lesions, and / or soothing the skin, and / or reducing the appearance of pores (and thus smoothing the skin), and / or reducing or preventing redness and / or skin inflammation, and / or reducing sebum secretion, and / or making the skin less shiny and / or oily in appearance, and / or improving the skin in a subject having acne, pimple-prone skin or acne-prone skin, comprising the step of topically administering to the subject an effective amount of a polylysine dendrimer or composition thereof preferably according to any one of [7] to

[10] above.

[19] Use of a polylysine dendrimer, preferably according to any one of [1] to

[18] above, in the manufacture of a topical composition for the management or treatment of acne-prone, breakout-prone or acne-prone skin.

Claims

1. A cosmetic or pharmaceutical agent for the management of acne-prone or pimple-prone skin or for the treatment or prevention of acne vulgaris, comprising a polylysine dendrimer or a salt thereof as an active ingredient, said polylysine dendrimer being a second generation non-conjugated poly-L-lysine dendrigraft having a DPn of 40-60.

2. 2. The cosmetic or pharmaceutical composition according to claim 1, wherein the polylysine dendrimer or a salt thereof is an active ingredient for restoring or rebalancing the microflora of the skin.

3. 2. The cosmetic or pharmaceutical composition according to claim 1, wherein the polylysine dendrimer or its salt is an active ingredient for restoring the diversity of C. acnes in the skin.

4. The cosmetic or pharmaceutical agent according to any one of claims 1 to 3, wherein the polylysine dendrimer or a salt thereof is an active ingredient that reduces the abundance of acnegenic C. acnes strains belonging to phylotypes IA1, IA2, IB or IC in the skin.

5. The cosmetic or pharmaceutical agent according to any one of claims 1 to 4, wherein the polylysine dendrimer or a salt thereof is an active ingredient that increases the abundance of non-acnegenic C. acnes strains selected from C. acnes strains belonging to phylotype II or III in the skin.

6. The polylysine dendrimer or salt thereof may further comprise one of the following: - improving the appearance and feel of the skin, and / or - restoring skin comfort, and / or - prevention, improvement or treatment of acne breakouts, and / or - Anti-inflammatory effect on the skin, and / or - reducing or preventing skin redness or skin irritation, and / or - reduced sebum production, and / or - reduction of visible lesions such as comedones, pustules and papules, and / or - Improved skin desquamation The cosmetic or pharmaceutical composition according to any one of claims 1 to 5, wherein the active ingredient has the activity of

7. The cosmetic or pharmaceutical composition according to any one of claims 1 to 6, wherein the polylysine dendrimer is a second generation non-conjugated poly-L-lysine dendrigraft having a DPn of 46-50.

8. A cosmetic or pharmaceutical composition according to any one of claims 1 to 7, wherein the polylysine dendrimer is a poly-L-lysine dendrigraft having a linear poly-L-lysine core, the ε-amino groups of which are each substituted by a poly-L-lysine moiety.

9. 9. The cosmetic or pharmaceutical composition according to claim 8, wherein the linear poly-L-lysine core contains 6 to 10 lysine residues in length and / or the poly-L-lysine moieties grafted onto the ε-amino groups have a length of 2 to 6 lysine residues.

10. 10. The cosmetic or pharmaceutical composition of claim 9, wherein the linear poly-L-lysine core contains 8 lysine residues in length and the poly-L-lysine moiety grafted onto the ε-amino group has a length of 5 lysine residues.

11. A cosmetic or pharmaceutical composition according to any one of claims 1 to 10, in which the polylysine dendrimer is in the form of a polycationic dendrimer in which the counter anion is an acetate anion.

12. 12. A cosmetic or medicament according to any one of claims 1 to 11, which is present in a cosmetic composition selected from the group consisting of a soothing cream, an exfoliating product, a daily cream or gel product, a clarifying toner or lotion, a purifying cleanser, an acne-fighting cream or stick, and a concealer stick or cream, said cosmetic composition being used on acne-prone, breakout-prone or acne-prone skin.

13. 13. A cosmetic or pharmaceutical composition according to any one of claims 1 to 12, used in combination with another active ingredient selected from the group consisting of vitamin A, retinoids, bactericides, azelaic acid, salicylic acid, anti-inflammatory agents, anti-redness agents, anti-inflammatory agents and combinations thereof.

14. A topical composition for use in the management of acne-prone, acne-prone or breakout-prone skin, comprising a polylysine dendrimer as an active ingredient and one or more excipients, said polylysine dendrimer being a second generation non-conjugated poly-L-lysine dendrigraft having a DPn of 40-60.

15. A topical composition for use according to claim 14, wherein said polylysine dendrimer is a polylysine dendrimer according to any one of claims 7 to 11.

16. - 0.1 to 100 ppm of polylysine dendrimer, - 0% to 20% of one or more additional active agents, and - 70% to 99.9999% of one or more excipients A topical composition for use according to claim 14 or 15, comprising: The percentages are expressed by weight based on the total weight of the composition. Topical compositions.

17. 1. A cosmetic method for improving the appearance and feel of skin in a subject having breakout-prone or acne-prone skin, comprising topically administering to said subject an effective amount of a polylysine dendrimer or a composition thereof, said polylysine dendrimer being a second generation non-conjugated poly-L-lysine dendrigraft having a DPn of 40-60.

18. A cosmetic method according to claim 17, wherein the polylysine dendrimer is a polylysine dendrimer according to any one of claims 7 to 11.

19. 1. Use of a polylysine dendrimer in the manufacture of a topical composition for the treatment or prevention of acne vulgaris, wherein said polylysine dendrimer is a second generation non-conjugated poly-L-lysine dendrigraft having a DPn of 40-60.

20. 20. The use according to claim 19, wherein the topical composition is for restoring or rebalancing the microflora of acne-prone skin.

21. The use according to claim 19 or 20, wherein the polylysine dendrimer is a polylysine dendrimer according to any one of claims 7 to 11.

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