Cosmetic uses of porous metal oxide microspheres against blue light

Abstract

Cosmetic uses against blue light of porous metal oxide microspheres The invention relates to the non-therapeutic cosmetic use of porous microspheres comprising a metal oxide to protect the skin, skin appendages and / or mucous membranes against the unsightly and / or unpleasant and / or uncomfortable effects of blue light and / or to reduce and / or slow down said effects on the skin, skin appendages, and / or mucous membranes, said microspheres having: - an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 1 µm to 30 µm, - pores whose average diameter D50 measured by scanning electron microscopy (SEM) ranges from 50nm to 250nm and - an average porosity measured by mercury porosimetry ranging from 0.40 to 0.65.Another object of the invention consists of a non-therapeutic cosmetic care process comprising the application to the skin and / or mucous membranes and / or skin appendages of porous microspheres or of a cosmetic composition comprising them.

Description

Title of the invention: Cosmetic uses against blue light of porous metal oxide microspheres Technical field

[0001] The present invention relates to the non-therapeutic cosmetic use of porous metal oxide microspheres for protecting the skin, skin appendages, in particular the hair, and / or mucous membranes against the unsightly and / or unpleasant and / or uncomfortable effects of blue light and / or for reducing and / or slowing down said effects on the skin, skin appendages, in particular the hair, and / or mucous membranes. Prior art

[0002] The solar radiation spectrum is distributed over different wavelength intervals including the ultraviolet (UV; 100-400 nm), visible (401-700 nm) and infrared region (>700 nm). UV radiation represents a highly energetic part of the electromagnetic spectrum reaching the Earth's atmosphere. This region is subdivided into three wavelength bands: UVC (<280 nm), UVB (280-320 nm) and UVA (320-400 nm). While UVC is effectively blocked by oxygen, ozone and nitrogen molecules in the upper atmosphere and the majority of UVA passes through the ozone layer of the stratosphere, UVB radiation is only partially absorbed by stratospheric ozone. The infrared and visible regions account for the vast majority of solar emissions that penetrate the atmosphere. The visible spectrum is composed of a range of wavelength intervals of light that can be perceived by the human eye as colors.The rainbow is a typical example of these different visible colors. Solar radiation is composed of 25% to 30% blue light, depending on the reference solar spectrum.

[0003] Blue light is therefore high-energy visible (HEV) light with a wavelength in the range 401 nm to 500 nm. The sun is the main source of natural blue light, but humans are also increasingly exposed to blue light from artificial sources, which vary widely in distribution spectrum. Blue LEDs emitting blue light in the range 401 nm to 495 nm are considered more hazardous than green and red LEDs. The dominant wavelength of electronic devices has been estimated to be 448 nm (blue light), 535 nm (green light) and 599 (red light).

[0004] Although ultraviolet radiation from the sun is among the most ubiquitous damaging environmental factors from which human skin must protect itself, Recent advances have highlighted the important role of visible light, and in particular blue light, in premature skin aging due to the generation of oxidative stress (Nakashima Y, Ohta S, Wolf AM. Blue light-induced oxidative stress in live skin - Free Radie Biol Med. Jul; 108:300-310, 2017). This publication mentions that blue light, especially the shorter wavelength, could contribute to skin aging in a similar way to UVA. Thus, depending on the wavelength and the applied dose, blue light influences the physiological responses of the skin.As blue light has the most energetic wavelength of visible light, it penetrates the deepest into the skin, not only into the epidermis but also into the dermis generating oxidative stress and producing proteases that degrade the extracellular matrix of the dermis (Saint-Aurel G, Kiening M, Haguet V, Sullerot M, Escaich S, Ramchum R. The double nature ofblue light on skin dependent pathways. IFSCC Congress Munich. ID 560, 2018).

[0005] In the stratum corneum, blue light contributes to the formation of carbonyl proteins that deteriorate the epidermal barrier and alter skin color (Mizutani T, Sumida H, Sagawa Y, Okano Y, Masaki H. Carbonylated proteins exposed to UVA and to blue light generate reactive oxygen species through a type 1 photosen-sitizing reaction. J Dermatol Sci. Dec;84(3):314-321, 2016). The skin is an organ in constant contact with the outside world. It therefore plays a role of exchange but also and above all as a barrier to the outside world. The superficial layer of the skin, called the stratum corneum, constitutes the first barrier protecting the skin, in the form of a thin film. This, by its hydrophobic nature, constitutes a barrier to the diffusion of water, the main constituent of cells, and thus prevents dehydration. However, there are still so-called transepidermal water losses or otherwise called insensible water losses.If the stratum corneum is weakened, for example due to exposure to blue light, the skin barrier is broken and these insensible water losses increase. The skin becomes dry and more vulnerable to external aggressions. Maintaining water content through the role of the skin barrier is therefore essential for maintaining the functionality and aesthetic appearance of the skin.

[0006] Blue light at about 450 nm promotes keratinocyte differentiation and reduces the antioxidant capacity of fibroblasts (Opldnder Cl, Hidding S, Wemers FB, Bom M, Pallua N, Suschek CV. Effects ofblue light irradiation on human dermal fi-broblasts. J Photochem Photobiol B. May 3;103(2):118-25. 2011). Other studies have shown that blue light increases the amount of reactive oxygen species (ROS), protein carbonyls, metalloproteinase-1 (MMPI) and 8-OHdG (8-oxo-7,8-dihydro-2'-deoxyguanosine). MMP-1 and 8-OHdG are associated with premature aging. In particular MMPI is a metalloproteinase belonging to the family of enzymes involved in the degradation of the extracellular matrix, mainly dermal collagen including type I collagen, type IV collagen, fibronectin and laminins. Pollutants, UV or blue light can thus cause the expression of MMPI and can therefore lead to premature aging of the skin.

[0007] Type I collagen is found in particular in many human tissues such as tendons, ligaments, cornea and skin. Type I collagen is the majority collagen in the skin. It is one of the fibrillar collagens along with collagen III and V. It is collagen that gives tissues their mechanical resistance, thus playing a major role in maintaining their firmness. Blue light, by degrading collagen via MMPI, contributes to reducing skin firmness.

[0008] The most visible signs of premature skin aging caused by blue light appear on the face: the skin relaxes and the first wrinkles form and become visible. The firmness and density of the skin and mucous membranes are also degraded during premature aging induced by blue light. During aging, the formation of elastic fibers and collagen fibers decreases and under the action of oxidative stress induced for example by blue light, its degradation by MMPs and elastases increases. However, it has been observed that, under the effect of oxidative stress, part of the elastin synthesis in the deep dermis is also increased and accumulates in an anarchic manner in the form of elastin aggregate, thus contributing to the loss of elasticity.

[0009] The physical appearance and phenotypic aspects of keratin fibers of the skin appendages, including hair, such as color, density, curl, shine, volume, flexibility, and style, play an important role in social communication and self-esteem. From a functional point of view, hair also plays a role in protecting the scalp against external aggressions, particularly against ultraviolet radiation and blue light. It also helps maintain body temperature and provides tactile sensations.

[0010] During aging, particularly induced by blue light, the structural and functional qualities of the keratin fiber of the skin appendages, particularly the hair fiber, deteriorate. Hair and eyelashes are finer and more fragile. Hair is also more difficult to style and structure. Eyelashes and eyebrows are more difficult to apply and make up. The aging of the keratin fiber of the skin appendages, particularly the hair, includes the aging of the keratin fiber, particularly the hair fiber, and the aging of the hair follicle. The scalp, which contains the hair follicles, also plays a very important role in the behavior and aging of the hair follicle and consequently in the quality and growth of the hair fiber.

[0011] The keratin fiber of the cutaneous appendages is an inert structure of the appendage type. It is composed mainly of dead keratinized cells. Different types of keratin fibers are distinguished according to their location, growth and functions: eyelashes, eyebrows, hairs, especially beard and mustache, and hair, also called capillary fibers. Generally speaking, three major concentric parts constitute a keratin fiber: the medulla (or medullary canal) in the center, the cortex in the intermediate zone, and finally the cuticle forming the surface scales. The cortical zone represents the major part of the hair shaft (90% of the total weight). It is the seat of pigmentation and gives the keratin fiber its physical and mechanical properties. The cuticle is the protective envelope of the keratin fiber, formed of highly keratinized, non-pigmented cells forming the external scales of the hair.The medulla is located in the center of the hair shaft. It is made up of large, anucleate cells that are light or poorly pigmented compared to the cortical cells.

[0012] The organ allowing the synthesis of the keratin fiber of the cutaneous appendages and in particular the hair is the hair follicle. It extends under the scalp in the case of hair and under the epidermis of the skin in the case of other keratin fibers and can be divided into three segments of roughly similar length: the infundibulum or superficial segment, the isthmus or median segment, the bulb or lower segment. The hair follicle is made up of living cells of the keratinocyte, fibroblast and melanocyte type and extracellular matrix. The organization, the cellular and molecular interactions allow the synthesis of the hair shaft. It is created at the level of the deepest part of the hair follicle: the bulb, and grows towards the surface of the skin, in particular for the hair on the surface of the scalp.The hair shaft, previously surrounded by cells, becomes free in the infundibulum at the level of the mouth of the sebaceous canal, an appendage that accompanies the hair follicle. The keratin fiber of the cutaneous appendages, particularly the capillary fiber visible at the root of the scalp for the hair or at the junction with the skin, can be called an emerging fiber. The fiber not visible at the root contained in the skin, particularly the scalp, can be called a pre-emergent fiber. The average growth of a hair fiber lasts 3-4 years on average. Its growth rate is estimated at lem / month under normal average conditions. The shaft takes about 2 weeks from the seat of its creation to the surface of the scalp. An emerging shaft of 6 cm takes about 6 months to be formed.

[0013] With aging, the quality of the fiber of the skin appendages decreases, making it more fragile in contact with its environment. Aged hair, especially prematurely, is finer, more damaged, more brittle than young hair. The hair lacks volume, shine and vitality.

[0014] Blue light directly alters the structural and functional properties of the hair fiber. Thus, aged hair is more damaged, finer and in particular is difficult to style and shape compared to younger hair and is brittle, especially split ends. This loss of surface quality of the hair is visible and unsightly. The hair also reflects less light and is therefore visibly duller, less shiny, less luminous. This aging also has an impact on hair loss, which can result in a perception of fragility and hair loss over time. The hair thus appears less dense. The other keratin fibers of the cutaneous appendages are exposed to the same aging phenomenon, altering their quality and quantity, in a particularly unsightly and often unwanted manner for the eyelashes, eyebrows and nails.

[0015] Furthermore, at the level of the hair follicle bulb, in particular the hair follicle, mature melanocytes specialized in the synthesis of pigments (melanin) transfer these pigments to the keratinocytes of the hair follicle, or matrix cells, which produce the keratin fiber, in particular the hair. During aging, the quantity of pigments transferred to the keratin fiber of the cutaneous appendages, in particular the hair, decreases. This loss of pigmentation of the keratin fiber may be due to defects in the genesis of melanin or to the loss in the number of melanocytes that produce it. The speed and duration of growth of the keratin rod, in particular the hair, also decreases, as does its diameter. Not all keratin rods of the cutaneous appendages, in particular the hair, lose their pigment synchronously over time.The graying or whitening of keratin fibers in the skin appendages, including eyelashes, eyebrows, beard, mustache, and hair, with age is the overall visual consequence of pigmented and non-pigmented keratin rods, the latter appearing white. Lightening of eyelashes, eyebrows, beard, mustache, and hair may result from dilution of the pigment, an increase in the frequency of non-pigmented keratin fibers in the skin appendages, including hair, or an increase in the loss of pigmented keratin fibers, including pigmented hair.

[0016] There is therefore a need to find new cosmetic active ingredients that can protect the skin and / or mucous membranes and / or skin appendages against blue light and its unsightly and / or unpleasant and / or uncomfortable effects such as premature aging and weakening of the skin barrier.

[0017] The Applicant has discovered that metal oxide microspheres have the property of protecting the skin, mucous membranes and skin appendages against blue light, in particular having an anti-blue light filter effect.

[0018] Such microspheres in fact have the unique capacity, thanks to the presence of pores with a monodisperse or bimodal size distribution, to be able to target the reflection of a precise wavelength. Indeed, the size of the pores and their quantity (porosity) as well as the size of the microspheres can be carefully chosen for this purpose thanks to the prior manufacture of a polymer template / model. Thus, the Applicant has discovered that particular metal oxide microspheres having an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 1 pm to 30 pm, pores with an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 50 nm to 250 nm and an average porosity measured by mercury porosimetry ranging from 0.4 to 0.65, could, when found on the skin, mucous membranes and / or cutaneous appendages, in particular prevent the transmission of blue light.

[0019] The microspheres according to the invention offer the advantage of being suitable for all skin types regardless of type, complexion and radiance. Another advantage of the present invention is that the spheres have great stability and can be used in powder form or in composition. They are inert, which makes it easy to formulate them in any type of cosmetic composition, whether lipophilic or hydrophilic. Another advantage is that the spheres can be used with the conventional ingredients of cosmetic compositions,

[0020] Metal oxide spheres have already been described in patent applications WO2020 / 183108 and WO2020 / 182936 in the context of cosmetic applications. However, these applications do not describe or suggest the protective effect of these microspheres against blue light and its unsightly and / or unpleasant and / or uncomfortable effects. Statement of the invention

[0021] The present invention thus relates to the non-therapeutic cosmetic use of porous microspheres comprising, advantageously consisting of, a metal oxide to protect the skin, the skin appendages, in particular the hair, and / or the mucous membranes against the unsightly and / or unpleasant and / or uncomfortable effects of blue light and / or to reduce and / or slow down said effects on the skin, the skin appendages, in particular the hair, and / or the mucous membranes, said microspheres having: - an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 1 pm to 30 pm, - pores with an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 50nm to 250nm and - an average porosity measured by mercury porosimetry ranging from 0.40 to 0.65.

[0022] For the purposes of the present invention, the term “mucosa” means the ocular mucosa, the vaginal mucosa, the urogenital mucosa, the anal mucosa, the nasal mucosa and / or the buccal, labial and / or gingival mucosa, preferentially the mucosae most exposed to blue light, in particular the ocular and / or labial and / or nasal mucosa.

[0023] For the purposes of the present invention, the term "skin" means the skin of the face and body including the scalp and the term "scalp" means the temporal areas of the scalp, the frontal area, the parietal area and the vertex or top of the skull.

[0024] For the purposes of the present invention, the term “cutaneous appendages” means hair, eyelashes, eyebrows, beard, moustache and / or nails, preferably hair.

[0025] For the purposes of the present invention, the term "blue light" means light having a wavelength ranging from 401 to 500nm, advantageously from 415 to 490nm, more advantageously from 420 to 480nm, and in particular from 430 to 460 nm.

[0026] The use according to the invention is cosmetic, and preferably by topical application to at least one area concerned or a part of healthy skin, healthy mucosa and / or healthy cutaneous appendages, preferably the hair, preferably in humans.

[0027] For the purposes of the present invention, the term "cosmetic use" means a non-therapeutic, non-pharmaceutical use of the spheres according to the invention, preferably intended, in particular, for healthy skin, in particular a healthy scalp, and / or healthy skin appendages, in particular healthy hair, and / or healthy mucous membranes.

[0028] For the purposes of the present invention, the term "part of skin" and / or "area of ​​skin" referred to as "healthy" means a part of the skin and / or an area of ​​skin, described as non-pathological by a dermatologist, that is to say which does not present any infection, inflammation, in particular in the form of sunburn, disease or skin conditions such as folliculitis, candidiasis, psoriasis, ichthyosis, impetigo, eczema, acne, boils, abscesses, herpes, ecthyma, erysipelas or dermatitis, varicose veins, rosacea or telangiectasia, pathologies or wounds or injuries or burns or does not suffer from solar elastosis, which is not reactive skin or skin with atopic tendency. In particular, it is a part of skin and / or mucous membrane made up of cells described as “normal” by a doctor, that is to say, non-cancerous cells.

[0029] The term "topical application", as used herein, means applying the microspheres according to the present invention, optionally in the form of an active ingredient and / or composition, to the surface of the skin including the scalp, the skin appendages, in particular the hair, and / or the mucous membranes, in particular by direct application, such as by massage with circular movements, or by spraying the microspheres onto the surface of the relevant area of ​​the skin and / or the mucous membranes and / or the skin appendages.

[0030] For the purposes of the present invention, the term "protecting the skin and / or mucous membranes and / or skin appendages" means at least partially maintaining the structure and / or visual properties and / or biomechanical properties and / or surface properties and / or texture and / or sensory qualities of the skin and / or mucous membranes and / or skin appendages, preferably keratin fibers, even more preferably hair. This protection is preferably evaluated when the skin and / or mucous membranes and / or skin appendages are exposed to blue light.

[0031] In particular, the protection of the skin and / or mucous membranes and / or skin appendages against the unsightly and / or unpleasant and / or uncomfortable effects of blue light can be evaluated by analyzing the MMPI content in the dermis or epidermis or the 8-OHdG content in the skin. This analysis is carried out by immunolabeling under the conditions indicated in Example 2.

[0032] This analysis is in particular carried out on skin treated with the microspheres according to the invention subjected to blue light radiation, in particular at 85J / cm2 (wavelength 401-500 nm of the visible light spectrum with a peak at 455 nm for 4 hours), and compared to the analysis results obtained with skin not treated with the microspheres according to the invention and subjected to similar blue light radiation, in particular as described in example 2.

[0033] The reduction in the MMPI content in the dermis of the skin treated with the microspheres according to the invention is advantageously at least 10%, more advantageously at least 20%.

[0034] The reduction in the MMPI content in the epidermis of the skin treated with the microspheres according to the invention is advantageously at least 30%, more advantageously at least 50%.

[0035] The reduction in the 8-OHdG content in the skin treated with the microspheres according to the invention is advantageously at least 20%, more advantageously at least 30%.

[0036] According to the present invention, the "unsightly and / or unpleasant and / or uncomfortable effects of blue light" are advantageously chosen from aging of the skin and / or mucous membranes and / or skin appendages and / or alteration of the skin and / or mucosal barrier and / or dehydration of the skin and / or mucous membranes and / or skin appendages and / or alteration of the biomechanical properties of the skin and / or mucous membranes and / or skin appendages.

[0037] In particular, the “unsightly effects of blue light” may consist of the appearance of unsightly irregularities in the relief, in particular the microrelief, and / or the texture of the skin, mucous membranes and / or cutaneous appendages and / or irregularities in the color of the skin, mucous membranes and / or cutaneous appendages, in particular making the complexion uneven.

[0038] According to the present invention, the unsightly irregularities of the relief, in particular of the microrelief, and of the texture of the skin are wrinkles and fine lines, in particular lion's wrinkle and crow's feet, roughness and rough appearance.

[0039] According to the present invention, the irregularities in skin color are pigment spots, in particular age spots or hyperpigmented or depigmented spots, pregnancy mask, redness, but also loss of radiance of the complexion, dull complexion and dark circles.

[0040] According to a preferred embodiment, the unsightly effects of blue light on the skin and / or mucous membranes are selected from alteration of the microrelief of the skin and / or mucous membranes, the appearance of wrinkles and / or fine lines, loss of radiance of the complexion, lack of homogeneity of the complexion, the appearance of a dull complexion and / or dark circles and / or pigment spots, sagging of the skin and / or loss of tone and / or elasticity and / or firmness and / or density of the skin and / or mucous membranes and / or alteration of the surface and / or texture and / or visual properties and any mixture thereof.

[0041] The unsightly effects of blue light on skin appendages, preferably hair, are in particular the alteration of its visual properties and / or its surface and / or texture properties, the appearance of a dull, brittle appearance. For hair, the unsightly effects also include the appearance of a brittle, friable, damaged appearance and / or difficulty in shaping them, in particular for hair, in styling them, and / or split ends.

[0042] The unsightly effects of blue light on the mucous membranes include the appearance of a dull, cracked, withered and / or damaged appearance as well as scales.

[0043] According to the present invention, the “unpleasant and / or uncomfortable effects of blue light” may consist of the appearance of a sensation of tightness, tension, tingling, prickling, and / or roughness of the skin and / or mucous membranes and / or the alteration of the sensory qualities of the skin and / or mucous membranes and / or cutaneous appendages, in particular hair.

[0044] Thus advantageously the non-therapeutic cosmetic use of the microspheres according to the invention is to prevent and / or slow down - the appearance of wrinkles and / or fine lines and / or pigment spots on the skin and / or mucous membranes, and / or - loss of radiance of the complexion of the skin and / or mucous membranes and / or lack of homogeneity of the complexion of the skin and / or mucous membranes and / or - sagging skin and / or -loss of tone and / or elasticity and / or firmness and / or density of the skin and / or mucous membranes and / or - whitening and / or graying of the skin appendages and / or - dehydration and / or insensible water loss from the skin and / or mucous membranes and / or - alteration of the microrelief of the skin and / or mucous membranes and / or - alteration of the surface and / or texture and / or visual properties and / or sensory qualities of the skin and / or mucous membranes and / or cutaneous appendages, in particular hair.

[0045] This use is not to improve the appearance and / or comfort of the skin and / or skin appendages and / or mucous membranes, in particular by masking effect, but is to prevent the occurrence of unsightly and / or unpleasant and / or uncomfortable effects of blue light or at least to slow down their appearance.

[0046] Generally speaking, the prevention and / or reduction of unsightly effects can be visualized and evaluated by microscopy and / or by analysis of high-resolution photography, including measurement of the brightness of the area of ​​skin, mucous membrane and / or skin appendages.

[0047] The prevention and / or slowing down of the loss of radiance of the complexion, known as "radiance" or "glow" in English, can in particular be measured by an objective instrumental method. This in vivo measurement method consists of taking high-resolution photographs in a crossed polarized configuration of the faces of volunteers at 45° before and after application of the tested product. On the basis of these digital photographs, an image analysis makes it possible to extract and quantify specific parameters (for example: L*, a*, b*, C, h°) related to the color, radiance, homogeneity, and texture of the skin.

[0048] Similarly, the so-called "gloss" in English can in particular be measured according to this method on the basis of high-resolution photographs in crossed polarized and parallel polarized configuration of the face of the volunteers taken at 45° before and after application of the tested product. On the basis of these digital photographs, an image analysis makes it possible to extract and quantify specific parameters related to the gloss such as the specular gloss and the contrast gloss.

[0049] For the purposes of the present invention, the term "insensible water loss" means passive diffusion and insensible perspiration measured at the cutaneous or mucosal level. Also called transepidermal water loss or TEWL (transepidermal water loss), insensible water loss can be measured by different methods, in particular in vivo, in particular via an evaporimeter, a tewameter, in particular in vitro, in particular by the open cylinder technique described in Example 1 of patent application WO 2014 / 027163 and / or ex vivo. Thus, for example, insensible water loss is measured by the technique described in Example 1 of patent application WO 2014 / 027163 in an open cylinder and the reduction is determined relative to an untreated control. This technique is inspired by those described in the publications Lieb et al. "A new in vitro method for transe- epidermal water loss: a possible method for moisturizer evaluation », J. Soc. Cosmet. Chem. ,March 1988, 39, 107-109 and Strussmann et al. « Water permeability of skin care products in relation to molecular and environmental influence », Int. Jounal of Cosmetic Science, 1993, 15, 227-233. However, carried out in an oven and therefore in a dry atmosphere and at high temperature (45°C), this test accentuates and amplifies the phenomenon of insensible water losses, allowing measurement in particularly severe conditions.

[0050] For the purposes of the present invention, the term "water content of the skin and / or mucous membranes" means the quantity of water contained in the epithelia, in particular the epidermis and / or the epithelium of the mucous membranes. This content thus reflects the state of hydration. There are different methods for measuring the water content of the skin and / or mucous membranes, in particular in vivo and in particular via the corneometer, and / or by measuring desquamation via the comeofix, or in vitro, in particular via the measurement of dielectric conductivity, in particular according to the method described in example 4 of patent application WO 2014 / 027163.

[0051] For the purposes of the present invention, the term "preventing or slowing down the loss of firmness" means preventing and / or slowing down, for aesthetic purposes, the loss of firmness of the skin and / or mucous membranes subjected to blue light radiation, in particular by comparison between skin and / or mucous membranes treated using the microspheres according to the invention and subjected to blue light radiation and untreated skin and / or mucous membranes subjected to blue light radiation or not subjected to blue light radiation.

[0052] Conventional methods for measuring skin firmness consist of measuring the depth of its possible deformations, while those aimed at measuring skin elasticity consist of measuring its capacity to return to its initial state after twisting and / or deformation.

[0053] The prevention or reduction of the loss of firmness can be measured according to conventional methods, in particular by in vivo measurement using a cutometer, a densiscore, a torquemeter or even a dynaskin associated with a dermatop and in particular by comparison between skin and / or mucous membranes treated using the microspheres according to the invention and subjected to blue light radiation and untreated skin and / or mucous membranes subjected to blue light radiation or not subjected to blue light radiation.The prevention or reduction of the loss of elasticity can be measured according to conventional methods, in particular by in vivo measurement, using a ballistometer or a corneovacuometer and in particular by comparison between skin and / or mucous membranes treated using the microspheres according to the invention and subjected to blue light radiation and skin and / or mucous membranes not treated and subjected to blue light radiation or not subjected to. a radiation of blue light.

[0054] Conventional techniques for measuring the protection of skin appendages make it possible to measure the capacity of the product being evaluated to maintain a visual, structural or functional state of the skin appendage subjected to blue light radiation, preferably of the keratin fiber subjected to blue light radiation, still preferably of the hair comparable to the state of a skin appendage not subjected to blue light radiation, preferably of the keratin fiber not subjected to blue light radiation, still preferably of the hair not subjected to blue light radiation.

[0055] Conventional techniques can be used to test the effectiveness of the product being evaluated in its solvent, or of a hair formula (shampoo, conditioner, mask, lotion, or other). They can be implemented on a sampled skin appendage (ex vivo technique) or on a skin appendage in place on an individual (in vivo technique).

[0056] As an example of the methods used to evaluate the protection of skin appendages, preferably keratin fibers and even more preferably hair, we can cite: - observation of the cuticle by electron microscopy: this technique involves observing the condition and / or quality of the cuticle, by visualizing and quantifying the detached scales as an indicator of surface damage. Damaged hair shows detachment of the scales, whereas protected hair appears smoother on the surface and its scales are sealed. - The study of differential scanning calorimetry (DSC): this method makes it possible to determine internal damage to the hair by measuring the denaturation temperature or enthalpy and thus respectively the evaluation of the stability of the non-helical proteins forming the cement of the matrix or the keratins (alpha-helices) of the cortex. The lower the temperature or enthalpy, the greater the damage to the hair. A protected hair is in fact a hair stable to temperature. - Analysis of the tension force on dry and / or wet hair: the evaluation of the functional and mechanical properties of the hair is carried out by measuring elasticity, deformation capacity, resistance of the hair in response to a tension force. Parameters such as tension force, elastic modulus, breaking force and breaking point make it possible to evaluate these biomechanical properties. These parameters reflect the state of internal damage to the hair fiber. Protected hair is hair whose elastic and deformation properties are maintained.

[0057] Damaged hair is rough, more difficult to style and more brittle at styling. Hair protection can therefore have a beneficial effect on these styling properties, which can also be measured.

[0058] By way of example, the styling evaluation methods which can be used according to the invention are: - Evaluation of styling strength on dry and / or wet hair: biophysical evaluation of the ease of styling hair by measuring the force generated when passing a comb through it. High styling strength indicates damaged hair. Products are tested for their properties in facilitating styling or detangling hair. Undamaged hair, because it is protected, is easier to style and detangle. - The study of friction forces for hair surface roughness: evaluation of the friction forces of a strand of hair when passing metal bars. Damaged hair is rough and presents greater friction forces than undamaged hair. Protected hair is smoother and presents a reduction in friction forces. - Styling resistance analysis: assessment of hair breakage after repeated styling of a strand of hair. Damaged hair breaks more easily during repeated styling. Protected hair breaks less.

[0059] Damaged hair appears rough, brittle, difficult to style, dull. Hair protection helps maintain the sensory qualities of healthy, undamaged hair: smooth, soft, easy to detangle, easy to style, easy to shape, shiny, stronger, more resistant.

[0060] For example, the evaluation methods used are: - Sensory tests on strands of hair, carried out by external volunteers trained to define their visual or tactile sensations. - Evaluation tests by experts (hairdressers) or self-assessment by consumer questionnaires. The effectiveness of a product in its formula is evaluated according to visual or tactile quality criteria perceptible on the hair.

[0061] According to the invention, the term "structure of the cutaneous appendages" means the state of the cutaneous appendages, in particular the cuticle and even more preferably the scales of the cutaneous appendages. The structure of the cutaneous appendages can thus be measured by the above-mentioned techniques of observation of the cuticle by electron microscopy and study of differential scanning calorimetry.

[0062] According to the invention, the term "visual properties of the skin appendages" means brightness, shine and color. The visual properties of the skin appendages can in particular be evaluated by the visual sensory tests mentioned above.

[0063] According to the invention, the term “biomechanical properties of the cutaneous appendages” means their qualities to the touch, in particular their softness, their silky and / or smooth character and their flexibility, as well as their resistance, their elasticity, their deformation and their strength as well as their ease of shaping and / or styling.

[0064] According to the invention, the term "biomechanical properties of the skin and / or mucous membranes" means their qualities to the touch, in particular their softness, their silky and / or smooth character and their suppleness, their tone, elasticity, firmness, density, their microrelief, their surface and / or texture and / or visual properties and / or their sensory qualities.

[0065] According to the invention, the term “structure of the skin and / or mucous membranes” means the state of the skin and / or mucous membranes, in particular the skin barrier.

[0066] According to the invention, the term "visual properties of the skin and / or mucous membranes" means the shine, the brightness and the color, in particular the radiance of the complexion and / or the homogeneity of the complexion.

[0067] The biomechanical properties of the cutaneous appendages can be measured in particular by analyzing the tension force on dry and / or wet hair and / or the styling evaluation methods and / or the tactile sensory tests mentioned above.

[0068] The microspheres according to the invention are porous metal oxide microspheres. Such microspheres are photonic beads, which means that they exhibit a degree of periodic color variations.

[0069] The porous microspheres according to the invention mainly contain the metal oxide. Advantageously, they consist essentially of the metal oxide. Preferably, they consist exclusively of metal oxide.

[0070] Advantageously, the porous microspheres comprise between 60% and 99.9% of metal oxide, preferably at least 70%, more preferably at least 80%, more preferably at least 90%, more preferably 99.9% by weight relative to the total weight of the microspheres.

[0071] According to the invention, the metal oxides include transition metal oxides, metalloids and earth metals compatible with cosmetic and / or dermatological use, such as, for example, silica, titanium, alumina, zirconia, cerium, iron oxide, zinc oxide, indium oxide, tin oxide, chromium oxide, mixed metal oxide, and combinations thereof. Preferably, the metal oxide is chosen from the group consisting of SiO2, TiO2, ZnO and mixtures thereof, advantageously it is SiO2.

[0072] In an advantageous embodiment, the porous microspheres according to the invention may comprise, for example, from 60% by weight to 99.9% by weight of metal oxide and from 0.1% by weight to 40% by weight of light-absorbing agents, by total weight of the spheres. According to one embodiment of the invention, the spheres contain from 0.3%, preferably 0.5%, preferably at least 1%, more preferably at least less than 5% by weight of light absorbing agents, relative to the total weight of the spheres.

[0073] According to an alternative and preferred embodiment, the microspheres according to the invention do not contain a light absorber and / or the cosmetic composition which contains them does not contain a light absorber either. Indeed, light absorbers such as TiO2 can have a certain toxicity. However, the inventors have surprisingly discovered that even without a light absorber, the microspheres according to the invention have an immediate anti-blue light filter effect.

[0074] Advantageously, the light-absorbing agent(s) are selected from the group consisting of organic and inorganic pigments, compatible with cosmetic and / or dermatological application, in particular on the skin, mucous membranes and / or cutaneous appendages.

[0075] According to an advantageous preferred embodiment, the porous microspheres according to the invention have an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 1.1 pm to 20 pm, advantageously from 1.2 pm to 14 pm, in particular from 1.3 pm to 10 pm, more particularly from 1.5 to 4.5 pm, even more particularly from 1.6 pm to 4.4 pm, for example an average diameter chosen from 1 pm, 2 pm, 3 pm, 4 pm, 5 pm, 6 pm, 7 pm, 8 pm, 9 pm, 10 pm, 11 pm, 12 pm, 13 pm, 14 pm, 15 pm, 16 pm, 17 pm, 18 pm, 19 pm, 20 pm, 21 pm, 22 pm, 23 pm, 24 pm, 25 pm, 26 pm, 27 pm, 28 pm, 29 pm or 30 pm. Thus, they are not nanospheres in order to avoid their penetration into the deep layers of the skin and / or mucous membranes and to preferentially have a surface effect. The microspheres according to the invention therefore advantageously remain on the surface of the skin and / or mucous membranes and / or cutaneous appendages.

[0076] In a preferred embodiment of the invention, the average pore diameter D50 of the microspheres measured by scanning electron microscopy (SEM) ranges from 80 nm to 250 nm, advantageously from 100 nm to 245 nm, in particular from 145 nm to 235 nm, more particularly from 180 nm to 225 nm, even more particularly from 195 nm to 217 nm, for example chosen from: 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140nm, 145nm, 150nm, 155nm, 160nm, 165nm, 170nm, 175nm, 180nm, 185nm, 190nm, 191nm, 192nm, 193nm, 194nm, 195nm, 196nm, 197nm, 198 nm, 199 nm, 200 nm, 201 nm, 202 nm, 203 nm, 204 nm, 205 nm, 206 nm, 207 nm, 208nm, 209nm, 210nm, 211nm, 212nm, 213nm, 214nm, 215nm, 216nm, 217 nm, 218nm, 219nm, 220nm, 225nm, 230nm, 235nm, 240nm, 245nm or 250nm.

[0077] In a preferred embodiment of the invention, the porous microspheres have an average porosity chosen from: 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64 or 0.65, preferably ranging from 0.45 to 0.60, more preferably 0.50 to 0.60.

[0078] According to the invention, the size of the microspheres and / or pores is a synonym for the diameter of the microspheres and / or pores and is determined by scanning electron microscopy (SEM). The average diameter of the microspheres and / or pores (or average size) is understood to be the D50, meaning that half of the population is below and the other half is above. It is obtained by analyzing 50 to 70 microspheres and / or 50 to 70 pores of different microspheres by scanning electron microscopy using ImageJ image analysis software.

[0079] The average porosity of a microsphere refers to the total pore volume, as a fraction of the volume of the entire microsphere. The average porosity may also be referred to as the "volume fraction." It is a dimensionless quantity.

[0080] Mercury porosimetry analysis is used to characterize the porosity of spheres. Mercury porosimetry involves applying a controlled pressure into the sample to be measured immersed in mercury. The external pressure is applied so that the mercury penetrates into the pores / holes of the material. The amount of pressure required is inversely proportional to the size of the pores / holes. The mercury porosimeter then provides volume and pore size distributions. The mercury porosimeter generates volume and pore size distributions from the pressure data versus the intrusion data generated by the instrument using the Washbum equation.

[0081] In an advantageous embodiment, the microspheres according to the invention do not contain and / or are not used in combination with another blue light filter and / or an anti-UV filter and / or a sunscreen and / or in a cosmetic composition which contains them. Thus the microspheres according to the invention are not used as a booster for blue light filters and / or to increase the SPF (sun protection factor) of a sunscreen composition.

[0082] In an advantageous embodiment, the porous microspheres according to the invention do not comprise a coating layer on their surface containing a hydrophobic compound. In a particularly advantageous embodiment, the porous spheres according to the invention do not comprise a coating layer on their surface.

[0083] According to a particular embodiment of the invention, the porous microspheres according to the invention do not comprise a coating layer on their surface containing a polyorganosiloxane, in particular a silicone compound.

[0084] The porous microspheres comprising a metal oxide according to the invention can be prepared using a sacrificial polymer template. Such porous microspheres exhibit a color observable by the human eye, in particular a blue color.

[0085] "A color observable to the naked eye" means a color that is observable by a majority of people. This can be for any sample of microspheres distributed over a given area, for example, over 1 cm2, 2 cm2, 3 cm2, 4 cm2, 5 cm2 or 6 cm2, 7 cm2, 8 cm2, 9 cm2, 10 cm2, 11 cm2, 12 cm2, 13 cm2, 14 cm2 or 15 cm2. This can also mean that it is observable by the CIE 1931 2° standard observation pattern and / or by the CIE 1964 10° standard observation pattern. The observation background of the color can be of different kinds, for example, white, black, or anything intermediate between black and white.

[0086] The microspheres can be prepared by a method as described in patent application US2019 / 0076809 or in one of patent applications WO2020 / 183108 and WO2020 / 182936.

[0087] Thus, according to one embodiment, an aqueous colloidal dispersion containing polymer particles and a metal oxide is prepared, the polymer particles typically being on the nanoscale. The aqueous colloidal dispersion is then mixed in an oily continuous phase, for example with a microfluidic device, to produce a water-in-oil emulsion. Aqueous emulsion droplets are obtained, collected and dried to form the microspheres containing the polymer and metal oxide nanoparticles. The polymer nanoparticles (nanospheres) are then removed, for example by calcination, to provide spherical, micrometer-scale particles of metal oxide containing a high degree of porosity and nanoscale pores. The spheres may contain uniform pore diameters, due to the use of spherical and monodisperse polymer particles.

[0088] For example, a drop of emulsion containing polymer nanospheres and a metal oxide is dried to remove the solvent, thereby producing a microsphere formed of polymer nanospheres with the metal oxide in interstitial spaces between the polymer nanospheres (template microspheres or "forward structure"). The polymer nanospheres define an interstitial space. Calcination results in removal of the polymer, thereby providing a metal oxide microsphere having high porosity or a large interstitial volume (reverse structure).

[0089] The porous metal oxide microspheres are advantageously sintered, leading to a continuous, consolidated, thermally and mechanically stable solid structure.

[0090] In some embodiments, the formation of the droplets and their collection take place in the microfluidic device.

[0091] Microfluidic devices are for example narrow channel devices having a microscale junction adapted to produce uniform droplets and connected to a collection reservoir.

[0092] The microfluidic devices contain, for example, a junction having a channel width ranging from 10 μm to about 100 μm. These devices are, for example, made of polydimethylsiloxane (PDMS) and can be prepared for example by soft lithography. An emulsion can be prepared inside the device by pumping an aqueous dispersed phase and an oily continuous phase in a defined ratio, thus forming an emulsion by mixing the two phases. Alternatively, an oil-in-water emulsion can be used.

[0093] Preferably, the polymer is selected from the group consisting of poly(meth)acrylic acid, poly(meth)acrylates, polystyrenes, polyacrylamides, polyethylene, polypropylene, polylactic acid, polyacrylonitrile, as well as their derivatives and salts, their copolymers and their combinations. Preferably, the polymer is selected from the group consisting of polystyrenes, for example a polystyrene / acrylic acid copolymer, polystyrene / poly(ethylene glycol) methacrylate or polystyrene / styrene sulfonate.

[0094] The weight ratio (weight / weight) of polymer / metal oxide nanoparticles ranges, for example, from about 0.1 / 1 to about 10.0 / 1 or from about 0.5 / 1 to about 10.0 / 1. Advantageously, this ratio is: 0.1 / 1, 0.5 / 1, 1.0 / 1, 1.5 / 1, 2.0 / 1, 2.5 / 1, 3.0 / 1, 3.5 / 1, 4.0 / 1, 5.0 / 1, 5.5 / 1, 6.0 / 1, 6.5 / 1, 7.0 / 1, 7.5 / 2.5, 8.0 / 1, 9.0 / 1 or 10.0 / 1, in particular 7.5 / 2.5.

[0095] The continuous oily phase comprises, for example, an organic solvent, a silicone oil or a fluorinated oil. According to the invention, the term “oil” designates an organic phase immiscible with water. Organic solvents include hydrocarbons, such as heptane, hexane, toluene, xylene, as well as alcohols, such as methanol, ethanol, propanol, etc.

[0096] The emulsion droplets are collected, dried and the polymer is removed.

[0097] Drying is carried out using conventional techniques, for example by irradiation with microwave, in a thermal oven, under vacuum, in the presence of a dehydrating / absorbing agent or a mixture of these techniques.

[0098] The polymer is removed according to conventional techniques, for example by calcination, pyrolysis or by a solvent. The calcination is carried out according to one embodiment at temperatures ranging from 200°C to about 1200°C. According to one embodiment, the calcination temperature is at least 200°C, preferably at least 500°C, more preferably at least 1000°C. Alternatively, the calcination temperature is from 200°C to about 700°C. The calcination is carried out for a suitable duration, for example ranging from 0.1 hour to about 12 hours, preferably from 1 hour to 8 hours. In certain embodiments, the calcination is carried out for at least 0.1 hour, for at least 1 hour, for at least 5 hours or for at least 10 hours.

[0099] Alternatively, the liquid dispersion comprising the polymer and metal oxide nanoparticles is formed in an oily dispersed phase and in an oily phase. aqueous solution to form an oil-in-water emulsion. The oily droplets can thus be collected and dried in the same way as the aqueous droplets.

[0100] Alternatively, a liquid dispersion comprising the polymer and metal oxide nanoparticles is prepared and is spray dried to form the polymer template / model microspheres without forming a liquid / liquid emulsion. In some embodiments of the spray drying techniques, a liquid solution or dispersion is fed (e.g., pumped) into an atomizing nozzle with a compressed gas inlet. The feed is pumped through the atomizing nozzle to form liquid droplets. The droplets are surrounded by a preheated gas in the evaporation chamber, resulting in evaporation of the solvent to produce solid particles. The dried particles are carried by the drying gas through the cyclone and deposited in the collection chamber. Usable gases include nitrogen and / or air.

[0101] In one embodiment of the spray drying method, the feed liquid contains an aqueous or oil phase, the polymer nanoparticles, and the metal oxide. The polymer template / model microspheres contain the polymer nanoparticles with the metal oxide in the interstitial spaces between the polymer nanoparticles. The polymer nanoparticles define the interstitial spaces. Spray drying techniques include inkjet spray drying methods.

[0102] In spray drying techniques, air and / or gas may be considered as the continuous phase with a dispersed liquid phase (liquid-in-gas emulsion). In some embodiments, the spray drying comprises an inlet temperature of at least 100°C, 105°C, 110°C, 115°C, 120°C, 130°C, 140°C, 150°C, 160°C or 170°C to 180°C, 190°C, 200°C, 210°C, 215°C or 220°C, in particular 100°C. In some embodiments the feed rate is 1 mL / min, 2 mL / min, 5 mL / min, 6 mL / min, 8 mL / min, 10 mL / min, 12 mL / min, 14 mL / min or 16 mL / min to 18 mL / min, 20 mL / min, 22 mL / min, 24 mL / min, 26 mL / min, 28 mL / min or 30 mL / min, in particular it is 10 mL / min. The spray drying techniques are in particular described for example in patent application U52016 / 0170091.

[0103] The microspheres obtained are spherical or quasi-spherical and are on the micrometric scale. The polymer nanoparticles used as models / templates are also spherical, on the nanometric scale, they are monodisperse and have an average diameter ranging from 50 nm to about 999 nm, advantageously from 50 nm to 500 nm, in particular from 100 nm to 400 nm. Advantageously, the polymer nanoparticles have an average diameter of 50 nm, 75 nm, 100 nm, 130 nm, 160 nm, 190 nm, 210 nm, 240 nm, 270 nm, 300 nm, 330 nm, 360 nm, 390 nm, 410 nm, 440 nm, 470nm, 500nm, 530nm, 560nm, 590nm, 620nm, 650nm, 680nm, 710nm, 740nm, 770nm, 800nm, 830nm, 860nm, 890nm, 910nm, 940 nm, 970 nm or 990 nm.

[0104] The metal oxide used can also be in the form of particles, such particles then being able to be on the nanometric scale.

[0105] The metal oxide in dispersion may be provided in the form of metal oxide or in the form of a precursor of the metal oxide, such as for example by the sol-gel technique.

[0106] Drying the polymer / metal oxide droplets followed by polymer removal results in microspheres having uniform cavities (pores). In general, in the described processes, each droplet forms a single microsphere. The pore diameters are dependent on the size of the polymer particles. A shrinkage or compaction phenomenon may occur during polymer removal, producing pore sizes slightly smaller than the initial size of the polymer particles, for example ranging from 10% to 40% smaller than the size of the initial polymer particle. The pore diameter is as uniform as were the shape and size of the polymer nanoparticles.

[0107] In some embodiments, the porous sphere has a solid center at the core and porosity toward the outer surface of the sphere.

[0108] In other embodiments the porous spheres have an empty center with porosity increasing toward the interior of the spheres.

[0109] In certain embodiments, there is thus a porosity gradient towards the center or towards the outside of the sphere.

[0110] In other preferred embodiments of the invention, the porosity is distributed uniformly throughout the volume of the microspheres.

[0111] In the porous microsphere according to the invention, the average diameter of the microspheres is significantly larger than the average diameter of the pores. For example, the average diameter of the microspheres is generally at least 5 times, preferably at least 10 times, preferably at least 15 times, more preferably 20 times, more preferably 25 times larger than the average diameter of the pores.

[0112] In some embodiments, the ratio of the average diameter of the microspheres to the average diameter of the pores is at least 5:1, at least 10:1, at least 15:1, at least 40:1, at least 50:1, at least 60:1, at least 70:1, at least 80:1, or at least 90:1.

[0113] Polymer microsphere designs comprising monodisperse polymer nanospheres can result in metal oxide microspheres having similar pores in diameter, once the polymer is removed.

[0114] Preferably, most of the porous microspheres have a color observable to the naked eye, in particular a blue color.

[0115] The porous microspheres according to the present invention may have an angle-dependent or angle-independent color. An "angle-dependent color" means an observed color that depends on the angle of the incident light or the angle between the observer and the observed color area. An angle-independent color means that the observed color does not substantively depend on the angle of the incident light or the angle between the observer and the observed color area.

[0116] Microspheres having an angle-dependent color can be obtained in particular by using monodisperse polymer nanospheres. They can also be obtained when the step of drying the liquid droplets for providing the template of the polymer microspheres is carried out gently, thus allowing the polymer nanospheres to order themselves.

[0117] Microspheres whose color is independent of the angle can be obtained when the step of drying the liquid droplets is carried out rapidly, not allowing the polymer nanospheres to order.

[0118] Advantageously, the porous microspheres are themselves also monodisperse.

[0119] "Most of the microspheres" means the population of microspheres. This may be an amount of > 0.1 mg, > 0.2 mg, > 0.3 mg, > 0.4 mg, > 0.5 mg, > 0.7 mg, > 1.0 mg, > 2.5 mg, > 5.0 mg, > 10.0 mg or > 25.0 mg. Most of the microspheres may be free of other compounds.

[0120] "Microscale" or "micro-" means a size ranging from about 1 pm to about 999 pm. "Nanoscale" or "nano-" means a size ranging from about 1 nm to about 999 nm.

[0121] The term "monodispersed" for the population of porous microspheres or polymer nanospheres means particles which have a homogeneous shape and a homogeneous diameter. The population of spheres is thus said to be monodispersed when 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% of the number of particles have a diameter of ± 7%, ± 6%, ± 5%, ± 4%, ± 3%, ± 2% or ± 1% relative to the average diameter of the population of spheres.

[0122] Removal of the monodisperse population of polymer nanospheres provides metal oxide microspheres having a population of pores having an average diameter.

[0123] Thus the microspheres according to the invention comprising a metal oxide are prepared by a method comprising the following steps: - Form a liquid dispersion of polymer nanoparticles and a metal oxide; - Form liquid droplets from the dispersion; - Drying the liquid droplets of the microspheres comprising the nanospheres of polymer and metal oxide; - Remove the polymer nanospheres from the model microspheres to provide the porous metal oxide spheres.

[0124] According to an advantageous embodiment, the liquid droplets are aqueous. According to an alternative, the liquid droplets are oily.

[0125] According to a preferred embodiment, the method comprises a continuous phase and mixing the liquid dispersion with this continuous phase to form an emulsion containing the dispersed liquid dispersion droplets. According to a particular embodiment, the continuous phase is oily and the mixing is carried out between the continuous oily phase and the aqueous liquid dispersion to form a water-in-oil emulsion containing aqueous droplets.

[0126] According to an alternative embodiment, the continuous phase is aqueous and mixing is carried out between the continuous aqueous phase and the oily liquid dispersion to form an oil-in-water emulsion containing lipid droplets.

[0127] According to yet another alternative embodiment, the continuous phase is gaseous and mixing is carried out between the continuous gaseous phase and the aqueous liquid dispersion to form a water-in-gas emulsion containing aqueous droplets.

[0128] According to an advantageous embodiment, the method comprises the subsequent steps of collecting the droplets, drying the droplets and removing the polymer nanospheres from the microsphere template.

[0129] According to the present invention, the porous microspheres are used alone, in particular in powder form (100%), or in composition, in particular cosmetic, at a concentration ranging from 0.01 to 20%, advantageously ranging from 0.1 to 5%, preferably ranging from 0.5% to 3%, more preferably from 1% to 2%, by weight relative to the total weight of the composition.

[0130] The porous microspheres according to the invention can be used alone, in particular in the form of a cosmetic active ingredient or in a composition intended to be in contact with the skin, the appendages and / or the cutaneous mucous membranes, such as for example a cosmetic composition, preferably intended for topical application.

[0131] The active ingredient and / or the cosmetic compositions containing the porous spheres according to the invention are preferably intended for the cosmetic protection of the skin, including the scalp as well as the cutaneous appendages, preferably the hair.

[0132] In another embodiment, the spheres according to the invention can be incorporated into a cosmetic composition further comprising at least one cosmetically acceptable excipient.

[0133] For the purposes of the present invention, the term “cosmetically ac- acceptable » a topically acceptable compound and / or solvent, i.e. not inducing an allergic response on contact with the skin, including the human scalp, mucous membranes and skin appendages, non-toxic, non-unstable, or their equivalents, undue.

[0134] The cosmetic composition according to the invention can be presented in all the galenic forms conventionally used for topical application to the skin including the scalp, mucous membranes and cutaneous appendages, such as liquid or solid forms or even in the form of liquid under pressure.They may in particular be formulated in the form of an aqueous or oily solution, in particular a lotion, a cream or an aqueous gel or an oily gel, in particular in a pot or tube, in particular a shower gel, a shampoo, a conditioner, a milk, an oil, an emulsion, a hydrogel, a microemulsion or a nanoemulsion, in particular oil-in-water or water-in-oil or multiple or silicone, a serum, a lotion, in particular in a glass bottle, plastic or in a dosing bottle or in an aerosol or spray, an ampoule, a liquid or solid soap, a paste, an ointment, a mousse, a mask, a lacquer, a patch, an anhydrous product, preferably liquid, pasty or solid, for example in the form of a stick, in particular in a stick or in powders, preferably, a cream, a serum or a lotion.

[0135] It may also be a makeup product or a makeup removal product. In particular, the cosmetic composition is chosen from the group consisting of a serum, a lotion, a cream, a shampoo, a conditioner, an oil, a milk, an ointment, a paste, a mousse, an emulsion, a hydrogel, a shower gel, a mask, a lacquer, a spray, a wax, a mascara, a makeup pencil, a varnish, a powder, in particular a makeup powder, a stick, even more preferably it is a cream, a serum or a lotion. It may also be a powder, in particular a makeup powder, a stick foundation, compositions for beard care, after shaving and / or hair removal. According to an advantageous embodiment, the cosmetic composition according to the invention is at least slightly gelled and / or comprises an oily phase, preferably of the oily composition or oil-in-water or water-in-oil emulsion or lotion type.

[0136] The compositions according to the invention may contain any suitable solvent and / or any suitable vehicle and / or any suitable cosmetically acceptable excipient, optionally in combination with other compounds of interest.

[0137] Advantageously, the composition does not comprise a UV filter, in particular a sun filter, and / or other anti-blue light filters.

[0138] Therefore, for these compositions, the cosmetically acceptable excipient contains, for example, at least one compound chosen from the group consisting of preservatives, emollients, emulsifiers, surfactants, moisturizers, thickeners, conditioners, matting agents, stabilizers, antioxidants, texturizing agents, glossing agents, film-forming agents, solubilizers, pigments, colorants and perfumes. These excipients are preferably chosen from the group consisting of amino acids and their derivatives, polyglycerols, esters, cellulose polymers and derivatives, Lanolin derivatives, phospholipids, lactoferrins, lactoperoxidases, sucrose-based stabilizers, vitamins E and its derivatives, natural and synthetic waxes, vegetable oils, triglycerides, unsaponifiables, phytosterols, vegetable esters, silicones and its derivatives, protein hydrolysates, Jojoba oil and its derivatives, lipo / water-soluble esters, betaines, aminoxides, plant extracts, sucrose esters, titanium dioxides, glycines, and parabens,and more preferably from the group consisting of butylene glycol, steareth-2, steareth-21, glycol-15 stearyl ether, cetearyl alcohol, phenoxyethanol, methylparaben, ethylparaben, propylparaben, butylparaben, butylene glycol, natural tocopherols, glycerin, dihydroxycetyl sodium phosphate, isopropyl hydroxycetyl ether, glycol stearate, triisononanoin, octyl cocoate, polyacrylamide, isoparaffin, laureth-7, a carbomer, propylene glycol, glycerol, bisabolol, a dimethicone, sodium hydroxide, PEG 30-dipolyhydroxysterate, capric / caprylic triglycerides, cetearyl octanoate, dibutyl adipate, grape seed oil, jojoba oil, magnesium sulfate, EDTA, cyclomethicone, xanthan gum, citric acid, sodium lauryl sulfate, mineral waxes and oils, isostearyl isostearate, propylene glycol dipelargonate, propylene glycol isostearate, PEG 8,Beeswax, hydrogenated palm oil glycerides, lanolin oil, sesame oil, cetyl lactate, lanolin alcohol, castor oil, titanium dioxide, lactose, sucrose, low density polyethylene, isotonic saline solution.

[0139] Many cosmetically active ingredients are known to those skilled in the art to improve the appearance of the skin and / or protect it. Those skilled in the art know how to formulate cosmetic or dermatological compositions to obtain the best effects. Furthermore, the compounds described in the present invention may have a synergistic effect when combined with each other. These combinations are also covered by the present invention. The CTFA Cosmetic Ingredient Handbook, Second Edition (1992) describes various cosmetic and pharmaceutical ingredients commonly used in the cosmetic and pharmaceutical industry, which are particularly suitable for topical use.Examples of these classes of ingredients include, but are not limited to, the following compounds: abrasive, absorbents, compounds for aesthetic purposes such as perfumes, pigments, dyes, essential oils, astringents, anti-acne agents, anti-flocculating agents, anti-foaming agents, . antimicrobial agents (e.g. iodopropyl butylcarbamate), antioxidants, binders, biological additives, buffering agents, bulking agents, chelating agents, additives, biocidal agents, denaturants, thickeners, and vitamins, and derivatives or equivalents thereof, film-forming materials, polymers, opacifying agents, pH adjusters, reducing agents, depigmenting or lightening agents (e.g. hydroquinone, kojic acid, ascorbic acid, magnesium ascorbyl phosphate, ascorbyl glucosamine), conditioning agents (e.g. humectants).

[0140] In a particularly advantageous manner, the microspheres according to the invention can be used, optionally in a cosmetic composition, as the sole agent for protecting the skin and / or appendages and / or mucous membranes against the unsightly and / or unpleasant and / or uncomfortable effects of blue light or in combination with other active agents having complementary and conventional properties in cosmetic compositions such as, for example, those chosen from: - moisturizing agents: one or more hydration-promoting agents such as a polysaccharide extracted from Cassia angustifolia seeds marketed under the name Hyalurosmooth™ by the applicant, or an agent chosen from one of the combinations containing pullulan, sodium hyaluronate and sodium alginate marketed under the name PatcH2O™ by the applicant or one or more of the compounds of the natural moisturizing factor (Natural Moisturizing Factor) or a natural honey extract marketed by the applicant under the name Melhydran™ and / or a compound from the glucosyl glyceride family, in particular hexosyl glyceride, an extract of Litchi chinensis pericarp under the name Litchiderm™ by the applicant; - an agent stimulating the synthesis of fibronectin, in particular a corn extract, such an extract being marketed in particular by the applicant under the name DelinerTM - an agent for protecting the fibroblast growth factor (FGF2) of the extracellular matrix against its degradation and / or denaturation, in particular an extract of Hibiscus Abelmoscus as described in the patent application in the name of the applicant filed under number FR0654316 and / or an agent for stimulating the growth of fibroblasts, for example a fermented soybean extract containing peptides, known under the name PhytokineTM marketed by the applicant and also described in patent application EPI 119344 B1 (Laboratoires Ex-panscience), and preferably a combination of these two extracts; - an agent stimulating laminin synthesis, in particular a malt extract modified by biotechnology, such an extract being marketed in particular by the applicant under the name Basaline TM; and an agent stimulating lipid synthesis such as a biotechnology-modified potato extract (solarium tuberosum) marketed by the applicant under the name Lipidessence™; - an agent stimulating the expression and / or activity of Hyaluronan synthase 2 (HAS2) such as the plant extracts described in patent application FR2 893 252 A1 and in particular an aqueous extract of Galanga (Alpinia galanga) marketed under the name Hyalufix™ by the applicant; - an agent stimulating the synthesis of lysyl oxidase like (LOXL) such as those described in patent application FR2855968, and in particular a dill extract marketed under the name Lys'lastine™ by the applicant; - one or more anti-pollution agents such as an extract of Argania spinosa leaves marketed under the name Arganyl™ by the applicant or an extract of Moringa oleifera seeds marketed under the name Purisoft™ by the applicant or an extract of Eperuafalcata root marketed under the name Eperuline™ by the applicant; - an agent stimulating the synthesis of intracellular ATP, in particular an extract of the algae Laminaria digitata; - an agent with global anti-aging action, particularly anti-pigment spots, in particular niacinamide or vitamin B3; - an antibacterial and / or sebum regulating agent, and / or sebum absorber such as retinoids, sarcosine, zinc salts in particular zinc gluconate, zinc salicylate, azelaic acid, and / or their derivatives and mixtures, an extract of Orthosiphon stamineus marketed under the name MAT XS™ Bright by the applicant, an extract of Bixa Orellana marketed under the name Bix'Activ™ by the applicant, the antibacterial extracts described in patent application FR2863893, and in particular an extract of Boldo in particular that marketed under the name Betapur™ by the applicant, or talc, - and any of their mixtures.

[0141] The use of the porous microspheres according to the present invention is particularly advantageous in that it allows an immediately effective and lasting action on all types of skin including the scalp, on the cutaneous appendages, preferably the hair and on the mucous membranes.

[0142] Preferably, the porous microspheres according to the invention, preferably in the form of a cosmetic composition according to the invention, are applied to at least one area of ​​the body exposed to blue light, this or these areas being preferably a surface of the body chosen from the skin of the face, including the forehead, cheeks, nose, temples, the T zone (forehead, nose and chin), under the eyes, the peri-orbital zone, in particular the dark circles, the contour of the lips and / or the chin, the scalp, the neck, the back, the shoulders, the forearms, the thorax, the hands, the hair, beard, eyelashes, eyebrows, bust, legs, feet, armpits, hands, décolleté, stomach, arms, thighs, hips, buttocks, waist, torso.

[0143] The present invention thus also relates to a non-therapeutic cosmetic care method comprising the topical application to at least one area of ​​skin and / or mucous membranes and / or skin appendages, in particular hair, of the porous microspheres according to the invention, advantageously to all or part of the skin and / or mucous membranes of the body and / or face chosen from the scalp, legs, thighs, arms, stomach, décolleté, neck, all or part of the face, forehead, chin, lips, lip contour, eye contour, the so-called "T" zone of the face, and / or to all or part of the skin appendages, more preferably the hair, preferably to at least one surface chosen from a surface of the body chosen from the skin of the face, including the forehead, cheeks, nose, temples, the T zone (forehead, nose and chin), under the eyes, the peri-orbital zone, in particular dark circles, the lip contour and / or the chin,scalp, neck, back, shoulders, forearms, chest, hands, hair, beard, eyelashes, eyebrows, bust, legs, feet, armpits, hands, décolleté, stomach, arms, thighs, hips, buttocks, waist, torso, and hair.

[0144] The microspheres according to the invention are particularly suitable for use on any type of skin, mucous membranes and / or appendages, in particular Caucasian, Asian, African as well as on any type of skin, in particular on young skin and / or skin showing the first signs of aging and / or for mature skin, i.e. men or women aged at least 50, in particular postmenopausal women.

[0145] The cosmetic compositions according to the invention are preferably of the leave-in type.

[0146] Advantageously, the porous microspheres according to the invention, preferably in the form of a composition intended for topical application, preferably cosmetic according to the invention, are used in regular topical application and preferably at least once a day, advantageously twice a day. Preferably, the cosmetic composition is applied to the skin.

[0147] The microspheres can be used in powder form but also in the form of a cosmetic ingredient formulated in liquid form. For their formulation as a cosmetic ingredient, the microspheres are then preferably suspended in glycerin and / or in another solvent, in particular a polar solvent such as water, alcohols, in particular propanediol, glycols in particular butylene glycol, propylene glycol, polyols or a mixture thereof, preferably a hydroglycolic mixture, still preferably containing a glycol chosen from butylene glycol, propylene glycol, caprylyl glycol, hexylene glycol and mixtures thereof. Particularly advantageously, the microspheres according to the invention are suspended in an aqueous solution containing glycerin, hexylene glycol, caprylyl glycol or a mixture thereof.

[0148] The invention also relates to a non-therapeutic cosmetic care method comprising the application to at least one area of ​​skin and / or mucous membrane and / or cutaneous appendages of porous microspheres comprising, advantageously consisting of, a metal oxide or a cosmetic composition comprising them to protect the area of ​​skin, cutaneous appendages, in particular hair, and / or mucous membrane against the unsightly and / or unpleasant and / or uncomfortable effects of blue light and / or to reduce and / or slow down said effects on this area of ​​skin, cutaneous appendages, in particular hair, and / or mucous membranes,the unsightly and / or unpleasant and / or uncomfortable effects being advantageously chosen from the aging of the skin and / or mucous membranes and / or cutaneous appendages and / or the alteration of the cutaneous and / or mucosal barrier and / or the dehydration of the skin and / or mucous membranes and / or cutaneous appendages and / or the alteration of the biomechanical properties of the skin and / or mucous membranes and / or cutaneous appendages, said microspheres having: , - an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 1 pm to 30 pm, - pores with an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 50nm to 250nm and - an average porosity measured by mercury porosimetry ranging from 0.40 to 0.65.

[0149] Advantageously, the cosmetic care method according to the invention is characterized in that the porous microspheres and / or the cosmetic composition comprising them are applied topically to all or part of the skin and / or mucous membranes of the body and / or face chosen from the scalp, legs, thighs, arms, stomach, décolleté, neck, all or part of the face, forehead, chin, lips, lip contour, eye contour, the so-called "T" area of ​​the face, and / or to all or part of the cutaneous appendages, more preferably the hair.

[0150] Advantageously, the cosmetic care process according to the invention is characterized in that the porous microspheres and / or the cosmetic composition comprising them are as defined below: - the metal oxide is chosen from the group consisting of SiO2, TiO2, ZnO and their mixtures, advantageously it is SiO2; and / or - the microspheres have an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 1.3 to 10 pm, in particular from 1.5 to 4.5 pm; and / or - the average diameter D50 of pores of the microspheres measured by electronic microscopy scanning electron microscope (SEM) ranges from 100 to 245 nm, in particular from 180 to 225 nm; and / or - the microspheres do not contain and / or are not used in combination with another blue light filter and / or a UV filter and / or a sunscreen and / or in a cosmetic composition which contains them; and / or - the porous microspheres are included in a cosmetic composition, at a content ranging from 0.01% to 20% by weight, advantageously from 0.1% to 5% by weight, still advantageously from 0.5% to 3% by weight, in particular from 1% to 2% by weight, relative to the total weight of the composition; and / or - the cosmetic composition comprises at least one cosmetically acceptable excipient and that this composition is chosen from a serum, a lotion, a cream, a shampoo, a conditioner, an oil, a milk, an ointment, a paste, a mousse, an emulsion, a hydrogel, a shower gel, a mask, a lacquer, a spray, a wax, a mascara, a makeup pencil, a varnish, a powder, in particular a makeup powder, a stick.

[0151] Advantageously, the cosmetic care process according to the invention is for preventing and / or slowing down - the appearance of wrinkles and / or fine lines and / or pigment spots on the skin and / or mucous membranes, and / or - loss of radiance of the complexion of the skin and / or mucous membranes and / or lack of homogeneity of the complexion of the skin and / or mucous membranes and / or - sagging skin and / or -loss of tone and / or elasticity and / or firmness and / or density of the skin and / or mucous membranes and / or - whitening and / or graying of the skin appendages and / or - dehydration and / or insensible water loss from the skin and / or mucous membranes and / or - alteration of the microrelief of the skin and / or mucous membranes and / or - alteration of the surface and / or texture and / or visual properties and / or sensory qualities of the skin and / or mucous membranes and / or cutaneous appendages, in particular hair.

[0152] Advantageously, the invention also relates to a cosmetic treatment method for protecting the skin, skin appendages, in particular the hair, and / or mucous membranes against the unsightly and / or unpleasant and / or uncomfortable effects of blue light and / or for reducing and / or slowing down said effects on the skin, skin appendages, in particular the hair, and / or mucous membranes of an individual who needs it / who wants it, comprising the steps: - The identification on the individual of an area of ​​skin and / or skin appendages, in particular hair, and / or mucous membrane likely to be subjected to a blue light radiation and / or that one wishes to protect against the unsightly and / or unpleasant and / or uncomfortable effects of blue light and / or reduce and / or slow down said effects, and - The topical application to this area of ​​skin and / or skin appendages, in particular hair, and / or mucous membrane of a cosmetic composition containing the microspheres according to the invention in an effective amount to protect this area of ​​skin and / or skin appendages, preferably hair, and / or mucous membrane against the unsightly and / or unpleasant and / or uncomfortable effects of blue light and / or to reduce and / or slow down the effects thereof, namely advantageously in a microsphere content ranging from 0.01 to 20%, advantageously ranging from 0.1 to 5%, preferably ranging from 0.5% to 3%, more preferably from 1% to 2%, by weight relative to the total weight of the composition.

[0153] Other aims, characteristics and advantages of the invention will become clear to those skilled in the art upon reading the explanatory description which refers to examples which are given solely by way of illustration and which in no way limit the scope of the invention.

[0154] The examples are an integral part of the present invention and any feature appearing new over any prior art from the description taken as a whole, including the examples, is an integral part of the invention in its function and in its generality. Thus, each example has a general scope. Furthermore, in the examples, all percentages are given by weight unless otherwise indicated, the temperature is expressed in degrees Celsius unless otherwise indicated, and the pressure is atmospheric pressure unless otherwise indicated. Examples Example 1: Porous silica microspheres

[0155] A copolymer of styrene and acrylic acid is prepared as follows: 230 mL of deionized (DI) water is added to a 3-necked reaction flask equipped with a thermometer, condenser, magnetic stirring, and under a nitrogen atmosphere. The water is heated to 80°C and 10 g of styrene is added with stirring, followed by 100 mg of acrylic acid dissolved in 10 mL of deionized water, by syringe. 100 mg of ammonium persulfate is dissolved in 10 mL of deionized water and added by syringe to the mixture with stirring. The mixture is left stirring for 24 hours at 80°C. The colloidal polymer dispersion is allowed to cool to room temperature and is purified by centrifugation, thus forming polystyrene nanospheres having an average particle size of 250 nm. The aqueous colloidal dispersion of po lystyrene is diluted in deionized water at a content of 7.5% by weight, relative to the total weight of the composition and 2.5% by weight of silica nanoparticles relative to the total weight of the composition are added to the mixture. This dispersion therefore contains 7.5% by weight of polystyrene, 2.5% by weight of silica nanoparticles and 90% by weight of deionized water relative to the total weight of the composition. The mixture is subjected to ultrasonic treatment to prevent particle agglomeration.

[0156] The aqueous dispersion is spray dried under a nitrogen atmosphere (inlet temperature: 100°C, outlet temperature: 45°C, feed rate: 10 mL / min) to provide monodisperse model microspheres containing 75% by weight of polystyrene and 25% by weight of silica.

[0157] These model microspheres are then calcined in order to remove the polymer by placing them on a silicone plate, and carrying out a temperature increase from 40°C to 500°C at a rate of 2°C / min, then maintaining the temperature at 500°C for 2 hours, then finally lowering the temperature from 500°C to 40°C at a rate of 2°C / min. The monodisperse porous SiO2 microspheres thus obtained have an average diameter D50 of 3.01 ± 1.34 pm measured by scanning electron microscopy (SEM), an average pore diameter D50 of 206 ± 10 nm measured by scanning electron microscopy (SEM) and an average porosity measured by mercury porosimetry of 0.55. The microspheres are blue in color.

[0158] Example 2: Evaluation of skin protection against blue light on human skin explants

[0159] The microspheres obtained in Example 1 were incorporated into the Emulgade® CPE microemulsion gel marketed by BASF (INCI: Olus Oil (and) Glycerin (and) Lauryl Glucoside (and) Polyglyceryl-2-Dipolyhydroxystearate (and) Glyceryl Oleate (and) Dicaprylyl Carbonate at a content of 1.5% by weight relative to the total weight of the composition, with vigorous stirring (composition according to the invention). The spheres are inert, do not re-swell, and are suspended in the medium. Dispersion is better with vigorous stirring, avoiding agglomerates. The composition of the gel containing the microspheres is indicated in Table 1 below

[0160] [Tables 1] Ingredients % by weight Microspheres according to example 1 1.5 water 38.5 Emulgade® CPE of which 60 vegetable oil 12-24 glycerin 6-18 Polyglyceryl-2 Dipolyhydroxystearate 6-18 Lauryl Gucoside 6-12 Glyceryl Oleate 0.6-3 Dicaprylyl Carbonate 0.6-3 water 8.4-10.8

[0161] Skin explants were prepared from fresh abdominal biopsies obtained by plastic surgery (55-year-old women). The skin explants were cultured for 6 days in a standard EMEM (Eagle's Minimum Essential Medium) culture medium, at 37°C, 5% CO2, in a humid atmosphere with a humidity level of 95%.

[0162] The explants were treated every day for 5 days by topical application of 2 mg / cm2 of the composition according to the invention or a placebo (Emulgade® CPE microemulsion gel marketed by BASF not containing the microspheres according to the invention) (placebo control and blue light control). Then the explants in a Hanks' Balanced Salt Solution (HBSS) medium were irradiated (composition according to the invention and blue light control) with blue light at 85 J / cm2 (wavelength 401-500 nm of the visible light spectrum with a peak at 455 nm for 4 hours) using a solarbox® or were not irradiated (placebo control). The skin explants were then cultured for one more day in the defined medium before analysis.

[0163] The MMPI and 8-OHdG contents of the skin explants were evaluated by immunostaining. The skin explants were cut into thin sections (5 μm) using a microtome (Leica RM2125, Leica Biosystems) and transferred onto Superfrost® slides. MMPI was detected by a specific monoclonal antibody (mouse monoclonal clone 36665, R&D Systems). 8-OHdG was detected by a monoclonal antibody (mouse monoclonal clone N45-1, Gentaur Genprice). The primary antibodies were revealed using the streptavidin / biotin and peroxidase method (Vector VIP Peroxidase HRP kit, Vector Laboratories Inc.). The staining was observed by mi- optical microscope (Leica DMLB, Leica Microsystems or Olympus BX43, Olympus Life Science). Images were analyzed using image analysis software (CellAD imaging Systems, Olympus Life Science). The quality and viability of skin explants were assessed by Masson trichrome staining and checked by microscopic analysis.

[0164] The results are expressed as the mean ± standard deviation (SD; 3 explants per condition, 6 images per explant). The results are expressed as a percentage of the area occupied by the staining and were then normalized relative to the blue light control condition. Statistical differences between these conditions were assessed using the Student t-test. The significance threshold was set at 5% (p<0.05). The “Statistics” column indicates the level of significance taking into account the chosen p-value. The mention p<0.05 thus designates a result significantly different from the chosen control. The mention p<0.01 designates a result very significantly different from the chosen control. The results concerning the 8-OHdG and MMPI contents in the epidermis and in the dermis are gathered respectively in Tables 2 to 4 below.

[0165] [Tables2] 8-OHdG content Mean (%) Standard deviation % difference (compared to blue light control) Statistics (compared to blue light control) placebo control (non-irradiated) 56 16 44 p<0.01 blue light control (placebo + blue light irradiation at 85 J / cm2) 100 24 composition according to the invention + blue light irradiation at 85 J / cm2 63 19 -37 p<0.05

[0166] Explants exposed to blue light showed a significant increase in 8-OHdG content in the skin (P<0.01). The microspheres according to the invention make lower 8-OHdG content by 37% (P<0.05).

[0167] [Tables 3] MMPI content in the epidermis Mean (%) Standard deviation % difference (compared to blue light control) Statistics (compared to blue light control) placebo control (non-irradiated) 44 6 56 p<0.01 blue light control (placebo + blue light irradiation at 85 J / cm2) 100 22 composition according to the invention + blue light irradiation at 85 J / cm2 45 13 -55 p<0.01

[0168] Explants exposed to blue light showed a significant increase in MMPI content in the epidermis (P<0.01). The microspheres according to the invention lower the MMPI content in the epidermis by 55% (P<0.01).

[0169] [Tables4] MMPI content in the epidermis Mean (%) Standard deviation % difference (compared to blue light control) Statistics (compared to blue light control) placebo control (non-irradiated) 63 18 37 p<0.01 blue light control (placebo + blue light irradiation at 85 J / cm2) 100 19 composition according to the invention + blue light irradiation at 85 J / cm2 77 30 -23 p<0.05

[0170] Explants exposed to blue light showed a significant increase in MMPI content in the dermis (P<0.01). The microspheres according to the invention lowered the MMPI content in the dermis by 23% (P<0.05).

[0171] These results were also compared with the results on the MMPI content in the dermis obtained with explants treated with a composition containing Tinosorb® M marketed by BASF and consisting of a broad spectrum UV filter based on micro-fine organic particle technology (INCI name: Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (and) water (and) Decyl Glucoside (and) Propylene Glycol (and) Xanthan Gum). Tinosorb® M shows absorption across the entire UV range and even achieves protection in visible blue light. Tinosorb® M at 4% by weight relative to the total weight of the composition in the Emulgade® CPE microemulsion gel marketed by BASF lowers the MMPI content in the dermis by 29% compared to the placebo control irradiated with blue light. The microspheres according to the invention in a content of 1.5% by weight relative to the total weight of the composition show a similar range of protection.

[0172] Thus, the topical application of the composition containing the microspheres according to the invention shows good protection against the increase in MMPI and 8-OHdG content caused by blue light (401-500nm with a peak at 455nm) in human skin.

[0173] Example 3: cosmetic compositions according to the invention

[0174] The porous microspheres used are those obtained in example 1 in powder form.

[0175] Example 3a): Fluid emulsion for the face

[0176] [Tables5] Phase Name Quantity (% by total weight) A Water 77.05 A Glycerin 2.00 A Preservative 1.00 B Carbomer (Rhéocare™) 0.20 C Lauryl glucoside, polyglyceryl-2, di-polyhydroxystearate, glycerin, cetearyl alcohol (Eumulgin™ VL 75) 2.00 C cetearyl alcohol 1.00 C Cocoglycerides 3.00 C Ethylhexyl stearate 3.00 C Dicaprylyl carbonate 4.00 D Sodium polyacrylate, dicaprylyl carbonate, polyglyceryl-3 caprate (Cosmedia™ Ace), 1.00 E Colorant CI 17200 0.10 E Pigments: mica, titanium dioxide, silica (Flamenco™ summit magenta M80H) 2.00 F microspheres according to the invention 3.00 F Perfume 0.65

[0177] The emulsion is prepared by the usual methods in the field well known to those skilled in the art, by introducing phase B into phase A and stirring until completely dispersed. The mixture is heated to 75-80°C as is phase C separately. Then phase C is added to the mixture with stirring. The mixture is left to cool with gentle stirring to room temperature and the compounds of phases E and F are added, one after the other. The whole is homogenized for 2 min. The pH is adjusted to 5.2.

[0178] Example 3b): Face cream

[0179] [Tableauxô] Phase Name Quantity (% in total weight) A Sucrose polystearate, cetyl palmitate 3.00 A Pentaerythrityl distearate 1.00 A Caprylic / capric triglyceryl 3.00 A Coco-caprylate / caprate 3.00 A Dicaprylyl carbonate 3.00 A Sodium polyacrylate 0.70 B Water 80.90 B Glycerin 2.00 B Sodium stearoyl glutamate 0.50 B Preservative qs C Microspheres according to the invention 0.5 C Water 1.75 D Perfume qs E pH adjuster (citric acid) qs

[0180] The cream is prepared by the usual methods in the field well known to those skilled in the art, by mixing phases A and B previously heated to 75°C, then adding phases C and D by mixing and adjusting the composition with phase E to a pH of 6.2 and a viscosity of 15,000 mPas (measured with a Brookfield apparatus (RVT; 23°C, spindle TC; 20 rpm).

[0181] Example 3c): shampoo

[0182] [Tables?] Phase Name Quantity (% by total weight) A Water 60.3 A Xanthan gum 1.2 B Decyl glucoside 14 B Dicaprylyl ether, decyl glucoside, glyceryl oleate 5 B Sodium cocoyl glutamate 12 B Coco-glucoside, glyceryl oleate 2 B Glycerin 3 B Preservative qs C pH adjuster (citric acid) qs D Perfume 0.5 D Microspheres according to the invention 0.01-10

[0183] The shampoo is prepared by the usual methods in the field well known to those skilled in the art, by mixing the 4 phases and adjusting the composition to a pH of 5.2 and a viscosity of 2200 mPas (measured with a Brookfield apparatus (RVT; 23°C, spindle 5; 50 rpm).

Claims

Claims

1. Non-therapeutic cosmetic use of porous microspheres comprising, advantageously consisting of, a metal oxide for protecting the skin, skin appendages, in particular the hair, and / or mucous membranes against the unsightly and / or unpleasant and / or uncomfortable effects of blue light and / or for preventing the occurrence and / or slowing down the appearance of said effects on the skin, skin appendages, in particular the hair, and / or mucous membranes, said microspheres having: - an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 1 pm to 30 pm, - pores whose average diameter D50 measured by scanning electron microscopy (SEM) ranges from 50 nm to 250 nm and - an average porosity measured by mercury porosimetry ranging from 0.40 to 0.65, characterized in that the microspheres do not contain and are not used in combination with another anti-blue light filter and in a cosmetic composition which contains it.

2. Use according to claim 1, characterized in that the unsightly and / or unpleasant and / or uncomfortable effects are chosen from aging of the skin and / or mucous membranes and / or cutaneous appendages and / or alteration of the cutaneous and / or mucosal barrier and / or dehydration of the skin and / or mucous membranes and / or cutaneous appendages and / or alteration of the biomechanical properties of the skin and / or mucous membranes and / or cutaneous appendages.

3. Use according to claim 1 or 2, for preventing and / or slowing down - the appearance of wrinkles and / or fine lines and / or pigment spots on the skin and / or mucous membranes, and / or - the loss of radiance of the complexion of the skin and / or mucous membranes and / or the lack of homogeneity of the complexion of the skin and / or mucous membranes and / or - skin sagging and / or - the loss of tone and / or elasticity and / or firmness and / or density of the skin and / or mucous membranes and / or - the whitening and / or graying of the skin appendages and / or - the dehydration and / or transepidermal water loss of the skin and / or mucous membranes and / or - the alteration of the microrelief of the skin and / or mucous membranes and / or - the alteration of the surface and / or texture and / or visual properties and / or sensory qualities of the skin and / or mucous membranes and / or cutaneous appendages, particularly hair.

4. Use according to any one of claims 1 to 3, characterized in that the metal oxide is chosen from the group consisting of SiO2, TiO2, ZnO and their mixtures, advantageously it is SiO2.

5. Use according to any one of claims 1 to 4, characterized in that the metal oxide is chosen from the group consisting of SiO2, TiO2 and ZnO.

6. Use according to any one of claims 1 to 5, characterized in that the microspheres have an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 1.3 to 10 pm, in particular from 1.5 to 4.5 pm.

7. Use according to any one of the preceding claims, characterized in that the average pore diameter D50 of the microspheres measured by scanning electron microscopy (SEM) ranges from 100 to 245 nm, in particular from 180 to 225 nm.

8. Use according to any one of the preceding claims, characterized in that the microspheres do not contain and / or are not used in combination with an anti-UV filter and / or a sun filter and / or in a cosmetic composition which contains them.

9. Use according to any one of the preceding claims, characterized in that the blue light has a wavelength ranging from 401 to 500nm, advantageously from 415 to 490nm, more advantageously from 420 to 480nm, and in particular from 430 to 460 nm.

10. Use according to any one of the preceding claims, characterized in that the porous microspheres are included in a cosmetic composition, at a content ranging from 0.01% to 20% by weight, advantageously from 0.1% to 5% by weight, still advantageously from 0.5% to 3% by weight, in particular from 1% to 2% by weight, relative to the total weight of the composition.

11. Use according to claim 10, characterized in that the cosmetic composition comprises at least one cosmetically acceptable excipient and that this composition is chosen from a serum, a lotion, a cream, a shampoo, a conditioner, an oil, a milk, an ointment, a paste, a mousse, an emulsion, a hydrogel, a shower gel, a mask, a lacquer, a spray, a wax, a mascara, a makeup pencil, a varnish, a powder, in particular a makeup powder, a stick.

12. Non-therapeutic cosmetic care method comprising the application to at least one area of ​​skin and / or mucous membrane and / or skin appendages of porous microspheres comprising, advantageously consisting of, a metal oxide or a cosmetic composition comprising them to protect the area of ​​skin, skin appendages, in particular hair, and / or mucous membrane against the unsightly and / or unpleasant and / or uncomfortable effects of blue light and / or to prevent the occurrence and / or slow down the appearance of said effects on this area of ​​skin, skin appendages, in particular hair, and / or mucous membranes,the unsightly and / or unpleasant and / or uncomfortable effects being advantageously chosen from aging of the skin and / or mucous membranes and / or skin appendages and / or alteration of the skin and / or mucosal barrier and / or dehydration of the skin and / or mucous membranes and / or skin appendages and / or alteration of the biomechanical properties of the skin and / or mucous membranes and / or skin appendages, said microspheres having: - an average diameter D50 measured by scanning electron microscopy (SEM) ranging from 1 pm to 30 pm, - pores whose average diameter D50 measured by scanning electron microscopy (SEM) ranges from 50 nm to 250 nm and - an average porosity measured by mercury porosimetry ranging from 0.40 to 0.65, characterized in that the microspheres do not contain and are not used in combination with another light filter blue and in a cosmetic composition which contains it.,

13. Cosmetic care method according to claim 12, characterized in that the porous microspheres and / or the cosmetic composition comprising them are applied topically to all or part of the skin and / or mucous membranes of the body and / or face chosen from the scalp, legs, thighs, arms, stomach, décolleté, neck, all or part of the face, forehead, chin, lips, lip contour, eye contour, the so-called "T" area of ​​the face, and / or to all or part of the skin appendages, more preferably the hair.

14. Cosmetic care method according to any one of claims 12 or 13, characterized in that the porous microspheres and / or the cosmetic composition comprising them are as defined in any one of claims 4 to 8 and 10 to 11.

15. Cosmetic care method according to any one of claims 12 to 14, for preventing and / or slowing down - the appearance of wrinkles and / or fine lines and / or pigment spots on the skin and / or mucous membranes, and / or - loss of radiance of the skin tone and / or mucous membranes and / or lack of homogeneity of the skin tone and / or mucous membranes and / or - sagging of the skin and / or -loss of tone and / or elasticity and / or firmness and / or density of the skin and / or mucous membranes and / or - whitening and / or graying of the skin appendages and / or - dehydration and / or insensible water loss from the skin and / or mucous membranes and / or - alteration of the microrelief of the skin and / or mucous membranes and / or - alteration of the surface and / or texture and / or visual properties and / or sensory qualities of the skin and / or mucous membranes and / or cutaneous appendages, in particular hair.