Implants containing silicone foam

Abstract

The present invention relates to a novel implant, particularly a breast implant, that is biodurable, biocompatible, provides a soft-tissue feel, and has reduced density. The implant comprises a shell and a filler surrounded by the shell, the filler comprising a silicone foam obtained from a foamable crosslinkable silicone composition comprising an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule, an organosilicon compound having at least two, and preferably at least three, silicon-bonded hydrogen atoms per molecule, a hydrosilylation catalyst, at least one porosifying agent that is water, a hydrogel, or an aqueous silicone emulsion, at least one chemical blowing agent, and a linear polydimethylsiloxane.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63 / 393,084, filed July 28, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] Technical Field The present invention relates to the field of implants, and more particularly to novel implants, particularly breast implants, that include silicone foam and provide a soft tissue feel and reduced density. [Background technology]

[0003] Today, reconstructive and cosmetic surgery has become a common practice, as implants can be implanted into almost any part of the body to create balance and harmony. Implants are used in reconstructive and cosmetic surgery. The use of implants is expected to increase due to an aging population, increased life expectancy and lifestyles, and improvements in implant technology. As used herein, the term "implant" refers to a medical device manufactured to replace missing biological structures, support damaged biological structures, or reinforce existing biological structures.

[0004] Implants are required to provide a specific three-dimensional shape and to maintain that shape for a certain period of time depending on the properties of the implant. Implants must also be biodurable so that they are not damaged by interactions with the human body, and they must also be biocompatible. The biocompatibility of a medium- or long-term implantable medical device refers to its ability to perform its intended function without causing undesirable local or systemic effects.

[0005] Of all types of cosmetic and reconstructive implants, breast implants were the most commonly introduced. Reconstructive breast surgery is performed to rebuild a woman's breasts affected by a mastectomy, while cosmetic breast surgery is performed to modify the appearance of a woman's breasts, for example, by adding implants to augment the breasts, correct asymmetry, change the shape, or correct deformities.

[0006] Additionally, implants are also being used in a variety of body implants, such as facial implants, such as eyebrow, nose, cheek, chin and lip implants, tracheal stents, implantable fat augmentation or replacement, such as gluteus maximus and cheek implants, or hard tissue implants, such as calf, biceps, triceps or abdominal muscles.

[0007] Most implants are constructed from silicone-based materials, which have long been recognized as one of, if not the, most biocompatible synthetic materials available.

[0008] A desirable improvement in implant technology remains the need for biocompatible, lightweight materials. For example, reducing the weight of breast implants is of interest to any company that manufactures them. Lightweighting not only improves patient ergonomics and reduces fatigue-related problems or injuries, but also reduces the amount of material required to manufacture the device. This is also relevant, for example, for tissue expansion products in mastectomy procedures for patients awaiting implants.

[0009] U.S. Patent Application Publication No. 2019 / 0314144 describes a method for producing a breast implant, which involves mixing a carbonate salt with hydrolyzed silicone to produce an elastic filler material containing a foam. In this context, carbon dioxide bubbles are generated by the reaction of a bicarbonate salt, such as sodium bicarbonate, with hydrochloric acid (HCl), a by-product of the hydrolysis of silicone monomers. Here, the foaming agent releases the bubbles through acidification. Managing the acidity of the final silicone foam can be a potential risk if it is intended for use as an implant.

[0010] WO 2020 / 072374 describes a kit for preparing customizable flesh that simulates silicone gel or silicone foam. This kit can be a custom solution for improving the sensory feel of implanted materials to match the feel of natural flesh. The kit includes at least three parts: a first part containing an alkenyl-containing organopolysiloxane and a hydrosilylation catalyst; a second part containing an alkenyl-containing organopolysiloxane and a hydrogen-containing organosilicon compound; and a third part containing a linear polydimethylsiloxane. According to one embodiment, the third part can further include a foaming agent capable of generating gas by chemical decomposition or evaporation. According to another embodiment, the foaming agent can be formulated in the fourth part of the kit. The foaming agent that generates gas at elevated temperatures can be a bicarbonate, particularly ammonium bicarbonate (NH4)HCO3, sodium bicarbonate (NaHCO3), calcium bicarbonate (Ca(HCO3)2), or other alkali metal bicarbonate. These blowing agents release CO2, creating hollow cells. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] US Patent Application Publication No. 2019 / 0314144 [Patent Document 2] International Publication No. 2020 / 072374 Summary of the Invention [Problem to be solved by the invention]

[0012] Currently, there remains a need for materials for manufacturing implants that are biodurable, biocompatible, provide a soft tissue feel, and have reduced density. [Means for solving the problem]

[0013] The present invention relates in particular to an implant comprising a shell and a filling surrounded by said shell, said filling comprising a silicone foam obtained from a foamable crosslinkable silicone composition comprising: at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule; at least one organosilicon compound B having at least two, preferably at least three, silicon-bonded hydrogen atoms per molecule; at least one hydrosilylation catalyst C; at least one porosifying agent D which is water, a hydrogel, or an aqueous silicone emulsion; at least one chemical blowing agent E; and At least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C between 50 mPa·s and 100,000 mPa·s Includes:

[0014] The silicone foam defined above can be referred to as a "double foam" silicone foam: On the other hand, hydrogen bubbles are generated in a state where a pore-forming agent D, which is water, a hydrogel, or an aqueous silicone emulsion, is incorporated into a polyaddition-crosslinkable silicone composition containing an organopolysiloxane A having silicon-bonded alkenyl groups, an organosilicon compound B containing silicon-bonded hydrogen atoms, and a hydrosilylation catalyst C; On the other hand, chemical blowing agents E release a gas, typically carbon dioxide, upon decomposition.

[0015] The inventors have found that the resulting dual foam silicone foam exhibits a low density, the foam's cell structure is much more homogeneous and stable than using one or the other of the foaming agents, while retaining a flesh-like feel, making it highly suitable for use as a filler material in implants, preferably breast implants. DETAILED DESCRIPTION OF THE INVENTION

[0016] Detailed Description of the Invention All viscosities discussed herein correspond to dynamic viscosity values measured at 25°C by well-known methods, such that viscosities measured in a Brookfield viscometer are independent of shear rate gradients.

[0017] Unless otherwise specified, all % or ppm contents are by weight.

[0018] The foamable crosslinkable silicone composition of the present invention comprises at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule. Preferably, organopolysiloxane A has at least two C groups per molecule. 2~6 An alkenyl group is attached to the silicon, which may consist of at least two siloxyl units of the formula: Y a R 1 b SiO (4-a-b) / 2 (In the formula: Y is C 2~6 alkenyl, preferably vinyl; ·R 1 is a monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably selected from an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, or a propyl group, a cycloalkyl group having 3 to 8 carbon atoms, and an aryl group having 6 to 12 carbon atoms; a=1 or 2, b=0, 1 or 2, and the sum of a+b=2 or 3. ), and optionally a unit of the formula: R 1 c SiO (4-C) / 2 (In the formula, R 1 has the same meaning as above, and c = 0, 1, 2, or 3. Preferably, organopolysiloxane A has a dynamic viscosity at 25°C of 100 mPa·s to 120,000 mPa·s, preferably 100 mPa·s to 80,000 mPa·s, more preferably 1,000 mPa·s to 50,000 mPa·s, and even more preferably 5,000 mPa·s to 20,000 mPa·s. The organopolysiloxane A can be preferably referred to as an organopolysiloxane oil.

[0019] The organopolysiloxane A can be a linear, cyclic or branched organopolysiloxane (resin). The foamable crosslinkable silicone composition according to the invention can contain a mixture of different organopolysiloxanes A.

[0020] According to one embodiment, organopolysiloxane A can be a linear organopolysiloxane. The linear organopolysiloxane is D or D Vi Siloxyl units and terminal M or M Vi It indicates a linear structure essentially formed from siloxyl units, D, D Vi M and MVi is defined as follows:D: R 1 2SiO 2 / 2 Siloxyl unit, D Vi :Y2SiO 2 / 2 or YR 1 SiO 2 / 2 siloxyl units selected from the group consisting of siloxyl units, M:R 1 3SiO 1 / 2 Siloxyl unit, M Vi :YR 1 2SiO 1 / 2 and Y2R 1 SiO 1 / 2siloxyl units selected from the group consisting of: 1 is as above.

[0021] End "M or M Vi Examples of the "unit" include a trimethylsiloxy group, a dimethylphenylsiloxy group, a dimethylvinylsiloxy group, and a dimethylhexenylsiloxy group.

[0022] "D or D Vi Examples of the "" unit include a dimethylsiloxy group, a methylphenylsiloxy group, a methylvinylsiloxy group, a methylbutenylsiloxy group, a methylhexenylsiloxy group, a methyldecenylsiloxy group, and a methyldecadienylsiloxy group.

[0023] Examples of linear or cyclic organopolysiloxanes that can be organopolysiloxane A according to the invention are: · Poly(dimethylsiloxane) containing dimethylvinylsilyl termini; · Poly(dimethylsiloxane-co-methylphenylsiloxane) containing dimethylvinylsilyl termini; · Poly(dimethylsiloxane-co-methylvinylsiloxane) containing dimethylvinylsilyl termini; · Trimethylsilyl-terminated poly(dimethylsiloxane-co-methylvinylsiloxane); and · Cyclic poly(methylvinylsiloxane).

[0024] Preferably, organopolysiloxane A has a content by weight of alkenyl units of 0.001% to 30%, preferably 0.01% to 10%, more preferably 0.02% to 5%.

[0025] According to a preferred embodiment, organopolysiloxane A contains terminal dimethylvinylsilyl units, and more preferably, organopolysiloxane A is a poly(dimethylsiloxane) containing dimethylvinylsilyl terminal groups. The number of dimethylsiloxane units can be between 5 and 1000, preferably between 100 and 600.

[0026] According to another embodiment, the organopolysiloxane A is 2~6 A branched organopolysiloxane (i.e., resin) containing alkenyl units is preferably selected from the group consisting of silicone resins of the formula: M Vi Q (wherein the alkenyl group bonded to the silicon atom is held by the M group); ·MM Vi Q (wherein the alkenyl group bonded to the silicon atom is carried by part of the M unit); ·MD Vi Q (wherein the alkenyl group bonded to the silicon atom is held by the D group); MDD Vi Q (wherein the alkenyl group bonded to the silicon atom is held by part of the D group); ·MM Vi TQ (wherein the alkenyl group bonded to the silicon atom is carried by part of the M unit); ·MM Vi DD Vi Q (wherein the alkenyl group bonded to the silicon atom is carried by a portion of the M and D units); and mixtures thereof (wherein M, M Vi , D and D Vi is as defined above, and T: formula R 1 SiO 3 / 2 and Q: a siloxyl unit of the formula SiO 4 / 2 where R is a siloxyl unit of 1 have the same meaning as above).

[0027] According to a preferred embodiment, the foamable crosslinkable silicone composition of the present invention comprises a mixture of at least one linear organopolysiloxane as defined above and at least one branched organopolysiloxane (i.e., resin) as defined above. For example, the foamable crosslinkable silicone composition of the present invention may comprise a mixture of a linear poly(dimethylsiloxane) containing dimethylvinylsilyl termini and a branched organopolysiloxane of formula M Vi Q.M.M. Vi Q, M.D.Vi Q, MDD Vi Q.M.M. Vi TQ or MM Vi DD Vi Q, preferably M Vi Q.M.M. Vi Q, M.D. Vi Q or MDD Vi The foamable cross-linkable silicone composition of the present invention may contain a mixture of the linear poly(dimethylsiloxane) and the silicone resin Q. The amount of linear poly(dimethylsiloxane) in the foamable cross-linkable silicone composition of the present invention may be in the range of 0.8 to 94% by weight, preferably 2.5 to 45% by weight, and more preferably 3.5 to 25% by weight of the total composition. The amount of silicone resin in the foamable cross-linkable silicone composition of the present invention may be in the range of 0 to 10% by weight, preferably 0.01 to 5% by weight, and more preferably 0.05 to 2% by weight of the total composition.

[0028] The foamable crosslinkable silicone composition of the present invention further comprises at least one organosilicon compound B having at least two, and preferably at least three, silicon-bonded hydrogen atoms per molecule. Organosilicon compound B is preferably an organohydrogenpolysiloxane compound containing at least two, and preferably at least three, hydrosilyl functional groups (or Si—H units) per molecule.

[0029] The organosilicon compound B may advantageously be a polyorganosiloxane containing at least two, preferably at least three, siloxyl units of the formula: H d R 2 e SiO (4-d-e) / 2 (In the formula: ·R 2 groups are the same or different and represent monovalent groups having 1 to 12 carbon atoms, d=1 or 2, e=0, 1 or 2, and d+e=1, 2 or 3; and optionally other units of the formula: R 2 f SiO (4-f) / 2 (In the formula, R 2 has the same meaning as above, and f=0, 1, 2 or 3.

[0030] In the above formula, multiple R 2 It is understood that when groups are present, they may be the same or different from one another. 2 R may represent a monovalent group selected from the group consisting of an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and an aryl group having 6 to 12 carbon atoms, which may be substituted with at least one halogen atom such as chlorine or fluorine. 2 can advantageously be selected from the group consisting of methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl and phenyl.

[0031] The symbol d is preferentially equal to 1.

[0032] The organosilicon compound B can have a linear, branched or cyclic structure. The degree of polymerization is preferably greater than or equal to 2. Generally, the degree of polymerization is less than 5,000.

[0033] In the case of linear polymers, the latter has the formula D:R 2 2SiO 2 / 2 or D':R 2 HSiO 2 / 2 and a siloxyl unit selected from units of the formula M:R 2 3SiO 1 / 2 or M':R 2 2HSiO 1 / 2 (In the formula, R 2 and wherein R 1 has the same meaning as above.

[0034] The viscosity of polyorganosiloxane B is preferably from 1 mPa·s to 5000 mPa·s, more preferably from 1 mPa·s to 2000 mPa·s, and even more preferably from 5 mPa·s to 1000 mPa·s.

[0035] Examples of organohydrogenpolysiloxanes which can be organosilicon compounds B according to the invention containing at least two hydrogen atoms bonded to the silicon atom are: · Poly(dimethylsiloxane) containing hydrodimethylsilyl termini; · Poly(dimethylsiloxane-co-methylhydrosiloxane) containing trimethylsilyl termini; · Poly(dimethylsiloxane-co-methylhydrosiloxane) containing hydrodimethylsilyl termini; · trimethylsilyl-terminated poly(methylhydrosiloxane); and · Cyclic poly(methylhydrosiloxane).

[0036] If the organosilicon compound B has a branched structure, it is preferably selected from the group consisting of silicone resins of the following formula: M'Q (where the hydrogen atoms bonded to the silicon atoms are held by M units), MM'Q (wherein the hydrogen atom bonded to the silicon atom is held by part of the M unit), MD'Q (wherein the hydrogen atom bonded to the silicon atom is held by a D group), MDD'Q (wherein the hydrogen atom bonded to the silicon atom is held by part of the D group), MM'TQ (wherein the hydrogen atom bonded to the silicon atom is held by part of the M unit), MM'DD'Q (wherein the hydrogen atoms bonded to the silicon atoms are carried by part of the M and D units), and mixtures thereof (M, M', D and D' are as defined above, T: a compound of formula R 2 SiO 3 / 2 and Q: a siloxyl unit of the formula SiO 4 / 2 where R is a siloxyl unit of 2 has the same meaning as above.

[0037] Preferably, organosilicon compound B has a content of hydrosilyl Si—H functional groups of 0.2 to 91% by weight, more preferably 3 to 80% by weight, and even more preferably 15 to 70% by weight.

[0038] Advantageously, the molar ratio of hydrosilyl SiH functional groups of organosilicon compound B to alkene functional groups of compound A is between 1 and 50, preferably between 2 and 30, more preferably between 3 and 20.

[0039] According to a preferred embodiment, the foamable crosslinkable silicone composition of the present invention comprises a mixture of at least one organosilicon compound B1 having at least three silicon-bonded hydrogen atoms per molecule and at least one organosilicon compound B2 having two silicon-bonded hydrogen atoms per molecule. The organosilicon compound B2 preferably contains terminal dimethylhydrogensilyl units, and more preferably is a poly(dimethylsiloxane) containing terminal dimethylhydrogensilyl groups. The number of dimethylsiloxane units in organosilicon compound B2 can be 1 to 200, preferably 1 to 150, and more preferably 3 to 120. Such organosilicon compound B2 can be described as a "chain extender" because it is believed to increase the mesh size of the network when crosslinked. Furthermore, organosilicon compound B1 having three or more silicon-bonded hydrogen atoms per molecule can be described as a "crosslinker." Preferably, organosilicon compound B1 is a poly(dimethylsiloxane-co-methylhydrosiloxane) containing trimethylsilyl and / or hydrodimethylsilyl termini.

[0040] The hydrosilylation catalyst C can be chosen in particular from platinum and rhodium compounds, but also from silicon compounds, such as those described, for example, in WO 2015 / 004396 and WO 2015 / 004397, germanium compounds, such as those described in WO 2016 / 075414, or nickel, cobalt, or iron complexes, such as those described in WO 2016 / 071651, WO 2016 / 071652, and WO 2016 / 071654. Catalyst C is preferably a compound derived from at least one metal belonging to the platinum group. These catalysts are well known and in particular the complexes of platinum with organic products described in U.S. Pat. Nos. 3,159,601, 3,159,602, 3,220,972 and EP 0 057 459, 0 188 978 and 0 190 530, and the complexes of platinum with vinylated organosiloxanes described in U.S. Pat. Nos. 3,419,593, 3,715,334, 3,377,432 and 3,814,730 can be used.

[0041] Preferably, catalyst C is a compound derived from platinum. Preferably, catalyst C is a Karstedt platinum catalyst.

[0042] The foamable crosslinkable silicone composition according to the present invention comprises water, a hydrogel or an aqueous silicone emulsion as pore-forming agent D. Water can be added directly to the foamable crosslinkable silicone composition. Advantageously, water can be introduced in the form of an aqueous silicone emulsion, such as a direct oil-in-water silicone emulsion or an inverse water-in-oil silicone emulsion, which comprises a continuous silicone oil phase, an aqueous phase and a stabilizer.

[0043] According to one embodiment, water is introduced via a silicone oil-in-water emulsion having a water content of about 60% by weight. Introducing water into the foamable cross-linkable silicone composition via an emulsion improves the dispersibility of water in the foamable cross-linkable silicone composition and its stability during storage.

[0044] According to one embodiment, an emulsifier can be added together with the water or aqueous silicone emulsion. Those skilled in the art can select the emulsifier from among typical emulsifiers. Examples include anionic emulsifiers, cationic emulsifiers, amphoteric emulsifiers, and nonionic emulsifiers. Among these, nonionic surfactants, which are believed to have minimal effect on the hydrosilylation reaction, are most preferred. The emulsifier can be added in an amount such that the weight ratio of emulsifier to water is 1:5 to 5:1, preferably 2:1 or 1:2.

[0045] Some of the hydrosilyl functional groups of organosilicon compound B react with the water provided by porosifying agent D to form gaseous hydrogen, allowing good foaming of the composition.

[0046] The foamable crosslinkable silicone composition according to the present invention comprises at least one chemical foaming agent E. Preferably, the chemical foaming agent E is at least one hydrogen carbonate (also commonly referred to as "bicarbonate"). More preferably, the chemical foaming agent E is selected from the group consisting of ammonium hydrogen carbonate (NH4)HCO3, sodium hydrogen carbonate NaHCO3, calcium hydrogen carbonate Ca(HCO3)2, and mixtures thereof. Even more preferably, the chemical foaming agent E is ammonium hydrogen carbonate.

[0047] The chemical blowing agent E may have particles with a median particle size (D50) of ≦50 pm, more preferably ≦10 pm. According to a preferred embodiment, the particles of chemical blowing agent E may be crushed and sieved before use.

[0048] For ease of application and manufacturing, the chemical blowing agent E can be pre-dispersed in the organopolysiloxane A, for example at a level of 30% to 60% by weight, and finally, any additives that help stabilize the shelf life of the resulting composition can be incorporated.

[0049] The foamable cross-linkable silicone composition according to the present invention comprises at least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C of 50 mPa·s to 100,000 mPa·s, preferably 50 mPa·s to 70,000 mPa·s, more preferably 100 mPa·s to 20,000 mPa·s, even more preferably 200 mPa·s to 5,000 mPa·s, and even more preferably 1,000 mPa·s to 2,000 mPa·s.

[0050] According to a first embodiment of the invention, the linear polydimethylsiloxane F has the formula: (CH3)3SiO (SiO(CH3)2) n Si(CH3)3(I) In the formula, n is an integer of 50 to 900, preferably 50 to 700.

[0051] According to a second embodiment of the invention, the linear polydimethylsiloxane F has the formula: (CH3)3SiO(SiO(CH3)2) n Si(CH3)2(Y) (II) In the formula, Y is C 2~6 It is alkenyl, preferably vinyl, and n is an integer of 50 to 900, preferably 50 to 700. The above compound has exactly one silicon-bonded alkenyl group per molecule.

[0052] Preferably, the linear polydimethylsiloxane F according to the present invention consists of a mixture of linear polydimethylsiloxanes (I) and (II) as defined above. The weight ratio (I):(II) can be from 100:0 to 0:100, or from 90:10 to 10:90, or from 80:20 to 20:80, or from 70:30 to 30:70. The foamable crosslinkable silicone composition according to the present invention can be free of, or substantially free of, linear polydimethylsiloxane (II). The linear polydimethylsiloxane F according to the present invention consists of one or several linear polydimethylsiloxanes (I) as defined above.

[0053] The foamable crosslinkable silicone composition of the present invention may optionally contain additives. Examples of suitable additives include elasticity additives, reinforcing fillers, thermally or electrically conductive fillers, nanoparticles, silicone resins, pigments, antibacterial agents, UV stabilizers, dyes, pigments, fragrances, flavors, essential oils, flame retardant additives, heat stabilizers, rheology modifiers, viscosity modifiers, thickeners, adhesion promoters, biocides, preservatives, enzymes, peptides, surfactants, reactive diluents, active pharmaceutical ingredients, excipients, or cosmetic ingredients. The content of additives is typically less than 5 wt %, preferably less than 2.5 wt %, and more preferably less than 1 wt %, based on the total weight of the foamable crosslinkable silicone composition. Those skilled in the art can select suitable additives according to the intended application and general knowledge in the technical field.

[0054] According to one embodiment, the foamable crosslinkable silicone composition of the present invention can optionally contain at least one filler, preferably a reinforcing filler, which can typically improve the mechanical strength of the cured silicone elastomer article. The filler can be precipitated silica, fumed (or pyrogen) silica, colloidal silica, and mixtures thereof. These active reinforcing fillers have a specific surface area of at least 10 m2 as determined by the BET method. 2 / g, preferably 50m 2 / g~400mm 2 In a preferred embodiment, the silica reinforcing filler has a molecular weight of at least 10 m / g as determined by the BET method. 2 / g, preferably 50m 2 / g~400m 2 The fumed silica has a specific surface area in the range of 0.01 to 10% by weight, preferably 0.01 to 5% by weight, and more preferably 0.05 to 2% by weight of the total composition.

[0055] According to one embodiment, the foamable crosslinkable silicone composition according to the present invention comprises (by weight, based on the total weight of the composition): 1.99% to 98.99% of a partial mixture of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule, at least one organosilicon compound B having at least two, preferably at least three, silicon-bonded hydrogen atoms per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D, which is water, a hydrogel, or an aqueous silicone emulsion; At least one chemical blowing agent E, 0.01% to 2%; and 1% to 98% of at least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C of 50 mPa·s to 100,000 mPa·s.

[0056] According to another embodiment, the foamable crosslinkable silicone composition according to the present invention comprises (by weight, based on the total weight of the composition): 4.95% to 49.95% of a partial mixture of at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule, at least one organosilicon compound B having at least two, preferably at least three, hydrogen atoms bonded to silicon per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D, which is process water, a hydrogel, or a process aqueous silicone emulsion; At least one chemical blowing agent E, 0.05% to 1.5%; and 50% to 95% of at least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C of 50 mPa·s to 100,000 mPa·s.

[0057] According to another embodiment, the foamable crosslinkable silicone composition according to the present invention comprises (by weight, based on the total weight of the composition): 6.9% to 24.9% of a partial mixture of at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule, at least one organosilicon compound B having at least two, preferably at least three, hydrogen atoms bonded to silicon per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D, which is water, a hydrogel, or an aqueous silicone emulsion; 0.1% to 1.0% of at least one chemical blowing agent E; and 75% to 93% of at least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C of 50 mPa·s to 100,000 mPa·s.

[0058] Within the above embodiment, the submixture of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule, at least one organosilicon compound B having at least two, and preferably at least three, silicon-bonded hydrogen atoms per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D that is water, a hydrogel, or an aqueous silicone emulsion can have the following composition (by weight, based on the total weight of the submixture): 40% to 95% of at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule; 1% to 20% of at least one organosilicon compound B having at least two, preferably at least three, hydrogen atoms bonded to silicon per molecule; 2 to 400 ppm (calculated by weight of platinum metal) of at least one platinum hydrosilylation catalyst C; 0.3% to 2.5% of at least one porosifying agent D, which is water, a hydrogel, or an aqueous silicone emulsion.

[0059] More preferentially, the partial mixture may have the following composition (by weight relative to the total weight of the partial mixture): 50% to 90% of at least one organopolysiloxane A having at least two alkenyl groups bonded to silicon per molecule; 3% to 15% of at least one organosilicon compound B having at least two, preferably at least three, hydrogen atoms bonded to silicon per molecule; 5 ppm to 200 ppm of at least one platinum hydrosilylation catalyst C; 0.5% to 1.5% of at least one porosifying agent D, which is water, hydrogel, process aqueous silicone emulsion.

[0060] Another object of the present invention relates to a method for producing such an implant. The implant comprises a shell and a filler enclosed by the shell. According to one embodiment, the filler enclosed by the shell consists of or essentially consists of the silicone foam according to the present invention. According to other embodiments, in addition to the foam, the filler may also comprise other elements, including flexible bodies, for example, air- or gas-containing bodies. According to one embodiment, the filler enclosed by the shell comprises hollow microspheres. Examples of suitable hollow microspheres include hollow glass microspheres or hollow ceramic microspheres.

[0061] Hollow glass microspheres are sometimes called "hollow glass beads" or "hollow glass bubbles." They are small, hollow spheres of hardened silica (glass) that vary in size and density depending on the grade. They have a thick enough shell to maintain structural rigidity. Their hollow nature makes them very lightweight, and their density varies with size and wall thickness. They appear as a white powder in bulk. The primary differences between grades are their size, strength, and density, with the strength of the microspheres being expressed in terms of average isotropic crush strength.

[0062] According to one embodiment, the hollow glass beads are hollow borosilicate glass microspheres.

[0063] According to one embodiment, the hollow glass microspheres have a density of 0.10 grams per cubic centimeter (g / cm 3)~0.75g / cm 3 It has a true density in the range of

[0064] The term "true density" refers to the quotient obtained by dividing the mass of a sample of hollow glass microspheres by the true volume of the mass of the glass bubbles measured with a gas pycnometer. "True volume" refers to the total volume of the glass bubbles, not the bulk volume.

[0065] According to a preferred embodiment, the hollow glass microspheres are selected from: 1.3M™ Glass Bubble Floated Series (A16 / 500, G18, A20 / 1000, H20 / 1000, D32 / 4500, H50 / 10000 EPX glass bubble products) and 3M™ Glass Bubble Series (K1, K11, K15, S15, S22, K20, K20HS, K25, S32, S32LD, S35, XLD3000, S28HS, S35, K37, S38, S38HS, S38XHS, S32HS, K46, K42HS, S42XHS, S60, S60HS, iM16K, iM30K glass bubble products, etc.; not limited to). The glass bubbles exhibit a variety of crush strengths ranging from 250 psi to 27,000 psi (at which point 10% by volume of the first plurality of glass bubbles collapses). Other glass bubbles sold by 3M, such as 3M™ Glass Bubbles - HGS Series and surface-treated 3M™ Glass Bubbles, can also be used in accordance with the present invention. 2. Hollow glass microspheres sold by Potters Industries under the SPHERICEL® trademark (e.g., the following products: 110P8, 60P18, 34P30, 25P45) or those sold under the Q-Cel® Lightweight trademark (e.g., the following products: 6014, 6019, 7019, 6019S, 5020, 5020FPS, 7023, 7028, 2058, 6036, 7037, 7040S, 6042S, 6048, 5070S).

[0066] Suitable hollow glass microspheres may be surface-treated or untreated. Surface-treated hollow glass microspheres may typically be hydrophobic. Examples of surface treatment agents include silane coupling agents such as aminopropyltriethoxysilane, y-glycidoxypropyltrimethoxysilane, y-(methacryloyloxy)propyltrimethoxysilane (also known as silane coupling agent KH-570), and sodium methylsiliconate.

[0067] Hollow ceramic microspheres, also known as cenospheres, are lightweight, inert hollow spheres filled with inert air or gas and are typically produced as a by-product of coal combustion in thermal power plants. Silica and alumina are the primary components. Cenospheres vary in color from gray to almost white and have a density of approximately 0.4 g / cm. 3 ~0.8g / cm 3 It flows like a liquid and looks like a powder. Suitable cenospheres are either untreated or surface treated with a silane coupling agent such as one or more of 3-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 4-aminopropylmethyldimethoxysilane, or 3-aminopropylmethyldiethoxysilane.

[0068] Commercially available examples of hollow ceramic microspheres include Z-Light™ Spheres Microspheres available from 3M™ Company (e.g., the following products: 3M™ Z-Light™ Spheres G-3125, G-3150, G-3500).

[0069] According to a first embodiment, the object of the present invention is a method for producing an implant comprising a shell and a filling surrounded by said shell, comprising the following steps: (1a) mixing the components of the foamable crosslinkable silicone composition according to the invention and as defined above to obtain a filled precursor of a silicone foam, (1b) filling a mould with said filled precursor of a silicone foam, and (1c) foaming and crosslinking said filled precursor of a silicone foam to obtain an implant.

[0070] Those skilled in the art can select appropriate additives according to their general knowledge in the art. The shell can be, for example, a silicone elastomer, preferably vulcanized silicone rubber, and can be single-layered or multi-layered, smooth or textured, barrier-coated, or covered with polyurethane foam. Conventional breast implant shells have a multi-layer or laminated structure. Specifically, such shells include an outer "burst-resistant" layer and an inner "barrier" layer sandwiched between the outer layers and effective in resisting silicone bleeding. For example, a low-diffusion silicone elastomer shell can be made from an outer layer of dimethyl-diphenylsilicone elastomer having a 5% diphenyl polymer mole percent and a barrier layer of dimethyl-diphenylsilicone elastomer having a 15% diphenyl polymer mole percent. Another suitable example of a flexible shell that can be used in accordance with the present invention is a flexible shell comprising a substantially homogeneous layer surrounding and in direct contact with the core silicone gel, the flexible shell being made from a silicone elastomer comprising a polydimethylsiloxane backbone having pendant diphenyl groups, such that the mole percent of said diphenylsiloxane units is about 15%.

[0071] Flexible implant shells can be manufactured by conventional dip-molding or spray-molding methods. Dip-molding typically involves dipping a suitably shaped mandrel into a silicone elastomer dispersion, while spray-molding involves spraying the silicone elastomer dispersion onto a suitably shaped mandrel. The shell is then peeled from the mandrel, and any holes in the shell caused by the molding process are repaired. The hollow interior of the shell can be filled with the filling precursor of the present invention using the opening in the patch. The opening in the patch is then sealed with a silicone adhesive, and the prosthesis is heat-cured. Another method for forming implant shells is rotational molding, such as the system and method described in U.S. Pat. No. 6,602,452. Alternatively, shells can be manufactured by injection molding.

[0072] According to another embodiment of the present invention, there is provided a method for producing an implant comprising a shell and a filling surrounded by said shell, the method comprising the steps of: (2a) mixing the components of the foamable cross-linkable silicone composition of the present invention as defined above to obtain a filled precursor of a silicone foam; (2b) foaming and cross-linking the filled precursor of a silicone foam; and (2c) forming a shell around the silicone foam to provide an implant. The method includes:

[0073] According to said embodiment, step (2b) can preferably be carried out in a mold so that the silicone foam can have a particular desired shape.

[0074] The shell can be obtained in step (2c) according to a method known to those skilled in the art as described above, but the silicone foam obtained in step (2b) can be used instead of a suitably shaped mandrel. For example, step (2c) can be preferably carried out by immersing the silicone foam obtained in step (2b) in a silicone elastomer dispersion. Alternatively, step (2c) can be preferably carried out by spraying the silicone elastomer dispersion onto the silicone foam obtained in step (2b).

[0075] Steps (1c) and (2b) of the method of the present invention (i.e., foaming and crosslinking the filled precursor to form a silicone foam) can be carried out by heating at a temperature ranging from 50°C to 200°C, preferably from 100°C to 170°C. The temperature in step (c) can be adjusted depending on the decomposition temperature of the chemical foaming agent E. For example, the decomposition temperature of ammonium bicarbonate is approximately 60°C. The temperatures in steps (1c) and (2b) can be set to preferably 60°C or higher so that both foaming and crosslinking proceed substantially simultaneously. Alternatively, steps (1c) and (2b) can be initiated at room temperature, and the temperature can then be increased to separately control foaming and crosslinking by chemical foaming agent E.

[0076] Another object of the present invention is to provide a novel method for additive manufacturing of 3D shaped articles composed of said silicone foams, which also allows for the production of complex shaped objects made of such biocompatible materials.

[0077] One object of the present invention relates to a method for additive manufacturing of 3D shaped articles, in particular articles for use in medical devices, made from silicone foam, comprising the following steps: (3a) printing a portion of said foamable crosslinkable silicone composition as defined above in a 3D printer to form a deposit on a support material SM, which is a gel or microgel suitable for 3D gel printing of a silicone foam, said deposit being achieved by an apparatus having at least one delivery unit positionable in the x-, y- and z-directions; (3b) partially or fully foaming and crosslinking the printed foamable crosslinkable silicone composition to obtain a silicone foam deposit within said support material SM; (3c) optionally repeating steps (a) and (b) several times until the desired 3D shape is obtained; (3d) removing the support material SM mechanically or via dissolution in a solvent; and (3e) Recovering a 3D shaped article composed of silicone foam.

[0078] According to a specific embodiment, step (3b) can be carried out by heating at a temperature ranging from 50°C to 200°C, preferably from 100°C to 170°C. The temperature in step (3b) can be adapted depending on the decomposition temperature of the chemical blowing agent E. For example, the decomposition temperature of ammonium bicarbonate is approximately 60°C. The temperature in step (3b) can be set to preferably 60°C or higher so that both foaming and crosslinking proceed substantially simultaneously. Alternatively, step (3b) can be initiated at room temperature, and the temperature can then be increased to separately control foaming and crosslinking by the chemical blowing agent E. This specific embodiment can advantageously provide a desiliconized foam with anisotropic properties.

[0079] Printing is preferably performed layer-by-layer with a 3D printer, which can be selected from an extrusion 3D printer or a material jetting 3D printer. 3D printing generally relates to a host of related technologies used to manufacture physical objects from computer-generated, e.g., computer-aided design (CAD), data sources. A "3D printer" is defined as a machine used for 3D printing, and "3D printing" is defined as the manufacture of an object by the deposition of material using printheads, nozzles, and other printer technology.

[0080] In a preferred embodiment, a method for producing an article composed of a silicone foam according to the present invention uses an extrusion 3D printer. The foamable cross-linkable silicone composition is extruded through a nozzle. The nozzle may be heated to aid in the extrusion of the addition-cross-linkable silicone composition. The foamable cross-linkable silicone composition extruded through the nozzle may be supplied from a cartridge-like system. A coaxial cartridge system with a static mixer and only one nozzle may also be used. The pressure is adapted to the extruded fluid, the average diameter of the associated nozzle, and the printing speed. Due to the high shear rate generated during nozzle extrusion, the viscosity of the foamable cross-linkable silicone composition is significantly reduced, allowing for the printing of fine layers. The cartridge pressure can vary from 1 bar (i.e., atmospheric pressure) to 28 bar, preferably from 1 bar to 10 bar, and most preferably from 2 bar to 8 bar. To withstand such pressures, an adapted device using an aluminum cartridge can be used. The nozzle and / or build platform move in the xy (horizontal) plane to complete a cross-section of the object, and then move in the z-axis (vertical) plane once a layer is completed. The nozzle has a high xyz movement accuracy of about 10 pm. After printing each layer in the x- and y-work plane, the nozzle is displaced in the z-direction a distance sufficient for the next layer to be applied to the x- and y-work location. In this way, 3D articles are produced one layer at a time, from bottom to top. The average diameter of the nozzle is related to the layer thickness. In one embodiment, the layer diameter is comprised between 50 pm and 2000 pm, preferably between 100 pm and 800 pm, and most preferably between 100 pm and 500 pm. Advantageously, the printing speed is comprised between 1 mm / s and 50 mm / s, preferably between 5 mm / s and 30 mm / s, to obtain the best compromise between good accuracy and production speed.

[0081] The support material SM is a gel or microgel suitable for 3D gel printing of silicone foam. The gel or microgel provides constant support for the liquid material during 3D printing. This allows for more complex objects to be printed at a faster pace without the need for additional supports. The support material SM can be selected by one of skill in the art from among the materials disclosed in, for example, WO 2019 / 215190 and WO 2020 / 127882, or U.S. Patent Application Publication Nos. 2015 / 0028523, 2018 / 0036953, and 2018 / 0057682. Further details can be found in the chemistry publication: "Poloxamer / Poly(ethylene glycol) Self-Healing Hydrogel for High-Precision Freeform Reversible Embedding of Suspended Hydrogel" by Arthur Colly, Christophe Marquette and Edwin-Joffrey Courtial (Langmuir 2021,37,14,4154-4162).

[0082] According to one embodiment of the claimed method, the support material SM can be provided as a matrix, for example in a container, and placed at the required temperature. According to another embodiment, the support material SM can be delivered simultaneously or at staggered intervals with the foamable cross-linkable silicone composition at specific locations using an apparatus having at least one delivery unit positionable in the x, y, and z directions.

[0083] The 3D shaped article made from the silicone foam recovered from step (3e) can be advantageously used as a medical device. In the framework of the present invention, said 3D shaped article made from silicone foam can be used as an implant, preferably as a breast implant.

[0084] According to a particular embodiment, the object of the present invention is the manufacture of an implant comprising a shell and a filling surrounded by said shell, the method comprising obtaining a 3D shaped article made of silicone foam according to the method described above and forming a shell around said silicone foam to obtain the implant.

[0085] Alternatively, the silicone foam and shell of the present invention can be 3D printed simultaneously using a specially designed 3D printer equipped with a dual nozzle system that allows the shell and infill to be 3D printed simultaneously.

[0086] After completing the implant of the present invention, the steps required to manufacture the finished product may be similar to those known in the art, such as packaging the filled implant and sterilizing the packaged implant.

[0087] The implant according to the invention can be a breast implant, a facial implant such as an eyebrow, nose, cheek, chin and lip, or another body implant such as a tracheal stent, an implantable fat augmentation or replacement such as a gluteus maximus, breast or cheek implant, or hard tissue such as a calf, biceps, triceps or abdominal muscle. Preferably, the implant according to the invention is a breast implant.

[0088] Various embodiments of the present invention may be better understood by reference to the following examples, which are provided for illustrative purposes, but the present invention is not limited to the examples set forth herein. [Example]

[0089] raw materials: Organopolysiloxane A1 = A mixture of multiple polydimethylsiloxane oils having dimethylvinylsilyl terminal units, with a viscosity at 25°C ranging from about 4,000 mPa to about 100,000 mPa·s, and an average viscosity at 25°C of about 10,000 mPa·s. Organopolysiloxane A2=MD ViQ (where the vinyl group attached to the silicon atom is held by the D group) Organopolysiloxane B1 = Poly(methylhydrogensiloxane) with trimethylsilyl terminal units, having a viscosity of about 20 mPa·s at 25°C Organopolysiloxane B2 = Polydimethylsiloxane with dimethylvinylsilyl terminal units, viscosity at 25°C 7 mPa·s Catalyst C = 10 wt. % platinum metal, known as the Karstedt catalyst Emulsion D = Silicone emulsion containing approximately 59.5% water by weight Foaming agent E1 = ammonium bicarbonate Foaming agent E2 = Finely ground ammonium bicarbonate mixed with silica and polydimethylsiloxane oil (NH4HCO3 content = 50% by weight) Polydimethylsiloxane F1 = PDMS with a viscosity of approximately 1000 mPa·s at 25°C Polydimethylsiloxane F2 = PDMS with a viscosity of approximately 5000 mPa·s at 25°C Polydimethylsiloxane F3 = A mixture of polydimethylsiloxane oils (PDMS and polydimethylsiloxane with one dimethylvinylsilyl end unit and one trimethylsilyl end unit) with an average viscosity of approximately 300 mPa·s at 25°C. Polydimethylsiloxane F4 = A mixture of polydimethylsiloxane oils (PDMS and polydimethylsiloxane with one dimethylvinylsilyl end unit and one trimethylsilyl end unit) with an average viscosity of approximately 1000 mPa·s at 25°C. Polydimethylsiloxane F5 = A mixture of polydimethylsiloxane oils (PDMS and polydimethylsiloxane with one dimethylvinylsilyl end unit and one trimethylsilyl end unit) with an average viscosity of approximately 2000 mPa·s at 25°C. Polydimethylsiloxane F6 = A mixture of polydimethylsiloxane oils (PDMS and polydimethylsiloxane with one dimethylvinylsilyl end unit and one trimethylsilyl end unit) with an average viscosity of approximately 20,000 mPa·s at 25°C.

[0090] Comparative Example 1: A foamable crosslinkable silicone composition was prepared by mixing the ingredients listed in Table 1 below:

[0091] [Table 1]

[0092] The resulting hydrogen-blown silicone foam exhibited high rigidity, but its texture was not very similar to that of human tissue.

[0093] Comparative Example 2: The silicone foam described in International Publication No. 2020 / 072374, a prior art document listed in Table 14, was reproduced. The raw materials (linear PDMS, dimethylvinylsilyl-terminated polydimethylsiloxane, platinum catalyst, crosslinker, and ammonium bicarbonate) were mixed and maintained at 150°C for 30 minutes to allow crosslinking and foaming to occur. The silicone foam was exclusively chemically foamed. This material had a significantly improved feel compared to Comparative Example 1, but the cell structure was very irregular, raising concerns about its uniform texture and manufacturing.

[0094] Examples 1-6: A foamable crosslinkable silicone composition was prepared by mixing the ingredients listed below in Table 2. After mixing, the temperature was maintained at 150° C. for 60 minutes.

[0095] [Table 2]

[0096] The silicone foam obtained by the present invention is a simultaneous foam of hydrogen-blown and chemically-blown foams, and exhibits low density, low weight, good cell structure, and a natural tissue-like feel.

[0097] Examples 7-9: A foamable crosslinkable silicone composition was prepared by mixing the ingredients listed below in Table 3. After mixing, the temperature was maintained at 150°C for 60 minutes.

[0098] [Table 3]

[0099] Examples 10-15: Typical composition of hydrogen-blown silicone foam "H2B Foam": 67.10% by weight of a mixture of polydimethylsiloxane oils having dimethylvinylsilyl terminal units and having an average viscosity of about 1,000 mPa·s at 25°C; · 11.2 wt.% treated fumed silica; · 0.64% by weight of water; · 0.64% by weight of emulsifier; 0.03% by weight of Karstedt's catalyst (containing 10% by weight of platinum metal); · poly(methylhydrogensiloxane) having 20.00 wt. % trimethylsilyl terminal units and a viscosity of about 20 mPa·s at 25°C; 0.39% by weight of ethynylcyclohexanol.

[0100] A foamable crosslinkable silicone composition was prepared by mixing the ingredients listed below in Table 4. After mixing, the temperature was maintained at 150°C for 60 minutes.

[0101] [Table 4]

[0102] PVP10 = Polyvinylpyrrolidone; average molecular weight 10,000 PVP40 = Polyvinylpyrrolidone; average molecular weight 40,000

[0103] Example 16: Example 10 was reproduced, except that the composition of the hydrogen-blown silicone foam "H2B Foam" contained 14.6 wt. % (instead of 11.2 wt. %) of treated fumed silica and 63.7 wt. % (instead of 67.1 wt. %) of the same mixture of several polydimethylsiloxane oils. The silicone foams obtained with the compositions of Examples 7 to 16 exhibit low density, low weight, and good cell structure.

[0104] [Table 5]

Claims

1. 1. An implant comprising a shell and a filling surrounded by said shell, wherein said filling comprises a silicone foam obtained from a foamable cross-linkable silicone composition, said foamable cross-linkable silicone composition comprising: at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule; at least one organosilicon compound B having at least two, preferably at least three, silicon-bonded hydrogen atoms per molecule; at least one hydrosilylation catalyst C; at least one porosifying agent D which is water, a hydrogel, or an aqueous silicone emulsion; at least one chemical blowing agent E; and At least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C between 50 mPa·s and 100,000 mPa·s Implants including.

2. 2. The implant of claim 1, wherein said organopolysiloxane A is a linear organopolysiloxane; preferably, said organopolysiloxane comprises terminal dimethylvinylsilyl units, more preferably, said organopolysiloxane A is a poly(dimethylsiloxane) comprising dimethylvinylsilyl end groups.

3. The organopolysiloxane A is C 2～6 It is a branched organopolysiloxane containing alkenyl units; preferably, it has the following formula: ・M Vi Q (wherein the alkenyl group bonded to the silicon atom is held by the M group); ・MM Vi TQ (wherein the alkenyl group bonded to the silicon atom is carried by part of the M unit); ・MD Vi Q (wherein the alkenyl group bonded to the silicon atom is held by a D group); MDD Vi Q (wherein the alkenyl group bonded to the silicon atom is held by part of the D group); ・MM Vi TQ (wherein the alkenyl group bonded to the silicon atom is carried by part of the M unit); ・MM Vi D.D. Vi Q (wherein the alkenyl group bonded to the silicon atom is carried by a portion of the M and D units); and mixtures thereof, wherein M:R 1 3 SiO 1 / 2 Siloxyl unit, M Vi : YR 1 2 SiO 1 / 2 and Y 2 R 1 SiO 1 / 2 a siloxyl unit selected from the group consisting of: D:R 1 2 SiO 2 / 2 Siloxyl units, D Vi :Y 2 SiO 2 / 2 or YR 1 SiO 2 / 2 a siloxyl unit selected from the group consisting of siloxyl units, T: a siloxyl unit of formula R 1 SiO 3 / 2 and Q: a siloxyl unit of the formula SiO 4 / 2 The symbol Y represents a siloxyl unit of C 2～6 alkenyl, preferably vinyl, and the symbol R 1 is a monovalent hydrocarbon radical having 1 to 12 carbon atoms, preferably selected from alkyl radicals having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, cycloalkyl radicals having 3 to 8 carbon atoms, and aryl radicals having 6 to 12 carbon atoms.

4. 2. The implant of claim 1, wherein the foamable crosslinkable silicone composition comprises a mixture of at least one linear organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule and at least one branched organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule.

5. 5. The implant of claim 1, wherein the foamable crosslinkable silicone composition comprises a mixture of at least one organosilicon compound B1 having at least three hydrogen atoms bonded to silicon per molecule and at least one organosilicon compound B2 having two hydrogen atoms bonded to silicon per molecule.

6. The implant according to any one of claims 1 to 5, wherein the pore-forming agent D is an aqueous silicone emulsion.

7. The implant according to any one of claims 1 to 5, wherein said pore-forming agent D is a mixture of water and at least one emulsifier.

8. The chemical blowing agent E is preferably ammonium bicarbonate (NH 4 ) HCO 3 , sodium bicarbonate NaHCO 3 , calcium bicarbonate Ca(HCO 3 ) 2 8. The implant according to claim 1, wherein the chemical foaming agent E is at least one bicarbonate selected from the group consisting of: and mixtures thereof, more preferably ammonium bicarbonate.

9. The linear polydimethylsiloxane F is a mixture of linear polydimethylsiloxanes (I) and (II), with a weight ratio of (I):(II) of 100:0 to 0:100, wherein the linear polydimethylsiloxane (I) is represented by the following formula: (CH 3 , 3 t0.834597575 Subscribe Us 3 , 2 , n Si(CH 3 , 3 (I) wherein n is an integer of 50 to 900, preferably 50 to 700; and the linear polydimethylsiloxane (II) has the following formula: (CH 3 , 3 t0.834597575 Subscribe Us 3 , 2 , n Si(CH 3 , 2 (Y) (II) (Wherein, Y is C 2～6 The implant according to any one of claims 1 to 8, wherein n is an integer between 50 and 900, preferably between 50 and 700.

10. An implant according to any one of claims 1 to 9, wherein the foamable crosslinkable silicone composition comprises (by weight relative to the total weight of the composition): 1.99% to 98.99% of a submixture of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule, at least one organosilicon compound B having at least two, and preferably at least three, silicon-bonded hydrogen atoms per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D which is water, a hydrogel, or an aqueous silicone emulsion; 0.01% to 2% of at least one chemical blowing agent E; and 1% to 98% of at least one linear polydimethylsiloxane F having a dynamic viscosity at 25°C of 50 mPa·s to 100,000 mPa·s.

11. 11. The implant of claim 10, wherein a submixture of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule, at least one organosilicon compound B having at least two, preferably at least three, silicon-bonded hydrogen atoms per molecule, at least one hydrosilylation catalyst C, and at least one pore-forming agent D which is water, a hydrogel, or an aqueous silicone emulsion has the following composition (by weight, based on the total weight of the submixture): 40% to 95% of at least one organopolysiloxane A having at least two silicon-bonded alkenyl groups per molecule; 1% to 20% of at least one organosilicon compound B having at least two, preferably at least three, hydrogen atoms bonded to silicon per molecule; from 2 to 400 ppm (calculated as the weight of platinum metal) of at least one platinum hydrosilylation catalyst C; 0.3% to 2.5% of at least one porosifying agent D which is water, a hydrogel, or an aqueous silicone emulsion.

12. An implant according to any one of claims 1 to 11, wherein the filling surrounded by the shell comprises silicone foam and further comprises hollow microspheres, preferably hollow glass microspheres.

13. 13. An implant according to any of claims 1 to 12, wherein the implant is a breast implant, a facial implant such as an eyebrow, nose, cheek, chin and lip implant, or another body implant such as a tracheal stent, an implantable fat augmentation or replacement such as a gluteus maximus or cheek implant; or a hard tissue such as a calf, biceps, triceps or abdominal muscle, preferably the implant is a breast implant.

14. 1. A method of manufacturing an implant comprising a shell and a filling surrounded by said shell, the method comprising the steps of: (1a) mixing the components of the foamable cross-linkable silicone composition according to any one of claims 1 to 13 to obtain a filled precursor of a silicone foam; (lb) filling the shell with said filled precursor of silicone foam; and (lc) foaming and crosslinking said filled precursor of silicone foam to obtain an implant.

15. 1. A method for producing an implant comprising a shell and a filling surrounded by said shell, comprising the steps of: (2a) mixing the components of the foamable cross-linkable silicone composition according to any one of claims 1 to 13 to obtain a silicone foam precursor; (2b) foaming and crosslinking the filled precursor of the silicone foam; and (2c) forming the shell around the silicone foam to obtain an implant; A method comprising:

16. 1. A method for additive manufacturing of 3D shaped articles composed of silicone foam, particularly for use in medical devices, comprising the steps of: (3a) printing a portion of the foamable crosslinkable silicone composition according to any one of claims 1 to 13 in a 3D printer to form a deposit on a support material SM, which is a gel or microgel suitable for 3D gel printing of a silicone foam, said deposit being achieved by an apparatus having at least one delivery unit positionable in the x-, y- and z-directions; (3b) partially or fully foaming and crosslinking the printed foamable crosslinkable silicone composition to obtain a silicone foam deposit within said support material SM; (3c) optionally repeating steps (a) and (b) several times until the desired 3D shape is obtained; (3d) removing the support material SM mechanically or via dissolution in a solvent; and (3e) recovering 3D shaped articles composed of silicone foam. A method comprising:

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