Ceskoslovenska Akademie Ved

Ceskoslvnska Akademie Ved

Jiri Sulc

Zuzana Krcova

Karel Smetana

Petr Vondracek

Sarka Pitrova

Zuzna Krcova

Petr Lopour

Jiri Vacik

KrcovaZuzana

Krcova

The present invention concerns rubber-based composite materials swellable with water and associated methods of production. A swellable rubber material according to the present invention comprises a vulcanized non-silicone rubber selected from the group consisting of natural rubber, butadiene-styrene rubber, bromobutyl rubber, and ethylene-propylene rubber; and a hydrogel filler cross-linked by a crosslinking agent, wherein the composite material is vulcanizable at a temperature up to 150.degree. C., is thermoformable, possesses shape memory after thermoforming, and is swellable with water or aqueous solutions.

Rubbers swellable with water and aqueous solutions and the method for

A lens made from a non-hydrophilic acrylate or methacrylate polymer or copolymer for application in an aqueous medium inside a human eye or on its surface, i.e., an intraocular or contact lens, is provided wherein the originally non-hydrophilic surface layer has been hydrophilized by a partial hydrolysis or sulfonation in such a way that a gradient of swelling results such that the swelling decreases from a maximum on the very surface to a minimum in the non-swelling core, which is unaffected by hydrophilization. Accordingly, light reflexes are eliminated or at least substantially reduced as well as the tendency of the surface to grow cells, the irritation of neighboring living tissues, and the formation of pressure necroses.

Lenses from polymeric derivatives of acrylic and methacrylic acids

A method for the formation of hydrophilic layers on the surface of objects comprised of polymeric esters, nitriles, or combinations thereof, derived from acrylic acid, methacrylic acid, or both, by means of hydrolysis caused by strong acid at elevated temperatures, wherein the solubility of the polymer in warm acid is reduced by the addition of a salt which does not react with said polymer. Preferably, the salt is a salt of the strong acid employed to hydrolyze the polymer. The thickness of the hydrophilic layer may be controlled through control of the concentration of the salt. Optionally, the surface layer containing hydroxyl groups may be thickened by treatment with multifunctional primary or secondary alcohol which may, prior to treatment, have been esterified with a weaker acid than the acid employed for purposes of performing the hydrolysis.

Method for the formation of thin hydrophilic layers on the surface of

An intraocular hydrogel lens with shape memory swelling in water or in isotonic solution, as is physiologic saline, which is deformed before implantation into a shape suitable for operative insertion, for example, into the shape of a rod, is made, at least in part, from a crosslinked synthetic hydrogel containing acid and/or basic groups.

Intraocular hydrogel lens with shape memory

Contact lens or intraocular lens from lightly crosslinked polymer of 2-hydroxyethyl methacrylate or from such its copolymer, where the 2-hydroxyethyl methacrylate component prevails over the second nonhydrophilic component, which contains a hydrophilic swellable transparent surface layer and an inner part of lower swellability than the surface layer, whereby the swellability of the surface layer decreases continuously from the surface towards the inner part to the swellability level of the inner part. The swellability of the surface layer is at the surface of up to 98% and the thickness of the surface layer is at utmost 100 .mu.m. The finally shaped lens is treated with an alkaline reacting solution of a salt, in which the lens does not swell and the lens is then freed of all soluble substances by washing.

Contact or intraocular lens from lightly crosslinked polymer or

The invention pertains to a soft intracameral lens determined for the location in the posterior chamber of eye. The soft intracameral hydrogel lens has its front supporting and centering convex part determined for leaning against iris having in front a rotation symmetrical shape of a sphere, paraboloid or hyperboloid and passing into the broadest circumference by a surface which shape is equal to or approaches a shape of lateral area of cone, while the hinder supporting part of the lens with a spherical, planar, or moderately convex or concave-curved shape for leaning against a hinder capsula or a membrane from vitreous body in a large surface area. The hinder supporting part is broadened and forms on the edge a retaining ring reaching over the front part as much as by 1.5 mm, whereas the central thickness of the lens ranges between 1 to 3.5 mm. The surface of the soft intracameral lens may be formed, at least in part, from a soft hydrogel containing at least 70% of water at 20.degree. C. in the state of equilibrium swelling. the lens may have a spherical shape and be provided on the circumference with a supporting collar from soft hydrogel. The lens may also contain inside in its optical axis an inner part, e.g. a Fresnel lens, with a higher refractive index of light than has the surrounding part of the lens.

Soft intracameral lens

The solution pertains to an intraocular optical system consisting of a hollow elastically deformable insert (7), following the shape of capsula lentis (6) at least in main lines, leaning against the inner wall of capsula lentis and keeping it moderately tensioned, which insert (7) consists of a front element (1) and rear element (2) and an elastic element (3) placed between them, may be provided with openings (9) allowing the flow of liquid, and contains one to four lenses (4,5) placed in the main axis of eye, whereas at least one of these lenses is connected with the insert (7) in such a way, that it moves axially at the contraction and release of accommodation muscles and thus changes its position between the retina and cornea. The insert (7) is made from biocompatible materials as are silicone elastomers, hydrogels, advantageously elastic and with the shape memory, for example, from partially dried hydrogels with the hydrophilized surface, or from material with the glass-transition temperature T.sub.g from -5.degree. C. to 45.degree. C. or with T.sub.g adjusted to meet this requirement, for example, by swelling hydrogels into a non-equilibrium state. The insert (7) deformed into a rod-like form with the diameter less than 3 mm can be introduced into an eye through a very small incision.

Intraocular optical system

The invention pertains to a soft intracameral lens intended for location in the posterior chamber of the eye. The soft intracameral hydrogel lens has a front supporting and centering convex part intended for leaning against the iris having a rotational symmetrical shape of a sphere, paraboloid, or hyperboloid and passing into the broadest circumference by a surface, the shape of this surface being equal to or approaching the shape of the lateral area of a cone, while the hinder, or rear, supporting part of the lens has a spherical, planar, or moderately convex or concave-curved shape and a large surface area for leaning against a hinder capsula or a membrane of the vitreous body. The hinder supporting part is broadened and forms on its edge a retaining ring which reaches over the front part by as much as 1.5 mm, whereas the central thickness of the lens ranges between 1 to 3.5 mm. The surface of the soft intracameral lens may be formed, at least in part, from a soft hydrogel containing at least 70% water at 20.degree.C. in the state of equilibrium swelling. The lens may have a spherical shape and be provided on the circumference with a supporting collar manufactured from a soft hydrogel. The lens may also contain inside, in its optical axis, an inner part, e.g., a Fresnel lens, having a higher refractive index of light than the material which surrounds the inner part of the lens.

A hard introcular lens having shape memory consisting of a copolymer having a glass transition temperature (T.sub.g) from 40.degree. C. to 60.degree. C. that is deformable into the shape of a straight or bent rod with a diameter of 1 to 4 mm at a temperature above its T.sub.g temperature and cooled to fix the deformation for insertion into the human eye through a small incision. After insertion into the eye the deformed lens will soften and relax to its original undeformed shape by elevating its temperature with a rinsing solution above 40.degree. C. and will maintain its final shape after a subsequent temperature reduction at normal body temperature of about 37.degree. C. whereby the lens becomes a hardened lens.

Hard intraocular lens with the shape memory

Method for the formation of hydrophilic layers on the surface of objects made from polymeric esters and/or nitriles of acrylic acid and/or methacrylic acid by means of hydrolysis caused by stron acids at elevated temperature, where the solubility of polymer in warm acid is reduced by addition of a salt which alone does not react with the polymer, advantageously of a salt of the used acid. The thickness of the hydrophilic layer may be controlled by changing the concentration of salt and the survace layer containing hydroxyl groups may be at the same time or subsequently thickened by treatment with a multifunctional primary or secondary alcohol, whereas the alcohol groups may be previosuly, at least in part, esterified with an acid which is weaker than is the acid used for hydrolysis. By separation of the processing into at least two steps carried out under different conditions (time, pressure, concentration of components, temperature) it is possible to obtain the hydrophilic layer which is more swellable and softer on the surface than in the depth. The object of the invention relates also to a novel intraocular lens or contact lens article having good optical geometry and mechanical properties comprising (a) a core of hydrophobic polymer of a nitrile, as ester of acrylic acid, or an ester of methacrylic acid (b) a relatively, thin surface layer on said article comprised of a water-swellable, water-insoluble, inert, biocompatible hydrophilic polymer characterized by a recurring unit ##STR1## wherein R is hydrogen or methyl, and wherein A is hyrdrogen, alkali metal, or a monovalent polyhydric group characterized by two or more primary and/or secondary hydroxyl group and (c) said hydrophilic layer and said hydrophobic core being chemically and integrally united to form said lens or intraocular lens.

Contact lens or intraocular lens from lightly crosslinked polymer of 2-hydroxyethyl methacrylate or from such its copolymer, where the 2-hydroxyethyl methacrylate component prevails over the second nonhydrophilic component, which contains a hydrophilic swellable transparent surface layer and an inner portion of lower swellability than the surface layer, whereby the swellability of the surface layer decreases continuously from the exterior of the surface layer towards the inner portion to the swellability level of the inner portion. The swellability of the exterior of the surface layer is at the surface layer of up to 98% and the thickness of the surface layer is at utmost 100 .mu.m. The finally shaped lense is treated with an alkaline reacting solution of a salt, in which the lens does not swell and the lens is then freed of all soluble substances by washing.

The invention pertains to a new design of contact lenses and to the method of their manufacturing. The contact lens comprising a carrier portion and a hydrophilic supporting portion mediating the contact of the lens with the eye surface, wherein both these parts are made from different materials, with the supporting portion being divided into two or more independent pieces protruding above the concave surface of the lens and lead from the lens circumference towards the lens center which is left free, with gaps being provided between individual pieces. The supporting part is made from a water-swelling synthetic crosslinked hydrogel which has, in the state of full swelling with physiological saline, a swelling capacity of about 40 to 95 percent, whereas the carrier optical portion is made from a transparent material having a modulus of elasticity at least twice that of the modulus of elasticity of the supporting portion. The supporting portion forms a gap of at least 0.01 mm between the eye surface and the uncovered part of the lens.

Contact lens and the method of manufacturing thereof

The invention relates to a synthetic intraocular lens swellable in physiologic saline which is made from a polymer or a copolymer, at least one component of which is hydrophylic and the other one may be hydrophobic, crosslinked or non-crosslinked, whereas the content of swelling agent in it is below the equilibrium state whereby its glass-transition temperature T.sub.g is between -5.degree. C. and 45.degree. C. The lens is deformed above T.sub.g into a form suitable for surgical insertion, cooled below T.sub.g, and stored and surgically applied at the temperature below T.sub.g, and then relaxed in eye by post-swelling and heating. The lens may be incompletely swollen, instead in physiologic saline or water, in another physiologically harmless liquid, advantageously in glycerol.

Synthetic intraocular lens swellable in swelling agent and a method for

A method and apparatus for the polymerization cast molding of lenses from hydrophilic gels. A hydrophobic liquid which is essentially immiscible with a hydrophilic polymerization mixture is introduced into a mold having a hydrophobic surface, followed by dosing of the hydrophilic monomer mixture which is allowed to polymerize to form a drop which is pressed, while polymerizing, into the mold with a punch having a hydrophobic molding surface. The polymerizing monomer mixture is maintained under the pressure of the punch until the end of the polymerization. Any overflow of the two liquids is allowed to escape between the mold and the punch. The apparatus comprises a concave mold with an inner hydrophobic, rotation-symmetrical surface, and a punch with a hydrophobic molding surface which when placed in relationship to the mold has an overflow space formed between the mold and the punch.

Method for polymerization cast molding of lenses from hydrophilic gels

Hydrophilic silicones composite contain 10 to 150 wt. parts of a powdered hydrogel filler with particle size 10.sup.-6 to 10.sup.-1 mm on 100 parts by weight of crosslinked silicone polymer which forms a continuous matrix of the composite. The used hydrogel filler is formed made of physically or chemically crosslinked polymers or copolymers of polyol or dihydroxyether monomethacrylates, amides of methacrylic or acrylic acid or their N-monosubstituted and N,N-disubstituted derivatives, or a multiblock copolymer of acrylonitrile with acrylamide and/or acrylic acid. The hydrogel filler is mixed into the non-crosslinked silicone rubber, which is, after shaping, crosslinked by the known procedure of silicone rubber vulcanization at temperatures ranging from 15.degree. to 200.degree. C. These composites are substantially stronger, more plastic, and absorb more water than expected. Tensile strength and shape memory are improved. The composites are useful as biomaterials.

Growing community of inventors

Prague, Czechia

Jiri Sulc