Viscoelastic collagen solution for ophthalmic use and method of preparation

Claim 2

A chemically-modified collagen compound which comprises at least two native collagen molecules which are coupled at at least one lysine epsilon amino group present on each said collagen molecule by a coupling group, characterized in that said coupling group comprising at least two moieties selected from the group consisting of carbonyl and sulfonyl groups.

Claim 3

The chemically-modified collagen compound of Claim 1 further characterized in that said carbonyl and/or sulfonyl groups present in said coupling group are linked to each other through saturated or unsaturated alkylene, arylene or mixed alkylene-arylene coupling chains having less than twenty carbon atoms, wherein said alkylene and/or arylene coupling chains may also contain heteroatoms selected from the group consisting of oxygen, sulfur and nitrogen, and may be substituted in available aromatic positions by carboxyl groups, straight or branched chain alkyl groups of 1 to 4 carbon atoms, straight or branched chain alkoxy groups of 1 to 4 carbon atoms, halogens and other non-reactive moieties, and in available aliphatic positions by carboxyl groups and alkyl or alkoxy groups of 1 to 4 carbon atoms.

Claim 4

The chemically-modified collagen compound of Claim 1 further characterized in that said coupling group has the general formula: -B-A-B-wherein B is independently CO, S0 2 or combinations thereof; and A is selected from the group consisting of: (1) an aromatic group having 6 to 20 carbon atoms: wherein Ar is independently selected from the group consisting of an aromatic ring having 6 to 10 carbon atoms, a heteroaromatic ring containing atoms selected from the group consisting of C, N, O and S, and having 5 to 10 atoms, or combinations thereof; J is hydrogen or (̵L)̵ b B, wherein L is selected from the group consisting of phenylene, an alkylene of 1 to 4 carbon atoms, and an oxyalkylene of 1 to 4 carbon atoms, b is 0 or 1, and B is as defined hereinabove, with the proviso that only one J in the chain may be (̵L)̵ b B, with all other J's being hydrogen; n is 0 or 1; a is 0 or an integer having a value of between 1 and 4; and D is independently selected from the group consisting of 0, CO, S, SO, SO 2 , -S0 2 -NH-, -NH-CO-NH-, wherein m is an integer having a value of between 1 and 3, R is selected from the group consisting of phenyl, and a straight or branched chain alkyl or acyl group having 1 to 4 carbon atoms; and J is as defined and restricted hereinabove; (3) an aromatic group having 6 to 10 carbon atoms, wherein said aromatic group may be substituted in available positions by J wherein J is as defined and restricted hereinabove; (4) a heteroaromatic group containing atoms selected from the group consisting of C, N, 0 and S, and having from 5 to 14 ring atoms, wherein said heteroaromatic group may be substituted in available positions by J, wherein J is as defined and restricted hereinabove; (5) an aliphatic or arylaliphatic chain which contains one or two olefinic or acetylenic groups and which contains 2 to 20 carbon atoms, wherein said chain may be substituted in available positions by J, wherein J is as defined and restricted hereinabove; (6) an alicyclic ring which may be partially unsaturated, having 3 to 15 carbon atoms, wherein said alicyclic ring may be substituted in available positions by J wherein J is as defined and restricted hereinabove; (7) a heterocyclic ring which may be saturated or unsaturated and which contains atoms selected from the group consisting of C, N, O and S, and which has from 5 to 12 ring atoms, wherein said heterocyclic ring may be substituted in available positions by J wherein J is as defined and restricted hereinabove; wherein t is an integer having a value of between 1 and 8; E is independently selected from the group consisting of O, NRJ, S, SO, S0 2 , CO, CONH, S0 2 NH and NHCONH, wherein R is as defined hereinabove, and m is an integer having a value of between 1 and 3; J is as defined and restricted hereinabove; s is an integer having a value of between 2 and 8; p is 0 or an integer having a value of between 1 and 4; q is 0 or 1; and r is 0 or an integer having a value of between 1 and 8, provided that when q is 1, r is greater than 0; and wherein G is independently selected from the group consisting of an aromatic ring having 6 to 10 carbon atoms, a heteroaromatic ring having 5 to 10 atoms, and a heterocyclic ring having 5 to 10 atoms, wherein the heteroaromatic and heterocyclic rings contain atoms selected from the group consisting of C, N, 0 and S; J is as defined and restricted hereinabove; w is an integer having a value of between 1 and f3; E and q are as defined hereinabove; y is 1 or 2; and v is 0 or an integer having a value of between 1 and 4, provided that when q is 1, v is not 0.

Claim 5

The chemically-modified collagen compound of Claim 1 further characterized in that at least a portion of the lysine epsilon amino groups which are not linked to said coupling groups are linked to amine-modifying groups, which amine-modifying groups are selected from the group consisting of saturated or unsaturated alkane sulfonamide and carboxamide groups, arene sulfonamide and carboxamide groups and mixed saturated or unsaturated alkane-arene sulfonamide and carboxamide groups, which amine-modifying groups have between 2 and 20 carbon atoms and are terminated by one or two carboxylic or sulfonic acid moieties, wherein said amine-modifying group may also contain up to 5 heteroatoms selected from the group consisting of oxygen, sulfur and nitrogen, and may be substituted in available aromatic and aliphatic positions by carboxyl groups, alkyl and alkoxy groups having 1 to 4 carbon atoms and halogens.

Claim 6

The chemically-modified collagen compound of Claim 1 further characterized in that at least 60 percent of the lysine epsilon amino groups which are not linked to said coupling groups are linked to amine-modifying groups, which amine-modifying groups are selected from the group consisting of saturated or unsaturated alkane sulfonamide and carboxamide groups, arene sulfonamide and carboxamide groups and mixed saturated or unsaturated alkane-arene sulfonamide and carboxamide groups, which amine-modifying groups have between 2 and 20 carbon atoms and are terminated by one or two carboxylic or sulfonic acid moieties, wherein said amine-modifying group may also contain up to 5 heteroatoms selected from the group consisting of oxygen, sulfur and nitrogen, and may be substituted in available aromatic and aliphatic positions by carboxyl groups, alkyl and alkoxy groups having 1 to 4 carbon atoms and halogens.

Claim 7

The chemically-modified collagen compound of Claim 4 further characterized in that said amine-modifying group has the general formula: -b-A(B-K) z wherein z is 0, 1 or 2, B and A are as defined hereinabove with the proviso that J is hydrogen, and K is OH.

Claim 8

A viscoelastic collagen solution comprising 0.5 to 5.0 percent by weight of the collagen compound of Claim 4 dissolved in a physiological buffer solution, further characterized in that the coupling group is present in said chemically-modified collagen compound to such an extent that a 2 percent by weight solution of said collagen compound in said physiological buffer has a steady state viscosity of 0.15 to 10 6 to 4.0 x 10 6 centipoise at a shear rate of 0.10 seconds- 1 ; a steady state viscosity of 0.20 x 10 5 to 7.5 x 10 5 centipoise at a shear rate of 1.0 seconds- 1 ; a steady state viscosity of 0.3 x 10 4 to 1.0 x 10 5 centipoise at a shear rate of 10.0 seconds- 1 ; and a steady state viscosity of 0.45 x 10 3 to 2.0 x 10 4 centipoise at a shear rate of 100 seconds- 1 .

Claim 9

A viscoelastic collagen solution comprising about 0.5 to 5.0 percent by weight of the collagen compound of Claim 4 dissolved in a physiological buffer solution, further characterized in that the coupling group is present in said chemically-modified collagen compound to such an extent that a 2 percent by weight solution of said collagen compound in said physiological buffer has a melt temperature of between 32°C and 48°C.

Claim 10

A method of making the chemically-modified collagen compound of Claim 1 characterized by the steps of (a) adding to an aqueous solution of at least 0.05 percent by weight native collagen, a coupling agent in an amount equal to 1 to 600 moles of coupling agent per mole of native collagen, said coupling agent selected from the group consisting of di- and tri-carboxylic acid halides, di- and tri-sulfonyl halides, di- and tri-anhydrides, di-and tri-reactive active esters, and compounds having at least two moieties selected from the group consisting of carboxylic acid halide, sulfonyl halide, anhydride and active ester; and (b) reacting said native collagen and said coupling agent at a pH of above 8 and at a temperature of between 0 and 35°C, for a time period sufficient to either react or hydrolyze substantially all of said coupling agent.

Claim 11

The method of Claim 9 further characterized in that said coupling agent is selected from the group consisting of terephthaloyl chloride: bicyclo-(2,2,2)-oct-7-ene-2,3,5,6- tetracarboxylic-2,3,5,6-dianhydride: 1,2,4,5-benzenetetracarboxylic dianhydride; p-fluorosulfonylbenzenesulfonyl chloride; and wherein the pH of the reaction mixture is initially maintained at 3 to 5.5 before raising the pH to above 8.

Claim 12

The method of Claim 9 further characterized in that said method additionally comprises the steps of: (c) adding to said reaction mixture a mono-reactive amine-modifying agent, said amine-modifying agent being selected from the group consisting of anhydrides, acid halides, sulfonyl halides and active esters, in an amount equal to at least 100 moles of amine-modifying agent per mole of native collagen; and (d) conducting the amine-modification reaction at a pH of greater than 8 and at a temperature of between 0 and 35°C, for a time period sufficient to either react or hydrolyze substantially all of said amine-modifying agent.

Claim 13

A method of making the chemically-modified collagen compound of Claim 5 characterized by the steps of: (a) adding to an aqueous solution of at least 0.05 percent by weight native collagen, a coupling agent in an amount equal to I to 600 moles of coupling agent per mole of native collagen and a mono-reactive amine-modifying agent in an amount equal to at least 50 moles of amine-modifying agent per mole of native collagen; said coupling agent selected from the group consisting of di-and tri-carboxylic acid halides, di- and tri-sulfonyl halides, di- and tri-anhydrides, di-and tri-reactive active esters and compounds having at least two moieties selected from the group consisting of carboxylic acid halide, sulfonyl halide, anhydride and active ester; and wherein said amine-modifying agent is selected from the group consisting of anhydrides, acid halides, sulfonyl halides and active esters; (b) allowing the reaction mixture to react at a pH of greater than 8 and at a temperature of between 0 and 35°C, for a time period sufficient to either react or hydrolyze substantially all of said coupling agent and said amine-modifying agent; (c) adding to the reaction mixture of step (b) additional mono-reactive amine-modifying agent in an amount equal to at least 50 moles of modifying agent per mole of native collagen; and (d) allowing the reaction mixture of step (c) to react at a pH of greater than 8 and at a temperature of between 0 and 35°C, for a period of time sufficient to either react or hydrolyze substantially all of said modifying agent.

Claim 14

A method of making the chemically-modified collagen compound of Claim 5 characterized by the steps of: (a) adding to an aqueous solution of at least 0.05 percent by weight native collagen a mono-reactive amine-modifying agent in an amount equal to at least 25 moles of amine-modifying agent per mole of native collagen, said amine-modifying agent being selected from the group consisting of anhydrides, acid halides, sulfonyl halides and active esters; (b) allowing the reaction mixture of step (a) to react at a pH of greater than 8 and at a temperature of 0 to 35°C for a period of time sufficient to either react or hydrolyze substantially all of said amine-modifying agent; (c) adding to the mixture produced in step (b) a coupling agent in an amount equal to 1 to 600 moles of coupling agent per mole of native collagen; said coupling agent selected from the group consisting of di- and tri-carboxylic acid halides, di- and tri-sulfonyl halides, di- and tri-anhydrides and di- and tri-reactive active esters, and compounds having at least two moieties selected from the group consisting of carboxylic acid halide, sulfonyl halide, anhydride and active ester; and (d) allowing the reaction mixture of step (c) to react at a pH of greater than 8 and at a temperature of 0 to 35°C for a time period sufficient to either react or hydrolyze substantially all of said coupling agent; (e) adding to the reaction mixture of step (d) additional amine-modifying agent in a concentration of at least 75 moles of modifying agent per mole of native collagen; and (f) allowing the reaction mixture of step (d) to react at a pH of greater than 8, and at a temperature of between 0 and 35°C, for a period of time sufficient to either react or hydrolyze substantially all of said amine-modifying agent.

Claim 15

A method of replacing at least a portion of the aqueous or vitreous humor in a human or animal eye, said method characterized by introducing into the aqueous or vitreous chamber of said human or animal eye, an effective amount of the viscoelastic collagen solution of Claim 8.

Claim 16

A method of preventing fibrous tissue formation and consequent development of adhesion and scars which may occur in healing tissue during the normal healing process, said method characterized by introducing into a surgical site, either during surgery or post-operatively an effective amount of the viscoelastic solution of Claim 8.

Claim 17

A method of enhancing normal joint and tendon function in a human or animal by lubricating said joint or tendon, said method characterized by introducing into the synovial space associated with said joint or tendon an effective lubricating amount of the viscoelastic solution of Claim 8.

Claim 18

A method of separating healing tissues and maintaining said separation during the normal healing process after surgery, said method characterized by introducing into a surgical site, either during surgery or post-operatively, an effective amount of the viscoelastic solution of Claim 8.

Claim 19

A method of achieving hemostasis characterized by placing an effective amount of the chemically-modified collagen compound of Claim 1 or Claim 5 in contact with a bleeding wound.

Claim 20

A method of augmenting soft tissue characterized by placing an effective amount of the chemically-modified collagen compound of Claim 1 or Claim 5 in contact with the augmentation site.