EP0089145A2
Expired / Lapsed
EP
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Injectable cross-linked collagen implant material
Assignee: Cessione collagen Corp Dello Sta Soc
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Filing: 1983-03-03
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Granted: —
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Expires: 2003-03-03
Abstract
Abstract Chemically cross-linked atelopeptide collagen that is a viscous fluid and substantially free of residual cross-linking agent is prepared by: reconstituting atelopeptide collagen from solution by neutralizing the solution at a reduced temperature and a hypotonic ionic strength; cross-linking the reconstituted fibers with glutaraldehyde at a concentration and under conditions that produce a viscous cross-linked collagen; quenching the cross-linking reaction with an amino acid; and separating the viscous cross-linked atelopeptide collagen from the reaction mixture. This collagen is dispersed in an isotonic aqueous medium for use in dermal augmentation and is injectable and forms implants that have excellent persistence.
Inventors
- 👤 Thomas L. Smestad
- 👤 John Mcpherson
- 👤 Donald G. Wallace
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 00:26
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/435; C07K14/78; A; A61; A61L; A61L27/00; A61L27/14; A61L27/22; A61L27/24
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
24 words
Chemically cross-linked atelopeptide collagen . characterized in that it is: (a) a viscous fluid at 22°C; and (b) substantially free of residual cross-linking agent.
Claim 2
Dependent Claim
24 words
Chemically cross-linked atelopeptide collagen . characterized in that it is: (a) a viscous fluid at 22°C; and (b) substantially free of residual cross-linking agent.
Claim 3
Dependent Claim
26 words
The collagen of claim 1 further characterized in that the collagen has a viscosity in the range of about 700 to about 3000 cp at 22°C.
Claim 4
Dependent Claim
26 words
The collagen of claim 1 or 2 further characterized in that the amount of residual cross-linking agent in the collagen is less than about 20 ppm.
Claim 5
Dependent Claim
17 words
The collagen of claim 1, 2 or 3 further characterized in that the cross-linking agent is glutaraldehyde.
Claim 6
Dependent Claim
116 words
A process for preparing chemically cross-linked atelopeptide collagen that is a viscous fluid at 22°C and is substantially free of residual cross-linking agent characterized by steps: (a) reconstituting atelopeptide collagen from an acidic aqueous solution by neutralizing the solution at a reduced temperature and at a hypotonic ionic strength; (b) cross-linking the reconstituted atelopeptide collagen in an aqueous medium with a cross-linking agent that forms covalent bonds with the collagen at a concentration and under conditions sufficient to produce a cross-linked collagen that is a viscous fluid at 22°C; (c) quenching the cross-linking reaction with a quenching agent that reacts with the cross-linking agent; and (d) separating the viscous, cross-linked atelopeptide collagen from the reaction mixture.
Claim 7
Dependent Claim
116 words
A process for preparing chemically cross-linked atelopeptide collagen that is a viscous fluid at 22°C and is substantially free of residual cross-linking agent characterized by steps: (a) reconstituting atelopeptide collagen from an acidic aqueous solution by neutralizing the solution at a reduced temperature and at a hypotonic ionic strength; (b) cross-linking the reconstituted atelopeptide collagen in an aqueous medium with a cross-linking agent that forms covalent bonds with the collagen at a concentration and under conditions sufficient to produce a cross-linked collagen that is a viscous fluid at 22°C; (c) quenching the cross-linking reaction with a quenching agent that reacts with the cross-linking agent; and (d) separating the viscous, cross-linked atelopeptide collagen from the reaction mixture.
Claim 8
Dependent Claim
36 words
The process of claim 5 further characterized in that the cross-linked atelopeptide collagen has a viscosity of about 700 to about 3000 cp at 22 °C and contains less than about 20 ppm reactive cross-linking agent.
Claim 9
Dependent Claim
71 words
The process of claim 6 further characterized in that the temperature of step (a) is about 10°C to about 25°C, the ionic strength of step(a) is about 0.03 to about 0.1, and the final pH of step (a) is in the range of about 4.9 and about 10.0, the cross-linking agent is glutaraldehyde and the concentration of glutaraldehyde in the cross-linking reaction mixture is about 0.001% to about 0.05% by weight.
Claim 10
Dependent Claim
136 words
The process of claim 5 further characterized in that: the collagen is bovine corium collagen; the temperature of step(a) is about 10°C to about 25°C; the ionic strength of step(a) is about 0.03 to about 0.1; the final pH of step (a) is in the range of about 5 and about 8; the cross-linking agent is glutaraldehyde; the concentration of glutaraldehyde in the cross-linking reaction mixture is about 0.001% to about 0.05% by weight; the cross-linking reaction is carried out for about one-half hour to about one week; the quenching agent is glycine; the separation includes washing the viscous, cross-linked atelopeptide collagen to remove other reaction products and unreacted reactants; and the cross-linked atelopeptide collagen has a viscosity of about 700 to about 3000 cp at 22°C and contains less than about 20 ppm reactive aldehyde.
Claim 11
Dependent Claim
32 words
A collagen implant material for use in augmenting soft tissue in mammals characterized in that it comprises an aqueous suspension of the cross-linked atelopeptide collagen of claim 1, 2, 3 or 4.
References Cited (Backward Citations)
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