Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Arterial prosthesis – Stent structure
Patent
1986-06-24
1989-05-30
Lawrence, Evan
Prosthesis (i.e., artificial body members), parts thereof, or ai
Arterial prosthesis
Stent structure
623901, 623 66, 427 2, 427245, 264 41, A61F 200, B05D 500
Patent
active
048347477
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to the provision of a prosthesis material for use with a living body, the material produced showing mechanical compliance vis-a-vis soft body tissue and, furthermore, possessing biocompatibility. The invention includes a method for the manufacture of such material.
In using synthetic polymers as replacement material for various types of human tissue it is not only the biocompatibility properties of the polymer which is of critical importance to the performance of the material when used with a living body. In addition to biocompatibility and blood compatibility the mechanical compliance and porosity features are of basic importance. The available materials are not satisfactory in this respect. In other words, due to mechanical factors the applied material does not possess a mechanical performance which is in line with that of the surrounding natural tissue.
Accordingly, it is an object of the present invention to provide a prosthesis material of a synthetic nature showing mechanical compliance vis-a-vis soft body tissue at the same time possessing biocompatibility or blood compatibility.
Another object of the invention is to provide a prosthesis material for such use, which shows the desirable porosity in combination with mechanical resistance and compliance.
Yet another object of the invention is to provide a method for producing such prosthesis material, the method comprising a new feature of using a solvent of a special nature and a new precipitation technique in connection herewith.
Still another object is to provide a porous material of a fibrelike structure. In connection with extensive research and experimentation it has been found that a mono- or multilayered prosthesis material can be prepared starting from a solution of a copolymer in a mixed solvent and coating a substrate with a uniform thickness of such solution. The polymer is precipitated by evaporation and one or several consecutive layer(s) are applied to form a prosthesis material.
The invention is based on an entirely new concept of using a mixed solvent and a specific precipitation technique. The mixed solvent comprises as a first constituent a fluid which is miscible with the solvent but functions as a precipitating non-solvent with respect to polymer. Furthermore, the mixed solvent comprises a second constituent which is solvent for the polymer. In the polymer solution using a mixed solvent two criteria are of importance which will be further explained below.
The first criterion of the polymer mixed solvent solution is the feature that the solvent constituent thereof must have a higher rate of evaporation than the non-solvent constituent. The importance of this feature will be explained in the following.
The second criterion of the polymer mixed solvent solution is the feature that the degree of saturation thereof with regard to the polymer contents must be such that the polymer solution is near its precipitation point. By a saturation which is "near the precipitation point", is meant that the polymer solution used for preparing the mono- or multilayered material contains at least about 60% and preferably at least 80% by weight of the amount of polymer corresponding to a saturated solution of the same polymer in the same mixed solvent. It is preferred that the polymer solution used in the method of the invention contains no less than about 90% of the said amount of polymer.
In addition to these features of the polymer solution used for making the multilayered prosthesis material the invention also provides for a new precipitating technique which in principle resides in precipitating the substrate coating of the polymer solution by evaporating at least part of the solvent constituent or solvent fraction of the mixed solvent to precipitate the polymer to form a layer thereof on the substrate before applying another coating of polymer solution. Evaporation of the solvent constituent of the mixed solvent is facilitated by the fact that the solvent constituent is more voltaile than the non-solvent constituent o
REFERENCES:
patent: 3526224 (1970-09-01), Potts et al.
patent: 3546004 (1970-12-01), Schachowskoy et al.
patent: 3813466 (1974-05-01), Anderson
patent: 4135011 (1979-01-01), Mimura
patent: 4173689 (1979-11-01), Lyman et al.
patent: 4289125 (1981-09-01), Hung
Lawrence Evan
Medinvent S.A.
LandOfFree
Method of producing a multilayered prosthesis material and the m does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of producing a multilayered prosthesis material and the m, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of producing a multilayered prosthesis material and the m will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2149562