Title:  Modified polymers containing poly(2-hydroxyethyl(meth)acrylate segment in the molecule

United States Patent:  6,294,614

Assignee:  K. K. Vayu (Nagoya, JP)

Filed:  January 27, 1999

PCT NO:  PCT/JP97/02542

102(e) Date:  January 27, 1999

PCT PUB. Date:  February 5, 1998

Foreign Application Priority Data:  Jul 29, 1996[JP] (8-214973)

Modified polymers containing a poly(2-hydroxyethyl(meth)acrylate) chain as the hydrophilic polymer segment in which a hydrophobic polymer chain or a lipid residue of a sterol is bound to either end of the poly(2-hydroxyethyl(meth)acrylate) chain through a covalent bond or in which the poly(2-hydroxyethyl(meth)acrylate) chain is grafted onto the backbone chain at either end thereof. These modified polymers are excellent in compatibility with liquid or a living body, thus being advantageously usable particularly in medical fields.

DISCLOSURE OF DEVELOPMENT

The present inventors et al. have carried on research under the assumption that if a polymer can be provided in which the mobility of a hydrophilic polymer chain is enhanced separately from the formation of a micro phase separation structure in the solution of a block copolymer (or a copolymer) or the like, a higher resistance may be indicated against the adsorption of, for example, protein in body fluid, platelet in blood, or the like. This is not bound by theory, but if polymer chains having high mobility can be constructed on a certain surface, the adsorption of body fluid components can be expected to be strongly suppressed by the entropy elasticity of the chains as described above.

The present inventors et al. have found that the enlargement of mobility can be achieved by lowering the mobility of either end of the hydrophilic polymer chain by specific means. Specifically, when polyHEMA is used as the hydrophilic polymer chain, by appropriately lowering the mobility of either end thereof, for example, the glass transition temperature (which is, in one view, believed to correspond to the freezing or releasing of polymer chain segment motion or micro-Brownian motion) is remarkably lowered, as compared with a polymer in which such mobility is not lowered. They also found that the strong adsorption suppression against the blood fluid components can be observed as to the polymer.

Therefore, according to the present invention, there is provided a modified polymer containing a poly(2-hydroxyethyl(meth)acrylate) segment as a hydrophilic polymer chain in the molecule,

(A) a) one or two said segments being bonded to a hydrophobic polymer chain at either end thereof,

b) a plurality of said segments as a graft chain being bonded to a main polymer at either end thereof, or

c) said segment being bonded to a bulky lipid residue at either end thereof, and

(B) a glass transition temperature being about 45^oC. or less.

There is also provided a biologically compatible polymer composition which is prepared from solution or dispersion liquid containing the modified polymer.

There is further provided the use of the modified polymer for manufacturing a biologically compatible polymer composition such as a medical device or apparatus or covering the surface thereof.

Claim 1 of 12 Claims

What is claimed is:

1. A modified polymer containing at least a poly(2-hydroxyethyl(meth)acrylate) segment as a hydrophilic polymer chain in the molecule,

(A) the modified polymer being one of; (a) at least one said poly(2-hydroxyethyl(meth)acrylate) segment being bonded to a hydrophobic polymer chain at either end thereof; and (b) a plurality of said poly(2-hydroxyethyl(meth)acrylate) segments as a graft chain being bonded to a main polymer chain at either end thereof;

(B) a glass transition temperature of the modified polymer being about 45^oC. or less.

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