United States Patent:   6,018,033

Assignee:  Purdue Research Foundation (West Lafayette, IN)

Filed:  May 13, 1997

Polymerizable saccharide monomers are made by the reaction of a saccharose and a (meth)acrylate. Hydrophilic, hydrophobic and thermoreversible gels and foams are formed upon polymerization of the saccharide monomers. Hydrophilic sucrose monomers are synthesized by reaction of sucrose with an epoxy acrylate. Hydrophobic sucrose monomers are synthesized by reaction of sucrose with methacrylol chloride followed by acetyl chloride. Thermoreversible sucrose monomers are obtained by modifying sucrose with polymerizable substituents prepared from methacryloyl chloride and aminocarboxylic acids. The modified sucrose monomers are copolymerized with hydrophobic poly(alkyleneoxide) (meth)acrylates to produce hydrogels exhibiting inverse thermoreversible properties. The thermosensitive hydrogels are biodegradable and can be used in the area of controlled drug delivery.

SUMMARY OF THE INVENTION

The present invention is for novel unsaturated saccharide compounds that are polymerizable to form gels and foams. These saccharide compounds are represented hereinbelow by formulas (I-VII) as follows: 

In each of the above formulas, S represents a saccharide residue, R is hydrogen or a lower alkyl group, e.g., methyl, and n is an integer from 1 to 8. In formula (II), R' represents an alkyl, aryl or alkaryl group, and m is an integer from 0 to 7. In formula (III), R" represents an alkylene, arylene or alkarylene diradical. In formula (IV), R₁ represents a lower alkyl group. In formula (V), R₂ represents a lower alkyl group. In formula (VI), R₃ is hydrogen or methyl, and x is an integer from 1 to 10,000. In formula (VII), R₄ represents a diradical, which can be an alkylene chain, and aromatic group, or an alkaryl group, and R₅ represents hydrogen or a lower alkyl group.

A hydrophilic saccharide gel is formed by polymerizing a saccharide monomer having formula (I) above. A hydrophobic gel is formed by polymerizing a saccharide monomer having formula (II) above. A gel having inverse thermoreversible properties is formed by copolymerizing a saccharide monomer having formula (III) above with a poly(alkyleneoxide) (meth)acrylate monomer, as defined herein, with or without a crosslinking agent.

Polymerization of a saccharide monomer having formula (IV) or (V) above produces a hydrophobic saccharide gel. Whenever a saccharide monomer having formula (VI) or (VII) is polymerized, a hydrophilic gel is produced.

Foams can also be produced by polymerizing a saccharide monomer shown above in formulas (I-VII), in the presence of a blowing agent. Particularly preferred are foams that have been dehydrated with an organic solvent, such as ethanol or acetone. Such foams have hydrophilic, hydrophobic or inverse thermoreversible properties, respectively.

Preferred saccharides include mono-, di-, tri- and higher oligosaccharides. More preferably a disaccharide is employed, most preferably, sucrose.

Associated methods of forming the instant saccharide monomers and polymers from a saccharide and corresponding (meth)acrylate are contemplated.

Claim 1 of 41 Claims

1. A gel or foam formed by polymerizing a saccharide having a formula selected from formulas (I)-(VII) as follows: 

where S is a saccharide residue, R is hydrogen or a lower alkyl group, and n is an integer from 1 to 8; R' is an alkyl, aryl or alkaryl group, and m is an integer from 0 to 7; R" is an alkylene, arylene, or alkarylene diradical; R₁ is a lower alkyl group; R₂ is a lower alkyl group; R₃ is hydrogen or methyl, and x is an integer from 1 to 10,000; R₄ is an alkylene, arylene, or alkarylene diradical, and R₅ is hydrogen or lower alkyl.

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