An object of the present invention is to provide a gel material including a solvophilic polymer having a μm-scale porous structure.

A polymer gel in which solvophilic polymer units are cross-linked with each other, wherein the polymer gel contains a solvent and has a three-dimensional network structure having two regions: a first region in which the polymer units are densely present and a second region in which the polymer units are sparsely present, and a mesh size composed of the first region is from 1 to 500 μm.

Compositions and methods for sealing tissue of a patient in a wet environment are disclosed.

The present invention provides, among other things, compounds that include a water-soluble and non-peptidic polymer as well as a maleimidyl group. The compounds are useful as, among other things, polymeric reagents.

Compositions and methods for sealing tissue of a patient in a wet environment are disclosed.

The invention provides a bio-related substance bonded to a high-molecular-weight polyethylene glycol derivative that does not cause vacuolation of cells. The bio-related substance bonded to a degradable polyethylene glycol derivative is represented by the formula (A):

wherein m is 1-7, n1 and n2 are each independently 45-682, p is 1-4, R is an alkyl group having 1-4 carbon atoms, Z is an oligopeptide with 2-8 residues composed of neutral amino acids excluding cysteine, Q is a residue of a compound having 2-5 active hydrogens, D is the bio-related substance, L1, L2, L3, L4 and L5 are each independently a single bond or a divalent spacer, and y is 1-40.

A branched monodispersed polyethylene glycol represented by the formula (1):

##STR00001##

wherein X.sup.1 is a functional group that forms a covalent bond upon a reaction with a functional group present in a biofunctional molecule; n is an integer of 4 to 50, which represents number of repeating units of ethylene oxide units; and L.sup.1 represents a single bond, NH, -L.sup.2-(CH.sub.2).sub.m1 or -L.sup.2-(CH.sub.2).sub.m1-L.sup.3-(CH.sub.2).sub.2-, L.sup.2 represents an ether bond, an amide bond, an urethane bond or a single bond, L.sup.3 represents an ether bond, an amide bond or an urethane bond, and m1 and m2 represent each independently an integer of 1 to 5.

Bioactive coatings that are stabilized against inactivation by weathering are provided including a base associated with a chemically modified enzyme capable of enzymatically degrading a component of an organic stain, optionally a lipase or a lysozyme, and optionally a first polyoxyethylene present in the base and independent of the enzyme. The coatings are optionally overlayered onto a substrate to form an active coating facilitating the removal of organic stains or bacterial organic material.

A hydrophilic polymer derivative having a cyclic benzylidene acetal linker represented by the following formula (1):

##STR00001##

wherein R.sup.1 and R.sup.6 are each independently a hydrogen atom or a hydrocarbon group; R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently an electron-withdrawing or electron-donating substituent or a hydrogen atom; X.sup.1 is a chemically reactive functional group; P is a hydrophilic polymer; s is 1 or 2, t is 0 or 1, and s+t is 1 or 2; w is an integer of 1 to 8; and Z.sup.1 and Z.sup.2 are each independently a selected divalent spacer.

A biodegradable polyethylene glycol derivative in which a polyethylene glycol chain is linked by an acetal linker capable of accurately controlling the hydrolysis rate under different pH environments in the living body, and whose division rate into a polyethylene glycol chain of low molecular weight in the living body can be accurately controlled. The biodegradable polyethylene glycol derivative is represented by formula (1) or formula (2) as described.

The invention is directed to multi-functional N-maleimidyl polymer derivatives comprising a water soluble and non-peptidic polymer backbone having a terminal carbon, such as a poly(alkylene glycol), the terminal carbon of the polymer backbone being directly bonded to the nitrogen atom of a N-maleimidyl moiety without a linking group therebetween. The invention also provides two methods of preparing such linkerless N-maleimidyl polymer derivatives.