A polymer film can be adjusted to movement or a fine uneven surface of a living body and has excellent ability to adhere to a biological tissue. The polymer film includes a block copolymer having a structure in which branched polyalkylene glycol and polyhydroxyalkanoic acid are bound to each other, wherein the polymer film has a film thickness of 10 to 1000 nm. The branched polyalkylene glycol has at least three terminal hydroxyl groups per molecule, the mass percentage of the branched polyalkylene glycol relative to the total mass of the block copolymer is 1% to 30%, and a value obtained by dividing the average molecular weight of polyhydroxyalkanoic acid in the block copolymer by X that is the number of terminal hydroxyl groups present per a single molecule of the branched polyalkylene glycol is 10000 to 30000.

To provide a hydrophilic polymer derivative having a novel linker technique which is able to from a hydrophilic polymer pro-drug of a drug containing an amino group or the like in order to overcome the restrictions of conventional hydrophilic polymer pro-drugs. A hydrophilic polymer derivative containing a hydrophilic polymer moiety and an acetal moiety, wherein the hydrophilic polymer derivative contains a structure represented by formula (1) or formula (2): ##STR00001##

The present invention relates to a photochromic compound including a polyvalent residue on which at least one group having a photochromic moiety is substituted, and at least one long-chain group not containing a photochromic moiety and having a molecular weight of 300 or more is further substituted; and a curable composition containing the same. In accordance with the present invention, it is possible to provide a photochromic compound which has high solubility in a polymerizable compound serving as a matrix while retaining high photochromic characteristics and is hardly affected by the matrix; and a curable composition containing the same.

The compounds disclosed herein (e.g., compounds of Formula (I), (II), (III), and (IV)) comprise a lipid substructure comprising a hydrophobic moiety and a hydrophilic moiety; and two or more polymeric groups (e.g., two or more polyethylene glycol (PEG) groups). The compounds provided herein can be useful for delivery and expression of mRNA and encoded protein, e.g., as a component of liposomal delivery vehicle, and accordingly can be useful for treating various diseases, disorders and conditions, such as those associated with deficiency of one or more proteins.

##STR00001##

Disclosed herein are ketal compounds, oligomers, and polyketals that are obtained in both high purity and high yield. These ketals and polyketals are utilized for their ability to readily release small chemical molecules, preferably fragrance molecules. Also disclosed are the utility of ketals and polyketals as delivery vehicles for controlled release of fragrances over time and/or on demand.

The present invention relates to a photochromic compound including a polyvalent residue on which at least one group having a photochromic moiety is substituted, and at least one long-chain group not containing a photochromic moiety and having a molecular weight of 300 or more is further substituted; and a curable composition containing the same. In accordance with the present invention, it is possible to provide a photochromic compound which has high solubility in a polymerizable compound serving as a matrix while retaining high photochromic characteristics and is hardly affected by the matrix; and a curable composition containing the same.

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.

The present invention aims to provide a polymer capable of well dispersing hydrophobic particles. The present invention relates to a hydrophobic group-containing copolymer including a structural unit (A) derived from a hydrophobic group-containing monomer that is represented by the formula (1) and a structural unit (B) derived from a carboxylic acid-based monomer. The proportion of the structural unit (A) is from 16% by mass or more to 50% by mass or less based on 100% by mass of the structural units derived from all monomers constituting the copolymer, and the copolymer has a weight average molecular weight of 10,000 to 1,000,000. ##STR00001##

To provide a hydrophilic polymer derivative having a novel linker technique which is able to from a hydrophilic polymer pro-drug of a drug containing an amino group or the like in order to overcome the restrictions of conventional hydrophilic polymer pro-drugs. A hydrophilic polymer derivative containing a hydrophilic polymer moiety and an acetal moiety, wherein the hydrophilic polymer derivative contains a structure represented by formula (1) or formula (2):

##STR00001##

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.m2-, 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.