The invention provides a diamine crosslinking agent for acidic polysaccharides consisting of a diamine compound having a primary amino group at both terminals and an ester or thioester bond in the molecule, wherein the number of atom in the linear chain between at least one of the amino groups and the carbonyl carbon in the ester or thioester is 1 to 5; in particular, a diamine crosslinking agent for acidic polysaccharides which is represented by the general formula (I) below: ##STR00001##
[the symbols in the formula are as described in the specification]; a crosslinked acidic polysaccharide obtained by forming crosslinks by amide bonding between the amino groups in the diamine crosslinking agent and carboxyl groups in an acidic polysaccharide; and a medical material including the crosslinked product.

The present invention provides compositions and methods for the delivery of therapeutic agents to cells. In particular, these include novel cationic lipids and nucleic acid-lipid particles that provide efficient encapsulation of nucleic acids and efficient delivery of the encapsulated nucleic acid to cells in vivo. The compositions of the present invention are highly potent, thereby allowing effective knock-down of a specific target protein at relatively low doses. In addition, the compositions and methods of the present invention are less toxic and provide a greater therapeutic index compared to compositions and methods previously known in the art.

The present invention provides compositions and methods for the delivery of therapeutic agents to cells. In particular, these include novel cationic lipids and nucleic acid-lipid particles that provide efficient encapsulation of nucleic acids and efficient delivery of the encapsulated nucleic acid to cells in vivo. The compositions of the present invention are highly potent, thereby allowing effective knock-down of a specific target protein at relatively low doses. In addition, the compositions and methods of the present invention are less toxic and provide a greater therapeutic index compared to compositions and methods previously known in the art.

The invention provides a diamine crosslinking agent for acidic polysaccharides consisting of a diamine compound having a primary amino group at both terminals and an ester or thioester bond in the molecule, wherein the number of atom in the linear chain between at least one of the amino groups and the carbonyl carbon in the ester or thioester is 1 to 5; in particular, a diamine crosslinking agent for acidic polysaccharides which is represented by the general formula (I) below:

##STR00001##

[the symbols in the formula are as described in the specification]; a crosslinked acidic polysaccharide obtained by forming crosslinks by amide bonding between the amino groups in the diamine crosslinking agent and carboxyl groups in an acidic polysaccharide; and a medical material including the crosslinked product.

A compound useful as a release agent, and a release agent, a curable composition, and a nanoimprint lithography resin material each containing the compound are provided. More specifically, a calixarene compound with a molecular structure represented by the following structural formula (1) and a composition containing the calixarene compound are provided.

##STR00001##

wherein R.sup.1 denotes a structural moiety with a perfluoroalkyl group, R.sup.2 denotes a hydrogen atom, a polar group, a polymerizable group, or a structural moiety with a polar group or a polymerizable group, R.sup.3 denotes a hydrogen atom, an aliphatic hydrocarbon group that may have a substituent, or an aryl group that may have a substituent, n denotes an integer in the range of 2 to 10, and * denotes a bonding point with an aromatic ring.

Compounds having cytotoxic and/or anti-mitotic activity are disclosed. Methods associated with preparation and use of such compounds, as well as pharmaceutical compositions comprising such compounds, are also disclosed. Also disclosed are compositions having the structure: (T)-(L)-(D), wherein (T) is a targeting moiety, (L) is an optional linker, and (D) is a compound having cytotoxic and/or anti-mitotic activity.

Compounds having cytotoxic and/or anti-mitotic activity are disclosed. Methods associated with preparation and use of such compounds, as well as pharmaceutical compositions comprising such compounds, are also disclosed. Also disclosed are compositions having the structure: (T)-(L)-(D), wherein (T) is a targeting moiety, (L) is an optional linker, and (D) is a compound having cytotoxic and/or anti-mitotic activity.

According to the present invention, there is provided a method for producing carboxylic acid thioester, comprising reacting a compound represented by the following formula (I), carboxylic acid and thiol in the presence of a catalyst including at least one Group 2 metal compound. The production method is a production method which is simple in reaction operation, which places a small load on the environment and the human body and which enables carboxylic acid thioester to be catalytically obtained at a high yield even at a normal temperature and a normal pressure (25 C., 1 atm). In the formula (I), R.sup.1 and R.sup.2 each independently represent a hydrocarbon group having 1 to 20 carbon atoms. ##STR00001##

According to the present invention, there is provided a method for producing carboxylic acid thioester, comprising reacting a compound represented by the following formula (I), carboxylic acid and thiol in the presence of a catalyst including at least one Group 2 metal compound. The production method is a production method which is simple in reaction operation, which places a small load on the environment and the human body and which enables carboxylic acid thioester to be catalytically obtained at a high yield even at a normal temperature and a normal pressure (25 C., 1 atm). In the formula (I), R.sup.1 and R.sup.2 each independently represent a hydrocarbon group having 1 to 20 carbon atoms. ##STR00001##

Novel selective synthesis route to introduce primary alkyl groups on aromatic compounds is disclosed. The synthesis route is based on electrophilic aromatic substitutions of thionium ion species that are generated in-situ from aldehydes and thiols, affording benzyl sulfide that can be reduced with triethylsilane.