A fiber for protein adsorption has a water absorption percentage of 1 to 50%, and the fiber includes a polymer containing as repeat units an aromatic hydrocarbon or a derivative thereof, wherein part of aromatic rings contained in the repeat units are cross-linked through a structure represented by Formula (I). A column for protein adsorption uses the fibers. A in Formula (I) is selected from an alkyl aliphatic group, phenyl aromatic group and amino group.

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A fiber for protein adsorption has a water absorption percentage of 1 to 50%, and the fiber includes a polymer containing as repeat units an aromatic hydrocarbon or a derivative thereof, wherein part of aromatic rings contained in the repeat units are cross-linked through a structure represented by Formula (I). A column for protein adsorption uses the fibers. A in Formula (I) is selected from an alkyl aliphatic group, phenyl aromatic group and amino group.

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A method of preparing a hydrogel product comprising crosslinked glycosaminoglycan molecules, said method including: i) providing a glycosaminoglycan crosslinked by amide bonds, wherein the crosslinked glycosaminoglycans include ester crosslinks formed as byproducts during the amide crosslinking; and ii) subjecting the crosslinked glycosaminoglycans to alkaline treatment to hydrolyze ester crosslinks formed as byproducts during the amide crosslinking.

A method of preparing a hydrogel product comprising crosslinked glycosaminoglycan molecules, said method including: i) providing a glycosaminoglycan crosslinked by amide bonds, wherein the crosslinked glycosaminoglycans include ester crosslinks formed as byproducts during the amide crosslinking; and ii) subjecting the crosslinked glycosaminoglycans to alkaline treatment to hydrolyze ester crosslinks formed as byproducts during the amide crosslinking.

Provided is a method and apparatus for improving adhesion between a polymer article and a metal plate. The method includes providing a polymer article, and hydrolyzing a surface of the polymer article using an acidic solution to obtain carboxylic acid groups at the surface. The method also includes grafting polyphenols to the carboxylic acid groups by esterification that is catalyzed by the acidic solution, and chelating metal ions to the grafted polyphenols to form polyphenol-metal complexes. The apparatus includes a body formed by additive manufacturing, and a metal plating formed on a surface of the body by electroless metal plating after a surface preparation process. The surface preparation process includes treating the surface with an acidic solution to obtain carboxylic acid groups at the surface, treating the surface with a polyphenol solution to obtain polyphenols grafted to the carboxylic acid groups, and chelating metal ions to the polyphenols.

Provided is a method and apparatus for improving adhesion between a polymer article and a metal plate. The method includes providing a polymer article, and hydrolyzing a surface of the polymer article using an acidic solution to obtain carboxylic acid groups at the surface. The method also includes grafting polyphenols to the carboxylic acid groups by esterification that is catalyzed by the acidic solution, and chelating metal ions to the grafted polyphenols to form polyphenol-metal complexes. The apparatus includes a body formed by additive manufacturing, and a metal plating formed on a surface of the body by electroless metal plating after a surface preparation process. The surface preparation process includes treating the surface with an acidic solution to obtain carboxylic acid groups at the surface, treating the surface with a polyphenol solution to obtain polyphenols grafted to the carboxylic acid groups, and chelating metal ions to the polyphenols.

The present invention addresses the problem of providing, by a method in which an expensive manufacturing apparatus is not required, an implant material having osteoconductivity superior to that of an implant material containing an aromatic polyether ketone. The present invention pertains to: said method including immersing an aromatic polyether ketone in a strong base solution in the absence of a calcium ion, and immersing an aromatic polyether ketone, which is obtained by the immersing, in a liquid containing a phosphorus-containing compound; and an implant material obtained by said method.

The present invention addresses the problem of providing, by a method in which an expensive manufacturing apparatus is not required, an implant material having osteoconductivity superior to that of an implant material containing an aromatic polyether ketone. The present invention pertains to: said method including immersing an aromatic polyether ketone in a strong base solution in the absence of a calcium ion, and immersing an aromatic polyether ketone, which is obtained by the immersing, in a liquid containing a phosphorus-containing compound; and an implant material obtained by said method.

A method for at least partial deacetylation of a biopolymer comprising acetyl groups, including: a1) providing a biopolymer including acetyl groups; a2) reacting the biopolymer including acetyl groups with hydroxylamine (NH.sub.2OH) or a salt thereof at a temperature of 100° C. or less for 2-200 hours to form an at least partially deacetylated biopolymer; and a3) recovering the at least partially deacetylated biopolymer.

A method for at least partial deacetylation of a biopolymer comprising acetyl groups, including: a1) providing a biopolymer including acetyl groups; a2) reacting the biopolymer including acetyl groups with hydroxylamine (NH.sub.2OH) or a salt thereof at a temperature of 100° C. or less for 2-200 hours to form an at least partially deacetylated biopolymer; and a3) recovering the at least partially deacetylated biopolymer.