Polyionic dendrimer and hydrogel comprising same

Abstract

Provided is a hydrogel which comprises water as the main component at a high water content and has mechanical strength suitable for practical use and which exhibits high transparency and self-healing and shape-retaining properties. Also provided are both a material for the hydrogel and a novel polyionic dendrimer. A polyionic dendrimer which comprises a hydrophilic linear polymer as the core and polyester dendrons attached to both terminals of the linear polymer and in which cationic groups are bonded to the surfaces of the dendrons, said cationic groups being selected from the group consisting of guanidine group, thiourea group, and isothiourea group; a material for a hydrogel, which comprises the polyionic dendrimer and clay; and a hydrogel prepared using the material.

1 . A polyionic dendrimer, comprising: a hydrophilic linear polymer as the core, and dendrons attached to both terminals of the linear polymer, wherein a cationic group selected from the group consisting of a guanidine group, a thiourea group, and an isothiourea group is bonded to a surface of the dendron. 
     
     
         2 . The polyionic dendrimer according to  claim 1 , wherein the dendrons attached to both terminals of the linear polymer are composed of polyester. 
     
     
         3 . The polyionic dendrimer according to  claim 2 , wherein the polyester is a polyester composed of a saturated aliphatic carboxylic acid having 3 to 10 carbon atoms in which two or more hydroxyl groups are symmetrically substituted to have symmetric branching. 
     
     
         4 . The polyionic dendrimer according to  claim 1 , wherein the hydrophilic linear polymer as the core is a polyalkylene glycol. 
     
     
         5 . The polyionic dendrimer according to  claim 1 , wherein a cationic group selected from the group consisting of a guanidine group, a thiourea group, and an isothiourea group is bonded to the surface of the dendron via a polyether group. 
     
     
         6 . The polyionic dendrimer according to  claim 1 , wherein the polyionic dendrimer is a polyionic dendrimer that is represented by the following formula 1: 
       
         
           
           
               
               
           
         
         (in the formula, n represents the repeating number of polyethylene glycol in the core and is from 20 to 100000, m represents the repeating number of a linker group for introducing cationic groups to the surface and is from 1 to 6, g represents the generation of the dendron and is from 1 to 5, R represents a cationic group selected from the group consisting of a guanidine group, a thiourea group, and an isothiourea group, and X represents a hydrogen atom or a C 1 -C 7  alkyl group). 
       
     
     
         7 . The polyionic dendrimer according to  claim 6 , wherein the polyhydroxy carboxylic acid including X in the formula 1 is a saturated aliphatic carboxylic acid having 3 to 10 carbon atoms in which two or more hydroxyl groups are symmetrically substituted to have symmetric branching. 
     
     
         8 . The polyionic dendrimer according to  claim 6 , wherein X in the formula 1 is a methyl group. 
     
     
         9 . The polyionic dendrimer according to  claim 1 , wherein the cationic group selected from the group consisting of a guanidine group, a thiourea group, and an isothiourea group is a cationic group represented by the following formula 2, formula 3, or formula 4: 
       
         
           
           
               
               
           
         
       
     
     
         10 . The polyionic dendrimer according to  claim 1 , wherein the polyionic dendrimer is a polyionic dendrimer that is represented by the following formula 5: 
       
         
           
           
               
               
           
         
         (in the formula, n is from 20 to 100000). 
       
     
     
         11 . A material for a hydrogel, comprising: the polyionic dendrimer according to  claim 1  and a clay mineral. 
     
     
         12 . The material for a hydrogel according to  claim 11 , further comprising a linear polymer having an ionic side chain. 
     
     
         13 . The material for a hydrogel according to  claim 12 , wherein linear polymer having an ionic side chain is an alkali metal salt of polyacrylic acid or polymethacrylic acid. 
     
     
         14 . The material for a hydrogel according to  claim 11 , wherein the clay mineral is a clay mineral selected from the group consisting of a water-swellable smectite and a layer silicate salt. 
     
     
         15 . The material for a hydrogel according to  claim 11 , wherein the clay mineral is a clay mineral having a nano sheet structure. 
     
     
         16 . The material for a hydrogel according to  claim 11 , wherein the clay mineral is one or more kinds selected from the group consisting of montmorilonite, hectorite, saponite, bidelite, mica, and synthetic mica. 
     
     
         17 . The material for a hydrogel according to  claim 16 , wherein the clay mineral is a hectorite. 
     
     
         18 . A hydrogel, comprising: water in the material for a hydrogel according to  claim 11 . 
     
     
         19 . The hydrogel according to  claim 18 , wherein a water content is 80% or more relative to the material for a hydrogel. 
     
     
         20 . A protein-containing hydrogel, comprising: a physiologically active protein in the hydrogel according to  claim 18 . 
     
     
         21 . The protein-containing hydrogel according to  claim 20 , wherein the physiologically active protein is myoglobin or albumin.