Preparation And Properties Of Chitosan And Its Derivatives Composite Hydrogels

Due to the excellent biological activity,chitosan and its derivatives,as the biomedical materials,have attracted more and more attention.Konjac glucomannan is a kind of natural polymer materials,which has wide sources and good biocompatibility.The research on konjac glucomannan and its derivatives is currently a hot topic in the scientific community.In recent years,graphene oxide was used as additive for preparing composite hydrogels has attracted more and more attention due to its stable structure and excellent mechanical properties.In this article,oxidized konjac glucomannan was used as a cross-linking agent for CS-based,CMCS-based and HPCS-based hydrogels instead of glutaraldehyde and formaldehyde.Meanwhile,graphene oxide was added as additive.The effects of the addition of GO on the properties and structure of the hydrogels were researched.The main research contents and results are as follows:(1)Graphene oxide was prepared by a modified Hummers’ method and it was characterized by Fourier transform infrared spectroscopy(FT-IR),Transmission electron microscopy(TEM)and Raman spectroscopy.Oxidized konjac glucomannan was prepared through oxidation reaction of konjac glucomannan in the presence of sodium periodate.Composite hydrogels were prepared through the Schiff-base reaction between the aldehyde of oxidized konjac glucomannan(OKGM)and the amino of chitosan(CS).Meanwhile,different amount of graphene oxide(GO)was added as additive.The hydrogels was characterized by transform infrared spectroscopy(FT-IR)and the micro-morphology of hydrogels was analyzed by scanning electron microscopy(SEM).The influence of different GO content on properties including gelation time,swelling ability,water evaporation rate,mechanical properties and biocompatibility were investigated.The results show that the hydrogel samples have a continuous and stable three-dimensional network structure.The hydrogel samples have a very short gelation time,and the gelation time decreased from 20.8 s to 5.4 s with the GO content increased from 0 to 5 mg/ml.The hydrogels have showed a good swelling ability and appropriate water retention capacity.The swelling ability and water retention capacity of hydrogels were increased with the increase of GO content.The mechanical properties of hydrogels were significantly increased with loading of GO.The compressive strength and modulus are increased from 41.5 kPa to 105.2 kPa and increased from 0.13 MPa to 0.45 MPa as the GO content is increased from 0 to 5 mg/ml.Moreover,the hydrogels with GO have higher cell viabilities than hydrogels without GO.(2)Composite hydrogels were prepared through the Schiff-base reaction between the aldehyde of oxidized konjac glucomannan(OKGM)and the amino of carboxymethyl chitosan(CMCS).Meanwhile,different amounts of graphene oxide(GO)was added as additive.The hydrogels was characterized by transform infrared spectroscopy(FT-IR)and the micro-morphology of hydrogels was analyzed by scanning electron microscopy(SEM).The influence of different GO content on properties including gelation time,swelling ability,water evaporation rate,mechanical properties and biocompatibility were investigated.The results show that the hydrogel samples have a continuous and stable three-dimensional network structure.The hydrogel samples have a very short gelation time,and the gelation time decreased from 35.8 s to 18.6 s with the GO content increased from 0 to 5 mg/ml.The hydrogels have showed a good swelling ability and appropriate water retention capacity.The swelling ability and water retention capacity of hydrogels were increased with the increase of GO content.The mechanical properties of hydrogels were significantly increased with loading of GO.The compressive strength and modulus are increased from 85.1 kPa to 208.2 kPa and increased from 0.28 MPa to 1.11 MPa as the GO content is increased from 0 to 5 mg/ml.Moreover,the hydrogels with GO have higher cell viabilities than hydrogels without GO.(3)Composite hydrogels were prepared through the Schiff-base reaction between the aldehyde of oxidized konjac glucomannan(OKGM)and the amino of chitosan(CS).Meanwhile,different amounts of graphene oxide(GO)was added as additive.The hydrogels was characterized by transform infrared spectroscopy(FT-IR)and the micro-morphology of hydrogels was analyzed by scanning electron microscopy(SEM).The influence of different GO content on properties including gelation time,swelling ability,water evaporation rate,mechanical properties and biocompatibility were investigated.The results show that the hydrogel samples have a continuous and stable three-dimensional network structure.The hydrogel samples have a very short gelation time,and the gelation time decreased from 45.6 s to 24.3 s with the GO content increased from 0 to 5 mg/ml.The hydrogels have showed a good swelling ability and appropriate water retention capacity.The swelling ability and water retention capacity of hydrogels were increased with the increase of GO content.The mechanical properties of hydrogels were significantly increased with loading of GO.The compressive strength and modulus are increased from 49.8 kPa to 202.1 kPa and increased from 0.05 MPa to 0.34 MPa as the GO content is increased from 0 to 5 mg/ml.Moreover,the hydrogels with GO have better biocompatibility than hydrogels without GO.