Effects of cross-linking molecular weights in a hyaluronic acid-poly(ethylene oxide) hydrogel network on its properties.
We examined the effects of cross-linking molecular weights on the properties of a hyaluronic acid (HA)-poly(ethylene oxide) (PEO) hydrogel. Swelling behaviors, mechanical strength and rheological behaviors of the HA-PEO hydrogel were evaluated by employing different cross-linking molecular weights (100 kDa and 1.63 mDa) of the HAs in the hydrogel networks. The low molecular weight of HA was obtained in advance by treating high molecular weight HA with a hydrogen chloride solution. Methacrylation of HA was obtained by grafting aminopropylmethacrylate to its caroboxylic acid functional groups. While reduction of the HA molecular weights was confirmed by gel permeation chromatography, the degree of methacrylate grafting to the HA was measured by (1)H-nuclear magnetic resonance. Synthesis of the HA-PEO hydrogel was successfully achieved via the Michael-type addition reaction between the methacrylate arm groups in the HA and the six thiol groups in PEO. The hydrogel formation was not dependent upon the HA molecular weights and its gelation behaviors were markedly different. Compared to the properties of the high molecular weight HA-based PEO one, the low molecular weight HA-based hydrogel induced quicker hydrogelation, as observed from the behaviors of the elastic and viscous modulus. Furthermore, the low molecular weight HA-based hydrogel demonstrated stronger mechanical properties as measured with a texture analyzer, lower water absorption as measured with a microbalance and smaller pore sizes on its surface and cross section as observed with scanning electron microscopy. The information about the effects of the cross-linking molecular weights of the gel network on the properties of the HA-based PEO hydrogel may lead to better design of hydrogels, especially in tissue engineering applications.
Noh
Insup
I
Department of Chemical Engineering, Seoul National University of Technology, 172 Gongnung-dong, Nowon-gu, Seoul 139-743, Korea. insup@snut.ac.kr
Kim
Gun-Woo
GW
Choi
Yoon-Jeong
YJ
Kim
Mi-Sook
MS
Park
Yongdoo
Y
Lee
Kyu-Back
KB
Kim
In-Sook
IS
Hwang
Soon-Jung
SJ
Tae
Giyoong
G
D001672:Biocompatible Materials / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004548:Elasticity; D006244:Hardness; D006820:Hyaluronic Acid / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D008422:Materials Testing; D008970:Molecular Weight; D011092:Polyethylene Glycols / Q000737:chemistry*; D016062:Porosity; D013314:Stress, Mechanical; D014783:Viscosity
D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D020100:Hydrogels; D011092:Polyethylene Glycols; D006820:Hyaluronic Acid