Studies On Modification Of Polyhydroxyethyl Methacrylate Hydrogel And Loading Of Hyaluronic Acid

In this paper,tetraethylenepentamine(TEPA)was grafted onto PHEMA surface by amino groups induced epoxy ring opening reaction to form a cationic hydrogel surface to improve hydrophilicity and antifouling.In order to improve the biocompatibility of the hydrogel and extend it application,hyaluronic acid(HA)was used to deposite on the surface of the hydrogel.The main contents and results are as follows:(1)The glycidyl methacrylate(GMA)monomer with epoxy groups was introduced to prepare p(HEMA-co-GMA)hydrogels by using UV-initiated free radical crosslinking polymerization.The hydrogel modification was achieved by covalently grafting of TEPA onto p(HEMA-co-GMA)through epoxy ring opening reaction.The grafted hydrogels were charactrized by attenuated total reflectance Fourier transform infrared spectroscopy(ATR-FTIR)and scanning electron microscopy(SEM).The results proved that the surface modification had no significant effect on their morphologies.It was revealed that cationic hydrogels had remarkable resistance to lysozyme(Lyz)fouling while adhering to bovine serum albumin(BSA).Apparently,the cationic hydrogels prohibit the approach of same charged protein with reduced deposition and provide the driving force for oppositely charged protein adsorption.The antibacterial experimental results showed that the catonic hydrogel had bactericidal effect on both Escherichia coli and Staphylococcus aureus.In vitro cytotoxicity tests revealed that the caionic hydrogels were cytotoxic.(2)The loading and release behaviors of HA on the cationic hydrogel surface was investigated by cetyltrimethylammonium bromide(CTAB)turbidimetry.The results showed that HA was successful loaded on hydrogel surface,and the total loading of 1800kDa HA on the hydrogel was higher than that of 300kDa HA.The loading amount increased with the increase of amino group grafting ratio.The higher molecular weight HA deposited on the hydrogel took longer time to release than the lower one.The PHEMA hydrogels were further characterized by contact angle.It was found that the hydrophilicity of the hydrogels was significantly improved after loading HA.Furthermore,the HA loaded hydrogels showed antiadhesion against protein with same charge and enhanced adsorption to the protein with opposite charge;the 1800 kDa HA loaded hydrogel had better protein resistance than 300 kDa HA loaded hydrogel.In vitro cytotoxicity experiments showed that the biocompatibility of hydrogel was improved after HA loading.After HA release for 12h,the hydrogels maintained good hydrophilicity,anti-protein deposition and biocompatibility.