Synthetize Of High Strength Hydrogel And Adhesion Performance Of Bioactive Substance On Its Surface

Hydrogel is a three-dimensional polymer network containing a large number of polymerswith soft and smooth surface, good elasticity, permeability, biocompatibility, and ability ofsubstance exchange with the external environment, etc.. Therefore, it has attracted a widespread attention in various fields. However, the mechanical strength and stability of hydrogelare poor, which limited the application of hydrogel material. Hence, it is of great significanceto synthetize high-strength hydrogel. In this thesis, two-step process of AMPS and AAmmonomers to synthesize high-strength double-network hydrogel was investigated. We alsostudy on the effect of PEG, PVA adding into the hydrogel on the its property and on theadhesion behavior of biologically active substances on the hydrogel surface, which laid thefoundation of hydrogel’s application as anti-adhesion material..Firstly, the effects of different monomer concentration on the mechanical properties ofhydrogels, swelling properties were researched. The results show that when C_AMPS=1mol/L,C_AAm=4mol/L, the synthesis of the PAMPS/PAAm double network hydrogel compressivestrength reaches the maximum value of12.5Mpa, with a compression rate of90%. Themechanical strength of hydrogel with its own internal structure is inseparable. From the SEMimages it can be seen that hydrogel with network of1p4a show uniform pore size and evendistribution, which leads to greater deformation and the maximum mechanical strength; Withthe decreaseing of the monomer concentration, pore size in network increases, and thehydrogel swelling ratio is showing a decreasing trend.Sencondly, the effects of PEG, PVA on hydrogel mechanical properties, swellingproperties and internal structure are investigated. The results show that the accession of PEGdid not increase the mechanical strength of the hydrogel; when PVA was added into, thecompression strength of PAMPS single network hydrogel increased to273KPa, and itscompression deformation reached44%. Furthmore, the mechanical strength of doublenetwork hydrogels was also improved, the maximum compression strength reached18.26MPa,and compression rate98.7%was achieved. The toughness of the hydrogel has also beengreatly improved. The hydrogel swelling rate has been found to increase, compared withunmodified hydrogel, when hydrophilic PEG, PVA were added. The hydrogel swelling ratiogradually increased and water absorption capacity gradually was enhanced. The addition of PEG, PVA hydrogel changed the internal structure of single and double networks. It can beseen from the SEM images, that a single network hydrogel added with PEG has a smoothsurface, and the network mesh size did not change much in the PEG-modified double-networkhydrogel and the hydrogel that was not modified; Adding PVA into one network of hydrogelsurface gave rise to some folds and also some distributed minor network structure on thehydrogel surface. With the increasing of PVA content, the size of the network structure isfrom a few to several microns and the structure are relatively complete. While adding intodual network of PVA hydrogel network, the mixture of main network and thesecondary-network structure were appeared. The two network are mutually implicated andrestrained, and which is the key of greatly improved hydrogel properties.Finally, the antifouling performance of the hydrogel surface was studied by usinglaboratory microalgae adhesion and testing in real ocean. The descending order of adsorptionamount is PDMS>silica gel>PTFE>DN hydrogel>PEG-DN hydrogel>PVA-DN hydrogel.Thus, hydrogel material can be used in the marine anti-fouling fields. The cell surfacehydrogel behavior was also studied. Cytotoxicity test objective proofed that the hydrogelmaterial is non-toxic, biocompatible. Then the different growing patterns of the surface ofcells in the hydrogel cell behavior were studied. It was found that NB4cells, an adhesive cell,can grow well on the hydrogel surface, while A549cells, a suspend cell, adhered a little onthe hydrogel surface. Thus, the hydrogel materials have a certain anti-cell adhesion. Bycomparing the three kinds of hydrogel, we found that the two cells in the PVA-DN hydrogelsurface adhered a little. The PVA-DN hydrogel has the best ability of anti-cell adhesion, sothat it can be used to study on cell migration behavior and construct co culture system in vitro.