基于pH调节的CMCS-PMMS/PAAm复合水凝胶的构筑与性能研究

Preparation and properties of CMCS-PMMS/PAAm composite hydrogel based on pH-adjustment

以聚甲基丙烯酸甲酯-甲基丙烯酸/二氧化硅(Poly(MMA/MAA)/SiO_( 2),PMMS)、羧甲基壳聚糖(CMCS)、丙烯酰胺(AAm)为原料,EDC/NHS为催化剂,通过调节体系pH值和自由基聚合反应制备了系列CMCS-PMMS/PAAm复合水凝胶,并对其流变性能、力学性能、溶胀性能、导电性能及生物相容性进行研究.结果表明:pH值对复合水凝胶的流变性能具有较大影响,储能模量G′整体呈先减小后增大的趋势,当pH值为6时,G′最大为9200 Pa;在较低pH值条件下制备的复合水凝胶强度较大,较高pH值条件下则呈现软而韧的性质,且当pH值为9或10时,复合水凝胶能在较大压缩应变下保持良好的形态并拥有较好的拉伸性能和可循环压缩性能;该复合水凝胶具有良好的溶胀性能,即使在吸水达到溶胀平衡后,仍能保持形变恢复能力(纯水中平衡溶胀率可达860%);另外,它还具有良好的导电性能,其电导率最大可达2.98×10^(-4)S/cm,且具有良好的抗溶血性能与细胞相容性,所有复合水凝胶样品的溶血率均小于5%,细胞活性均在75%以上.

polymethyl methacrylate-methacrylic acid/silica(Poly(MMA/MAA)/SiO_( 2),that is,PMMS),carboxymethyl chitosan(CMCS),acrylamide(AAm)were used as raw materials,EDC/NHS as catalysis,the CMCS-PMMS/PAAm composite hydrogel was prepared by pH adjustment,free radical polymerization.The rheological properties,mechanical properties,swelling properties,electrical conductivity and biocompatibility of the hydrogels were studied.The results showed that the pH value had a great influence on the rheological properties of the composite hydrogel.The storage modulus(G′)decreased first and then increased.When the pH value was 6,the G′maximum was 9200 Pa;Hydrogels with low pH were stiff,and the ones with high pH were soft and tough.When the pH value was 9 or 10,the composite hydrogel could maintain a good shape under a large compressive strain.It had good tensile properties and cyclic compressibility.The composite hydrogel also had good swelling properties,and even after water absorption reached the swelling equilibrium,it could still maintain the deformation recovery ability(the equilibrium swelling rate in pure water could reach 860%).In addition,the hydrogel had good conductivity,the highest conductivity could reach 2.98×10^(-4) S/cm;and it had good anti-hemolysis performance and cell compatibility.The hemolysis rate of all composite hydrogel samples was less than 5%,and the cytoactive was more than 75%.