高密度自由醛基聚合物粉体材料的制备与应用

Preparation and Application of the Polymer Powder with High Density of Free Aldehyde Linkers

在酸性条件和剧烈搅拌下,将质量分数为2.0%的聚乙烯醇水溶液缓慢滴加到过量25%（质量分数）的戊二醛水溶液中,得到的产物不是凝胶,而是粒度在50～150 nm之间的刚性粉末.该粉末体相和表面依然保留着高密度的自由醛基.理论计算得出粉末中整体醛基的量大于5.5 mmol/g,而实验测得表面醛基的量大于1.6 mmol/g.将醛基粉体材料进一步和氨基化合物反应,其官能团分别转化为—NH2,—SH和—NH—NH2.这类新型的大分子化合物普遍具有三维的亲水性表面、足够数量且灵活的功能性官能团和低的荧光背景,是制备3D生物芯片的优良材料.其中,醛基和酰肼基粉末对肝素具有良好的固定效果,固定的肝素分子依然具有较高的抗凝血活性.

When a diluted poly （vinyl alcohol） （PVA） aqueous solution was slowly dropped into excess 25% glutaraldehyde solution, the obtained product was not the normally formed hydrogels（ by gelation method） but plastic white powder with numerous free -CHO groups on the surface. The density of the useful -CHO groups was both calculated in theory （ 〉 5.5 mmol/g） and chemically determined （ 〉 1.6 mmol/g）. The length of the -CHO linkers was prolonged by reacting with the amino compounds and the functional groups correspondingly changed to be -NH2, -SH, or -NH-NH2. All the synthesized macromolecular compounds generally have hydrophilic three-dimensional surface, in sufficient quantities and flexible functional groups and low fluorescent background, such synthesized macromolecular compounds are good for fabrication of the bio-mieroarrays, especially carbohydrate arrays. For example, the powders with groups of both the -CHO and -NH-NH2 were used to immobilize the heparin. Anticoagulant experiments show that the immobilized molecules still played a good biological function.