基于壳聚糖的超声耦合水凝胶垫制备及方法学分析

Preparation and methodological analysis of chitosan-based ultrasound-coupled hydrogel pads

摘要:

为探索制备基于壳聚糖的超声耦合水凝胶垫最佳工艺，探讨其在超声检查中的潜在应用价值，本研究以壳聚糖、2-丙烯酰胺-2-甲基丙磺酸、N-异丙基丙烯酰胺为主要材料，使用3因素3水平的正交试验优化自由基聚合法，制备基于壳聚糖的超声耦合水凝胶垫，对水凝胶垫的拉伸强度和超声图像质量进行表征。以原料比、聚合温度、冻干时间这3个因素为考察对象，筛选最优处方。采用扫描电子显微镜、万能试验机、超声诊断仪对其结构和性能进行表征。结果显示通过正交试验筛选出的最优处方为壳聚糖、2-丙烯酰胺-2-甲基丙磺酸、N-异丙基丙烯酰胺的比例为2:0.55:17.27，聚合温度25 ℃，冻干时间48 h。在此条件下制备的超声耦合水凝胶垫外观透明、内部为多孔结构、黏附性良好、拉伸强度较高；第10天时溶胀度才出现缓慢下降，具有良好的溶胀性能；超声图像质量与医用超声耦合剂相比无明显差别。本研究分析了不同制备工艺对基于壳聚糖的超声耦合水凝胶垫的成胶影响，所制备的水凝胶垫外观透明，对人体温和无刺激，为超声检查提供了良好的透声材料。

关键词:超声;水凝胶垫;自由基聚合法;正交试验

Abstract:

This study aims to optimize the process for preparing chitosan-based ultrasound- coupled hydrogel pads and investigate their application potential in ultrasonography. Chitosan, 2-acrylamido-2-methylpropanesulfonic acid, and N-isopropylacrylamide were used as the main materials to prepare chitosan-based ultrasound-coupled hydrogel pads. The free-radical polymerization conditions were optimized by a three-factor, three-level orthogonal test with the tensile strength and ultrasound image quality of the hydrogel pads as evaluation indicators. The optimal prescription was selected by optimizing three factors of raw material ratio, polymerization temperature, and freeze-drying time. The structure and performance of the hydrogel pads were characterized by a scanning electron microscope, a universal testing machine, and an ultrasonic diagnostic instrument. The results showed that the optimal prescription was as follows: the chitosan:2-acrylamide-2-methylpropanesulfonic acid:N-isopropylacrylamide ratio of 2:0.55:17.27, the polymerization temperature of 25 ℃, and the freeze-drying time of 48 h. The ultrasonically-coupled hydrogel pads prepared under these conditions were transparent, with a porous structure, good adhesion, and high tensile strength. The hydrogel pads had good swelling properties and the swelling degree decreased slowly on day 10. The quality of the ultrasound images obtained via chitosan-based hydrogel pads was not significantly different from that obtained via medical ultrasound coupling agent. In this study, we analyzed the effects of different preparation processes on the gel formation of chitosan-based ultrasound-coupled hydrogel pads. The hydrogel pads were transparent and mild and non-irritating to the human body, serving as an ultrasound transmission material for ultrasonography.

Key words:ultrasound;hydrogel pads;free-radical polymerization;orthogonal test