Kim Mi-Sook, Choi Yoon-Jeong, Noh Insup, Tae Giyoong
Department of Chemical Engineering, Seoul National University of Technology, Gongnung-dong 172, Nowon-gu, Seoul 139-743, Republic of Korea.
J Biomed Mater Res A. 2007 Dec 1;83(3):674-82. doi: 10.1002/jbm.a.31278.
We developed and characterized a novel in situ chitosan-poly(ethylene oxide) (PEO) hydrogel via two steps: 2-carboxyethyl acrylate molecules were grafted to the primary amine functional groups in chitosan in the first step and then Michael type addition reaction was processed between the grafted acrylate end groups and the thiol end groups in the PEO. Grafting of acrylate molecules to the amine groups in the deacetylated water soluble chitosan was confirmed by observing the new acrylate peaks by the FTIR and NMR spectra of the acrylated chitosan samples, as well as changes in relative viscosities of chitosan and acrylated chitosan. Formation of the chitosan-PEO hydrogel was visually observed with digital images after both gelation and hydration. Rheological analyses of the hydrogel formation were performed to detect its gelation time, phase angle changes, and visco-elastic properties over frequency and strain percentage. Their results indicated that the gelation process was completed within 10 min after mixing the precursor liquid solutions. An extent of water swelling, mechanical strength against compression and the morphologies of the hydrogel surface and cross sections after dehydration process were analyzed by microbalance measurement, texture analyzer, and scanning electron microscopy observation, respectively. Biological activities of the hydrogels were evaluated by observing smooth muscle cell behaviors such as cell adhesion and viability as well as by measuring the number of adhered cells on their surfaces.
我们通过两步法制备并表征了一种新型的原位壳聚糖-聚环氧乙烷（PEO）水凝胶：第一步，将丙烯酸2-羧乙酯分子接枝到壳聚糖的伯胺官能团上，然后使接枝的丙烯酸酯端基与PEO中的硫醇端基之间发生迈克尔型加成反应。通过观察丙烯酸化壳聚糖样品的FTIR和NMR光谱中的新丙烯酸酯峰以及壳聚糖和丙烯酸化壳聚糖相对粘度的变化，证实了丙烯酸酯分子接枝到脱乙酰化水溶性壳聚糖的胺基上。凝胶化和水合后，用数字图像直观地观察到壳聚糖-PEO水凝胶的形成。对水凝胶形成过程进行流变学分析，以检测其凝胶化时间、相角变化以及在不同频率和应变百分比下的粘弹性特性。结果表明，混合前体液体溶液后10分钟内凝胶化过程完成。分别通过微量天平测量、质构分析仪和扫描电子显微镜观察分析了水凝胶的水溶胀程度、抗压机械强度以及脱水过程后水凝胶表面和横截面的形态。通过观察平滑肌细胞行为（如细胞粘附和活力）以及测量其表面粘附细胞的数量来评估水凝胶的生物活性。
