通过麦克加成反应形成的三臂聚乙二醇丙烯酸酯可注射水凝胶的制备与表征

通过麦克加成反应在磷酸盐缓冲溶液中制备出一种基于三臂聚乙二醇丙烯酸酯的能快速固化的可注射水凝胶.采用倒置法测定了体系的凝胶化时间.通过红外,DMA,溶胀,降解等一系列测试,研究了该水凝胶的结构和物理化学性能.观察到通过控制前体溶液的浓度,可以控制凝胶的成胶时间和所形成凝胶的溶涨率.同时表明该水凝胶具备可注射性和可降解性.细胞毒性评价显示,该水凝胶浸提液无毒性,符合生物材料的安全评价标准.由于麦克加成反应可在人体生理条件(pH7.4,37℃)下快速进行,并且不需要任何引发剂、催化剂和有机溶剂,因此该反应非常适合应用于生物医用材料领域.

Preparation and Characterization of Injectable Hydrogels Made via Michael-Type Addition Reaction of Dithiothreitol with 3-Arm Acryloyl End-Capped PEG

A 3-Arm PEG(M_n=16900)was first reacted with acryloyl chloride to give rise to an acryloyl end-capped macromer.Afterthen,a kind of injectable hydrogels was prepared via Michael-type addition reaction of dithiothreitol with this macromer.The gelation time was visually determined when the mixture did not flow by inverting the vials.The hydrogel structure was characterized by using FTIR and DMA analyses as well as swelling and degradation tests.It was found that robust and transparent hydrogels were quickly formed in situ with high gel fractions.DMA measurements confirmed that the hydrogels hold intact 3D network structure.The gelation time and swelling ratio are adjustable by changing the concentration of macromer solution in PBS due to the fact that the number of reactive acrylates in unit volume is increased with the concentration of precursor solution making them more easily to be linked with DTT to form hydrogel networks.The results revealed this kind of hydrogels is injectable and degradable.Meanwhile,MTT evaluation also showed the good cell-compatibility for this kind of hydrogel material.As Michael-type addition can be smoothly carried out at physiological temperature and pH in the absence of any sensitizer or catalyst,and the reactants involved are all biocompatible,the as-prepared hydrogels have the potential to be used in the area of biomedical materials.