甲基丙烯酸钠修饰光交联海藻酸盐水凝胶支架的制备和表征

文题释义：甲基丙烯酸钠：是一种具有双功能的化学基团的有机小分子，一端含有2-甲基丙烯酰基，该基团具有良好的化学活性，可与化合物中的多种基团反应而修饰化合物；另一个功能集团就是拥有负电荷基团，能给修饰过的化合物材料表面带来稳定的负电荷。光引发剂：又称光敏剂，是一类能在紫外光区(250-420 nm)或可见光区(400-800 nm)吸收一定波长的能量，产生自由基、阳离子等，从而引发单体聚合交联固化的化合物。引发剂分子在紫外光区(250-400 nm)或可见光区(400-800 nm)有一定吸光能力，在直接或间接吸收光能后，引发剂分子从基态跃迁到激发单线态，经系间窜跃至激发三线态；在激发单线态或三线态经历单分子或双分子化学作用后，产生能够引发单体聚合的活性碎片，这些活性碎片可以是自由基、阳离子、阴离子等。按照引发机制不同，光引发剂可分为自由基聚合光引发剂与阳离子光引发剂，其中以自由基聚合光引发剂应用最为广泛。背景：光交联海藻酸盐水凝胶因具有良好的生物相容性、可微创注射等优势已为热门的组织工程研究材料，但是仍然存在强度不足、细胞黏附能力不足等问题。目的：构建载负电荷的光交联海藻酸盐水凝胶材料，探索其物理性能和细胞黏附性能变化。方法：利用海藻酸钠和2-氨乙基甲基丙烯酸酯盐酸盐制备甲基丙烯酸酯化海藻酸盐后，再与光引发剂和不同浓度甲基丙烯酸钠(0，20，40，60 mmol/L)混合制备载负电荷光交联海藻酸盐水凝胶，利用傅里叶红外光谱仪分析水凝胶的功能基团变化情况，扫面电镜观察水凝胶的表面形态，并测量其溶胀率。将MC3T3-E1细胞与各组水凝胶共培养48 h，采用活死染色与CCK-8法分析水凝胶的细胞毒性；接种MC3T3-E1细胞于4组水凝胶表面，在第4小时活死染色观察细胞早期黏附情况，第3天活死染色观察细胞伸展情况。结果与结论：①傅里叶红外光谱分析显示，甲基丙烯酸钠的引入可在水凝胶红外波普波数1 600 cm^-1左右处出现来自甲基丙烯酸钠的新波峰；②扫描电镜显示随着甲基丙烯酸钠浓度的增加，光交联海藻酸盐水凝胶的致密度增加，孔径减小；③溶胀率测试显示随着甲基丙烯酸钠浓度的升高，光交联海藻酸盐水凝胶的溶胀率逐渐降低；④活死染色显示4种水凝胶表面的细胞生长状态良好，细胞活性均在95%以上；CCK-8检测显示，载负电荷的光交联海藻酸盐水凝胶材料无细胞毒性；⑤随着甲基丙烯酸钠引入量的增加，载负电荷光交联海藻酸盐水凝胶表面的早期细胞黏附率逐渐增加，细胞伸展状态明显改善；⑥结果表明，甲基丙烯酸钠修饰的引入调节了光交联海藻酸盐水凝胶物理性能，并明显提高了其细胞黏附性能。ORCID: 0000-0002-1054-6002(赵德路)中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

Preparation and characterization of sodium methacrylate modified photocrosslinked alginate hydrogel scaffold

BACKGROUND:Photocrosslinked alginate hydrogel has been a popular bone tissue engineering material because of its excellent biocompatibility and minimally invasive injection,but there are still problems such as insufficient strength and poor cell adhesion.OBJECTIVE:To construct the negatively charged hydrogels by introducing sodium methacrylate into photocrosslinked alginate hydrogels,and to explore the changes in its physical performance and cell adhesion.METHODS:After preparation of methacrylated alginate by reacting sodium alginate with 2-aminoethyl methacrylate,methacrylated alginate,photoinitiator and sodium methacrylate(0,20,40,60 mmol/L)were homogeneously mixed.The negatively charged photocrosslinked alginate hydrogels were prepared under ultraviolet light.The functional groups of the hydrogels were analyzed by fourier transform infrared spectroscopy.The surface morphology of the hydrogels was observed by scanning electron microscopy and the swelling ratio was measured.MC3T3-E1 cells were cultured with each group of hydrogels for 48 hours,and the cytotoxicity of the hydrogels was investigated by cell counting kit-8 assay.MC3T3-E1 cells were seeded on the surface of each group of hydrogels.The early adhesion of the cells was observed by live/dead staining at the 4th hour,and cell spreading was observed on the 3rd day.RESULTS AND CONCLUSION:(1)Fourier transform infrared spectroscopy demonstrated that the introduction of sodium methacrylate could lead to a new peak at wavenumber of about 1600 cm-1 in the hydrogel infrared wave,which was from the sodium methacrylate.(2)Scanning electron microscope observed that the density of the negatively charged photocrosslinked alginate hydrogels increased and the pore size of the gels decreased with augment of concentrations of sodium methacrylate.(3)The swelling ratio of the hydrogel decreased with the increase of the concentration of sodium methacrylate.(4)The live/dead staining revealed that the cells grew well on the surface of each hydrogel,and the cell viability reached above 95%.The cell counting kit-8 assay results showed that the negatively charged photocrosslinked alginate hydrogels had no cytotoxicity.(5)The early cell adhesion rate increased gradually and the cell extension became better with the increase of concentration of sodium methacrylate.(6)In summary,the introduction of sodium methacryl into photocrosslinked alginate hydrogels can adjust its physical properties and significantly improve its cell adhesion.