复合锶离子光交联海藻酸盐水凝胶支架的机械和生物学性能

Effects of adding strontium ions into photocrosslinked alginate hydrogels on its mechanical and biological properties

背景:光交联藻酸盐水凝胶以其良好的稳定性、可控性和生物相容性而备受关注,然而其作为骨组织工程支架仍存在不足之处,如强度不足、细胞黏附性能较差、缺乏骨诱导性等。目的:在光交联海藻酸盐水凝胶支架中复合锶离子,探究其机械和生物学性能变化。方法:在甲基丙烯酸酯化海藻酸盐形成光交联水凝胶后,分别浸泡于不同浓度(0,10,30,50,80,100 mmol/L)锶离子溶液中,制备携锶离子光交联海藻酸盐水凝胶,测量其溶胀率、弹性模量,并用扫描电镜和能谱仪分析材料表面形态和元素。将MC3T3-E1细胞分别接种于不同浓度携锶离子光交联海藻酸盐水凝胶表面,培养第4小时,Live/Dead染色观察细胞黏附情况;培养第3天,Live/Dead染色观察细胞伸展情况。结果与结论:①扫描电镜显示,随着引入锶离子浓度的升高,携锶离子光交联海藻酸盐水凝胶的致密程度增加,孔径减小;②能谱仪检测显示,随着引入锶离子浓度的增加,携锶离子光交联海藻酸盐水凝胶表面锶离子含量递增;③随着引入锶离子浓度的增加,携锶离子光交联海藻酸盐水凝胶溶胀率呈逐渐降低的趋势,弹性模量呈逐渐升高的趋势;④随着引入锶离子浓度的提高,MC3T3-E1细胞在携锶离子光交联海藻酸盐水凝胶表面的早期黏附率呈递增趋势,细胞伸展越来越好;⑤结果表明,在光交联海藻酸盐水凝胶中引入锶离子,可提高其机械性能,促进细胞的黏附伸展。

BACKGROUND: Photocrosslinked alginate gels have been attracting great interest due to its good stability, controllability and biocompatibility.However, as bone tissue engineering scaffolds, it still has some deficiencies, such as insufficient strength, poor cell adhesion performance and lack of bone induction.OBJCTIVE: To explore the changes of mechanical and biological properties of photocrosslinked alginate gels doped strontium ions.METHODS: After methacrylated alginate to form photocrosslinked methacrylated alginate hydrogels, photocrosslinked alginate hydrogels chelated strontium ions strontium ion-co-photocrosslinked methacrylated alginate were prepared by soaking photocrosslinked methacrylated alginate in strontium ion solution of different concentrations(0, 10, 30, 50, 80 and 100 mmol/L). The swelling ratio and elastic modulus of the gels were measured, and the surface morphology and elements of the materials were analyzed by scanning electric microscope and energy dispersive spectroscopy, respectively. MC3 T3-E1 cells were seeded on the surface of photocrosslinked alginate gels that were incorporated with different concentrations of strontium ion for 4 hours, and then live/dead staining was used to observe the cell adhesion. The cell spreading on day 3 was determined by live/dead staining.RESULTS AND CONCLUSION:(1) Scanning electron microscope showed that the density of photocrosslinked alginate gels increased and the pore size decreased with the increase of strontium ion concentration.(2) Energy dispersive spectroscopy showed that the strontium content on the surface of the gels increased along with the augment of the strontium ion concentration.(3) With the increase of strontium ion concentration, the swelling ratio of the hydrogels gradually decreased while the elastic modulus of photocrosslinked alginate gels gradually increased.(4) As strontium ion concentration increased, the early adhesion rate of MC3 T3-E1 cells on the surface of photocrosslinked alginate gels was on a rise, and the cell extension gradually became better.(5) In summary, the addition of strontium ions into the photocrosslinked alginate gels can improve its mechanical properties and promote cell adhesion and extension.