超声增强藻酸钙凝胶支架材料孔隙率的研究

Ultrasonic enhancement of the porosity of alginate scaffold

藻酸钙凝胶具有三维立体多孔结构,能为细胞生长提供充分的附着空间,且具有良好的生物相容性和一定的机械强度,是一种理想的细胞支架材料.本文研究了藻酸钙三维支架材料的力学特性与氯化钙/藻酸钠的配比的关系,并提出采用低强度脉冲超声处理藻酸钙凝胶、基于超声空化效应增强藻酸钙凝胶孔隙率的新方法.实验采用交联合成方法制备藻酸钙凝胶支架材料,测量力学特性、孔洞的联通性与孔隙率,并利用绿色荧光蛋白的表达评价细胞的增殖能力.结果表明,当氯化钙/藻酸钠的配比为3:5时,凝胶的机械强度和弹性较好,力学性能稳定,为最佳配比参数.采用声压0.055 MPa的脉冲超声作用20 min,可以有效提高凝胶支架的孔隙率;且细胞在该支架中生长状态良好,呈现团簇状生长趋势.

Alginate scaffold with a three-dimensional （3D） porous structure can provide su？cient space for the cell to adhere, and has a good biocompatibility and mechanical strength. In this work, low-intensity pulsed ultrasound （LIPUS） is used to enhance the porosity of alginate scaffold based on acoustic cavitation. In the experiment, the alginate-calcium-based 3D scaffold culture system is fabricated with an optimum CaCl2/sodium alginate ratio of 3：5. The mechanical properties of alginate scaffold are measured and scanning electron microscopy is used to analyze the porosity of the scaffold. In addition, the microscopy observation of green fluorescent protein expression and the CCk-8 assessment are adapted to analyze the cell proliferation effect. Experimental results show that with LIPUS treatment under appropriate driving parameters （acoustic pressure 0.055 MPa and treatment time 20 min）, the porosity of the 3D scaffold can be significantly improved, which would benefit the cell growth in the scaffold.