Controlled patterning of magnetic hydrogel microfibers under magnetic tweezers

3D tailor-made biodegradable scaffold integrated with biological cells or molecules is of great importance for tissue engineering. This paper addresses an improved method for exploring magnetic tweezers in patterning and aligning magnetic hydrogel fiber to fabricate large-scale engineered cell-hydrogel constructs. Magnetic hydrogel fibers were fabricated based on microfluidic device. The fabricated hydrogel fiber is made of alginic acid sodium and with a diameter of 34 μm. Magnetic nanoparticles is added into the alginic acid sodium solution to append magnetic material inside the fibers. The magnetic material inside the hydrogel fiber is regulated by the microfluidic device. Magnetic tweezers system based on solenoid electromagnet is utilized to evaluate the magnetic response of the magnetic hydrogel fiber. Evaluation results show the hydrogel fiber can be maneuvered by the proposed system with a positioning resolution of sub-micro level. The cultivation results of hydrogel fiber with C2C12 cells shows the potential for real applications of the proposed method in tissue engineering.