Development of a Robotized Screening Method for Microfibers Based on Viscoelasticity

Fiber-shaped GelMA hydrogel has been widely applied in the fabrication of artificial muscle tissue. However, the hydrogel properties can be tuned by multi-parameters, including: degree of substitution, GelMA concentration, and initiator concentration, et al. Therefore, selecting an optimal parameter combination to achieve a desired neo-muscle outcome remains challenge. In this paper, we proposed a viscoelasticity based screening method for such optimization problem. To be easier to facilitate C2C12 cell aligned growth, stretched GelMA microfibers were fabricated by the high-throughput microfluidic spinning method instead of the tension loading methods. Afterwards, the viscoelastic properties of the microfibers with 12 parameter combinations were measured prior to and after 14 day of cell culture, respectively. Based on the measured data, we confirmed that the viscoelasticity changes of the microfibers were related with hydrogel degradation and neo-tissue formation, and the resulting three criteria were established to screen the optimal parameter combination. Compared with traditional immunofluorescence-based monitoring, our proposed method provides a new tool for the optimization study from perspective of viscoelasticity, and it has great application potential in biomaterials screening and 3D bioprinting for tissue engineering.