Characterizing mechanical properties of biological cells by microinjection.

Microinjection has been demonstrated to be an effective technique to introduce foreign materials into biological cells. Despite the advance, whether cell injection can be used to characterize the mechanical properties of cells remains elusive. In this paper, extending the previously developed mechanical model, various constitutive materials are adopted to present the membrane characteristics of cells. To demonstrate the modeling approach and identify the most appropriate constitutive material for a specific biomembrane, finite element analysis (FEA) and experimental tests are carried out. It is shown that the modeling results agree well with those from both FEA and experiments, which demonstrates the validity of the developed approach. Moreover, Yeoh and Cheng materials are found to be the best constitutive materials in representing the deformation behaviors of zebrafish embryos and mouse embryos (or oocytes), respectively. Also, the mechanical properties of zebrafish embryos at different developmental stages and mouse embryos (or oocytes) are characterized.