Migration of Osteoblast-like Cells on Extracellular Matrices-coated Culture Plate Using Cell Tracking System

Abstract

In this study, the migration of MC3T3-E1 osteoblast-like cells was examined on the culture plate coated with ECM, such as type I collagen, laminin or fibronectin. The cells were incubated in a self-made mini-incubator, with the same conditions as commercial CO2 incubator, placed on an inverted microscope and observed as a real time-mode. After 24 hr of incubation, the edge and center of single cell were detected by an automated cell tracking system. From the cell movement path, it was shown that the cells had a tendency to move randomly without any certain direction. Furthermore, it could be found that the cell movement speed was divided into three phases, attachment preparation phase, from 0 to T1 hr, accelerated movement phase, from T1 to T2 hr and speed maintenance phase, till 24 hr. At first phase, a cell moved slightly as like searching a local attachment site. Afterwards, the cell accelerated its speed and reached the maximum speed, Vmax. To estimate the cell migration speed, the migration index was defined as the value of the Vmax divided by T2-T1. The migration index of the MC3T3-E1 cells on fibronectin was 8.9, while those indexes on the type I collagen and laminin were respectively 5.3 and 5.1. These results suggested that all cells might have their own migration index according to their species or phenotypes and ECM type, and the migration speed could be inferred from those values without further study.