The migration of osteoblasts over substrata of discrete surface charge.

Osteoblasts, from the endocranial surface of neonate rat parietal bones, migrated over ion-exchange resin beads and phase-separation beads in vitro. The morphology of migrated osteoblasts was examined using a scanning electron microscope. The ion-exchange resin beads were either positively or negatively surface charged. The phase-separation model system described, using poly(methyl methacrylate) (PMMA) and lead poly-acrylate (LPA), presented morphologically discrete regions of positive and negative surface charge to single migrating osteoblasts. Osteoblasts migrated over both positively and negatively charged substrata. Close approximation of cells was noted on positively charged surfaces while a 'stand-off' morphology was characteristic of cells on negatively charged substrata. Dorsal cell-surface membrane activity was influenced by the surface charge of the colonized substratum.