Adhesion of suspension-cultured Catharanthus roseus cells to surfaces: effect of pH, ionic strength, and cation valency.
The correlation between the effects of pH, ionic strength and cation valency on the electrophoretic mobility and the extent of adhesion of suspension-cultured Catharanthus roseus cells to various polymer substrates is presented. The electrophoretic mobility of cells was unaltered in the pH range of 6-8, but decreased from approximately -2.2 x 10(-8) m V-1 s-1 and approached zero as the pH of the suspending liquid was decreased from 6 to 2. Similarly, the value of electrophoretic mobility decreased continuously as the ionic strength was increased from 0 to 1.0 M when cells were suspended in salt solutions of sodium chloride, calcium chloride, and aluminum chloride. However, using equimolar concentrations, the slope of the decrease in electrophoretic mobility increased following the sequence sodium chloride less than calcium chloride less than aluminium chloride. The electrophoretic mobility was near zero for suspensions containing 1.0 M calcium chloride or 0.1 M aluminium chloride. The extent of adhesion of the cells to the polymers sulphonated polystyrene less than polyethylene terephthalate less than polystyrene less than fluorinated ethylene-propylene followed this sequence. These results agree with a thermodynamic model of plant cell adhesion that implicates the importance of interfacial tensions in the adhesion process. However, higher levels of adhesion were generally observed when the electrophoretic mobility for the cells in the corresponding test liquid was at a minimum absolute value. These results can be explained by considering the effects of the electrolytic properties of the suspending liquid on the electrostatic repulsive interactions between the cells and the polymer surface in terms of a double-layer phenomenon and the DLVO theory.(ABSTRACT TRUNCATED AT 250 WORDS)
Facchini
P J
PJ
Department of Botany, University of Toronto, Ontario, Canada.
Neumann
A W
AW
DiCosmo
F
F
D001672:Biocompatible Materials; D002412:Cations; D002448:Cell Adhesion; D002478:Cells, Cultured; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D059828:Plant Cells; D013499:Surface Properties
D001672:Biocompatible Materials; D002412:Cations