Preparation of an RGD ALB conjugate. In vitro analysis of cellular responses

RGD (Arg-Gly-Asp) tripeptide was identified as the minimal active core peptide sequence common to adhesive proteins. In this paper, the authors report preparation of RGD containing peptide albumin conjugate (RGD ALB), and its effects on cellular adhesive function in vitro. RGD ALB was prepared via a coupling reaction of albumin with pentapeptide (GRGDS; Gly-RGD-Ser) by water soluble carbodiimide. Bovine endothelial cells (ECs) adhered to and spread well on a surface coated with RGD ALB, whereas few ECs adhered on surfaces coated with GRGESP-albumin conjugate (GRGESP peptide with little cell attachment activity; false control) and albumin. Cellular behavior, such as adhesion, spreading, growth, and migration, on surfaces coated with GRD-ALB, fibronectin (FN), and vitronectin (VN) were quantitatively examined. Adherent cell number on RGD ALB coated surfaces was larger than on those coated with FN and VN. Cell morphology on RGD ALB coated surfaces was similar to that on FN coated surfaces. The cell growth and migration activities on RGD ALB coated surfaces were almost equal to those coated with FN and VN. Thus, RGD ALB was found to promote cell adhesion, migration, and growth as effectively as fibronectin. This indicates that an artificial adhesive protein, simply derived with bioactive peptidyl ligand, can find versatile applications in fields in which cellular events play a critical role--for example, extracellular matrices and wound healing promotion aids.