Bone morphogenesis and surface charge.
The electrophoretic mobility of variously treated bone specimens, with and without bone morphogenetic activity, has been measured in physiological solutions. The Bone Morphogenetic Principle appears to be associated with a minimum negative surface charge on the implant that corresponds to that of normal undemineralized cortical bone in saline. Demineralization of cortical bone in 0.6 N HCI at 2 degrees consistently increases the bone negative surface charge, and biologically produces an implant with morphogenetic activity. It is suggested that through the mediation of the positively charges ionic layer surrounding the negative implant that the negatively charged mesenchymal cell is able to reside in very close contact with the surfaces of the implant. The binding force can be expected to be directly proportional to the degree of negativity of the implant. However, implants with a positive zeta potentaial will be surrounded by ions with a net negative charge so discouraging the stable positioning of mesenchymal cells in close contact with the implant. The negative surface charge corresponding to that of untreated cortical bone is apparently borderline in permitting such a close contact for a sufficiently long period of time for differentiation to follow.
D001846:Bone Development; D001857:Bone Matrix / Q000502:physiology; D001842:Bone and Bones / Q000502:physiology; D004553:Electric Conductivity; D004586:Electrophoresis; D006801:Humans; D013499:Surface Properties