Direct chemical bond of bioactive glass-ceramic materials to bone and muscle

The objective of this research is to achieve direct chemical bonding of structurally strong implant materials with hard and soft tissues. This objective has been achieved through the development of a series of surface-active bioglasses and bioglass-ceramics. A controlled release of Ca, P, and Na ions from the surface of the materials produces an alkaline pH and nutrient constituents at a time when the body can incorporate the ions into newly formed tissues. Optical and electron microscopy of in-vivo implants in rat femurs and muscles show the development of stable chemically bonded physiological interfaces after 6 weeks. Microstructure and crystallinity of the materials do not influence the bonding achieved. Mechanical measurements of the bond strength in bone show that the bone fractures before the interface does. In-vitro studies of protein epitaxy, hydroxyapatite crystallization, and solubility kinetics correlate with the proposed interfacial bonding theory.