Medical implants such as bone graft substitutes that include one or more cations are delivered in a local environment to promote osteogenesis. Zeolite loaded with a metal cation in combination with an implant such as a bone graft substitute can be used as an implant in the body to regulate protein transcription and translation. Also disclosed are methods of promoting osteogenesis in a patient in need thereof, methods for modulating bone formation and mineralization by implanting in a patient a medical implant comprising ion-exchangeable cations, and methods of regulating BMP gene expression in bone cells in a patient by controlling the delivery of certain cations through ionexchange via a zeolite incorporated in a bone substitute implanted in a patient so that BMP gene expression can be upregulated or downregulated appropriately.