Abstract
Bioelectrical investigations have long shown that surfaces of bone formation and resorption are negatively and positively charged respectively. We also know that in a number of experimental situations [1], implants of negatively-charged ion exchange resin (NCR= Sephadex, CM)are osteotropic, and that implants of positively-charged resin (PCR= Sephadex DEAE) strongly inhibit bone formation [2]. While the cellular mechanism of action for NCR is thought to involve the local production of transforming growth factor beta [3], the mechanics of PCR action is an unknown. Our laboratory has shown that PCR stunts the in vitro growth of medullary osteoprogenitor cells, normal and transformed osteoblasts, and a number of tumor cell lines [4], PCR was also able to strongly inhibit hamster pancreatic cell engraftment and the growth of established pancreatic cell tumors.
