title: In vitro and in vivo effects of tetrakisphosphonates on bone resorption, tumor osteolysis, ectopic calcification, and macrophages.
abstract: The biological effects of bisphosphonates in calcium-related disorders are attributed to the incorporation of the bisphosphonates in bone, enabling direct interaction with osteoclasts and/or osteoblasts. The high accumulation of bisphosphonates in bone, due to their high affinity to hydroxyapatite (HAP), is essential for mediating in vitro and in vivo activity. In this study we examined the activity of tetrakisphosphonates, molecules containing two P-C-P type bisphosphonate moieties connected by a carbon chain. The novel compounds were examined in a battery of in vitro and in vivo models including HAP formation and dissolution, ectopic calcification, bone resorption, tumor osteolysis, and of macrophage-like cells (anti- or pro-inflammatory properties). The inhibition of ectopic calcification was ranked as follows: geminal bisphosphonates > bisacylphosphonates > tetrakisphosphonates. Pamidronate, but not the tetrakisphosphonates, was an effective antiosteolytic agent. Neither DNTP (tetrasodium 1,9-dihydroxynonane 1,1,9,9-tetrakisphosphonate) nor the bisacylphosphonate, PiBP (pimeloylbisphosphonate) seem to possess strong macrophage suppressive or inductive effects and can be considered to be relatively inactive in terms of anti- or pro-inflammatory action. A significant anticalcification effect was caused by various phosphonates, such as the tetrakisphosphonates, but DNTP, a tetrakisphosphonate, was found toxic as it impeded somatic growth and bone development.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, The Hebrew University of Jerusalem, Israel.
authors.forename: J M
authors.initials: JM
authors.lastname: Van Gelder
authors.forename: E
authors.initials: E
authors.lastname: Breuer
authors.forename: A
authors.initials: A
authors.lastname: Schlossman
authors.forename: A
authors.initials: A
authors.lastname: Ornoy
authors.forename: J
authors.initials: J
authors.lastname: Mönkkönen
authors.forename: J
authors.initials: J
authors.lastname: Similä
authors.forename: T
authors.initials: T
authors.lastname: Klenner
authors.forename: H
authors.initials: H
authors.lastname: Stadler
authors.forename: B
authors.initials: B
authors.lastname: Krempien
authors.forename: N
authors.initials: N
authors.lastname: Patlas
authors.forename: G
authors.initials: G
authors.lastname: Golomb
mesh_terms: D000818:Animals; D001705:Bioprosthesis; D001862:Bone Resorption / Q000139:chemically induced*; D002114:Calcinosis / Q000473:pathology / Q000517:prevention & control*; D002279:Carcinoma 256, Walker / Q000188:drug therapy* / Q000473:pathology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004164:Diphosphonates / Q000138:chemical synthesis / Q000494:pharmacology* / Q000633:toxicity; D017886:Durapatite / Q000737:chemistry; D012968:Etidronic Acid / Q000494:pharmacology; D005260:Female; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D010014:Osteolysis / Q000473:pathology / Q000517:prevention & control*; D000077268:Pamidronate; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004164:Diphosphonates; D017886:Durapatite; D012968:Etidronic Acid; D000077268:Pamidronate