Osteoblast behaviour in the presence of bisphosphonates: Ultrastructural and biochemical in vitro studies

M.G. Gandolfi, A. Pugnaloni1, M. Mattioli-Belmonte1, R. Muzzarelli1, A. De Benedittis1, P. Mengucci1, C. Zucchini, M. Tesei1, R. Caudarella2, G. Biagini1

Institute of Histology, University of Bologna, Bologna; 1CIBAD - Centre for Innovative Biomaterials, University of Ancona, Ancona; 2Division of Metabolism and Internal Medicine, University of Bologna, S. Orsola Hospital, Bologna, Italy

ABSTRACT
Objective
A positive balance in bone remodelling is an important goal of bone metabolism both in the presence of the osteoporotic processes characteristic of ageing and, especially, of prosthetic implants. The aim of the present work was to obtain new information about the initial steps of osteoblastic growth in an in vitro osteoblastic model in the presence of two bisphosphonates.

Methods
Experiments were performed with Alendronate and Neridronate, two molecules used in the therapy of osteoporosis. Since differentiating features into osteoblastic cells are known to parallel the presence in the cytoplasm of alkaline phosphatase and osteocalcin, we also carried out immunohistochemical typing.

Results
Good differentiation and osteoblastic activity were generally observed in the cells in contact with these compounds, except for 10-4 Neridronate, where biochemical data clearly indicated its toxic effect on the cells.

Conclusion
The detection of osteoblastic markers associated with an ultrastructural picture of correct organellar morphology in our cultures further supports the hypothesis of a metabolically positive action of these molecules on osteoblasts.

Key words
Bisphosphonates, osteoblasts, in vitro study.


Please address correspondence and reprint requests to: Dr. Monica Mattioli Belmonte, PhD, CIBAD - Institute of Normal Human Morphology, University of Ancona, Via Tronto 10/A, 60020 Torrette (AN), Italy.

Clin Exp Rheumatol 1999; 17: 327-333.
© Copyright Clinical and Experimental Rheumatology 1999.