The Impact of Culture Variables on A 3d Human In Vitro Bone Remodeling Model; A Design of Experiments Approach.

Abstract

Human in vitro bone remodeling models, using osteoclast-osteoblast co-cultures, could facilitate the investigation of human bone remodeling while reducing the need for animal experiments. Although current in vitro osteoclast-osteoblast co-cultures have improved our understanding of bone remodeling, it is still unknown which culture conditions support both cell types. Therefore, in vitro bone remodeling models could benefit from a thorough evaluation of the impact of culture variables on bone turnover outcomes, with the aim to reach balanced osteoclast and osteoblast activity, mimicking healthy bone remodeling. Using a resolution III fractional factorial design, the main effects of commonly used culture variables on bone turnover markers in an in vitro human bone remodeling model were identified. Our model was able to capture physiological quantitative resorption - formation coupling along all conditions. Culture conditions of two runs showed promising results; conditions of one run could be used as a high bone turnover system and conditions of another run as a self-regulating system as the addition of osteoclastic and osteogenic differentiation factors was not required for remodeling. The results generated with this in vitro model allow for better translation between in vitro studies and to in vivo studies, towards improved preclinical bone remodeling drug development. This article is protected by copyright. All rights reserved.