Vis, M. A. M. | Search bioRxiv

bioRxiv2022

A dialysis medium refreshment cell culture set-up for an osteoblast-osteoclast coculture

Culture medium exchange leads to loss of valuable auto- and paracrine factors produced by the cells. However, frequent renewal of culture medium is necessary for nutrient supply and to prevent waste product accumulation. Thus it remains the gold standard in cell culture applications. The use of dialysis as a medium refreshment method could provide a solution as low molecular weight molecules such as nutrients and waste products could easily be exchanged, while high molecular weight components such as growth factors, used in cell interactions, could be maintained in the cell culture compartment. This study investigates a dialysis culture approach for an in vitro bone remodeling model. In this model, both the differentiation of human mesenchymal stromal cells (MSCs) into osteoblasts and monocytes (MCs) into osteoclasts is studied. A custom-made simple dialysis culture system with a commercially available cellulose dialysis insert was developed. The data reported here revealed increased osteoblastic and osteoclastic activity in the dialysis groups compared to the standard non-dialysis groups, mainly shown by significantly higher alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) activity, respectively. This simple culture system has the potential to create a more efficient microenvironment allowing for cell interactions via secreted factors in mono- and cocultures and could be applied for many other tissues.

bioengineering↗

bioRxiv2021

Osteoblast-osteoclast co-cultures: a systematic review and map of available literature

Drug research with animal models is expensive, time-consuming and translation to clinical trials is often poor, resulting in a desire to replace, reduce, and refine the use of animal models. One approach to replace and reduce the use of animal models in research is using in vitro cell-culture models. To study bone physiology, bone diseases and drugs, many studies have been published using osteoblast-osteoclast co-cultures. The use of osteoblast-osteoclast co-cultures is usually not clearly mentioned in the title and abstract, making it difficult to identify these studies without a systematic search and thorough review. As a result, researchers are all developing their own methods from the ground up, leading to conceptually similar studies with many methodological differences and, as a direct consequence, incomparable results. The aim of this study was to systematically review existing osteoblast-osteoclast co-culture studies published up to 6 January 2020, and to give an overview of their methods, predetermined outcome measures (formation and resorption, and ALP and TRAP quantification as surrogate markers for formation and resorption, respectively), and other useful parameters for analysis. Information regarding these outcome measures was extracted and collected in a database, and each study was further evaluated on whether both the osteoblasts and osteoclasts were analyzed using relevant outcome measures. From these studies, additional details on methods, cells and culture conditions were extracted into a second database to allow searching on more characteristics. The two databases presented in this publication provide an unprecedented amount of information on cells, culture conditions and analytical techniques for using and studying osteoblast-osteoclast cocultures. They allow researchers to identify publications relevant to their specific needs and allow easy validation and comparison with existing literature. Finally, we provide the information and tools necessary for others to use, manipulate and expand the databases for their needs.

cell biology↗