Objective
The successful application of biomaterials for bone regeneration and drug delivery requires a precise understanding of their degradation and resorbability to match the time course of tissue healing. In particular, biomimetic composites must be assessed for their responsiveness to various influences, such as tissue fluid exchange rates (which trigger material degradation), exposure to aggressive media (simulating osteoclastic resorption), and direct cellular resorption by osteoclasts (OCs).
This study aims to develop a controlled degradation environment—combining a flow chamber system with defined fluid compositions and exchange rates—to compare biomaterial degradation with actual osteoclastic resorption.

Methods & Results
To decouple osteoclast differentiation from resorption analysis, we established an osteoclast transfer culture system. Human monocytes were isolated from buffy coats, seeded on various culture substrates, and induced to differentiate into OCs. Using temperature-controlled detachment (UpCell™ plates), fully differentiated OCs were successfully transferred while maintaining their TRAP 5b and CTSK activity. These OCs generated significant resorption pits on dentin discs, calcium phosphate cements, chitinous scaffolds, gelatin/hydroxyapatite sponges and dentin discs (Figure 1).
Furthermore, biomaterial degradation was assessed in custom-built flow chambers under varying liquid flow rates and liquid compositions (simulated body fluid, phosphate buffered saline of different pH, citric acid). Comparing these degradation profiles with osteoclastic resorption data provided new insights into material stability and bioresorption mechanisms.

Conclusions
Our findings demonstrate that pre-differentiated OCs can be effectively transferred and re-seeded onto biomaterials of different morphologies while preserving their resorption activity. This approach enables a more precise characterization of biomaterials and their interaction with OCs. Additionally, degradation testing in controlled flow chamber systems provides a reliable pre-selection tool for biomaterial evaluation, optimizing subsequent cell culture and in vivo studies.