Comparison of different scaffold materials and different cell types in a 2D+ bioreactor system by LiMSy, a Live cell Monitoring System

Introduction. The use of a live cell monitoring system (LiMSy) is a valuable tool to investigate cell dynamics in real-time for various application domains. To obtain such a unique real-time monitoring approach, the validation of a 2D+ bioreactor system combined with sensor technology is being conducted. In addition, this 2D+ bioreactor system was used to investigate the influence of scaffold material and cell type in a comparative study. Materials and Methods. Human periosteal derived cells (hPDCs) and immortalized human bone marrow stem cells (ihBMSC) were seeded on either 2D+ titanium (Ti) or tantalum (Ta) scaffolds and cultured in a static or dynamic (bioreactor) condition. The influence of scaffold pretreatment and initial seeding conditions, such as time, seeding volume and cell density, was investigated in the two biomaterials in a static environment. Cell viability and proliferation were determined by measuring the metabolic activity and oxygen consumption in function of the flow rate. Therefore, a Presto Blue metabolic assay and sensor technology such as the spot (PreSens) and needle (Ocean Optics) oxygen sensors were used. Finally, endpoint analyses such as DNA measurements and Live/Dead images were carried out as a control. Results. In static conditions, hPDCs seeded on Ta scaffolds showed a similar or significant increased metabolic activity as compared to cells seeded on Ti scaffolds. The initial seeding density is the main factor influencing proliferation over time for Ti scaffolds, whereas in case of Ta scaffolds this is the initial seeding volume. hPDCs and ihBMSC showed different proliferation characteristics and a different correlation between metabolic activity and cell number. The oxygen consumption of hPDCs seeded on Ti scaffolds in a dynamic bioreactor system showed a positive correlation with the flow rate and was in agreement with the predicted oxygen consumption (as compared to the initially amount of seeded cells). Discussion and conclusion. Cell proliferation and viability differ between different cell types and scaffold materials in a 2D+ bioreactor system. This study provides promising results that in a next step should be combined with data-based modeling to achieve a real-time monitoring system suitable for different cell types and scaffold materials.status: publishe