Alginate scaffolds show good promise for tissue engineering using mesenchymal stem cells (MSCs). Alginate is biocompatible, non – immunogenic and alginate beads can be modified in a range of ways, not only to enhance the matrix stiffness and stability, but also to promote cell adhesion and direct differentiation towards a given phenotype.
The main objective in the present study was to encapsulate MSCs isolated from adipose tissue (ATMSCs) into alginate beads and study cell survival and bead stability during three weeks cultivation. Comparison of the cell amount obtained after 2D and 3D cultivation in alginate beads was performed by trypan blue staning and light microscopy. Beads stability was analysed by mechanical testing. The presence of ATMSCs in alginate beads was confirmed by Hematoxylin and eosin stain.
ATMSCs (0,5 million cells) were encapsulated into 1 mL of 1,5 % alginate solution, polymerised with 10mM Calcium chloride dihydrate and cultivated in culture medium containing Dulbecco’s modified Eagle medium with 1% antibiotic/antimycotic solution and 10% fetal bovine serum. The amount of ATMSCs obtained after cultivation in tissue culture flasks (T75) was comparable with the amount of ATMSCs cultivated in 3D alginate beeds after 3 weeks of cultivation. The stability of alginate beads cultured with ATMSCs measured by mechanical testing was lower compared with alginate beads without cells. This might be explained by the mechanical properties of the polymer being affected by the surrounding culture medium. However, alginate beads proved to be stable during 3 weeks cultivation and addition of Calcium chloride for stabilization purposes was not necessary.
ATMSCs maintained their original proliferative capacity and multipotency when cultured in alginate beads. Alginate beads with cells were stable after 3 weeks cultivation, but the robustness of ASCs to mechanical stresses doesn‘t increased in comparison with alginate beads without cells. Nevertheless, sphere-based cultivation approaches offer a beneficial technique to culture MSCs in a three dimensional context.
This work was supported by grant VEGA No.1/0772/13 and the Slovak Research and Development Agency under the contract No. APW-0684-12.