Dynamic cell culture on calcium phosphate microcarriers for bone tissue engineering applications

Developing appropriate cell culturing techniques to populate scaffolds has become a great challenge in tissue engineering. This work describes the use of spinner flask dynamic cell cultures to populate hydroxyapatite microcarriers for bone tissue engineering. The microcarriers were obtained through the emulsion of a self-setting aqueous α-tricalcium phosphate slurry in oil. After setting, hydroxyapatite microcarriers were obtained. The incorporation of gelatin in the liquid phase of the α-tricalcium phosphate slurry allowed obtaining hybrid gelatin/hydroxyapatite-microcarriers. Initial cell attachment on the microcarriers was strongly influenced by the speed of the dynamic culture, achieving higher attachment at low speed (40 r/min) as compared to high speed (80 r/min). Under moderate culture speeds (40 r/min), the number of cells present in the culture as well as the number of microcarrier-containing cells considerably increased after 3 days, particularly in the gelatin-containing microcarriers. At longer culture times in dynamic culture, hydroxyapatite-containing microcarriers formed aggregates containing viable and extracellular matrix proteins, with a significantly higher number of cells compared to static cultures.