Cellular response of Murine Osteoblasts to Cryopreservation: the influence of attachment to Hydroxyapatite (HA) scaffolds

This paper presents data relevant to the rational design of cryopreservation processes for tissueengineered bone. The effects of cell-scaffold interactions and cell-cell interactions on osteoblast viability and attachment to hydroxyapatite (HA) scaffolds following cryopreservation processing are defined experimentally. It is found that cryopreservation processing detaches osteoblasts from the HA scaffold and that cells suffer significantly more damage than when they are cryopreserved in liquid suspension. Thus, some aspect of cell-surface interaction is detrimental. The detrimental influence involves thermal modulations because when osteoblasts attached to HA are exposed to cryoprotective agents for two-step freezing without temperature change, morphological changes occur but little detachment or damage is observed. Enhanced post-thaw attachment and viability are realized for higher number densities of osteoblasts on the HA scaffold surface, indicating that some aspect of cellcell interaction is beneficial. Higher porosity HA scaffolds are better for cell attachment but porosity is not a statistically significant factor for post thaw viability.