Utlization of rheological parameters for the prediction of β-TCP suspension suitability to fabricate bone tissue engineering scaffold through foam replication method
In this study, aqueous suspensions of betatricalcium phosphate (β-TCP) containing various concentrations (0–0.8%, in w/w, based on the total weight of β-TCP constituent) of carboxymethyl cellulose (CMC) were prepared. The rheological properties of the suspensions, including cohesion, flowability, yield point, and recovery percentage, were evaluated. The shear stress-shear rate curve demonstrated that all suspensions exhibited non-Newtonian pseudoplastic behavior, and thus, in all slurries, viscosity decreased as the shear rate was increased. The lack of fluctuations in shear stress-shear rate curves resulted in improvement of suspension stability and a more controlled sedimentation upon addition of CMC. The addition of 0.8% CMC to the β-TCP slurry resulted in a maximum infinite shear viscosity, which means that this slurry can exhibit the best cohesiveness and wall thickness compared to other suspensions. Moreover, upon the increase of CMC concentration from 0.4%, the yield point of the β-TCP slurry was decreased, i.e., the suspension has a lower penetration force. The results showed that all suspensions were thixotropic in nature; however, the percentage of recovery decreased with increasing the CMC concentration, since it facilitates the movement of the slurry through the bulk of the template. Overall, the results suggest that β-TCP slurry containing 0.8% of CMC provides optimum characteristics for coating suspension on the polyurethane sponge.
Publisher URL: https://link.springer.com/article/10.1007/s41779-018-0187-2