Correlation between degradation and compressive strength of an injectable macroporous calcium phosphate cement

► The present macroporous CPC showed excellent injectability accompanied with prolonged setting time. ► The degradation of microspheres and compressive strength of CPC are in negative correlation. ► This product should be very useful if, in vivo, macroporous CPC can facilitate the ingrowth of new bone, which will fill up the deficiency of decreased compressive strength with degradation. Variation of compressive strength of a macroporous calcium phosphate cement (CPC) was investigated in the present study. Poly (lactide-co-glycolide acid) (PLGA) microspheres was incorporated with the CPC powder. Sodium citrate solution was used as the cement liquid phase. The formation of macropores and the decline in mechanical strength of the paste was investigated. The results showed that the macroporous CPC exhibited a good property of injectability but the self-setting time was slightly prolonged. With the degradation of PLGA microspheres, the weight loss increased and the average values of compressive strength of the paste was reduced dramatically. The formulation of negative correlation between compressive and weight loss was established as following: y2=−0.794y1+38.278. In conclusion, the present macroporous CPC showed that excellent injectability accompanied with the prolonged setting time, the degradation of microspheres and compressive strength of CPC are also in negative correlation. Regulate the acceleration of degeneration to a proper extents perhaps is another method to enhance the compressive strength in macroporous CPCs.