Preparation and compressive strength of α‐tricalcium phosphate/gelatin gel composite cement

Calcium orthophosphate-based biocomposites and hybrid biomaterials

“…For instance, Mickiewicz et al [463] reported that after a critical concentration (that depended on the type and molecular weight of the polymer, but was always around 10%), the polymer started forming a thick coating on the crystal clusters, preventing them from interlocking, originating plastic flow and, as a consequence, decreasing mechanical properties. More to the point, Fujishiro et al [456] reported a decrease in mechanical properties with higher amounts of gel, which was attributed to the formation of pores due to leaching of gelatin in solution. Therefore, it seems that mechanical properties, although improved by the addition of polymers, are still a limitation for the application of calcium orthophosphate-based IBS formulations in load-bearing sites [146].…”

“…For example, gelatin might be added to calcium orthophosphate cement formulations, primarily to stabilize the paste in aqueous solution before it develops adequate rigidity and, secondly, to improve the compressive strength [391,429,456]. Adding rod-like fillers to the cement formulations also caused an improvement in the mechanical properties [456].…”

Self-Setting Calcium Orthophosphate Formulations

“…Specifically, polysaccharides [120,132,[380][381][382][383], gelatin [317,[384][385][386][387][388][389][390] and polyacrylic acid [391][392][393] are of an interest due to their biocompatibility and good rheological properties. Only small amounts (a few weight %) are needed to dramatically increase the viscosity of the pastes.…”

“…For example, a 5 wt% sodium chondroitin sulfate solution is used as mixing liquid in Biopex ® [4,5]. In the case of gelatin, more than a 50% improvement of the compressive strength was detected [386]. The gelatin-containing formulations after setting were found to exhibit reduced crystallinity, much smaller CDHA crystals and a more compact microstructure; all these phenomena might be accounted for the improved mechanical properties [387].…”

“…In order to maintain a good cohesion and reduce filter pressing, the calcium orthophosphate formulations need to be more viscous (hence, less injectable) [4,5]. For example, they might be modified by addition of polysaccharides [120,132,[380][381][382][383] and/or gelatin [317,[384][385][386][387][388][389].…”