A study on the in vitro degradation properties of poly(l-lactic acid)/β-tricalcuim phosphate(PLLA/β-TCP) scaffold under dynamic loading

The objective of this study was to investigate the effects of dynamic loading on the in vitro degradation properties of poly(l-lactic acid)/β-tricalcuim phosphate(PLLA/β-TCP) composite scaffolds. These scaffolds were prepared by a technique, namely solvent self-proliferating/model compressing/particulate leaching, and they were incubated in a customized simulated body fluid (SBF) flow system under dynamic loading conditions for 6 weeks. The bioactivity and the degradation behaviors of the composite scaffolds were systematically investigated through the formation of apatite, the mass and porosity changes, the molecular weight changes of PLLA, the compressive strength changes, etc. Results show a high level of apatite deposition on the scaffolds, suggesting their good bioactivity in the SBF. Changes in mass, porosity, molecular weight and compressive strength of the scaffolds happened more under dynamic loading conditions than that under flow only SBF conditions. Dynamic loading with the investigated frequency promoted the degradation of the scaffolds, but did not markedly deteriorate the mechanical properties of the scaffolds. All the results suggest that the composite scaffolds have great potential to be applied in bone replacements or repairs under the in vivo load-bearing conditions.