Effect of physical stimulus on periosteal chondroplasia / 中华创伤骨科杂志

ABSTRACT

Objective To study the impact of physical stimulus on periosteal chondroplasia with an in- tention of reconstructing cartilage tissue that has a biomechanical function and can be created either entirely in vivo or in vitro and subsequently implanted into the patient.Methods A series of biomechanical test methods were designed in order to investigate the mechanical properties of engineered cartilage under a variety of mechanical stress stimulations.The periosteal explants were harvested from proximal medial tibias of New Zealand rabbits and secured onto poly-?-caprolactone(PCL)scaffolds.The composites(periosteum/PCL)were suspended in the spinner flask bioreactor and the spinner flask was located on the stirring machine.The stem cells were stimulated by fluid shear stress under magnetic bar stirring.Results In gross observation,the thickness and length of neo-cartilage with shear force stimulation were significantly greater than those without shear force.The direction of elongation was parallel with fluid flow direction,regardless of composite orientation.Secondary,two different zones based on various cell morphology and distribution were clearly observed.The thickness of the superficial zone was greater in samples exposed to high shear force compared with low shear force.The superficial zone protein and lubricant were found in the engineered cartilage under shear stress stimulation.Conclusion The results reveal that shear stress can not only influence proliferation and differentiation of stem cells,but also change chondrocyte morphology and increase extracellular matrix production.