Objective: To explore chemical component changes of dog bone at different lengthening time and in different bone regions of interest, and to evaluate the mineralization during Ilizarov lengthening process. Methods: Th...Objective: To explore chemical component changes of dog bone at different lengthening time and in different bone regions of interest, and to evaluate the mineralization during Ilizarov lengthening process. Methods: The ash weight, the concentrations of calcium, phosphorus and the calcium/phosphorus ratio were measured at different intervals (2, 4, 6, 8, 12 weeks) since lengthening and the lengthened part was compared with a control area at each interval. Results: The ash weight, the concentrations of calcium and phosphorus in the lengthened area differed at all development time. The calcium/phosphorus (Ca/P) ratio in the lengthened region remained significantly lower than that in the control region up to 12 weeks after the lengthening. Conclusions: These results suggest that also other inorganic ions play an important role in the mineralization process and that they become relatively more important since 8 weeks after the lengthening.展开更多
Objective： To deliver cells deep into injectable calcium phosphate cement（CPC） through alginate-chitosan（AC） microcapsules and investigate the biological behavior of the cells released from microcapsules into the...Objective： To deliver cells deep into injectable calcium phosphate cement（CPC） through alginate-chitosan（AC） microcapsules and investigate the biological behavior of the cells released from microcapsules into the CPC.Methods： Mouse osteoblastic MC3T3-E1 cells were embedded in alginate and AC microcapsules using an electrostatic droplet generator.The two types of cell-encapsulating microcapsules were then mixed with a CPC paste.MC3T3-E1 cell viability was investigated using a Wst-8 kit,and osteogenic differentiation was demonstrated by an alkaline phosphatase（ALP） activity assay.Cell attachment in CPC was observed by an environment scanning electron microscopy.Results： Both alginate and AC microcapsules were able to release the encapsulated MC3T3-E1 cells when mixed with CPC paste.The released cells attached to the setting CPC scaffolds,survived,differentiated,and formed mineralized nodules.Cells grew in the pores concomitantly created by the AC microcapsules in situ within the CPC.At Day 21,cellular ALP activity in the AC group was approximately four times that at Day 7 and exceeded that of the alginate microcapsule group（P0.05）.Pores formed by the AC microcapsules had a diameter of several hundred microns and were spherical compared with those formed by alginate microcapsules.Conclusions： AC microcapsule is a promising carrier to release seeding cells deep into an injectable CPC scaffold for bone engineering.展开更多
文摘Objective: To explore chemical component changes of dog bone at different lengthening time and in different bone regions of interest, and to evaluate the mineralization during Ilizarov lengthening process. Methods: The ash weight, the concentrations of calcium, phosphorus and the calcium/phosphorus ratio were measured at different intervals (2, 4, 6, 8, 12 weeks) since lengthening and the lengthened part was compared with a control area at each interval. Results: The ash weight, the concentrations of calcium and phosphorus in the lengthened area differed at all development time. The calcium/phosphorus (Ca/P) ratio in the lengthened region remained significantly lower than that in the control region up to 12 weeks after the lengthening. Conclusions: These results suggest that also other inorganic ions play an important role in the mineralization process and that they become relatively more important since 8 weeks after the lengthening.
基金supported by the National Natural Science Foundation of China(No.30772447)the Talent Introduction Project of Peking University Health Science Center(No.bmu2009139),China
文摘Objective： To deliver cells deep into injectable calcium phosphate cement（CPC） through alginate-chitosan（AC） microcapsules and investigate the biological behavior of the cells released from microcapsules into the CPC.Methods： Mouse osteoblastic MC3T3-E1 cells were embedded in alginate and AC microcapsules using an electrostatic droplet generator.The two types of cell-encapsulating microcapsules were then mixed with a CPC paste.MC3T3-E1 cell viability was investigated using a Wst-8 kit,and osteogenic differentiation was demonstrated by an alkaline phosphatase（ALP） activity assay.Cell attachment in CPC was observed by an environment scanning electron microscopy.Results： Both alginate and AC microcapsules were able to release the encapsulated MC3T3-E1 cells when mixed with CPC paste.The released cells attached to the setting CPC scaffolds,survived,differentiated,and formed mineralized nodules.Cells grew in the pores concomitantly created by the AC microcapsules in situ within the CPC.At Day 21,cellular ALP activity in the AC group was approximately four times that at Day 7 and exceeded that of the alginate microcapsule group（P0.05）.Pores formed by the AC microcapsules had a diameter of several hundred microns and were spherical compared with those formed by alginate microcapsules.Conclusions： AC microcapsule is a promising carrier to release seeding cells deep into an injectable CPC scaffold for bone engineering.
