Preoaration And Droderties Of Calcium Dhosphate-based Microcarriers For Cells

As one of three key factors, cells usually have been mixed into the scaffold materials ofinjectable bone tissue engineering to repair the bone fracture and damage directly. But shearstress derived from injection operation could damage cells and subsequently affect their livingand proliferation in vivo. Herein, construction of ideal carriers with appropriate geometricstructure and chemical composite for cells are very significant for the protection of cells andsubsequent success of injectable tissue engineering bone. Porous microsphere has been paidmore and more attention as it could protect cells from the shear stress and provide a3Dphysiological environment for normal phenotype expression of cells. Meanwhile, from a clinicalperspective, it can be effectively applied as an injectable system for minimally invasive surgery,reduce patient discomfort and risk of infection.In this paper, the porous calcium phosphate-based microsphere has been fabricated throughthe water-in-oil emulsion method, MG-63human osteosarcoma cells have been seeded on thesurface of microspheres to investigate its biocompatibility. The research aims to design andfabricate a kind of porous microsphere used as cell carriers, which can solve the problem of boneformation capacity limitation in the injectable bone tissue engineering. The specific contents andresults of the research are as follows:1. The microsphere with diameter of500±100m is fabricated through the water-in-oilemulsion method, camphene and gelatin had been used as porogen and agglomerant. The porousstrucure has been fabricated after removing the porogen from the microsphere through sinteringtreatment. The calcium phosphate power and its porous microsphere were characterized by TEM,XRD, TG, FE-SEM, FTIR, respectively. The influence of fabrication parameters, includingporogen content, high temperature sintering, post-processing of the porous structure of themicrospheres are discussed. The results showed that the sintering processing could affect theportiforium ratio of the microsphere. The pore of the microsphere with sintering slowly is closed.However, the portiforium ratio of microsphere after high temperature sintering treatment isincreased significantly. The microsphere was fabricated when camhene content was4.0g, whichhad an average pore diameter of30m and a higher portiforium ratio. Almost completely opening pore of microspheres could be fabricated after further post-hydrochloride treatment.2. The biocompatibility was investigated through the MG-63human osteosarcoma cellsculture on the microspheres in vitro. The results showed that the cells can attached and spreadactively on microspheres. Compared with non-porous microspheres, the open porousmicrospheres greatly enhanced the cell proliferation, which are also beneficial to the expressionof the phosphatase activity. So the microspheres with open pore allows for cell ingrowth, whichshowed great potential theoretical and application value as cell carriers in the injectable tissueengineering.