Study Of Compatibility For Magnesium To Use As A Scaffold In Bone Tissue Engineering

The present biomaterials neither natural nor man-made could satisfy the ideal extracellular matrix(ECM) for bone tissue engineering and have some defects,such as degrade too fast or too slow,insufficient in mechanical strength,bad biocompatibility and inflammatory response et al. So the urgent problem at present is to enlarge the source of scaffold for tissue engineering in order to satisfy the patients conveniently and economically.Magnesium is a macroelement that can be absorbed by human bodies and with high specific strength and stiffness, it has better toughness and processability compare to nonmetals. The density of magnesium is near to human bone tissue. Its resource is plentiful and the price is very cheap. So magnesium has a broad application prospect in the load-bearing site of bone tissue repair. But it has not been reported about the applied study on magnesium as the implants materials in our contry.In this paper, firstly we screen the materials treated with different methods by MTT assay and compare the results of co-culture experiments that the UMR106 cells were seeded directly on the materials surface with seeded in diffusion experiments. The results showed that the materials treated with alkali and heat were preferable significantly to those treated with alkali only or treated with nothing on cell viability. Furthermore, the materials with some coatings on the base of alkali and heat were better than that of none coatings on cell viability. In our study, the viability of UMR106 cells treated with diffusion from materials coated with calcium/ phosphorus (Ca/P),lysine (Lys) and MEM culture medium (MEM) is zero grade or first grade and this is suitable for tissue engineering according to GB/T 16886.5. While the materials coated with titanium dioxide (TiO₂) and polylactic acid (PLA) could not fit for the standard. After comparisons and analysis, we selected the materials coated with Lys and did futher studies on them. The results of alkaline phosphatase (ALP) assay showed that the UMR106 cells expressing high ALP levels after been seeding on the materials for a period of time. From this we can see that the cells have good osteogenesis on the scaffolds. The cells morphology was exhibited by scanning electron microscopy (SEM): the UMR106 cells can adhere to the surface of materials tightly and have multiple morphorous like itself. Besides, the pseudopodia stretching out and having contacts with each other. The results of single cell gel electrophoresis (SCGE) and flowcyto metry (FCM) also showed that the diffusion of materials had no damage to DNA and could not change the cell cycle.Besides, we analyzed the materials treated with different methods which affect the cell viability and the results showed that pH value, concentration of Mg²⁺ and surface roughness of materials were all factors affected the cell viability.This paper could serve as basic data and useful reference for the design and development of magnesium in application of bone tissue engineering.