In vitro antibacterial activity and biocompatibility of a porous scaffold containing magnesium / 中国组织工程研究

ABSTRACT

BACKGROUND: The three-dimensional organic/inorganic scaffold materials using polymer/bioceramic composites can endow the necessary physical and chemical properties and enhance the mechanical properties of the materials. However, most bone substitution materials cannot prevent infection at the defect site. It has been found that the degradation of magnesium can produce local alkaline environment, so that magnesium has certain antibacterial activity. OBJECTIVE: To investigate the in vitro antibacterial activity and cytocompatibility of magnesium-containing scaffolds. METHODS: Polylactic acid/β-tricalcium phosphate/magnesium porous scaffolds were prepared by low-temperature rapid prototyping technology. The PTM (21) and PTM (12) groups referred to two mixing mass ratios (β-tricalcium phosphatemagnesium = 21 and 12), respectively. Two scaffolds of polylactic acid (P group) and polylactic acid/β-tricalcium phosphate (PT group) were also prepared by low-temperature rapid prototyping technology. The surface morphology, pore size, porosity and compression modulus of the scaffolds were measured. Staphylococcus aureus (ATCC 35923) was seeded on the scaffolds of each group for 24 hours. The antibacterial activity of the scaffolds was observed through spread plate method and confocal laser scanning microscopy. Mouse preosteoblasts MC3T3-E1 were co-cultured with the scaffolds of each group. The cell attachment and proliferation were evaluated by cell counting kit-8 assay. RESULTS AND CONCLUSION: (1) A relatively uniform porous structure was found on the scaffold surfaces in each group. There were no significant differences in the pore size and porosity among groups (P > 0.05). (2) The compression modulus in the PTM (21) and PTM (12) groups were significantly higher than those in the P and PT groups (P 0.05). (4) After 6 hours of culture, the number of attached cells in the PT, PTM (21) and PTM (12) groups was greater than that in the P group (P 0.05). (5) At 1 day of culture, the cell proliferation in the PT group was superior to that in the P group (P 0.05). (6) These results indicate that the polylactic acid/β-tricalcium phosphate/magnesium scaffold not only possesses good antibacterial activity, but also exhibits excellent cytocompatibility and certain anti-compressive ability.