[Effects of MTA, iRoot SP and AH Plus on proliferation and differentiation of human periodontal ligament stem cells].

PURPOSE: To explore the effects of MTA, iRoot SP and AH Plus on periodontal ligament stem cells. METHODS: The periodontal ligament stem cells were cloned by limiting dilution culture method. The effects of MTA, iRoot SP and AH Plus on proliferation and apoptosis of periodontal ligament stem cells were detected by MTT and Annexin-V-FITC/PI double staining. Alizarin and qRT-PCR were used to evaluate the effect of MTA, iRoot SP and AH plus on osteogenesis of periodontal ligament stem cells. SPSS 21.0 software package was used for statistical analysis. RESULTS: MTA showed mild toxicity at 24 and 48 hours, AH Plus showed mild toxicity at 24 h. iRoot SP was the least (P<0.05) compared to MTA and AH Plus. The effect of three kinds of materials on apoptosis of periodontal ligament stem cells gradually decreased with the prolongation of time. Compared with the control group, the three kinds of materials were toxic at 3 d, the toxicity of MTA was the strongest and the toxicity of iRoot SP was the lowest(P<0.05). Mineralization nodules in MTA and iRoot SP group were significantly higher than those in AH Plus and control group. The expression of OC, RUNX2, COL1A and ALP gene was higher at 7, 14, 21 d than in the control group and the expression of iRoot SP mineralization was the greatest(P<0.05). CONCLUSIONS: The hardened iRoot SP is non-toxic to human periodontal ligament stem cells. Osteogenic ability and mineralization capacity of hardened iRoot SP on human periodontal ligament stem cells are better than MTA.

Corrosion resistance and antibacterial properties of hydroxyapatite coating induced by gentamicin-loaded polymeric multilayers on magnesium alloys.

As a result of their good biocompatibility, bioactivity, and mechanical properties, magnesium (Mg) alloys have received considerable attention as next generation biodegradable implants. Herein, in order to achieve a proper degradation rate and good antibacterial ability, we reported a novel hydroxyapatite coating induced by gentamicin (GS)-loaded polymeric multilayers for the surface treatment of the Mg alloy. The coating was characterized by X-ray diffraction, fourier transform infrared spectroscopy and scanning electron microscopy. The as-prepared hydroxyapatite coating showed the compact morphology and a well-crystallized apatite structure. This coating could improve the adhesion strength and reduce the corrosion rate of the substrate in simulated body fluid solution. Meanwhile, the drug release and antibacterial experiments demonstrated that the GS loaded specimen revealed a significant antimicrobial performance toward Staphylococcus aureus and had a prolonged release profile of GS, which would be helpful to the long-term bactericidal activity of the Mg implant. This coating showed acceptable biocompatibility via MTT assay and Live/dead staining. Thus, the multilayers-hydroxyapatite coated Mg alloy could improve the corrosion resistance and biocompatibility while delivering vital drugs to the site of implantation.