Objective To determine the antibacterial activities of the alginate impression materials impregnated with carboxymethyl chitosan.Methods Carboxymethyl chitosan with different replace positions,replace degrees,relative molecular masses and deacetyl degrees were added into the dental alginate impression materials by different ratios.Their antibacterial activities were determined using a method according to the Chinese and Japanese standards for testing antibacterial efficacy of antibacterial materials.Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC6538 were used in this test.Results O-carboxymethyl chitosan showed best antibacterial activity.O-carboxymethyl chitosan added into the alginate impression materials had the best antimicrobial activity on Escherichia coli and Staphylococcus aureus in the ratios of 1% and 1.4%,respectively.Its inhibitory bacteria rate could reach 99.99% along with the increase of deacetyl degree.Conclusion The alginate impression materials impregnated with carboxymethyl chitosan have a favorable antimicrobial activity.

Objective To evaluate the biocompatibility and antibacterial activities of the Ornidazole Slow-Release Membrane.Methods 1.The lower lips of 12 rats were sewed into 12 pockets and the pockets were immited with extracting solution of the ornidazole membrane, formaldehyde and normal saline respectively once per day.The specimens were examined histologically 7 days later.2.The dorsal muscles of 16 rats were implanted with the membranes or silk threads,and examined histologically 1 week and 2,4,6 weeks later respectively.3. The antibacterial activity against Streptococcus mutans and Fusobacterium nucleatum was observed on solid culture medium in vitro.Results The animal experiments showed the membranes were not irritative to the oral mucosa.It was found that the tissue reaction of the membranes was similar to that of the silk threads after implanted into dorsal muscles and the membranes had been degraded in the second week.And the membranes had effective antibacterial action against Streptococcus mutans and Fusobacterium nucleatum.Conclusion The Ornidazole Slow-Release Membrane possesses favorable biocompatibility and antibacterial activities.

Both Wnt/β-catenin signaling pathway and NF-κB signaling pathway are highly conservative pathways that regulate a variety of biological processes, and their cross-regulation have attracted attention in many biological and medical research fields. In this review, we summarize the cross-regulation between Wnt/β-catenin signaling pathway and NF-κB signaling pathway and discuss their involvement in the multi-directional differentiation of mesenchymal stem cells.