Chitosan has drawn more and more attention for their particular biological effect. Nanometer materials displayed great perspective in medical application. In the present paper, we reviewed the biological characteristic of chitosan, the preparation methods of chitosar nanoparticles, as well as the applications of chitosan and chitosan nanoparticles in tissue engineering.

Objective To compare the efficacy of open microwave ablation and repeat hepatectomy for recurrent small hepatocellular carcinoma.Methods The clinical data of 75 patients with recurrent small HCC who were admitted to our hospital from January 2007 to December 2010 were retrospectively analyzed.34 received microwave ablation (MWA group) and 41 received repeat hepatectomy (hepatectomy group).The perioperative condition,liver function recovery,the variation of AFP level,mobidities,hospitalization time and overall survival rate and disease-free survival rate were compared.Results The rate of complete elimination to tumor tissue was 100％ and the AFP levels returned to normal within 3 months in both groups.The mean average operation time in MWA group was shorter than that in hepatectomy group [(91 ±33) min vs (156 ±51) min,t =-6.399 5,P =0.000].The blood loss in MWA group was smaller than that in hepatectomy group [(87 ±62) ml vs (254 ± 134) ml,t =-6.691 5,P =0.000].Patients in PFRA group had a shorter hospital stay [(7.5 ± 2.2) d vs (11.3 ± 2.7) d,t =-6.588 8,P =0.000].The mobidities of the MWA group and hepateetomy group were 2.9％ (1/34) and 22.0％ (9/41),respectively (x2 =5.812 7,P =0.016).The overall survive rate of 1,3 and 5-year were 88.1％,68.8％ and 46.1％ in the MWA group,and 86.1％,71.5％ and 50.2％ in the hepatectomy group (x2 =0.16,P =0.692).The disease free survival rate of 1,3 and 5-year were 67.1％,38.2％ and 16.1％ in the MWA group,and 64.4％,45.5％ and 23.6％ in the hepatectomy group (x2 =0.03,P =0.870).Conclusions MWA can achieve survival benefits equivalent to hepatectomy for recurrent small HCC,and it is less traumatic.

Objective: To investigate the association between miR-146a single nucleotide polymorphism and genetic susceptibility to hepatocellular carcinoma (HCC). Methods: PubMed, Web of Science, Cochrane Library, Wanfang Data, and Google Scholar were searched for case-control studies on the association between miR-146a single nucleotide polymorphism and genetic susceptibility to HCC published up to October, 2016 in Chinese or English. The Q-statistics test was used to evaluate the heterogeneity of these articles. Results: A total of 18 articles with 5 610 cases and 7 531 controls were included for the meta-analysis. There was no significant association between miR-146a single nucleotide polymorphism and genetic susceptibility to HCC. The odds ratio (OR), 95% confidence interval (95% CI), and P values for the five genetic models were as follows: the allele model C/G (OR = 0.99, 95% CI 0.88-1.06, P = 0.440); the heterozygous model CG/GG (OR = 0.99, 95% CI 0.90-1.10, P = 0.898); the homozygous model CC/GG (OR = 0.91, 95% CI 0.75-1.10, P = 0.314); the dominant model CC+CG/GG (OR = 0.97, 95% CI 0.79-1.19, P = 0.759); the recessive model CG+GG/CC (OR = 1.05, 95% CI 0.94-1.18, P = 0.405). A subgroup analysis of race, source of control population, and Hardy-Weinberg equilibrium were performed in these five genetic models, and miR-146a single nucleotide polymorphism increased the susceptibility to HCC only in the control population-based subgroups of the recessive model CG+GG/CC (OR = 1.20, 95% CI 1.02-1.40, P = 0.024). There was no association between miR-146a rs2910164 polymorphism and susceptibility to HCC in all the other subgroups. A stratified analysis of HBV infection revealed that miR-146a rs2910164 polymorphism increased the risk of HBV-positive HCC (OR = 1.26, 95% CI 1.10-1.49, P = 0.001). Conclusion There is no significant association between miR-146a rs2910164 polymorphism and the risk of HCC, but miR-146a rs2910164 polymorphism may increase the risk of HBV-positive HCC.