Purpose Melittin was expressed in prokaryotic vector pGEX-2T for production. Methods Melittin gene synthesized with enterokinase digested sequence,the gene was cloned into vector pGEX-2T,and constructed a recombinant plasmid of pGEX-MEL. Then the recombinant vector was introduced into E. coli BL21 (DE3)for expression. Fusion protein was purified by affinity chromatography. Hemolytic activity of Melittin was detected. Results Analysis result showed that the expression products accumulate in the cells to about 29.5 % of total cell protein. Detection of western blot using ant-GST as the first antibody showed that a special blot was revealed among the expression products. It certified that we have succeeded in expressing the fusion protein. SDS-PAGE showed that most part of the products is resoluble. The purity of obtained protein is 95% , by through GST affinity chromatography system. Melittin is harvested with a recovery of 80% by EK digestion. Test results showed melittin has good hemolytic activity. Conclusion We have expressed Melittin successfully by prokaryotic expression system.

The repair of bone defects poses a great challenge for reconstructive surgeons. Although the development of tissue engineering has exhibited promise in replacing damaged bone, the fabrication of large constructs with functional blood vessels remains an obstacle. From the orthopedic surgeon's point of view, the generation of axially vascularized bone, which can anastomose with the recipient vessel, might be a solution to this medical problem. In this study, we aimed to prefabricate an axially vascularized bone by combining a β-TCP scaffold, arteriovenous loop (AVL), and cell sheet in a bioreactor in vivo. Twelve rabbits were randomly allocated into two groups: the experimental group (presence of AVL) and the control group (absence of AVL). The constructs were explanted at 8 weeks postoperatively. The histomorphometric results showed 42.8±5.9% of the bone area in the AVL group and 26.6±3.5% in the control group. Similarly, vessel analysis revealed the average vessel density in the AVL group (12.5±3.3) was significantly more than that in the control group (6.1±1.5, p<0.05). Our research indicated that the combination of a β-TCP scaffold, AVL and cell sheet might engineer vascularized bone. This prefabrication strategy might facilitate clinical translation of bone tissue engineering in reconstructing large bone defects.
Bioreactors ; Blood Vessels ; Bone and Bones ; Orthopedics ; Rabbits ; Surgeons ; Tissue Engineering

We analyzed the influenza surveillance data of Children′s Hospital of Suzhou University from 2016 to 2018 and estimated the hospitalization burden of children under 5 years old due to influenza infection in Suzhou. The results showed that the influenza virus positive rate of 1 451 severe acute respiratory infection (SARI) cases in Children′s Hospital of Suzhou University was 13.6% (95%CI: 11.8%-15.3%; 197 cases), among which the influenza pandemic intensity in 2017-2018 was relatively high, and A/H1N1 was the main pandemic virus. It was estimated that the hospitalization rate of influenza-related SARI in children under 5 years old in Suzhou was 6.9‰ (95%CI: 6.6‰-7.2‰), among which the hospitalization rate of children aged<6 months was higher, up to 11.4‰ (95%CI: 9.9‰-12.8‰).