Preparation of a recombinant tumor-targeting ribosome inactivating protein luffin-α-NGR and evaluation of its antitumor activity / 生物工程学报

Loofah seeds ribosome inactivating protein luffin-α was fused with a tumor-targeting peptide NGR to create a recombinant protein, and its inhibitory activity on tumor cells and angiogenesis were assessed. luffin-α-NGR fusion gene was obtained by PCR amplification. The fusion gene was ligated with pGEX-6p-1 vector to create a recombinant plasmid pGEX-6p-1/luffin-α-NGR. The plasmid was transformed into E. coli BL21, and the target protein was isolated and purified by GST affinity chromatography. The luffin-α-NGR fusion gene with a full length of 849 bp was successfully obtained, and the optimal soluble expression of the target protein was achieved under the conditions of 16 ℃, 0.5 mmol/L IPTG after 16 h induction. SDS-PAGE and Western blotting confirmed the recombinant protein has an expected molecular weight of 56.6 kDa. Subsequently, the recombinant protein was de-tagged by precision protease digestion. The inhibitory effects of the recombinant protein on liver tumor cells HepG2 and breast cancer cells MDA-MB-231 were significantly stronger than that of luffin-α. The Transwell and CAM experiment proved that the recombinant protein luffin-α-NGR also had a significant inhibitory effect on tumor cells migration and neovascularization. The inhibitory activity on tumor cells and angiogenesis of the recombinant luffin-α-NGR protein lays a foundation for the development of subsequent recombinant tumor-targeting drugs.

Low intensity pulsed ultrasound irradiating combined with guided bone regeneration for promoting the repair effect of periodontal bone defect / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the repair effect of low intensity pulsed ultrasound (LIPUS) irradiating combined with guided bone regeneration (GBR) on the defect of Beagle dog canines periodontal bone.</p><p><b>METHODS</b>Four canine teeth of every beagle dog (8 beagle dogs) were randomly distributed: Group 1 (LIPUS disposal + GBR+ autogenous bone graft group), group 2 (LIPUS disposal + autogenous bone graft group), group 3 (GBR + autogenous bone graft group), blank control group. The model of periodontal bone defect was established in the 1/3 part of the root buccal area. According to the group division, autogenous bone were grafted, group 1 and group 2 were disposed by LIPUS 20 min x d(-1). The intensity of ultrasound were 30 mW x cm(-2). Group 1 and group 3 were injected with Bio-Gide collagen membrane. The beagle dogs were executed at 6 and 8 weeks of the disposal of LIPUS and then Micro-CT test and analysis were conducted to periodontal bone defect area of each group.</p><p><b>RESULTS</b>By clinical observation, there were different degrees of shrinkages of the area of periodontal bone defect in each group. The Micro-CT test analysis indicated that there was a statistical difference among the number, the thickness as well as the size of bone trabecula of each group (P < 0.05). However, there was no statistical difference (P > 0.05) in terms of bone issue measurement index between 6 to B weeks of each group. Group 1 had the most new bone.</p><p><b>CONCLUSION</b>LIPUS has the potential to promote the repair of periodontal bone defect. Therefore the combination of LIPUS and GBR may be more conducive to the repair and regeneration of periodontal bone defect.</p>