Effects of different crosslinking treatments on the properties of decellularized small intestinal submucosa porous scaffolds / 北京大学学报(医学版)

OBJECTIVE@#To compare the effects of three different crosslinkers on the biocompatibility, physical and chemical properties of decellularized small intestinal submucosa (SIS) porous scaffolds.@*METHODS@#The SIS porous scaffolds were prepared by freeze-drying method and randomly divided into three groups, then crosslinked by glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodi-imide (EDC) and procyanidine (PA) respectively. To evaluate the physicochemical property of each sample in different groups, the following experiments were conducted. Macroscopic morphologies were observed and recorded. Microscopic morphologies of the scaffolds were observed using field emission scanning electron microscope (FESEM) and representative images were selected. Computer software (ImageJ) was used to calculate the pore size and porosity. The degree of crosslinking was determined by ninhydrin experiment. Collagenase degradation experiment was performed to assess the resistance of SIS scaffolds to enzyme degradation. To evaluate the mechanical properties, universal mechanical testing machine was used to determine the stress-strain curve and compression strength was calculated. Human bone marrow mesenchymal cells (hBMSCs) were cultured on the scaffolds after which cytotoxicity and cell proliferation were assessed.@*RESULTS@#All the scaffolds remained intact after different crosslinking treatments. The FESEM images showed uniformed interconnected micro structures of scaffolds in different groups. The pore size of EDC group[(161.90±13.44) μm] was significantly higher than GA group [(149.50±14.65) μm] and PA group[(140.10±12.06) μm] (P < 0.05). The porosity of PA group (79.62%±1.14%) was significantly lower than EDC group (85.11%±1.71%) and GA group (84.83%±1.89%) (P < 0.05). PA group showed the highest degree of crosslinking whereas the lowest swelling ratio. There was a significant difference in the swelling ratio of the three groups (P < 0.05). Regarding to the collagenase degradation experiment, the scaffolds in PA group showed a significantly lower weight loss rate than the other groups after 7 days degradation. The weight loss rates of GA group were significantly higher than those of the other groups on day 15, whereas the PA group had the lowest rate after 10 days and 15 days degradation. PA group showed better mechanical properties than the other two groups. More living cells could be seen in PA and EDC groups after live/dead cell staining. Additionally, the proliferation rate of hBMCSs was faster in PA and EDC groups than in GA group.@*CONCLUSION@#The scaffolds gained satisfying degree of crosslinking after three different crosslinking treatments. The samples after PA and EDC treatment had better physicochemical properties and biocompatibility compared with GA treatment. Crosslinking can be used as a promising and applicable method in the modification of SIS scaffolds.

Effect of procyanidine on the function and expression of miR-221 in human umbilical vein endothelial cells / 解放军医学杂志

Objective To study the effect ofprocyanidine (PC) on the proliferation and migration of human umbilical vein endothelial cells (HUVECs),determine the expression changes of miR-221,and to investigate the mechanism involved.Methods HUVECs were cultured in vitro and treated with PC (5,25,50,75,100μg/ml) for 24 hours,and a PC concentration of 50μg/ml was screened by CCK-8 assay for the follow up experiment,then the cell proliferation activity was detected by the wound healing assay.The expression of miR-221 in HUVECs was detected by real-time quantitative PCR;MiR-221 target genes were predicted in miRWalk database,and the target genes were analyzed by GO and KEGG pathway.Results Compared with the control group,the HUVECs treated with PC for 24h,their proliferation activity in PC 5μg/ml group did not change obviously (P＞0.05),and in PC 25,50,75 and 100μg/ml groups decreased in a concentration dependent manner (P＜0.01).Compared with the control group,the migration ability of PC 50μg/ml group decreased markedly (P＜0.01).Compared with the control group,the expression of miR-221 increased after treatment with PC 50μg/ml (P＜0.01).Go analysis indicated that the target genes of miR-221 were mainly related to cell proliferation,migration,gene translation and so on.The target genes related to cell proliferation and migration were ADAM17,KIT,PDGFD and so on.KEGG pathway analysis showed that the target genes of miR-221 enriched 5 signal pathways,such as FoxO,PI3K-Akt and so on.Conclusions Low concentration of PC has no effect on the proliferation activity of HUVECs.A certain concentration of PC can inhibit the proliferation and migration of HUVECs,of which the mechanism may be involved with the up-regulation of miR-221 and FoxO,PI3K-Akt and other signaling pathways.