RESUMO
Hydrogels are used in vascular tissue engineering because of their good biocompatibility. However, most natural hydrogels exhibit high swelling ratio, poor mechanical stability, and low durability, which are key limitations for wider applications. Amphiphilic and fatigue-resistant organohydrogels were fabricated here via the click chemical reaction of unsaturated functional microbial polyhydroxyalkanoates and polyethylene glycol diacrylate and a combination of two-dimensional material graphdiyne. These organohydrogels were maintained stable in body fluids over time, and their tensile moduli remained unchanged after more than 2000 cycles of cyclic stretching. The tubular scaffolds presented good biocompatibility and perfusion in vitro. After transplantation in vivo, the vascular grafts exhibited obvious cell infiltration and tissue regeneration, having a higher patency rate than the control group in 3 months. This fabrication method provides a strategy of improving and promoting the application of organohydrogels as implant materials for small-diameter vascular graft.
RESUMO
BACKGROUND: MicroRNAs(miRNAs) are key regulators of gene expression in plants, animals and some viruses. Hence, alteration of miRNA levels in cells or tissues is common for miRNA studies. Loss-of-function of miRNA can be achieved using antisense oligonucleotides, sponges and gene knockout models. METHODS: Here, we showed an efficient, rational and economical way to construct multi-targeted miRNA sponges with desired copies. Four copies of miRNA sponge are used as "building-blocks". RESULTS: These building-blocks, which can target same miRNA or different miRNAs, are linked together through ligation. Each time of ligation can double the number of sponge copies. CONCLUSIONS: In this way, we constructed lentivirus vectors harboring sponges targeting miR-21, miR-31 and miR-155 and the combination of two miRNA sponges can inhibit cancer cell growth significantly.