Globally growing problems related to cardiovascular diseases lead to a considerable need for synthetic vascular grafts. For small-caliber vascular prosthesis, it remains essential to fulfill rapid endothelialization, inhibit intimal hyperplasia, and prevent calcification for keeping patency. To modulate vascular regeneration, herein, we developed a bioactive trilayered tissue-engineered vascular graft encapsulating both microRNA-126 and microRNA-145 in the fibrous inner and middle layers, respectively. In vitro cell activities demonstrated that the trilayered electrospun membranes had significant biological advantages in enhanced growth and intracellular nitric oxide production of vascular endothelial cells, modulation of phenotypes of vascular smooth muscle cells (SMCs), and restraint of calcium deposition through fast-releasing microRNA-126 and slow-releasing microRNA-145. Histological and immunofluorescent analyses of in vivo implantation in a rat abdominal aorta interposition model suggested that the dual-microRNA-loading trilayered electrospun graft exerted a positive effect on accelerating endothelialization, improving contractile SMC regeneration, and promoting normal extracellular matrix formation. Meanwhile, the local bioactivity of microRNA-126 and microRNA-145 in the trilayered vascular graft could regulate inflammation and depress calcification possibly by facilitating transformation of macrophages into the anti-inflammatory M2 phenotype. These findings indicated that the trilayered electrospun graft by local delivery of dual microRNAs could be possibly used as a bioactive substitute for replacement of artificial small-caliber blood vessels.

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Clinical utility of small‐diameter vascular grafts is still challenging in blood vessel regeneration owing to thrombosis and intimal hyperplasia. To cope with the issues, modulation of gene expression via microRNAs (miRNAs) could be a feasible approach by rational regulating physiological activities of both vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs). Our previous studies demonstrated that individually loaded miRNA‐126 (miR‐126) or miRNA‐145 (miR‐145) in the electrospun membranes showed the tendency to promote vascular regeneration. In this work, the bilayered electrospun graft in 1.5‐mm diameter was developed by emulsion electrospinning to dual‐load miR‐126 and miR‐145 for target regulation of both VECs and VSMCs, respectively. Accelerated release of miR‐126 was achieved by introducing poly(ethylene glycol) in the inner electrospun poly(ethylene glycol)‐b‐poly(l‐lactide‐co‐caprolactone) ultrafine fibrous membrane, reaching 61.3 ± 1.2% of the cumulative release in the initial 10 days, whereas the outer electrospun poly(l‐lactide‐co‐glycolide) membrane composed of microfibers fulfilled prolonged release of miR‐145 for about 56 days. In vivo tests suggested that dual‐loading with miR‐126 and miR‐145 in the bilayered electrospun membranes could modulate both VECs and VSMCs for rapid endothelialization and hyperplasia inhibition as well. It is reasonably expected that dual target‐delivery of miR‐126 and miR‐145 in the electrospun vascular grafts has effective potential for small‐diameter vascular regeneration. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 371–382, 2019.

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The development of low carbon economy is closely related to the interests of all sectors of society, especially the main three to participate: the government, enterprises and the public. In this process, how to coordinate the interests of all parties and formulate a reasonable incentive mechanism has become an important task for the government. Studied on the analysis of the behavior status and goals of the government, enterprises and public on the background of low carbon economic development, then used the game method to quantify each object' interests of the target and relations. At last, designed incentive mechanism on the basis of incentive compatibility principle to meet the individual subject welfare maximization and, the greatest degree of protection for the development of low carbon economy.

As tissue regeneration material, electrospun fibers can mimic the microscale and nanoscale structure of the natural extracellular matrix (ECM), which provides a basis for cell growth and achieves organic integration with surrounding tissues. At present, the challenge for researchers is to develop a bionic scaffold for the regeneration of the wound area. In this paper, polyurethane (PU) is a working basis for the subsequent construction of tissue-engineered skin. poly(L-lactide-co-caprolactone) (PLCL)/carboxymethyl chitosan (CMCS) composite fibers were prepared via electrospinning and cross-linked by glutaraldehyde. The effect of CMCS content on the surface morphology, mechanical properties, hydrophilicity, swelling degree, and cytocompatibility were explored, aiming to assess the possibility of composite scaffolds for tissue engineering applications. The results showed that randomly arranged electrospun fibers presented a smooth surface. All scaffolds exhibited sufficient tensile strength (5.30–5.60 MPa), Young’s modulus (2.62–4.29 MPa), and swelling degree for wound treatment. The addition of CMCS improved the hydrophilicity and cytocompatibility of the scaffolds.