Electrospinning is a promising technique for preparing bioartificial blood vessels. Nanofibers prepared by electrospinning can simulate the structure of extracellular matrix to promote cell adhesion and proliferation. However, thorn-like protrusions can appear as defects on electrospun scaffolds and coaxial electrospun nanofibers often have no clear core/shell structure, which can seriously affect the quality of bioartificial blood vessels. To address these problems, Tween 80 is added to the electrospinning solution, which results in a stable Taylor cone, eliminates the thorn-like protrusions on electrospun bioartificial blood vessels, and reduces interfacial effects due to different core/shell solutions during coaxial electrospinning. Simulations, biomechanical tests, and in vivo studies were performed. The results demonstrate the excellent mechanical properties and biocompatibility of the bioartificial blood vessel. This research provides a useful reference for optimizing the electrospinning process for fabricating bioartificial blood vessels. Graphical Abstract

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Biomimetic vascular grafts with multi-layered nanostructures can mimic structure and function of native blood vessels, but it is often challenging. This study demonstrates the feasibility of using combinatorial electrospinning approach for designing triple-layered nanofibrous tubular scaffold with inner and outer layer made up of co-axial poly(lactic-co-glycolic acid) (PLGA)/gelatin nanofibers (PLGA-core/gelatin-shell) and the intermediate layer with PLGA nanofibers that mimics native vascular structure. The assessment of biomechanical and biological analysis showed enhanced mechanical strength, suture strength and biocompatibility when cultured with human umbilical vein endothelial cells (HUVECs). Altogether, the results suggest that the combinatorial electrospinning approach is potentially useful for the fabrication of biomimetic vascular grafts suitable for cardiovascular tissue engineering applications.

Electrospinning is promising approach for producing biomimetic vascular scaffolds. In particular, gelatin-based electrospun scaffolds offer excellent biocompatibility. However, gelatin-based vascular scaffolds are difficult to remove from the collector after electrospinning and cross-linking agents such as glutaraldehyde, which is commonly used to improve the strength of water-soluble electrospun gelatin, are highly toxic. Herein, we present a novel electrospinning method for preparing three-layered vascular scaffolds. First, Tween 80 was added to 2,2,2-trifluoroethanol as the polymer electrospinning solution and the gelatin electrospinning solution was mixed with polylactic acid and polycaprolactone, respectively. The three-layered vascular scaffold was fabricated by electrospinning an inner layer of gelatin, a middle layer of polyester, and another outer layer of gelatin. Finally, the electrospun scaffolds were cross-linked with microbial transglutaminase and vacuum dried. Biomechanical properties of the scaffold were determined by tensile testing. Furthermore, the structure and biocompatibility of the scaffolds were assessed by hydrophilicity tests, scanning electron microscopy, and cell seeding experiments. Our results suggest the proposed electrospinning method is suitable for preparing biomimetic vascular scaffolds for cardiovascular tissue engineering applications. Moreover, this paper provides a useful reference for the preparation and optimization of vascular scaffolds.

Microfluidic chips have the advantages of miniaturization, integration, and portability, and are widely used in the early diagnosis of major diseases, personalized medical treatment, environmental detection, health quarantine, and other fields. The existing microfluidic chip manufacturing process is difficult to operate because of complex three-dimensional channels, complicated manufacturing steps, limited printing materials, the difficulty of operating the bonding process, and the need to purchase expensive new equipment. In this paper, an integrated molding method for microfluidic chips that integrates 3D printing and polymer dissolution technology is proposed. First, the channel mold of poly(vinyl alcohol) (PVA) or high impact polystyrene (HIPS) is dissolved to complete the manufacturing of the microfluidic chip channel. The integrated 3D-forming method of microfluidic chips proposed in this paper can manufacture microchannels inside the microfluidic chip, avoid the bonding process, and eliminate the need for rapid alignment of microchannels, material modification, and other operations, thus improving the stability of the process. Finally, by comparing the microchannels made by PVA and HIPS, it is concluded that the quality of the microchannels made by HIPS is obviously better than that made by PVA. This paper provides a new idea for the fabrication of microfluidic chips and the application of HIPS.