Tri-Layered and Gel-Like Nanofibrous Scaffolds with Anisotropic Features for Engineering Heart Valve Leaflets.

3D heterogeneous and anisotropic scaffolds that approximate native heart valve tissues are indispensable for the successful construction of tissue engineered heart valves (TEHVs). In this study, novel tri-layered and gel-like nanofibrous scaffolds, consisting of poly(lactic-co-glycolic) acid (PLGA) and poly(aspartic acid) (PASP), are fabricated by a combination of positive/negative conjugate electrospinning and bioactive hydrogel post-processing. The nanofibrous PLGA-PASP scaffolds present tri-layered structures, resulting in anisotropic mechanical properties that are comparable with native heart valve leaflets. Biological tests show that nanofibrous PLGA-PASP scaffolds with high PASP ratios significantly promote the proliferation and collagen and glycosaminoglycans (GAGs) secretions of human aortic valvular interstitial cells (HAVICs), compared to PLGA scaffolds. Importantly, the nanofibrous PLGA-PASP scaffolds are found to effectively inhibit the osteogenic differentiation of HAVICs. Two types of porcine VICs, from young and adult age groups, are further seeded onto the PLGA-PASP scaffolds. The adult VICs secrete higher amounts of collagens and GAGs and undergo a significantly higher level of osteogenic differentiation than young VICs. RNA sequencing analysis indicates that age has a pivotal effect on the VIC behaviors. This study provides important guidance and a reference for the design and development of 3D tri-layered, gel-like nanofibrous PLGA-PASP scaffolds for TEHV applications.

Facile Fabrication of Electrospun Nanofibrous Aerogels for Efficient Oil Absorption and Emulsified Oil-Water Separation.

Developing superabsorbents for efficiently separating immiscible oil-water mixtures and oil-water emulsions are highly desirable for addressing oily wastewater pollution problems, but it remains a challenge. Ultralight nanofibrous aerogels (NFAs) with unique wetting properties show great potential in oily wastewater treatment. In this study, a facile and efficient method for producing hierarchical porous structured NFAs with hydrophobicity for high efficiency oil-water separation was developed. The synthesis included three steps: wet electrospinning, freeze drying, and in situ polymerization. The obtained NFA demonstrated outstanding oil absorption capacity toward numerous oils and organic solvents, as well as efficient surfactant-stabilized water-in-oil emulsion separation with high separation flux and excellent separation efficiency. Furthermore, these NFAs displayed excellent corrosion resistance and outstanding recoverability. We assume that the resultant NFAs fabricated by this facile strategy are highly promising as ideal oil absorbents for practical oily wastewater treatment under harsh conditions.