The main objective of this study was to prepare a hybrid three-dimensional scaffold that mimics natural tendon tissues. It has been found that a knitted silk shows good mechanical strength; however, cell growth on the bare silk is not desirable. Hence, electrospun collagen/polyurethane combination was used to cover knitted silk. A series of collagen and polyurethane solutions (4%-7% w/v) in aqueous acetic acid were prepared and electrospun. According to obtained scanning electron microscopy images from pure collagen and polyurethane nanofibers, concentration was set constant at 5% (w/v) for blend solutions of collagen/polyurethane. Afterward, blend solutions with the weight ratios of 75/25, 50/50 and 25/75 were electrospun. Scanning electron microscopy images demonstrated the smooth and uniform morphology for the optimized nanofibers. The least fibers diameter among three weight ratios was found for collagen/polyurethane (25/75) which was 100.86 ± 40 nm and therefore was selected to be electrospun on the knitted silk. Attenuated total reflectance-Fourier transform infrared spectra confirmed the chemical composition of obtained electrospun nanofibers on the knitted silk. Tensile test of the specimens including blend nanofiber, knitted silk and commercial tendon substitute examined and indicated that collagen/polyurethane-coated knitted silk has appropriate mechanical properties as a scaffold for tendon tissue engineering. Then, Alamar Blue assay of the L929 fibroblast cell line seeded on the prepared scaffolds demonstrated appropriate viability of the cells with a significant proliferation on the scaffold containing more collagen content. The results illustrate that the designed structure would be promising for being used as a temporary substitute for tendon repair.
Impact loadings essentially differ from static loadings due to a huge amount of the force applied to milliseconds under these loadings. Energy absorption of composites is proper criteria to examine the function against impact loading. Energy absorbers are widely used in the industry. At the same time, due to their unique properties, the use of strong self-compacting composites has been considered by the researchers. High tensile, compressive, and flexural strengths have made these concrete composites more eminent. In a comprehensive experimental work, using four basic mix designs, 64 rectangular composite panels were made with 100 mm 2 of area and 30, 45, 60, and 75 mm thickness and tested by impact loading. Compressive, tensile, and flexural strength tests were performed on all the four max designs. Steel fibers with percentages of 0, 0.25, 0.5, and 0.75 with 25 m of length were used to make the concrete composites. A hammer with 180 kg weight and 7500 J power was used as the impact loading with drop hammer test machine (DH-TM). The specimens were dynamically loaded by drop test from a 60 cm height. The use of steel fibers and expanded sheets in combination with each other significantly increases the energy absorption. Moreover, the initial peak force increases, while crushing length and deformation of the specimens reduce.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.