1(Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China） 2(Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, China)
Abstract：Objective: To mimic the tissue structure and physiological function of extracellular matrix (ECM) to fabricate electromagnetic nanofibrous scaffolds that are favorable for cell adhesion, proliferation and differentiation.Nanofibrous films were fabricated by coaxial electrospinning with gelatin as shell layer and polylactic acid (PLA) as core layer; meanwhile, magnetic nanoparticles (MNP) were added into the gelatin and PLA. The obtained nanofibrous films were pulverized and blended with carbon fiber (CF), followed by freeze-drying and crosslinking treatment to obtain three-dimensional (3D) porous scaffolds. The morphology and structure of the scaffolds were observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). The hysteresis loop was measured by vibrating sample magnetometer, the conductivity was measured using four point probe, and compression tests were carried out by universal material testing machine. The density and water absorption were also measured. CCK-8 and Western Blot were used to analyze the viability and function of the cells on the scaffolds. The scaffolds showed porous honeycomb microstructure, the pores were perforated with eachother. When CF content was 0, 1, 3 and 5 mg/mL, the density of scaffolds was 73.07, 72.56, 65.88 and 63.34 mg/cm3, the water absorption was 1164.60%, 1186.48%, 1284.835% and 1323.66%, the conductivity was 0, 0.0088, 0.2467 and 2.6625 s/m, and the saturated magnetization strength was 3.68, 3.15, 2.45 and 2.90 emu/g, respectively. The scaffolds up-regulated the expression of Cx43 and RhoA, as well as supported the growth of cardiomyocytes. The 3D porous electromagnetic composite scaffolds had both superparamagnetism and conductivity, the mechanical property was significantly improved by CF. The scaffolds supported growth and promoted the maturation of cardiomyocytes.
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