Preparation and optimization of composite scaffolds for rat H9C2 cardiomyocytes

Abstract

Objective To prepare composite scaffolds for rat H9C2 cardiomyocytes, and to optimize the scaffolds that facilitate the growth of H9C2 cardiomyocytes. Methods The electrospinning method was used to prepare three types of compo-site scaffolds, i.e., polycaprolactone (PCL)/chitosan (CS) scaffold (scaffold A), PCL/CS/zinc oxide (ZnO) scaffold (scaffold B), and PCL/CS/ZnO/carbon nanotubes (CNTs) scaffold (scaffold C), and the preparation of scaffolds was verified by the methods including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric (TG) analysis, and Raman spectroscopy. Electron microscopy and tensile stress, water contact angle, conductivity, and expansion rate tests were used to eva-luate the physical and chemical properties of the three types of scaffolds, and DAPI staining, electron microscopy, and CCK-8 assay were used to evaluate the biocompatibility of the three types of scaffolds. Results XRD, FTIR spectroscopy, TG analysis, and Raman spectroscopy showed that the three types of scaffolds were successfully prepared. Electron microscopy showed that scaffold C had a significantly longer fiber diameter than scaffold A (F=73.050,t=8.724,9.747,P<0.05). The tensile stress test showed that scaffold B had a significantly higher tensile stress than scaffolds A and C (F=13.833,t=3.641,3.802,P<0.05). The water contact angle test showed that all three types of scaffolds were hydrophilic. The conductivity test showed that scaffolds B and C had a significantly higher conductivity than scaffold A (F=798.780,t=32.155,30.048,P<0.05). The expansion rate test showed that for scaffold A, the expansion rate at 5 h after immersed in PBS buffer was significantly higher than that at 0.5 h (Fintra-group=53.103,P<0.05), and for scaffold C, the expansion rate at 2-5 h was significantly higher than that at 0.5 h (Fintra-group=103.748,P<0.05); at each time point of 0.5-4 h, scaffold A had a significantly higher expansion rate than scaffolds B and C, and at each time point from 0.5 to 2 h, scaffold B had a significantly higher expansion rate than scaffold C (Finter-group=35.226-162.448,P<0.05). DAPI staining and electron microscopy images showed that after the culture of H9C2 cardiomyocytes on the three types of scaffolds for 96 h, scaffolds B and C had a significant increase in the number of H9C2 cardiomyocytes compared with scaffold A. CCK-8 assay showed that the absorbance values of H9C2 on scaffolds A, B, and C at each time point from 18 h to 5 days were significantly higher than those at 12 h (Fintra-group=37.159-67.083,P<0.05), and at each time point from 12 h to 5 days, H9C2 on scaffold C had a significantly higher absorbance value than scaffolds A and B (Finter-group=26.039-80.994,P<0.05). Conclusion The composite scaffolds for rat H9C2 cardiomyocytes conform to the characteristics of extracellular matrix and can support the growth of cardiomyocytes, among which PCL/CS/ZnO/CNTs scaffolds show relatively high biocompatibility and have a greater potential than PCL/CS scaffolds in cardiac tissue engineering.

Keywords

• carboxymethylcellulose sodium|chitosan|extracellular matrix|tissue engineering|tissue scaffolds|myocytes cardic