Incorporating graphene oxide into biomimetic nano-microfibrous cellulose scaffolds for enhanced breast cancer cell behavior

Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10570-020-03078-w) contains supplementary material, which is available to authorized users.The impact of graphene oxide (GO) on normal cells has been widely investigated. However, much less is known on its effect on cancer cells. Herein, GO nanosheets were incorporated into electrospun cellulose acetate (CA) microfibers. The GO-incorporated CA (GO/CA) microfibers were combined with bacterial cellulose (BC) nanofibers via in situ biosynthesis to obtain the nano-microfibrous scaffolds. The GO/CA-BC scaffolds were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The GO/CA-BC scaffolds were used for breast cancer cell culture to evaluate the effect of GO on cancer cell behavior. Fluorescence images revealed large multicellular clusters on the surface of GO/CA-BC scaffolds. Compared to the bare CA-BC scaffold, the GO/CA-BC scaffolds not only showed enhanced mechanical properties but also improved cell proliferation. It is expected that the GO/CA-BC scaffolds would provide a suitable microenvironment for the culture of cancer cells which is necessary for drug screening and cell biology study.This work was supported by National Natural Science Foundation of China (Grant nos. 51572187, 51973058, 31660264, 31870963), the Key Research and Development Program of Jiangxi Province (No. 20192ACB80008), and the Youth Science Foundation of Jiangxi Province (No. 20181BAB216010), and Key Project of Natural Science Foundation of Jiangxi Province (No. 20161ACB20018).info:eu-repo/semantics/publishedVersio

Friction Weldability of a High Nb Containing TiAl Alloy

The friction weldability of Ti-45Al-8.5Nb-0.2W-0.2B-0.02Y alloy has been investigated by optimizing process parameters and analyzing the microstructures and tensile properties of the joints. The as-cast alloy with a nearly lamellar (NL) microstructure and the as-forged alloys with a duplex (DP) microstructure have been successfully welded. All the joints have a severe deformation zone (SDZ) and a transition zone (TZ) between the parent metal (PM) and SDZ. SDZ, showing a biconcave lens geometry, has a maximum thickness of hundreds of micrometers at the periphery. TZ is hundreds of micrometers thick. All SDZs have a fine-grained DP microstructure with a grain size of a few micrometers. For the joint of the as-cast alloy, the TZ consists of deformed lamellar colonies as the major constituent and partially recrystallized grains as the minor constituent. For the joint of the as-forged alloy, the TZ is similar to both the PM and SDZ, showing a DP microstructure. The grain size, volume fraction of γ grains, and the remnant lamellar colonies all increase with the distance from the SDZ. All joints presented perfect metallurgical bonding. The strengths of the joints are higher than those of the corresponding PMs. This indicates that the studied alloy has good friction weldability

Surface Modification of Q195 Structure Carbon Steel by Electrolytic Plasma Processing

In this study, we applied an emerging, environmentally friendly surface engineering technology, electrolytic plasma processing (EPP), for the surface modification of Q195 structure carbon steel surface pretreatment and further Zn coating. Treating the surfaces of Q195 structure carbon steel by EPP was a quite dynamic process, which was investigated using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The results shown that surface scale can be effectively remove after 40 s EPP treatment, and the EPP-treated Q195 structure carbon steel revealed a slight decrease in elastic modulus and hardness, but a substantial improvement in tensile (especially plastic) mechanical properties. Moreover, the further EPP modification conducted on the pretreated Q195 structure carbon steel sample for production of a layer of compact zinc coating with 15 μm thickness under an optimization EPP process. We also identified the modification mechanism of EPP to Q195 structure carbon steel, which may provide theoretical and practical guidance for future researchers and developers