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With the global commercialization of the fifth-generation (5G) network, many countries, including China, USA, European countries, Japan, and Korea, have started exploring 6G mobile communication network, following the tradition of "planning the next while commercializing one generation". Currently, studies on 6G networks are at the infancy stage. Research on the vision and requirements for 6G is still ongoing, and the industry is yet to clarify the key enabling technologies for 6G. However, 6G will certainly build on the success of 5G. Therefore, developing high-quality 5G networks and seamlessly integrating 5G with verticals are the priorities before 2030, when 6G is projected to be commercialized. Also, global 5G standards will keep evolving to better support vertical applications. As a milestone, the Third-Generation Partnership Project (3GPP) published Release 16 in July 2020, which continuously enhanced the capabilities of mobile broadband service based on Release 15 and realized the support for low-delay and high-reliability applications, such as Internet of Vehicles and industrial Internet. Currently, 3GPP is working on Releases 17 and 18, focusing on meeting the demands of medium-and high-data-rate machine communication with low-cost and high-precision positioning, which will be published in June 2022. Thus, 6G networks will further expand the application fields and scope of the Internet of Things to accommodate those services and applications that are beyond the capabilities of 5G networks. Herein, we present our vision, application scenarios, and key technological trends for 6G networks. Furthermore, we propose several future research opportunities in 6G networks with regard to industrialization and standardization.

In this article, the chitosan/gelatin/pectin (CGP) network films were prepared to build appropriate physicochemical and mechanical microenvironment for attachment, proliferation, and differentiation of mesenchymal stem cells (MSCs). Results suggested that the hydrophilicity and mechanical character of CGP composites films could be modulated via adjusting the pectin content in the composites. The investigations of attachment and proliferation behaviors of mesenchymal stem cells (MSCs) on the CGP films were carried out. The morphology of cells was observed with hematoxylin/eosin staining (HE) and scanning electron microscope (SEM). The osteogenic differentiation of MSCs was investigated via ALP and polymerase chain reaction (PCR). Results suggested that the CGP films have excellent biocompatibility. MSCs seeded on CGP (0.1) film show higher proliferation capacity compared with other samples. Moreover, osteogenic differentiation of MSCs also depends on the properties of the substrate. The MSCs seeded on CGP (0.5) expressed the highest ALP activity, osteogenic gene expression and mineral formation capacity. These results suggest that the composition of the CGP network films could effectively modulate their physicochemical and mechanical properties and further regulate the cell behaviors of MSCs.