Deoxycholic acid-modified microporous SiO2nanofibers mimicking colorectal microenvironment to optimize radiotherapy-chemotherapy combined therapy

From 1D Nanofibers to 3D Nanofibrous Aerogels: A Marvellous Evolution of Electrospun SiO2 Nanofibers for Emerging Applications

One-dimensional (1D) SiO2 nanofibers (SNFs), one of the most popular inorganic nanomaterials, have aroused widespread attention because of their excellent chemical stability, as well as unique optical and thermal characteristics. Electrospinning is a straightforward and versatile method to prepare 1D SNFs with programmable structures, manageable dimensions, and modifiable properties, which hold great potential in many cutting-edge applications including aerospace, nanodevice, and energy. In this review, substantial advances in the structural design, controllable synthesis, and multifunctional applications of electrospun SNFs are highlighted. We begin with a brief introduction to the fundamental principles, available raw materials, and typical apparatus of electrospun SNFs. We then discuss the strategies for preparing SNFs with diverse structures in detail, especially stressing the newly emerging three-dimensional SiO2 nanofibrous aerogels. We continue with focus on major breakthroughs about brittleness-to-flexibility transition of SNFs and the means to achieve their mechanical reinforcement. In addition, we showcase recent applications enabled by electrospun SNFs, with particular emphasis on physical protection, health care and water treatment. In the end, we summarize this review and provide some perspectives on the future development direction of electrospun SNFs.

SiO2 Fibers of Two Lengths and Their Effect on Cellular Responses of Macrophage-like Cells

The immunoreactivity or/and stress response can be induced by nanomaterials' different properties, such as size, shape, etc. These effects are, however, not yet fully understood. This study aimed to clarify the effects of SiO2 nanofibers (SiO2NFs) on the cellular responses of THP-1-derived macrophage-like cells. The effects of SiO2NFs with different lengths on reactive oxygen species (ROS) and pro-inflammatory cytokines TNF-α and IL-1β in THP-1 cells were evaluated. From the two tested lengths, it was only the L-SiO2NFs with a length ≈ 44 ± 22 µm that could induce ROS. Compared to this, only S-SiO2NFs with a length ≈ 14 ± 17 µm could enhance TNF-α and IL-1β expression. Our results suggested that L-SiO2NFs disassembled by THP-1 cells produced ROS and that the inflammatory reaction was induced by the uptake of S-SiO2NFs by THP-1 cells. The F-actin staining results indicated that SiO2NFs induced cell motility and phagocytosis. There was no difference in cytotoxicity between L- and S-SiO2NFs. However, our results suggested that the lengths of SiO2NFs induced different cellular responses.