Bioglass for skin regeneration 8 Haiyan Li 1 , Zhi Wu 1 , YanLing Zhou 2 , Jiang Chang 1, 2 1 Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China; 2 State Key Laboratory of Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China 8.1 Introduction of bioglass Compared with the traditional bioceramics, such as calcium sulfate and calcium phos- phate, bioglass (BG) displays relatively short application history. In the late 1960s, Professor Larry Hench found that the glass with the composition of 45% SiO 2 , 24.5% Na 2 O, 24.5% CaO, 6% P 2 O 5 (Bioglass) formed interfacial bonding with bone tissue when it was implanted in a bone defect in vivo [1]. It was one of the most important discoveries in biomaterial field that the implant could effectively promote bone regeneration in vivo [2]. Early in the 1980s, it was discovered that the BG with the highest levels of bioactivity could not only bond to bone tissue, but also bond to soft connective tissues [3]. From then on, great progresses on BG have been made: from melt-derived BG to sol-gel BG [4], from nano BG to 3D printing BG scaffold [5,6], from hard tissue repair to soft tissue repair, like wound healing [7,8], and from laboratory research to clinical application [9]. Based on the research of BG, in 2000, Professor Larry Hench proposed the new concept of “third generation biomaterials” that could regulate gene expression and cell behaviors [10]. The bioac- tive ions (such as Ca, Si, P, and B ions) released by BG during its degradation process contribute to the unique characteristics of BG [11], and it has been demonstrated that the dissolution products of BG play important roles in tissue regeneration through activating target cells [12]. In this section, the classification and properties of BG are briefly introduced firstly, followed by the main fabrication methods of BG. 8.1.1 Classification and properties of bioglass The structure of BG has two things in common: the network formers and network modifiers. Network formers are able to form glass structure and mainly include silica (SiO 2 ), phosphorus pentoxide (P 2 O 5 ), and boron trioxide (B 2 O 3 ). Network modifiers, by contrast, alter the glass structure by turning bridging oxygen atoms into nonbridg- ing oxygen atoms. Typical modifiers include the oxides of alkali or alkaline-earth metals, such as sodium, calcium, strontium, etc. [13]. Therefore, BG can be roughly divided into three categories: silicate-based BG (such as 45S5 Bioglass), phosphate- based BG, and borate-based BG. Silicate-based BGs have been extensively studied due to their excellent performance for tissue repair [14]. However, the advantages Biomaterials for Skin Repair and Regeneration. https://doi.org/10.1016/B978-0-08-102546-8.00008-X Copyright © 2019 Elsevier Ltd. All rights reserved.