Ligament, a fibrous connective tissue between bones, is a unique tissue in human anatomy because it has complex viscoelastic properties and is very tough. Moreover, it is an important tissue for regeneration because frequent injuries occur, but there are limited types of substitutes that can be used as a tissue replacement. In this study, we present a stem cell-laden fiber/hydrogel composite structure with a layered fibrous structure, which can enhance cell infiltration, topographical cue and mechanical properties. It can promote cell viability, proliferation, and differentiation of the ligament phenotype with the help of a growth factor. The mechanical properties of the developed structure were experimentally identified using tensile tests, while cell viability and various functionalities were verified through culture tests using mesenchymal stem cells.

Recently, three-dimensional (3D) cell culture and tissue-on-a-chip application have attracted attention because of increasing demand from the industries and their potential to replace conventional two-dimensional culture and animal tests. As a result, numerous studies on 3D in-vitro cell culture and microfluidic chip have been conducted. In this study, a microfluidic chip embracing a nanofiber scaffold is presented. A electrospun nanofiber scaffold can provide 3D cell culture conditions to a microfluidic chip environment, and its perfusion method in the chip can allow real-time monitoring of cell status based on the conditioned culture medium. To justify the applicability of the developed chip to 3D cell culture and real-time monitoring, HepG2 cells were cultured in the chip for 14 days. Results demonstrated that the cells were successfully cultured with 3D culture-specific-morphology in the chip, and their albumin and alpha-fetoprotein production was monitored in real-time for 14 days.