Guided assembly of cancer ellipsoid on suspended hydrogel microfibers estimates multi-cellular traction force

Cell culture on suspended fiber for tissue regeneration: A review

Cell culturing is a cornerstone of tissue engineering, playing a crucial role in tissue regeneration, drug screening, and the study of disease mechanisms. Among various culturing techniques, 3D culture systems, particularly those utilizing suspended fiber scaffolds, offer a more physiologically relevant environment than traditional 2D monolayer cultures. These 3D scaffolds enhance cell growth, differentiation, and proliferation by mimicking the in vivo cellular milieu. This review focuses on the critical role of suspended fiber scaffolds in tissue engineering. We compare the effectiveness of 3D suspended fiber scaffolds with 2D culture systems, discussing their respective benefits and limitations in the context of tissue regeneration. Furthermore, we explore the preparation methods of suspended fiber scaffolds and their potential applications. The review concludes by considering future research directions for optimizing suspended fiber scaffolds to address specific challenges in tissue regeneration, underscoring their significant promise in advancing tissue engineering and regenerative medicine.

Biointerface Fiber Technology from Electrospinning to Inflight Printing

Building two-dimensional (2D) and three-dimensional (3D) micro- and nanofibril structures with designable patterns and functionalities will offer exciting prospects for numerous applications spanning from permeable bioelectronics to tissue engineering scaffolds. This Spotlight on Applications highlights recent technological advances in fiber printing and patterning with functional materials for biointerfacing applications. We first introduce the current state of development of micro- and nanofibers with applications in biology and medical wearables. We then describe our contributions in developing a series of fiber printing techniques that enable the patterning of functional fiber architectures in three dimensions. These fiber printing techniques expand the material library and device designs, which underpin technological capabilities from enabling fundamental studies in cell migration to customizable and ecofriendly fabrication of sensors. Finally, we provide an outlook on the strategic pathways for developing the next-generation bioelectronics and "Fiber-of-Things" (FoT) using nano/micro-fibers as architectural building blocks.

Rheological and Biological Impact of Printable PCL-Fibers as Reinforcing Fillers in Cell-Laden Spider-Silk Bio-Inks

The development of bio-inks capable of being 3D-printed into cell-containing bio-fabricates with sufficient shape fidelity is highly demanding. Structural integrity and favorable mechanical properties can be achieved by applying high polymer concentrations in hydrogels. Unfortunately, this often comes at the expense of cell performance since cells may become entrapped in the dense matrix. This drawback can be addressed by incorporating fibers as reinforcing fillers that strengthen the overall bio-ink structure and provide a second hierarchical micro-structure to which cells can adhere and align, resulting in enhanced cell activity. In this work, the potential impact of collagen-coated short polycaprolactone-fibers on cells after being printed in a hydrogel is systematically studied. The matrix is composed of eADF4(C16), a recombinant spider silk protein that is cytocompatible but non-adhesive for cells. Consequently, the impact of fibers could be exclusively examined, excluding secondary effects induced by the matrix. Applying this model system, a significant impact of such fillers on rheology and cell behavior is observed. Strikingly, it could be shown that fibers reduce cell viability upon printing but subsequently promote cell performance in the printed construct, emphasizing the need to distinguish between in-print and post-print impact of fillers in bio-inks.