Fiber‐Based Mini Tissue with Morphology‐Controllable GelMA Microfibers

Abstract

The use of microscale fibers could facilitate nutrient diffusion in fiber‐based tissue engineering and improve cell survival. However, in order to build a functional mini tissue such as muscle fibers, nerve conduits, and blood vessels, hydrogel microfibers should not only mimic the structural features of native tissues but also offer a cell‐favorable environment and sufficient strength for tissue functionalization. Therefore, an important goal is to fabricate morphology‐controllable microfibers with appropriate hydrogel materials to mimic the structural and functional complexity of native tissues. Here, gelatin methacrylate (GelMA) is used as the fiber material due to its excellent biological performance, and a novel coaxial bioprinting method is developed to fabricate morphology‐controllable GelMA microfibers encapsulated in calcium alginate. By adjusting the flow rates, GelMA microfibers with straight, wavy, and helical morphologies could be obtained. By varying the coaxial nozzle design, more complex GelMA microfibers such as Janus, multilayered, and double helix structures could be fabricated. Using these microfibers, mini tissues containing human umbilical cord vein endothelial cells are built, in which cells gradually migrate and connect to form lumen resembling blood vessels. The merits of cytocompatibility, structural diversity, and mechanical tunability of the versatile microfibers may open more avenues for further biomedical research.

Electro‐Assisted Bioprinting of Low‐Concentration GelMA Microdroplets

“…However, alginate impedes the functionalization of encapsulated cells, as it is not synthetized from natural mammal materials. Gelatin methacryloyl (GelMA), which is synthetized from gelatin, has become more and more attractive owing to its remarkable biocompatibility for cellular functionalization and rapid crosslinking ability, which has led to its widespread application in mini‐tissue rebuilding, organ‐on‐a‐chip, and drug controlled release . A low concentration of GelMA has been reported to be more appropriate for cellular functionalization and growth, as it forms larger pores, while showing superior elasticity and an enhanced degradation profile.…”

Self‐Adaptive All‐In‐One Delivery Chip for Rapid Skin Nerves Regeneration by Endogenous Mesenchymal Stem Cells

“…Finally, with GPA and CGP as the outer layer and inner lumen, a core-shell microfiber aligned chip was fabricated by a one-step 3D coaxial printing techniques developed in our previous work. [28][29][30] The core-shell microfiber aligned chip with GPA as the shell, and PBS as the fluid filled in microchannel is named as G:P:Al-Chip (Figure 2a). The inner and outer diameters of the microfiber of G:P:Al-Chip are 820 and 1100 µm (Figure 2b), respectively.…”

Why choose 3D bioprinting? Part III: printing in vitro 3D models for drug screening

“…As a representative model, hydrogel microspheres have been widely applied in cell therapy, local tissue filling, as well as high-throughput drug screening [7]. In addition, cell-laden hydrogel microfibers with specific morphology and function have been applied as biomimicking models of a set of strip structures, such as muscle, nerve, and vessel [8].…”