Simple fabrication of inner chitosan‐coated alginate hollow microfiber with higher stability

Abstract

Sodium alginate (NaA) has been widely used as microfiber‐based scaffold material. However, Ca‐alginate microfiber might disintegrate in the physiological environment due to the loss of calcium ions, which will limit its long‐term application in tissue engineering. In this work, to enhance the stability of Ca‐alginate microfiber in the physiological environment, an inner chitosan coating was introduced to Ca‐alginate hollow microfiber by one step via a microfluidic device. A more stable composite microfiber with double cross‐linking layers was generated. The stability of the microfiber was studied in the PBS solution (pH 7.4) to identify the coating effect on the hollow structure. The results revealed that chitosan component bonded an NaA layer to form a stable polyelectrolyte complex membrane in the inner wall of the microfiber, which stabilized the hollow region even though the Ca‐alginate shell was disintegrated by PBS solution. In addition, the introduction of chitosan coating improved the inner environment of the low affinity of alginate to cell surfaces and facilitated the cell adhesion and culture in the microfiber. HepG2 cells in the microfibers displayed favorable cell viability and proliferation ability. We believe that this work will lead to the development of innovative methodologies and materials for both cell culture and tissue engineering application. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2527–2536, 2019.

Simple Fabrication of Multicomponent Heterogeneous Fibers for Cell Co‐Culture via Microfluidic Spinning

“…Type A‐B‐A microfibers with cells in the core were obtained by adding NCI‐H1650 cells into component B ( Figure 5 A and Supporting Information 3). To maintain the microstructure of the microfibers for long‐term cell culture, we added 0.1% chitosan to the cell culture medium to prevent fiber swelling 25,26. After several days of culture, we found that the cells had continuously proliferated and spread toward the fiber edge.…”

“…For example, electrospinning microfibers must be removed with organic solvents before they can be used as a substrate for cell culture, which limits the construction of more complex 3D tissues. In contrast, some wet spinning systems include mild conditions, good biocompatibility, and no volatile solvent, such as those to prepare CaA fiber,21–24 calcium alginate/chitosan composite fiber,25,26 poly(ethylene glycol) diacrylate (PEGDA) fiber,27,28 and poly(ethylene glycol dimethacrylate) (PEGDMA) fiber 29. The fibers obtained with these methods directly encapsulate biomolecules and cells and facilitate cell 3D culture/co‐culture and microtissue formation in vitro 30,31.…”

Cell‐Inspired All‐Aqueous Microfluidics: From Intracellular Liquid–Liquid Phase Separation toward Advanced Biomaterials

“…All‐aqueous multiphase jets have been applied as important templates in fabrication of 1D biomaterials, such as hydrogel fibers and woven fabrics, which have great potentials in fields of tissue engineering scaffolds, implantable hydrogel device and biosensors, as well as wearable electronic devices …”

Cell encapsulation in liquified compartments: Protocol optimization and challenges

“…incorporated magnetic nanoparticles within the multilayers, evidencing the versatile feature of the LbL technique [5]. The polyelectrolyte complexation of alginate (core) and poly(L-lysine) (shell), as pioneered by Lim and Sun [23], was also reported to produce liquid-core/shell fibers as cell encapsulation systems [24,25]. Besides alginate/chitosan as cell encapsulation membranes, modified gelatin incorporating phenolic hydroxyl groups was used [21].…”