Double-Network Hydrogel with Tunable Mechanical Performance and Biocompatibility for the Fabrication of Stem Cells-Encapsulated Fibers and 3D Assemble

Abstract

Fabrication of cell-encapsulated fibers could greatly contribute to tissue engineering and regenerative medicine. However, existing methods suffered from not only unavoidability of cell damaging conditions and/or sophisticated equipment, but also unavailability of proper materials to satisfy both mechanical and biological expectations. In this work, a simple method is proposed to prepare cell-encapsulated fibers with tunable mechanical strength and stretching behavior as well as diameter and microstructure. The hydrogel fibers are made from optimal combination of alginate and poly(N-iso-propylacrylamide)-poly(ethylene glycol), characteristics of double-network hydrogel, with enough stiffness and flexibility to create a variety of three dimensional structures like parallel helical and different knots without crack. Furthermore, such hydrogel fibers exhibit better compatibility as indicated by the viability, proliferation and expression of pluripotency markers of embryonic stem cells encapsulated after 4-day culture. The double-network hydrogel possesses specific quick responses to either of alginate lyase, EDTA or lower environmental temperature which facilitate the optional degradation of fibers or fibrous assemblies to release the cells encapsulated for subsequent assay or treatment.

Engineering of Hydrogel Materials with Perfusable Microchannels for Building Vascularized Tissues

“…For instance, maleimide functionalized PVA and PEG‐thiol can form hydrogel after mixing, on account of the rapid reaction between maleimides and thiols . For thermogelation, thermosensitive poly( N ‐isopropylacrylamide) (PNIPAM)‐PEG, P(NIPAM‐HEMA), and P(NIPAM‐AA) have been developed. Since the easy control of light stimulus on precise space and defined time, photocrosslinkable hydrogels are useful for engineering hydrogel scaffold with complex structures.…”

“…Cells with cell‐tracker green/red were laden in the microfibers, respectively. Reproduced with permission . Copyright 2016, Nature Publishing Group.…”

“…Attributed to the fibrillar architecture of the extruded microfibers, textile technology can be well applied for assembling the microfibers into organized larger 3D constructs . For example, two strands of cell‐laden hydrogel microfibers can be assembled into locked knot structure by hand (Figure E) . To allow better assembly, Onoe et al let the microfibers be withdrawn into thin capillaries.…”

A mechanically strengthened polyacrylamide gel matrix fully compatible with electrophoresis of proteins and nucleic acids

“…Material scientists have utilised various strategies in efforts to significantly increase the mechanical strength of hydrogels . One approach is to utilise a second interpenetrated network that sacrificially dissipates stress to reduce crack propagation of the primary matrix, the so‐called ‘double network’ gels . Other methods include ‘smart design’ through careful attention to network homogeneity and/or the chemical componentry of the matrix , and crosslinking and/or reinforcement by polymerisation with organic microspheres or dispersed nanoparticles (e.g.…”

Necklace‐Like Microfibers with Variable Knots and Perfusable Channels Fabricated by an Oil‐Free Microfluidic Spinning Process

“…Fiber materials have drawn extensive attentions especially for their promising applications in medical and biological fields . With the merit of shape‐adaptability, these materials have been applied to mimic many aspects of physiological microenvironment in vivo.…”