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

Zhe Liang,Guoan Luo,Qionglin Liang,Mingyu Ding,Peidi Xu,Lili Li,Chenguang Liu

doi:10.1038/srep33462

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.

Highlights

Fabrication of cell-encapsulated fibers is one of the hottest emerging topics on tissue engineering and regenerative medicine as the potential to be used as fundamental components[1,2,3]
In this work we proposed a simple method to prepare cell-laden double-network hydrogel (DNH) fibers made of PNIPAAm-PEG and alginate with tunable stiffness and flexibility
Cells were fixed into hydrogel fibers during the procedure if they were mixed into pre-gel solution at the beginning

Summary

Introduction

Fabrication of cell-encapsulated fibers is one of the hottest emerging topics on tissue engineering and regenerative medicine as the potential to be used as fundamental components[1,2,3]. The requirement for a simple, versatile, and low-cost system for the fabrication of cell-laden fibers is urgent. Creating a reinforced double-network hydrogel (DNH) combining the advantages of both natural-derived and synthetic hydrogels may be a possible strategy to solve the problem. To address these issues, in this work we proposed a simple method to prepare cell-laden DNH fibers made of PNIPAAm-PEG and alginate with tunable stiffness and flexibility. The resulting system has the ability to form mechanically stable, porous, hydrated three dimensional network These DNH fibers can be assembled into a variety of three dimensional constructs and cells encapsulated can be released through various pathways, among which a non-chemical adding method is highlighted. The availability, biocompatibility and degradability make it attractive for numerous biomedical applications, in fields of tissue engineering and regenerative medicine

Methods

Results

Discussion

Conclusion