Hybrid Cross‐Linking Characteristics of Hydrogel Control Stem Cell Fate

Abstract

Controlling hydrogel structures by combination of physical and chemical cross-links provides a novel system to regulate (stem) cell fate. In this study, we designed a polyethylene glycol (PEG)-based hydrogel where the polymer chains contain both physical and chemical cross-linking units in the same chain with self-assembling L-tyrosine-based dipeptides and photopolymerizable polyacrylate groups, respectively. It is shown that hydrogel architectures derived from this polymer are correlated to the cross-linking mechanisms. Combination of these cross-links controls three-dimensional gel architecture to regulate stem cell behavior in these hydrogels. Particularly, interaction of mesenchymal stem cells with the hydrogel enabled cellular aggregation to enhance chondrogenic differentiation as observed from the deposition of chondrogenic matrix. Increased chondrogenesis was due to enhanced cell-cell adhesion, which was mediated by gel morphology. This study shows the interplay of physical and chemical cross-links in hydrogels to regulate stem cell function and provides a novel molecular engineering tool for controlling hydrogel properties.

An antibacterial chitosan-based hydrogel as a potential degradable bio-scaffold for alveolar ridge preservation

“…The porous structure of hydrogels can simulate ECM, which is advantageous to the proliferation, differentiation, and gene expression of stem cells in bone regeneration. 56,57 In contrast, the cross-section of hydrogels presented lamellar structures, as shown in Fig. 1h and i, demonstrating that the hydrogels prepared here were anisotropic.…”

Engineering Smart Composite Hydrogels for Wearable Disease Monitoring

“…Therefore, people tend to use multiple cross-linking mechanisms to prepare hydrogel materials with diverse properties. The free combination of various physical or chemical cross-linking mechanisms makes hydrogels more flexible and tunable, significantly expanding the application boundaries of hydrogels [ 73 , 74 ]. Hu et al [ 75 ] prepared polyacrylamide/C-dot (PAM/C-dot) hydrogel with extraordinary mechanical, recoverable, and swelling properties by incorporating carbon nanodots (C-dots) as physical cross-linking agents and lubricants into low-chemically cross-linked PAM networks.…”

Reinforcement of nanofibrillar hydrogels via cyclodextrin and self-assembling peptide interactions for controlled drug delivery

“…Conventional strategies to enhance the mechanical strength of hydrogels rely on chemical cross-linking, which involves the use of cross-linking agents 16–20 or external stimuli such as UV and visible light. 21,22 However, these chemical cross-linking methods may induce undesirable effects on the activities of drugs and lead to additional toxicity.…”