Tunable Mechanical, Antibacterial, and Cytocompatible Hydrogels Based on a Functionalized Dual Network of Metal Coordination Bonds and Covalent Crosslinking

Abstract

Tissue engineering has become a rapidly developing field of research because of the increased demand from regenerative medicine, and hydrogels are a promising tissue engineering scaffold because of their three-dimensional structures. In this study, we constructed novel hydrogels of gelatin methacrylate (GelMA) hydrogels modified with histidine and Zn (GelMA-His-Zn(II)), which possessed fascinating antibacterial properties and tunable mechanical properties because of the formation of a functionalized dual network of covalent crosslinking and metal coordination bonds. The introduction of metal coordination bonds not only improves the strength of the GelMA hydrogels with covalent crosslinking but also makes their mechanical properties tunable via adjustments to the concentration of Zn. The synergistic effect of Zn and the imidazole groups gives the GelMA-His-Zn(II) hydrogels fascinating antibacterial properties (up to 100% inhibition). Counting the colony forming units and compression tests confirmed the fascinating antibacterial abilities and tunable mechanical properties, respectively, of the GelMA-His-Zn(II) hydrogels. In addition, Cell Counting Kit-8 assays, cytoskeletal staining assays, and live/dead assays confirmed the excellent cytocompatibility of the GelMA-His-Zn(II) hydrogels. Therefore, the GelMA-His-Zn(II) hydrogels are promising for applications in tissue engineering.

Molecular engineering of metal coordination interactions for strong, tough, and fast-recovery hydrogels

“…However, it remains a challenge to combine these outstanding mechanical properties with fast recovery. In most of these polymers, histidine residues or imidazole groups were randomly distributed in the polymer chains (37) or linked to the very end of multiarmed polymers (38). The histidine residues or imidazole groups did not form special binding sites and bound to metal ions independently.…”

Design of polymer-based antimicrobial hydrogels through physico-chemical transition

“…Defined as three-dimensional (3D) scaffolds composed by the chemical or physical entanglement of natural and/or synthetic polymer chains, hydrogels appear as suitable materials counteracting the microbial effects thanks to their biostability, biocompatibility and biomimetic physico-chemical properties, including swelling behavior [15,16]. Different strategies have emerged to develop hydrogels for antimicrobial applications: through the adsorption of antimicrobial agents [17,18], the encapsulation of metal particles or polycationic groups [19][20][21][22], the material modification with covalent linkers to graft antibacterial peptides or synthetic compounds [23][24][25].…”

Role of hyaluronic acid based hydrogel in management of wound healing effect

“…The suggested connection for the presence of increased HA in the wound bed and enhanced re-epithelialization has led to the development of a range of HA-containing biomaterials as wound dressings (Guanghui et al, 2011). In wound treatment, the wound dressing materials with superior properties is typically used to 2facilitate wound healing, in which hydrogels with high water content, flexible mechanical property, and good biocompatibility is considered as a promising candidate for practical application (Li et al, 2018;Yi et al, 2018;Li et al, 2019). Firstly, by providing a porous structure and suitable swelling ratio, hydrogel matrix can allow for oxygen presence, remove wound exudates, maintain a moist wound bed to promote wound healing (Kaoru et al, 2010;Rakhshaei and Namazi, 2017).…”