Novel injectable gallium-based self-setting glass-alginate hydrogel composite for cardiovascular tissue engineering

Abstract

Composite biomaterials offer a new approach for engineering novel, minimally-invasive scaffolds with properties that can be modified for a range of soft tissue applications. In this study, a new way of controlling the gelation of alginate hydrogels using Ga-based glass particles is presented. Through a comprehensive analysis, it was shown that the setting time, mechanical strength, stiffness and degradation properties of this composite can all be tailored for various applications. Specifically, the hydrogel generated through using a glass particle, wherein toxic aluminium is replaced with biocompatible gallium, exhibited enhanced properties. The material's stiffness matches that of soft tissues, while it displays a slow and tuneable gelation rate, making it a suitable candidate for minimally-invasive intra-vascular injection. In addition, it was also found that this composite can be tailored to deliver ions into the local cellular environment without affecting platelet adhesion or compromising viability of vascular cells in vitro.

A Review of Bioactive Glass/Natural Polymer Composites: State of the Art

“…Ga 3+ was also crosslinked with alginate in order to control gallium release [240] during degradation. Additionally, Ga/alginate composites showed higher compression strength compared to that measured for Al/alginate composites because Ga is expected to exhibit a higher degree of alginate crosslinking [241]. The compressive strength and elastic modulus increased with an increasing amount of gallium (Ga) in bioactive glass composition as in [242], and the reactive oxygen species (ROS) were reduced by Ga ions [243].…”

Gallium containing bioactive materials: A review of anticancer, antibacterial, and osteogenic properties

“…Increased strength after surface modification of glasses (acid washing). [ 75 , 107 ] B 2 O 3 –CaO–K 2 O–MgO–Na 2 O–P 2 O 5 1Ag 2 O/CeO 2 /CuO/Fe 2 O 3 /Ga 2 O 3 /SrO/Y 2 O 3 /ZnO in wt.% In vitro degradation study in SBF. Evaluation of neuronal survival and neurite outgrowth in dorsal root ganglion from E11 chicks.…”

“…The addition of gallium has been shown to have a significant influence on the structural and thermal properties of bioactive glasses. When Ga is added into a silicate glass structure, it can act, similarly to Al 3+ , both as network former and network modifier [ 74 , 75 ] due to its ability to be incorporated in tetrahedral (coordination number CN = 4, GaO 4 ) and octahedral (CN = 6, GaO 6 ) structural units [ [76] , [77] , [78] ]. The studies show that Ga predominantly acts as a network former, however, a threshold level may exist where Ga starts to act as a network modifier [ 79 ].…”

Specialty Tough Hydrogels and Their Biomedical Applications

“…[207] In terms of injectable scaffolds, Clarkin et al developed a composite scaffold by using galliumbased glass particles to control the gelation of alginate hydrogels and thus, enhance alginate's mechanical properties. [208] The composite exhibited strengths over four times the strength needed to…”