Manganese-based Methacrylated Gellan Gum Hydrogels as Injectable System for Image-guided Cell Delivery

INTRODUCTION: Hydrogels hold a great potential on the scope of cell-based therapies and can be used to unravel several bottlenecks of these approaches [1]. Herein, we intend to develop injectable manganese-based methacrylated gellan gum hydrogels that can be monitored via MRI imaging.
METHODS: 0.75% (w/v) methacrylated gellan gum (GG-MA) solutions were supplemented with 0.1 and 1 mM of MnCl2 (Sigma-Aldrich) and further crosslinked with artificial cerebrospinal fluid (aCSF). The resulting hydrogels were characterized regarding their injectability, stability and MRI signal. As proof-of-concept, human-derived adipose stem cells (hASC) were encapsulated in 0.1 mM MnCl2 GG-MA hydrogels and cultured for 7 days. During the culture period, cell viability was assessed using Live/Dead staining kit (Thermo Fisher).
RESULTS & DISCUSSION: All the prepared formulations are injectable, with the force needed to inject gel solution being lower or similar to the force needed to inject water. After the 7 days of incubation in aCSF, hydrogel degradation was approximately 20% for all the formulations tested. T1-weighted MRI scans showed that formulation with 0.1mM MnCl2 exhibits a higher MRI signal. Therefore, in vitro studies were performed using this condition. hASCs encapsulated into hydrogel fibers remained alive up to 7 days of culture.
CONCLUSIONS: Manganese-based GG-MA hydrogels were successfully prepared. These hydrogels hold great potential for image-guided cell delivery approaches, when minimally invasive procedures are envisaged.