Abstract
Introduction
Intervertebral disc degeneration (IVDD) associated with low back pain is a major contributor to global disability. Current treatments are poorly efficient in the long-term resulting in medical complications. Therefore, minimally invasive injectable therapies are required to repopulate damaged tissues and aid regeneration. Among injectable biomaterials, self-assembling peptide hydrogels (SAPHs) represent potential candidates as 3D cell carriers. Moreover, the advent of graphene-related materials has opened the route for the fabrication of graphene-containing hydrogel nanocomposites to direct cellular fate. Here, we incorporated graphene oxide (GO) within a SAPH to develop a biocompatible and injectable hydrogel to be used as cell carrier to treat IVDD.
Methods and results
Hydrogel morphology and mechanical properties have been investigated showing high mechanical properties (G'=12kPa) comparable with human native nucleus pulposus (NP) tissue (G'=10kPa), along with ease of handling and injectability in dry and body fluid conditions. Hydrogel nanocomposites resulted biocompatible for the encapsulation of bovine NP cells, showing higher viability (>80%) and metabolic activity in 3D cell culture over 7 days, compared to GO-free hydrogels. Moreover, GO has demonstrated to bind TGF-β3 biomolecules with high efficiency, suggesting the use of GO as local reservoir of growth factors within the injected hydrogel to promote extracellular matrix deposition and tissue repair.
Conclusions
Our results show that incorporation of GO within the SAPH improves cell viability and metabolic activity. Furthermore, its tissue-mimicking mechanical properties and chemical tunability make it a promising candidate as injectable carrier of NP cells for the treatment of IVDD. Part of this work has been published (DOI: 10.1016/j.actbio.2019.05.004).
Conflicts of interests: No conflicts of interest
Sources of funding: The authors thank the EPSRC & MRC CDT in Regenerative Medicine for its financial support (EP/L014904/1).
