Event Abstract Back to Event Injectable platform hydrogel for musculoskeletal regeneration Abbey Thorpe1, Christine L. Le Maitre1 and Chris Sammon2 1 Sheffield Hallam University, Biomedical Research Centre, United Kingdom 2 Sheffield Hallam University, Materials and Engineering Research Institute, United Kingdom Introduction: We describe the utilisation of precipitation polymerisation of poly (N-isopropylacrylamide) (pNIPAM) at the surface of dispersed Laponite® platelets that resist aggregation and can be maintained for long periods of time as a low viscosity liquid. Whilst in this colloidal liquid state, live cells, small molecules or particles can easily be incorporated. Upon cooling to body temperature the pNIPAM chains spontaneously transform to the 'coil' conformation, establishing multiple physical interactions and leading to irreversible gel formation without further addition of reagents (Fig 1), indicating it is an ideal platform for numerous tissue regeneration applications. Typically aqueous pNIPAM solutions are free-flowing liquids at room temperature and upon heating above ~32oC they form weak gels. The incorporation of a crosslinker increases the mechanical strength of the gel but the material ceases to be a liquid at lower temperatures and cannot easily be injected. Here we show how the incorporation of different triggers into the hydrogel via the use of a suitable comonomer and/or the incorporation of additives such as hydroxyapatite can induce differentiation of human mesenchymal stem cells (hMSC) into bone, disc or cartilage dependant on target tissue. Methods: pNIPAM-Laponite® hydrogels were synthesised and the incorporation of comonomers and guest molecules were investigated to determine effects on setting temperature, mechanical properties and cellular behaviour. MSCs were incorporated in hydrogels with or without hydroxyapatite and investigated under hypoxic conditions to investigate differentiation towards osteoblasts and nucleus pulposus cells of the intervertebral disc. Results and Discussion: The solidified, mechanically robust pNIPAM-Laponite® hydrogels were shown to be fully biocompatible without the usual need for any purification steps and could be tailored to mechanically mimic a range of natural tissue types via the choice of comonomer and/or the incorporation of additives such as hyaluronic acid, hydroxyapatite. Tailored differentiation to osteoblast like cells or nucleus pulposus cells was successfully achieved over a 6 week time course, with appropriate deposition of matrix and marker expression (Fig 2). Conclusions: The relative simplicity and clinical convenience of the hydrogel synthesis method described here could provide an effective and minimally-invasive treatment platform for orthopaedic regenerative medicine. The ability to uniformly incorporate cells and other additives prior to injection and gelation opens up an extensive range of biological opportunities. In particular, the inherent low viscosity of the colloidal hydrogel enables application through fine bore needles minimising damage to the target tissues and enabling the hydrogel to fill micro fissures, which is not currently possible with existing hydrogel systems. The authors would like to thank EPSRC (EP/H000275/1, EP/I016473/1) for funding. Keywords: Cell Differentiation, Hydrogel, Regenerative Medicine, 3D scaffold Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: New Frontier Oral Topic: Regenerative medicine: biomaterials for control of tissue induction Citation: Thorpe A, Le Maitre CL and Sammon C (2016). Injectable platform hydrogel for musculoskeletal regeneration. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.00672 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Abbey Thorpe Christine L Le Maitre Chris Sammon Google Abbey Thorpe Christine L Le Maitre Chris Sammon Google Scholar Abbey Thorpe Christine L Le Maitre Chris Sammon PubMed Abbey Thorpe Christine L Le Maitre Chris Sammon Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.