Engineering personalized constructs for intervertebral disc regeneration

Lower Back Pain associated to intervertebral disc (IVD) degeneration is estimated to affect up to 80% of the population at some time in their lives, presenting a huge socio-economic impact in industrialized countries, since it is one of the main causes of medical visits, work absenteeism and hospitalization (1). One possible strategy addresses total IVD substitution/regeneration which should comprise personalized approaches by means of using reverse engineering, i.e. combining imaging techniques (e.g. MRI and micro-CT) and 3Dbioprinting technology. The implantation of custom-made implants closely mimicking native IVD and possessing an appropriate size, shape, mechanical performance, and biodegradability can improve recovery time after surgery and help to restore spine biofunctionality. Hydrogels have become especially attractive as matrices for developing a wide variety of tissue engineered tissues and organs (2). Nevertheless, one of the main disadvantages of processing hydrogels is the difficulty to shape them in predesigned geometries even when Rapid Prototyping technologies are used. The difficulties are mostly related with the difficulty in controlling the gelation event. In this work, a two-stage strategy is proposed. In the first stage, human IVD datasets (MRI or CT) are adequately analyzed for developing accurate 3D models that mimic the native IVD sub-compartments. In the second stage, 3D anatomical scaffolds are printed and characterized thoroughly in vitro, in terms of physico-chemical, mechanical and biological performances.