title: A photopolymerized composite hydrogel and surgical implanting tool for a nucleus pulposus replacement.
abstract: Nucleus pulposus replacements have been subjected to highly controversial discussions over the last 40 years. Their use has not yet resulted in a positive outcome to treat herniated disc or degenerated disc disease. The main reason is that not a single implant or tissue replacement was able to withstand the loads within an intervertebral disc. Here, we report on the development of a photo-polymerizable poly(ethylene glycol)dimethacrylate nano-fibrillated cellulose composite hydrogel which was tuned according to native tissue properties. Using a customized minimally-invasive medical device to inject and photopolymerize the hydrogel insitu, samples were implanted through an incision of 1 mm into an intervertebral disc of a bovine organ model to evaluate their long-term performance. When implanted into the bovine disc model, the composite hydrogel implant was able to significantly re-establish disc height after surgery (p < 0.0025). The height was maintained after 0.5 million loading cycles (p < 0.025). The mechanical resistance of the novel composite hydrogel material combined with the minimally invasive implantation procedure into a bovine disc resulted in a promising functional orthopedic implant for the replacement of the nucleus pulposus.
authors.affiliation: Laboratory of Biomechanical Orthopedics, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland; Laboratory of Applied Photonics Devices, Institute of Microengineering, EPFL, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schmocker
authors.affiliation: Laboratory of Biomechanical Orthopedics, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland; Laboratory of Polymer and Composite Technology, Institute of Materials, EPFL, Switzerland.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Khoushabi
authors.affiliation: Tissue and Organ Mechanobiology, Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland.
authors.forename: Daniela A
authors.initials: DA
authors.lastname: Frauchiger
authors.affiliation: Tissue and Organ Mechanobiology, Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Gantenbein
authors.affiliation: Centre Hospitalier Universitaire Vaudois, Orthopedic Department, Lausanne, Switzerland.
authors.forename: Constantin
authors.initials: C
authors.lastname: Schizas
authors.affiliation: Laboratory of Applied Photonics Devices, Institute of Microengineering, EPFL, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Moser
authors.affiliation: Laboratory of Polymer and Composite Technology, Institute of Materials, EPFL, Switzerland.
authors.forename: Pierre-Etienne
authors.initials: PE
authors.lastname: Bourban
authors.affiliation: Laboratory of Biomechanical Orthopedics, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland. Electronic address: dominique.pioletti@epfl.ch.
authors.forename: Dominique P
authors.initials: DP
authors.lastname: Pioletti
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002417:Cattle; D002482:Cellulose / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D020007:Implants, Experimental; D007403:Intervertebral Disc / Q000601:surgery*; D055959:Intervertebral Disc Degeneration / Q000601:surgery*; D008027:Light; D008689:Methacrylates / Q000737:chemistry*; D019060:Minimally Invasive Surgical Procedures; D057139:Nanofibers / Q000737:chemistry; D000070614:Nucleus Pulposus / Q000601:surgery*; D011092:Polyethylene Glycols / Q000737:chemistry*; D058105:Polymerization
chemical_list: D001672:Biocompatible Materials; D008689:Methacrylates; C421283:poly(ethylene glycol)-dimethacrylate; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols; D002482:Cellulose
keywords: Medical device; Minimally invasive surgery; Nano-cellulose fibers; Orthopedic implant; Photopolymerization; poly(ethylene-glycol)dimethacrylate