title: Biological Treatment Approaches for Degenerative Disk Disease: A Literature Review of In Vivo Animal and Clinical Data.
abstract: METHODS
  Literature review.
  
  
  OBJECTIVE
  Degenerative disk disease (DDD) has a negative impact on quality of life and is a major cause of morbidity worldwide. There has been a growing interest in the biological repair of DDD by both researchers and clinicians alike. To generate an overview of the recent progress in reparative strategies for the treatment of DDD highlighting their promises and limitations, a comprehensive review of the current literature was performed elucidating data from in vivo animal and clinical studies.
  
  
  METHODS
  Articles and abstracts available in electronic databases of PubMed, Web of Science, and Google Scholar as of December 2014 were reviewed. Additionally, data from unpublished, ongoing clinical trials was retrieved from clinicaltrials.gov and available abstracts from research forums. Data was extracted from the most recent in vivo animal or clinical studies involving any of the following: (1) treatment with biomolecules, cells, or tissue-engineered constructs and (2) annulus fibrosus repair.
  
  
  RESULTS
  Seventy-five articles met the inclusion criteria for review. Among these, 17 studies involved humans; 37, small quadrupeds; and 21, large quadrupeds. Findings from all treatments employed demonstrated improvement either in regenerative capacity or in pain attenuation, with the exception of one clinical study.
  
  
  CONCLUSIONS
  Published clinical studies on cell therapy have reported encouraging results in the treatment of DDD and resultant back pain. We expect new data to emerge in the near future as treatments for DDD continue to evolve in parallel to our greater understanding of disk health and pathology.
authors.affiliation: Weill Cornell Brain and Spine Center, Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, United States.
authors.forename: Yu
authors.initials: Y
authors.lastname: Moriguchi
authors.affiliation: Weill Cornell Brain and Spine Center, Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, United States.
authors.forename: Marjan
authors.initials: M
authors.lastname: Alimi
authors.affiliation: Weill Cornell Brain and Spine Center, Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, United States.
authors.forename: Thamina
authors.initials: T
authors.lastname: Khair
authors.affiliation: Weill Cornell Brain and Spine Center, Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, United States.
authors.forename: George
authors.initials: G
authors.lastname: Manolarakis
authors.affiliation: Weill Cornell Brain and Spine Center, Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, United States.
authors.forename: Connor
authors.initials: C
authors.lastname: Berlin
authors.affiliation: Department of Biomedical Engineering, Cornell University, Ithaca, New York, United States.
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Bonassar
authors.affiliation: Weill Cornell Brain and Spine Center, Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, New York, United States.
authors.forename: Roger
authors.initials: R
authors.lastname: Härtl
keywords: annular repair; back pain; cell therapy; disk regeneration; growth factor; intervertebral disk; platelet-rich plasma; tissue engineering