title: The paths of musculoskeletal scaffold research leading to long-term effects.
abstract: OBJECTIVE
  Developing successful musculoskeletal scaffolds for specific tissue replacement has many challenges. Ideal scaffolds support the physiologic needs of the ingrowth tissue until new cells establish a matrix approximating the biomechanical properties of the original tissue or organ construct. Short- and long-term effects on matrix formation and surrounding tissue are critical for clinical applications.
  
  
  METHODS
  This is a review of scaffold development of alginate, fibrin, and poly glycolic and polylactic acid scaffolds by three laboratories.
  
  
  RESULTS
  Varied chain structures of alginate modified with an RGD-containing peptide sequence (G4RGDY) promotes cell multiplication. Given the proper mix of chain size and radiation used to reduce chain size, the adjusted rate of degradation showed no long-term effect at 21 weeks in vitro. To date, there are no long-term fibrin-based scaffold constructs. Plasmid DNA-laden 75:25 PLGA microspheres were able to have the microsphere incorporated into the polymer solution, resulting in sustained plasmid DNA release for more than 70 days without significant surrounding tissue effects.
  
  
  CONCLUSIONS
  Years of research on the same construct are required before long-term effects of tissue engineering scaffolds can be determined.
authors.affiliation: Department of Orthopaedics, Henry Ford Hospital, Dearborn, MI 48202, USA.
authors.forename: Fred R T
authors.initials: FR
authors.lastname: Nelson
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D005337:Fibrin / Q000737:chemistry*; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D009141:Musculoskeletal System; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D005337:Fibrin