title: Linking of bone morphogenetic protein-2 to resorbable fracture plates for enhancing bone healing.
abstract: OBJECTIVE
  To test whether bone morphogenetic protein (BMP)-2 may be covalently linked to resorbable fracture repair plates using an ester-hydrolysis reaction and determining whether the linked compound can facilitate bone growth.
  
  
  METHODS
  Laboratory in vitro experiments.
  
  
  METHODS
  Resorbable fracture repair plates were partially hydrolyzed using varying concentrations of acid or base. This intermediate was then reacted with EDAC (1-ethyl-3[-3-dimethylamino propyl carbodiimide) to form an EDAC intermediate, which was then reacted with either horseradish peroxidase (HRP), interleukin (IL)-2, or BMP-2. Compound binding to the plate was confirmed by immunofluorescent staining. Confirmation of protein function was determined by the following assays: HRP's ability to cleave peroxide, IL-2's ability to stimulate lymphocytes, and BMP-2's ability to stimulate C3H10T1/2 cells to generate alkaline phosphatase.
  
  
  RESULTS
  Three compounds (HRP, IL-2, and BMP-2) were successfully linked to plates as confirmed by immunofluorescence staining or functional testing. Compounds demonstrated better covalent linking to plates under basic conditions. HRP, IL-2, and BMP-2 retained function after binding as measured by cleaved peroxide levels, lymphocytes proliferation, and alkaline phosphatase production.
  
  
  CONCLUSIONS
  Covalent linking of compounds such as HRP, IL-2, and BMP-2 to resorbable plates is possible and represents a novel protein delivery technique. BMP-2 covalently linked to resorbable plates may be used to facilitate bone healing. Covalent linking of compounds to plates represents a novel method for delivering concentrated levels of growth factors to a specific site and potentially extending their half-life. Further investigation into this application for bone healing may lead to quicker healing.
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, University of California Irvine School of Medicine, Orange, California 92868, USA. tshibuya@uci.edu
authors.forename: Terry Y
authors.initials: TY
authors.lastname: Shibuya
authors.forename: Ashish
authors.initials: A
authors.lastname: Wadhwa
authors.forename: Kevin H
authors.initials: KH
authors.lastname: Nguyen
authors.forename: Abraham M
authors.initials: AM
authors.lastname: Panossian
authors.forename: Sanghun
authors.initials: S
authors.lastname: Kim
authors.forename: Hausin
authors.initials: H
authors.lastname: Wong
authors.forename: Steven
authors.initials: S
authors.lastname: Feinberg
authors.forename: Eyiyemisi C
authors.initials: EC
authors.lastname: Damisah
authors.forename: P Ryan
authors.initials: PR
authors.lastname: Camilon
authors.forename: Hoang
authors.initials: H
authors.lastname: Bang
mesh_terms: D020341:Absorbable Implants; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000378:metabolism* / Q000627:therapeutic use; D001860:Bone Plates; D005147:Facial Bones / Q000293:injuries; D017102:Fracture Healing / Q000502:physiology*; D006735:Horseradish Peroxidase / Q000378:metabolism / Q000627:therapeutic use; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism / Q000627:therapeutic use; D012887:Skull Fractures / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D046509:Tissue Culture Techniques; D016212:Transforming Growth Factor beta / Q000378:metabolism* / Q000627:therapeutic use
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D007376:Interleukin-2; D016212:Transforming Growth Factor beta; D006735:Horseradish Peroxidase