title: Polyethylene glycol improves elution properties of polymethyl methacrylate bone cements.
abstract: BACKGROUND
  Bone cements are used as adjuncts to fracture fixation methods and can also function as a local drug delivery system. The ability to elute drugs makes bone cement a promising and powerful chemotherapy treatment modality for osseous tumors. However, because of poor elution rates, the clinical application of this drug delivery mode remains challenging. Soluble fillers, such as sugars, salts, or biocompatible polymers, offer a solution to improve elution rates. This study quantified the effect of polyethylene glycol (PEG) on the elution properties of three commercially available bone cements.
  
  
  METHODS
  Two grams of Vertebroplastic, Palacos, and Confidence bone cement powder containing three concentrations (0%, 20%, or 50%) of PEG filler were hand mixed with 10 mg of methotrexate. This powder mixture was then polymerized with 1.0 mL of the cement specific liquid monomer. The cylindrical elution samples were placed in saline solution and methotrexate elution was recorded for 720 h.
  
  
  RESULTS
  The cumulative and daily elution rate increased as the concentration of PEG increased for each bone cement. However, the percent of increase depended on the bone cement used. Cumulative methotrexate elution increased by 40%-54% in case of the highest PEG filler concentration when compared with controls.
  
  
  CONCLUSIONS
  PEG soluble filler offers a promising method for improving methotrexate drug elution in bone cement. Future studies need to optimize the PEG and bone cement ratio that produces the greatest drug elution profile without sacrificing the biomechanical properties of bone cement.
authors.affiliation: Department of Orthopedic Surgery, Einstein Medical Center, Philadelphia, Pennsylvania. Electronic address: handalj@einstein.edu.
authors.forename: John A
authors.initials: JA
authors.lastname: Handal
authors.affiliation: Department of Orthopedic Surgery, Einstein Medical Center, Philadelphia, Pennsylvania.
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Tiedeken
authors.affiliation: Department of Orthopedic Surgery, Einstein Medical Center, Philadelphia, Pennsylvania.
authors.forename: Grigory E
authors.initials: GE
authors.lastname: Gershkovich
authors.affiliation: Department of Internal Medicine, Largo Medical Center, Largo, Florida.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kushner
authors.affiliation: Family Medicine, Forbes Hospital, Monroeville, Pennsylvania.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dratch
authors.affiliation: Department of Orthopedic Surgery, Einstein Medical Center, Philadelphia, Pennsylvania.
authors.forename: Solomon P
authors.initials: SP
authors.lastname: Samuel
mesh_terms: D001843:Bone Cements; D016503:Drug Delivery Systems; D008727:Methotrexate / Q000008:administration & dosage*; D011092:Polyethylene Glycols / Q000494:pharmacology*; D019904:Polymethyl Methacrylate / Q000737:chemistry*
chemical_list: D001843:Bone Cements; D011092:Polyethylene Glycols; D019904:Polymethyl Methacrylate; D008727:Methotrexate
keywords: Bone cement; Chemotherapy; Methotrexate; Porogen; Soluble fillers