title: The effect of poloxamer 407-based hydrogel on the osteoinductivity of demineralized bone matrix.
abstract: BACKGROUND
  Demineralized bone matrix (DBM) is used for bone healing due to its osteoinductivity, but it requires a carrier for clinical application. Here, we report the effects on the osteoinductivity of DBM by use of a poloxamer 407-based hydrogel as the carrier, compared to sterile water.
  
  
  METHODS
  DBM-W and DBM-H represent 27 wt% of DBM with sterile water and DBM with a poloxamer 407-based hydrogel, respectively. Both of the compositions were applied to human mesenchymal stem cell (MSC) cultures, and monitored for alkaline phosphatase (ALP) staining and ALP activity. Six 10-week-old athymic nude rats were used for abdominal muscle grafting with either DBM-W or DBM-H, and were tested by plane radiography, microfocus X-ray computed tomography (CT), and decalcified histology to evaluate ectopic bone formation.
  
  
  RESULTS
  The DBM-W group showed stronger ALP staining at 7, 14, and 21 days of treatment, and significantly higher ALP activity at 7 and 14 days of treatment, compared to the DBM-H group. Plane radiography could not confirm the radio-opaque lesions in the rat ectopic bone formulation model. However, ectopic bone formation was observed in both groups by micro-CT. Compared to the DBM-H group, the DBM-W group showed higher bone volume, percent bone volume and trabecular number, and the difference in percent bone volume was statistically significant. Decalcified histology found bony tissue with lamellation in both groups.
  
  
  CONCLUSIONS
  Our results suggest that poloxamer 407-based hydrogel has efficacy as a DBM carrier since it shows ectopic bone formation, but its effects on the quality and quantity of osteoblastic differentiation in rat abdominal ectopic bone and MSC are considered negative.
authors.affiliation: Department of Orthopedic Surgery, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea. ; Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University, Seoul, Korea.
authors.forename: Jae Hyup
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Institute of Medical and Biological Engineering, Medical Research Center, Seoul National University, Seoul, Korea.
authors.forename: Hae-Ri
authors.initials: HR
authors.lastname: Baek
authors.affiliation: Department of Orthopedic Surgery, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyung Mee
authors.initials: KM
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyun-Kyung
authors.initials: HK
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seung Bin
authors.initials: SB
authors.lastname: Im
authors.affiliation: Department of Orthopedic Surgery, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yong Sung
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ji-Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Bong-Soon
authors.initials: BS
authors.lastname: Chang
authors.affiliation: Department of Orthopedic Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Choon-Ki
authors.initials: CK
authors.lastname: Lee
mesh_terms: D000818:Animals; D001857:Bone Matrix / Q000502:physiology*; D018929:Cell Culture Techniques; D003648:Decalcification Technique; D005079:Excipients / Q000494:pharmacology*; D020100:Hydrogels / Q000494:pharmacology; D008297:Male; D059630:Mesenchymal Stem Cells / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects*; D020442:Poloxamer / Q000494:pharmacology*; D051381:Rats; D011923:Rats, Nude
chemical_list: D005079:Excipients; D020100:Hydrogels; D020442:Poloxamer
keywords: Carrier; Demineralized bone matrix; Osteoinductivity; Poloxamer 407-based hydrogel