In Vivo Evaluation of Commercially Available Gel-Type Polyethylene Glycol Membrane for Carrier of Recombinant Human Bone Morphogenetic Protein-2.
OBJECTIVE
This study evaluated a commercially available, 3-dimensional gel-type polyethylene glycol (PEG) membrane as a carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2) using a rat calvarial defect model. Another gel-type carrier, fibrin-fibronectin system (FFS), was used as a positive control.


METHODS
Critical-size defects were made in the rat calvarium, which were allocated to 1 of 10 groups comprising 2 healing periods and biomaterial conditions: 1) sham control, 2) FFS only, 3) FFS plus BMP-2, 4) PEG only, and 5) PEG plus BMP-2. Radiographic and histologic analyses were performed at 2 and 8 weeks after surgery.


RESULTS
After 2 weeks, some parts of the FFS were biodegraded and extensive cellular infiltration was observed at sites that received FFS or FFS plus BMP-2. The PEG membrane retained its augmented volume without cellular infiltration at sites that received PEG or PEG plus BMP-2. After 8 weeks, the FFS was completely degraded and replaced by new bone and connective tissues. In contrast, the volume of residual PEG was similar to that at 2 weeks, with slight cellular infiltration. In particular, there was progressive bone regeneration around micro-cracks and resorbed outer surface in the PEG + BMP-2 group. Although the PEG + BMP-2 group showed increased area and percentage of new bone, there was no statistical relevance after 2 and 8 weeks in histomorphometric analyses. However, the appearance of the healing differed (with new bone formation along micro-cracks in the PEG + BMP-2 group), and further studies with longer healing periods are needed to draw conclusions about clinical applications.


CONCLUSIONS
Evidence of mechanical stability and new bone formation along micro-cracks when using PEG plus BMP-2 might support the PEG membrane as a candidate carrier material for rhBMP-2.
PhD Student, Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Korea.
Ji-Woong
JW
Jang
Clinical Assistant Professor, Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Korea.
Jung-Seok
JS
Lee
Associate Professor, Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Korea.
Ui-Won
UW
Jung
Professor and Department Head, Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Korea.
Chang-Sung
CS
Kim
Professor, Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Korea. Electronic address: KSCHO@yuhs.ac.
Kyoo-Sung
KS
Cho
D000818:Animals; D001846:Bone Development / Q000187:drug effects; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage*; D004337:Drug Carriers / Q000008:administration & dosage*; D005782:Gels / Q000008:administration & dosage; D008297:Male; D008567:Membranes, Artificial; D011092:Polyethylene Glycols / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000008:administration & dosage; D012886:Skull / Q000000981:diagnostic imaging / Q000187:drug effects / Q000254:growth & development / Q000293:injuries*; D016212:Transforming Growth Factor beta / Q000008:administration & dosage*; D055114:X-Ray Microtomography
D055396:Bone Morphogenetic Protein 2; D004337:Drug Carriers; D005782:Gels; D008567:Membranes, Artificial; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D011092:Polyethylene Glycols