Accession Number : ADA614821


Title :   Space Maintenance and New Bone Formation with Polyurethane Biocomposites in a Canine Saddle Defect


Descriptive Note : Abstract


Corporate Author : ARMY INST OF SURGICAL RESEARCH FORT SAM HOUSTON TX


Personal Author(s) : Talley, A D ; Kalpaci, K A ; Zienkiewicz, K J ; Wenke, J C ; Guelcher, S A


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a614821.pdf


Report Date : 01 May 2014


Pagination or Media Count : 2


Abstract : Large mandibular defect reconstruction presents a continual challenge in oral and maxillofacial surgery. Growth factors such as recombinant human bone morphogenetic protein-2 (rhBMP-2) incorporated in scaffolds for tissue engineering promote cellular infiltration, induce osteoblast differentiation, and enhance new bone formation. Biodegradable polyurethane (PUR) biocomposites containing allograft bone particles are reported to be effective carriers for rhBMP-2 and support new bone growth.1 Moreover, incorporation of allograft bone particles increases the mechanical properties of the graft, which is important for space maintenance in mandibular defects. However, allograft presents biological challenges, as even a low dose of rhBMP-2 combined with allograft can result in transient resorption.2 Additionally, combining recombinant human growth factor with allograft bone introduces regulatory concerns. Mastergraft (MG) is an osteoconductive, biphasic ceramic composed of 85% -tricalcium phosphate ( -TCP) and 15% hydroxyapatite (HA) that is similar in mineral content to natural bone.3 45S5 Bioactive glass (BG) is a resorbable material that has been used effectively in a variety of bone regeneration applications.4 In the present study, we investigated the ability of injectable PUR/MG and PUR/BG biocomposites with two doses of rhBMP-2 to heal saddle defects in the canine mandible. Methods: The biodegradable polyurethane was synthesized from a lysine triisocyanate (LTI) and polyethylene glycol (PEG) prepolymer, a polyester triol (450 g/mol), and triethylene diamine catalyst. Treatment groups included the biocomposite containing 45% MG or 45% BG with a low dose of 100 g/mL rhBMP-2 or a high dose of 400 g/mL rhBMP-2 (n=4/group). The lyophilized rhBMP-2 was hand-mixed with the PUR and injected into saddle defects (4/animal) measuring approximately 7-8 mm apicocoronal by 8-10 mm mesiodistal.


Descriptors :   *COMPOSITE MATERIALS , *MANDIBLE , *SURGICAL TRANSPLANTATION , CERAMIC MATERIALS , DOGS , GLASS , POLYURETHANE RESINS , PROTEINS


Subject Categories : Anatomy and Physiology
      Medicine and Medical Research
      Laminates and Composite Materials


Distribution Statement : APPROVED FOR PUBLIC RELEASE