biostudies-literatureDeBaun MROREFUS Department of DefenseNIAMS NIH HHSNIH1368-1374https://www.ebi.ac.uk/biostudies/studies/S-EPMC8940692biostudies-literatureUnknown53(4)<h4>Objectives</h4>High energy long bone fractures with critical bone loss are at risk for nonunion without strategic intervention. We hypothesize that a synthetic membrane implanted at a single stage improves bone healing in a preclinical nonunion model.<h4>Methods</h4>Using standard laboratory techniques, microspheres encapsulating bone morphogenic protein-2 (BMP2) or platelet derived growth factor (PDGF) were designed and coupled to a type 1 collagen sheet. Critical femoral defects were created in rats and stabilized by locked retrograde intramedullary nailing. The negative control group had an empty defect. The induced membrane group (positive control) had a polymethylmethacrylate spacer inserted into the defect for four weeks and replaced with a bare polycaprolactone/beta-tricalcium phosphate (PCL/β-TCP) scaffold at a second stage. For the experimental groups, a bioactive synthetic membrane embedded with BMP2, PDGF or both enveloped a PCL/β-TCP scaffold was implanted in a single stage. Serial radiographs were taken at 1, 4, 8, and 12 weeks postoperatively from the definitive procedure and evaluated by two blinded observers using a previously described scoring system to judge union as primary outcome.<h4>Results</h4>All experimental groups demonstrated better union than the negative control (p = 0.01). The groups with BMP2 incorporated into the membrane demonstrated higher average union scores than the other groups (p = 0.01). The induced membrane group performed similarly to the PDGF group. Complete union was only demonstrated in groups with BMP2-eluting membranes.<h4>Conclusions</h4>A synthetic membrane comprised of type 1 collagen embedded with controlled release BMP2 improved union of critical bone defects in a preclinical nonunion model.InjuryA bioactive synthetic membrane improves bone healing in a preclinical nonunion model.PMC8940692R01 AR074458R01AR072613R01 AR057837R01AR057837U01AR069395U01 AR069395W81XWH18SBAA1- BA180237R01 AR072613R01AR074458Lui EKim CDeBaun MRLin SBai YStahl AMPan CCKim SGardner MJSalazar BPStanford iTEAM groupYang YPMoeinzadeh SWadhwa HGoodnough LHfalseA bioactive synthetic membrane improves bone healing in a preclinical nonunion model.<h4>Objectives</h4>High energy long bone fractures with critical bone loss are at risk for nonunion without strategic intervention. We hypothesize that a synthetic membrane implanted at a single stage improves bone healing in a preclinical nonunion model.<h4>Methods</h4>Using standard laboratory techniques, microspheres encapsulating bone morphogenic protein-2 (BMP2) or platelet derived growth factor (PDGF) were designed and coupled to a type 1 collagen sheet. Critical femoral defects were created in rats and stabilized by locked retrograde intramedullary nailing. The negative control group had an empty defect. The induced membrane group (positive control) had a polymethylmethacrylate spacer inserted into the defect for four weeks and replaced with a bare polycaprolactone/beta-tricalcium phosphate (PCL/β-TCP) scaffold at a second stage. For the experimental groups, a bioactive synthetic membrane embedded with BMP2, PDGF or both enveloped a PCL/β-TCP scaffold was implanted in a single stage. Serial radiographs were taken at 1, 4, 8, and 12 weeks postoperatively from the definitive procedure and evaluated by two blinded observers using a previously described scoring system to judge union as primary outcome.<h4>Results</h4>All experimental groups demonstrated better union than the negative control (p = 0.01). The groups with BMP2 incorporated into the membrane demonstrated higher average union scores than the other groups (p = 0.01). The induced membrane group performed similarly to the PDGF group. Complete union was only demonstrated in groups with BMP2-eluting membranes.<h4>Conclusions</h4>A synthetic membrane comprised of type 1 collagen embedded with controlled release BMP2 improved union of critical bone defects in a preclinical nonunion model.2022-01-01T00:00:00Z2022 Apr2025-04-19T13:29:46.73Z2025-02-19T01:14:05.703ZS-EPMC89406923507861710.1016/j.injury.2022.01.015