Demineralized Bone Matrix Group Research Articles

Histopathological Evaluation of Eggshell and DBM Combination on the Repair of Critical Size Experimental Calvarial Bone Defects in Rats.

Fracture repair is a constant clinical challenge, and finding a method to promote and improve restoration is a primary goal for researchers. This is examined from various perspectives, such as fewer complications, increased speed, and cost-effectiveness. The present study aimed to investigate the effectiveness of eggshell powder, compared to the commercial form of demineralized bone matrix (DBM), in critical-size defects in rat calvarial bone. In this study, 40 adult male Wistar rats were selected and randomly divided into four groups of 10. The first group was the control group (C), the second was the eggshell powder group (E), the third was the DBM group (D), and the fourth was the one simultaneously receiving eggshell powder and DBM (DE). In these groups, a 5 mm diameter defect was created in the calvaria using a trephine. All animals received the appropriate treatment for their group. Each group was then divided into two subgroups of five. On days 30 and 60 post-surgery, these subgroups were euthanized, followed by sampling and histopathology examinations. After evaluating the repair percentage using Quick Photo software, the DE group had the highest repair percentage on days 30 and 60. Groups E and D had similar recovery percentages, with group D having a slightly higher one. There was a significant difference between all three groups and the control group. In conclusion, eggshell powder may potentially serve as a suitable substitute for some transplants.

Content of bone morphogenetic protein 2 in demineralized bone matrix prepared from different long bones and study of the osteogenic properties in vitro

To measure the concentration of bone morphogenetic protein 2 (BMP-2) in demineralized bone matrix (DBM) prepared from different long bones and to evaluate the osteoinductivity of different DBM on MC3T3-E1 cells. Different bones from the same cadaver donor were used as the initial materials for making DBM, which were divided into ulna group (uDBM), humerus group (hDBM), tibia group (tDBM), and femur group (fDBM) according to the origins, and boiled DBM (cDBM) was taken as the control group. The proteins of DBM were extracted by guanidine hydrochloride, and the concentrations of BMP-2 were determined by ELISA assay. Then the DBM were co-cultured with MC3T3-E1 cells, the proliferation of MC3T3-E1 cells was observed by cell counting kit 8 (CCK-8) assay. The osteogenic differentiation ability of MC3T3-E1 cells was qualitatively observed by alizarin red, alkaline phosphatase (ALP), and Van Gieson staining, and the osteogenic differentiation ability of MC3T3-E1 cells was quantitatively analyzed by ALP content. Linear regression was used to analyze the effect of BMP-2 concentration in DBM on ALP synthesis. There were significant differences in the concentration of BMP-2 among the DBM groups (P<0.05). The concentrations of BMP-2 in the lower limb long bone were higher than those in the upper limb long bone, and the concentration of BMP-2 in the fDBM group was about 35.5 times that in the uDBM group. CCK-8 assay showed that the cells in each group continued to proliferate within 5 days of co-culture, and the absorbance (A) values at different time points were in the order of cDBM group<uDBM group<hDBM group<tDBM group<fDBM group. After co-culture for 14 days, the expressions of ALP, calcified nodules, and collagen fibers in each group were consistent with the distribution of BMP-2 concentration in DBM. The order of ALP content from low to high was cDBM group<uDBM group<hDBM group<tDBM group<fDBM group, and the differences between the groups were significant (P<0.05). Linear regression analysis showed that =0.361+0.017x, the effect of BMP-2 concentration in DBM on cellular ALP content was significant (t=3.552, P=0.005); for every 1 ng/g increase in BMP-2 concentration, ALP content would increase by 0.017 [95%CI (0.006, 0.027)] U/100 mL. The concentration of natural BMP-2 in different long bones varies greatly, and the lower limb long bone is higher than the upper limb long bone. The harvested location of bone material was an important factor affecting the osteoinductivity of DBM.

Use of biphasic calcium phosphate versus demineralized bone matrix: retrospective clinical and CT analysis of posterolateral fusion results.

Bone graft extenders have been developed to prevent donor site morbidity associated with iliac crest bone graft, but few studies compared the efficacy of various substitutes. Our purpose was to determine fusion rate and clinical outcome in patients undergoing lumbar arthrodesis using demineralized bone matrix (DBM) and biphasic calcium phosphate (BCP). Patients with degenerative spondylolisthesis undergoing one-level or two-level arthrodesis of lumbar spine were retrospectively reviewed. Two treatment groups placed either BCP or DBM, in addition to local autograft in lumbar posterolateral space. Three-dimensional CT exam and dynamic flexion-extension radiographs at postoperative 2-year were assessed for posterolateral fusion status and pain scale and Oswestry Disability Index (ODI) for clinical outcome. Of the 148 patients reviewed (including 23 in one- and 58 patients in two-level in BCP group, and 47 in one- and 20 patients in two-level in DBM group), no significant differences were found in terms of age, sex, BMI, smoking, diabetes, steroids, number of level fused, non-union rate or revision surgery between BCP and DBM groups. Significantly improved pain scale of back and leg and ODI were found in both groups postoperatively without group difference. We found a comparable fusion rate in one-level surgery (100% versus 93.6%) and a superior fusion rate of BCP group in two-level surgery (98.3% versus 80.0%, p = 0.01). Being a bone graft extender without osteoinductive property, with local autograft, BCP is comparable to DBM for one- and superior for two-level fusion. No significant difference was found in clinical outcomes.

Comparative Analysis of ABM/P-15, Bone Morphogenic Protein and Demineralized Bone Matrix after Instrumented Lumbar Interbody Fusion.

ABM/P-15 (anorganic bone matrix/15-amino acid peptide fragment) is a commercially available synthetically manufactured P-15 collagen peptide fragment, that is adsorbed on ABM. This study was done to investigate the efficacy of ABM/ P-15 in achieving fusion in the lumbar spine and comparing it with that of recombinant bone morphogenic protein-2 (rhBMP-2) and demineralized bone matrix (DBM). A retrospective observational study of prospectively collected data of 140 patients who underwent lumbar spinal fusion surgeries in a single specialty spine hospital between 2016 and 2020, with a minimum 6-month follow-up was conducted. Based on the material used for the augmentation of the bone graft at the fusion site, the patients were divided into three categories namely ABM/P-15, rhBMP-2, and DBM group. ABM/P-15, rhBMP-2, and DBM were used in 46, 44, and 50 patients, respectively. Patient characteristics like age, gender, bone mineral density, smoking history, and presence of diabetes mellitus were comparable amongst the three groups. Average follow-up was 16.0±5.2, 17.9±9.8, and 26.2±14.9 months, respectively in ABM/P-15, rhBMP-2, and DBM groups. The fusion was achieved in 97.9%, 93.2%, and 98% patients while the average time-to-union was 4.05±2.01, 10±4.28, and 9.44±3.49 months (p<0.001), respectively for ABM/P-15, rhBMP-2, and DBM groups. The average pre-operative Visual analogue scale score was 6.93±2.42, 7.14±1.97, 7.01±2.14 (p=0.900) for ABM/P-15, rhBMP-2 and DBM groups, respectively, which reduced to 1.02±0.80, 1.21±0.96, and 0.54±0.70 (p=0.112), respectively at the last follow up. Pre-operative Oswestry disability index scores were 52.7±18.02, 55.4±16.8, and 53.56±19.6 (p=0.751) in ABM/P-15, rhBMP-2, and DBM groups, which post-operatively reduced to 33.77±15.52, 39.42±16.47, and 38.3±15.89 (p=0.412) and further to 15.74±8.3, 17.41±10.45, and 16.76±9.81 (p=0.603), respectively at the last follow-up. ABM/P-15 appears to achieve union significantly earlier than rhBMP-2 and DBM in lumbar spinal fusion cases while maintaining a comparable clinical and complication profile.

Effect of Demineralized Bone Matrix, Bone Marrow Mesenchymal Stromal Cells, and Platelet-Rich Plasma on Bone Tunnel Healing After Anterior Cruciate Ligament Reconstruction: A Comparative Micro-Computed Tomography Study in a Tendon Allograft Sheep Model

Background:The effect of demineralized bone matrix (DBM), bone marrow–derived mesenchymal stromal cells (BMSCs), and platelet-rich plasma (PRP) on bone tunnel healing in anterior cruciate ligament reconstruction (ACLR) has not been comparatively assessed.Hypothesis:These orthobiologics would reduce tunnel widening, and the effects on tunnel diameter would be correlated with tunnel wall sclerosis.Study Design:Controlled laboratory study.Methods:A total of 20 sheep underwent unilateral ACLR using tendon allograft and outside-in interference screw fixation. The animals were randomized into 4 groups (n = 5 per group): Group 1 received 4mL of DBM paste, group 2 received 10 million BMSCs in fibrin sealant, group 3 received 12 mL of activated leukocyte-poor platelet-rich plasma, and group 4 (control) received no treatment. The sheep were euthanized after 12 weeks, and micro-computed tomography scans were performed. The femoral and tibial tunnels were divided into thirds (aperture, midportion, and exit), and the trabecular bone structure, bone mineral density (BMD), and tunnel diameter were measured. Tunnel sclerosis was defined by a higher bone volume in a 250-µm volume of interest compared with a 4-mm volume of interest surrounding the tunnel.Results:Compared with the controls, the DBM group had a significantly higher bone volume fraction (bone volume/total volume [BV/TV]) (52.7% vs 31.8%; P = .020) and BMD (0.55 vs 0.47 g/cm3; P = .008) at the femoral aperture and significantly higher BV/TV at femoral midportion (44.2% vs 32.9%; P = .038). There were no significant differences between the PRP and BMSC groups versus controls in terms of trabecular bone analysis or BMD. In the controls, widening at the femoral tunnel aperture was significantly greater than at the midportion (46.7 vs 41.7 mm2; P = .034). Sclerosis of the tunnel was common and most often seen at the femoral aperture. In the midportion of the femoral tunnel, BV/TV (r = 0.52; P = .019) and trabecular number (r S = 0.50; P = .024) were positively correlated with tunnel widening.Conclusion:Only DBM led to a significant increase in bone volume, which was seen in the femoral tunnel aperture and midportion. No treatment significantly reduced bone tunnel widening. Tunnel sclerosis in the femoral tunnel midportion was correlated significantly with tunnel widening.Clinical Relevance:DBM might have potential clinical use to enhance healing in the femoral tunnel after ACLR.

Simultaneous Treatment of Photobiomodulation and Demineralized Bone Matrix With Adipose-Derived Stem Cells Improve Bone Healing in an osteoporotic bone defect.

Introduction: The ability of simultaneous treatment of critical-sized femoral defects (CSFDs) with photobiomodulation (PBM) and demineralized bone matrix (DBM) with or without seeded adipose-derived stem cells (ASCs) to induce bone reconstruction in ovariectomized induced osteoporotic (OVX) rats was investigated. Methods: The OVX rats with CSFD were arbitrarily separated into 6 groups: control, scaffold (S, DBM), S + PBM, S + alendronate (ALN), S + ASCs, and S + PBM + ASCs. Each group was assessed by cone beam computed tomography (CBCT) and histological examinations. Results: In the fourth week, CBCT and histological analyses revealed that the largest volume of new bone formed in the S + PBM and S + PBM + ASC groups. The S + PBM treatment relative to the S and S + ALN treatments remarkably reduced the CSFD (Mann-Whitney test, P = 0.009 and P = 0.01). Furthermore, S + PBM + ASCs treatment compared to the S and S + ALN treatments significantly decreased CSFD (Mann Whitney test, P = 0.01). In the eighth week, CBCT analysis showed that extremely enhanced bone regeneration occurred in the CSFD of the S + PBM group. Moreover, the CSFD in the S + PBM group was substantially smaller than S, S + ALN and S + ASCs groups (Mann Whitney test, P = 0.01, P = 0.02 and P = 0.009). Histological observations showed more new bone formation in the treated CSFD of S + PBM + ASCs and S + PBM groups. Conclusion: The PBM plus DBM with or without ASCs significantly enhanced bone healing in the CSFD in OVX rats compared to control, DBM alone, and ALN plus DBM groups. The PBM plus DBM with or without ASCs significantly decreased the CSFD area compared to either the solo DBM or ALN plus DBM treatments.

Study on the correlation between the content of bone morphogenetic protein 2 in demineralized bone matrix and its osteogenic activity in vitro and in vivo

To investigate the correlation between the content of bone morphogenetic protein 2 (BMP-2) in demineralized bone matrix (DBM) and its osteogenic activity in vitro and in vivo, in order to choose a simple and convenient method to evaluate the osteogenic activity of DBM. The left mid-femoral tissues of 9 donors were taken, and DBMs (S1-S9) were prepared by dynamic decalcification process, and inactivated DBM (control group) was prepared at the same time. Protease inhibitor method, collagenase method, guanidine hydrochloride/ethylene diamine tetraacetic acid (EDTA) method, and RIPA lysate method were used to extract BMP-2 in S1-S9 and inactivated DBMs. The BMP-2 content was measured and the differences between DBMs were compared. Then the S1-S9 and inactivated DBMs were co-cultured with mouse embryonic osteoblasts MC3T3-E1, respectively. The cell proliferation was detected by MTT method and fluorescence staining, and alkaline phosphatase (ALP) activity was detected at the same time. Thirty BALB/c male nude mice were divided into 10 groups, namely S1-S9 DBM groups (S1-S9 groups) and inactivated DBM group (control group), with 3 mice in each group. Muscle pockets of the middle thighs were prepared on both hindlimbs of mice in each group, and implanted corresponding DBM materials. At 4 weeks after operation, the samples were taken for HE staining observation and semi-quantitative evaluation, and the new bone formation score was calculated. The BMP-2 content of DBM derived from different donor bones was distinct. The BMP-2 content obtained by different extraction methods for DBM prepared from the same donor bone was also different, and the extraction efficiency of the guanidine hydrochloride/EDTA method was the highest. In vitro cell experiments, MTT test displayed that cell proliferations and ALP activity were significantly higher in S4 and S6 groups than in other groups at each time point after co-cultivation ( P<0.05). Moreover, the cell proliferation of S4 group was the most significant at 7 days ( P<0.05); fluorescence staining demonstrated that the osteoblasts of each group was in good condition, but the osteoblasts of S1, S2, S3, S4, and S6 groups were significantly more than other groups. In vivo ectopic osteogenesis experiments, the cartilage and new bone formation could be seen in the bone graft area of S1-S6 groups at 4 weeks after operation, and with the increase of BMP-2 content, the more new bone formation induced by the material, the higher the score of new bone formation of the material ( P<0.05). Among them, S4 and S6 groups contained a large number of chondrocytes and osteoblasts in the osteogenesis area. The osteogenic activity of DBM can be evaluated through BMP-2 quantitative detection combined with in vitro osteoblast proliferation and differentiation experiments.

Effect of demineralized bone matrix modified by laminin α4 chain functional peptide on H-type angiogenesis and osteogenesis to promote bone defect repair

Based on the cell-extracellular matrix adhesion theory in selective cell retention (SCR) technology, demineralized bone matrix (DBM) modified by simplified polypeptide surface was designed to promote both bone regeneration and angiogenesis. Functional peptide of α4 chains of laminin protein (LNα4), cyclic RGDfK (cRGD), and collagen-binding domain (CBD) peptides were selected. CBD-LNα4-cRGD peptide was synthesized in solid phase and modified on DBM to construct DBM/CBD-LNα4-cRGD scaffold (DBM/LN). Firstly, scanning electron microscope and laser scanning confocal microscope were used to examine the characteristics and stability of the modified scaffold. Then, the adhesion, proliferation, and tube formation properties of CBD-LNα4-cRGD peptide on endothelial progenitor cells (EPCs) were detected, respectively. Western blot method was used to verify the molecular mechanism affecting EPCs. Finally, 24 10-week-old male C57 mice were used to establish a 2-mm-length defect of femoral bone model. DBM/LN and DBM scaffolds after SCR treatment were used to repair bone defects in DBM/LN group ( n=12) and DBM group ( n=12), respectively. At 8 weeks after operation, the angiogenesis and bone regeneration ability of DBM/LN scaffolds were evaluated by X-ray film, Micro-CT, angiography, histology, and immunofluorescence staining [CD31, endomucin (Emcn), Ki67]. Material related tests showed that the surface of DBM/LN scaffold was rougher than DBM scaffold, but the pore diameter did not change significantly ( t=0.218, P=0.835). After SCR treatment, DBM/LN scaffold was still stable and effective. Compared with DBM scaffold, DBM/LN scaffold could adhere to more EPCs after the surface modification of CBD-LNα4-cRGD ( P<0.05), and the proliferation rate and tube formation ability increased. Western blot analysis showed that the relative expressions of VEGF, phosphorylated FAK (p-FAK), and phosphorylated ERK1/2 (p-ERK1/2) proteins were higher in DBM/LN than in DBM ( P<0.05). In the femoral bone defect model of mice, it was found that mice implanted with DBM/LN scaffold had stronger angiogenesis and bone regeneration capacity ( P<0.05), and the number of CD31 hiEmcn hi cells increased significantly ( P<0.05). DBM/LN scaffold can promote the adhesion of EPCs. Importantly, it can significantly promote the generation of H-type vessels and realize the effective coupling between angiogenesis and bone regeneration in bone defect repair.

Ridge Augmentation Comparing a Cancellous Block Allograft to an Osteoinductive Demineralized Bone Matrix Allograft: A Randomized, Controlled, Blinded Clinical Trial.

Twenty-six patients with a horizontal ridge defect were entered into this 4-month randomized, controlled, blinded clinical trial to compare a cancellous block allograft to a demineralized bone matrix (DBM) allograft for ridge augmentation. Six patients were excluded from the study, leaving 20 for data interpretation. Both groups had a xenograft overlay and a collagen membrane. For the Block group there was a significant gain of 4.8 ± 1.9 mm (P = .00002; 95% confidence interval [CI]: 3.49 to 6.21), while the DBM group gained 4.6 ± 2.4 mm (P = .0002; 95% CI: 2.88 to 6.36). Vertical change was minimal for both groups (P > .05). The Block group had a mean of 40% vital bone while the DBM group had 35%.

Comparison of Fusion Rate between Demineralized Bone Matrix versus Autograft in Lumbar Fusion : Meta-Analysis

The demineralized bone matrix (DBM) as the bone graft material to increase the fusion rate was widely used in spinal fusion. The current study aimed to compare the fusion rate of DBM to the fusion rate of autograft in lumbar spine fusion via meta-analysis of published literature. After systematic search, comparative studies were selected according to eligibility criteria. Checklist (risk of bias assessment tool for non-randomized study) was used to evaluate the risk of bias of the included nonrandomized controlled studies. The corresponding 95% confidence interval (95% CI) were calculated. We also used subgroup analysis to analyze the fusion rate of posterolateral lumbar fusion and lumbar interbody fusion. Eight studies were finally included in this meta-analysis. These eight studies included 581 patients. Among them, 337 patients underwent spinal fusion surgery using DBM (DBM group) and 204 patients underwent spinal fusion surgery with mainly autologous bone and without using DBM (control group). There was no significant differences of fusion rate between the two groups in posterolateral fusion analysis (risk ratio [RR], 1.03; 95% CI, 0.90–1.17; p=0.66) and interbody fusion analysis (RR, 1.13; 95% CI, 0.91–1.39; p=0.27). Based on the available evidence, the use of DBM with autograft in posterolateral lumbar spine fusion and lumbar interbody fusion showed a slightly higher fusion rate than that of autograft alone; however, there was no statistically different between two groups.

Does demineralized bone matrix enhance tendon to bone healing after rotator cuff repair in a rabbit model

Background: The purpose of this study was to compare the histologic outcomes after rotator cuff (RC) repair between with demineralized bone matrix (DBM) augmentation and without DBM and to evaluate the role of DBM for tendon-to-bone (TB) healing in a rabbit model. Methods: Twenty-six adult male New Zealand white rabbits were randomly allocated to the control group (n = 13) or the DBM group (n = 13). A chronic RC tear was generated on the right shoulder of all rabbits. In the control group, RC repair was achieved by a standard transosseous technique. In the DBM group, RC repair was achieved using the same technique, and DBM was interposed between the cuff and bone. After 8 weeks, the RC tendon entheses from all rabbits were processed for gross and histologic examination. Results: In the control group, the tendon midsubstance was disorganized with randomly and loosely arranged collagen fibers and rounded fibroblastic nuclei. The TB interface was predominantly fibrous with small regions of fibrocartilage, especially mineralized fibrocartilage. In the DBM group, the tendon midsubstance appeared normal and comprised densely arranged collagen fibers, with orientated crimped collagen fibers running in the longitudinal direction of the tendon. These fibers were interspersed with elongated fibroblast nuclei. The TB interface consisted of organized collagen fibers with large quantities of fibrocartilage and mineralized fibrocartilage. Conclusion: DBM augmentation at the RC-to-bone interface enhances TB healing after RC repair.

Ridge Augmentation Comparing an Allograft Plus Autogenous Bone Chips to an Osteoinductive Demineralized Bone Matrix

The primary aim of this randomized, controlled, blinded, clinical trial was to compare a mix of particulate allograft and harvested autogenous particles (Autogenous) to an osteoinductive demineralized bone matrix (DBM) allograft on clinical and histologic outcomes for horizontal ridge augmentation procedure. Fourteen patients with a horizontal ridge defect with at least 1 adjacent tooth were entered into this study. The test group of 7 subjects received corticocancellous particulate allograft (Mineross) mixed with autogenous bone chips (70:30) harvested using a bone scraper (SafeScraper TWIST). Seven subjects in the control group received DBM (Optecure-CCC). Both groups had a corticocancellous particulate allograft overlay and an acellular dermis membrane (ADMG) (AlloDerm GBR) to cover the grafts. For the Autogenous group, there was a gain of 3.5 ± 1.4 mm while the DBM group gained 3.8 ± 1.6 mm (P < 0.05). Vertical change was minimal for both groups (P > 0.05). The Autogenous group had a mean of 35% vital bone while the DBM had 39% (P > 0.05). Both treatments provided similar gain of ridge width and minimal loss of ridge height. The autogenous bone chips did not provide any additional benefit when compared with allograft alone that had lot verified osteoinductive activity.

Comparison of Cortical Ring Allograft and Plate Fixation with Autologous Iliac Bone Graft for Anterior Cervical Discectomy and Fusion.

Study DesignA retrospective cohort study.PurposeTo compare the clinical and radiological outcomes of patients who underwent anterior cervical discectomy and fusion (ACDF) supplemented with plate fixation using allograft with those who underwent ACDF using tricortical iliac autograft. Overview of LiteratureAs plate fixation is becoming popular, it is reported that ACDF using allograft may have similar outcomes compared with ACDF using autograft.MethodsForty-one patients who underwent ACDF supplemented with plate fixation were included in this study. We evaluated 24 patients who used cortical ring allograft filled with demineralized bone matrix (DBM) (group A) and 17 patients who used tricortical iliac autograft (group B). In radiological evaluations, fusion rate, subsidence of grafted material, cervical lordosis, fused segmental lordosis, and radiological adjacent segment degeneration (ASD) were observed and analyzed with preoperative and postoperative plain radiographs. Clinical outcomes were evaluated using the Neck Disability Index score, Odom criteria, and Visual Analog Scale score of neck and upper extremity pain. Radiological union was determined by dynamic radiographs using cutoff values of 1 mm of interspinous motion as the indication of pseudarthrosis.ResultsThere was no significant difference in the fusion rate, graft subsidence, cervical lordosis, fused segmental lordosis, and ASD incidence between the groups. Operative time was shorter in group A (136 min) than in group B (141 min), but it was not significant (p>0.05). Blood loss was greater in group B (325 mL) than in group A (210 mL, p=0.013). There was no difference in the clinical outcomes before and after surgery.ConclusionsIn ACDF with plate fixation, cortical ring allograft filled with DBM group showed similar radiological and clinical outcomes compared with those of the autograft group. If the metal plate is reinforced, using cortical ring allograft could be a viable alternative to autograft.

Clinical and CT Analysis of Lumbar Spine Arthrodesis: β-Tricalcium Phosphate Versus Demineralized Bone Matrix.

Background:Bone graft substitutes have been developed to circumvent donor site morbidity associated with iliac crest bone graft, but sparse literature compares the efficacy of various substitutes. Two commonly used bone graft substitutes used in lumbar fusion are β-tricalcium phosphate (BTP) and demineralized bone matrix (DBM).Methods:A retrospective review of patients who underwent instrumented posterolateral lumbar fusion was conducted by a single surgeon from January 2013 to December 2016. Patients were divided into two groups based on whether DBM or BTP as graft in conjunction with local autograft. Clinical outcomes scores were collected at a minimum of 1-year follow-up. Postoperative CT scans were evaluated to assess fusion.Results:Forty-one patients (DBM, 21 and BTP, 20) were reviewed. No significant differences were found in terms of age, sex, body mass index, smoking, diabetes, steroids, osteoporosis, American Society of Anesthesiologists classification, number of levels fused, estimated blood loss, length of stay, or surgical time between the DBM and BTP groups. A trend was found toward lower revision surgery (zero versus 15%), improved visual analog scale scores (postoperative change of 1.81 versus 3.25; P = 0.09), and higher rates of fusion (90% versus 70%; P = 0.09) in the DBM group compared with the BTP group.Conclusions:No significant difference was found in clinical outcomes at 1 year, with a trend toward a higher fusion rate and lower revision surgery with DBM.

Effect of guided bone regeneration on bone quality surrounding dental implants

Bone quality as well as its quantity at the implant interface is responsible for determining stability of the implant system. The objective of this study is to examine the nanoindentation based elastic modulus (E) at different bone regions adjacent to titanium dental implants with guided bone regeneration (GBR) treated with DBM and BMP-2 during different post-implantation periods. Six adult male beagle dogs were used to create circumferential defects with buccal bone removal at each implantation site of mandibles. The implant systems were randomly assigned to only GBR (control), GBR with demineralized bone matrix (DBM), and GBR with DBM + recombinant human bone morphogenetic protein-2 (rhBMP-2) (BMP) groups. Three animals were sacrificed at each 4 and 8 weeks of post-implantation healing periods. Following buccolingual dissection, the E values were assessed at the defects (Defect), interfacial bone tissue adjacent to the implant (Interface), and pre-existing bone tissue away from the implant (Pre-existing). The E values of BMP group had significantly higher than control and DBM groups for interface and defect regions at 4 weeks of post-implantation period and for the defect region at 8 weeks (p < 0.043). DBM group had higher E values than control group only for the defect region at 4 weeks (p < 0.001). The current results indicate that treatment of rhBMP-2 with GBR accelerates bone tissue mineralization for longer healing period because the GBR likely facilitates a microenvironment to provide more metabolites with open space of the defect region surrounding the implant.

Demineralized bone matrix-based microcarrier scaffold favors vascularized large bone regeneration in vivo in a rat model.

Insufficient neo-vascularization of in vivo implanted cell-seeded scaffold remains a major bottleneck for clinical translation of engineered bone formation. Demineralized bone matrix is an ideal bone scaffold for bone engineering due to its structural and biochemical components similar to those of native bone. We hypothesized that the microcarrier form of demineralized bone matrix favors ingrowth of vessels and bone regeneration upon in vivo implantation. In this study, a rat model of femoral vessel pedicle-based bone engineering was employed by filling the demineralized bone matrix scaffolds inside a silicone chamber that surrounded the vessel pedicles, and to compare the efficiency of vascularized bone regeneration between microcarrier demineralized bone matrix and block demineralized bone matrix. The results showed that bone marrow stem cells better adhered to microcarrier demineralized bone matrix and produced more extracellular matrices during in vitro culture. After in vivo implantation, microcarrier demineralized bone matrix seeded with bone marrow stem cells formed relatively more bone tissue than block demineralized bone matrix counterpart at three months upon histological examination. Furthermore, micro-computed tomography three-dimensional reconstruction showed that microcarrier demineralized bone matrix group regenerate significantly better and more bone tissues than block demineralized bone matrix both qualitatively and quantitatively (p < 0.05). Moreover, micro-computed tomography reconstructed angiographic images also demonstrated significantly enhanced tissue vascularization in microcarrier demineralized bone matrix group than in block demineralized bone matrix group both qualitatively and quantitatively (p < 0.05). Anti-CD31 immunohistochemical staining of (micro-) vessels and semi-quantitative analysis also evidenced enhanced vascularization of regenerated bone in microcarrier demineralized bone matrix group than in block demineralized bone matrix group (p < 0.05). In conclusion, the microcarrier form of demineralized bone matrix is an ideal bone regenerative scaffold due to its advantages of osteoinductivity and vascular induction, two essentials for in vivo bone regeneration.

Propolis extract a new reinforcement material in improving bone healing: An in vivo study

BackgroundPropolis is known for its antioxidant, immune response modulating, and wound healing effects. In the present study in order to determine the bone healing capacity of the propolis extract, a critical sized, nonunion, radial bone defect model was repaired in rat, using chitosan and demineralized bone matrix (DBM) scaffolds along with propolis extract. Materials and methodsSeventy-two radial bone defects in 36 healthy male rats were randomly divided into 6 groups (n = 12/group). The groups included autograft, defect or untreated group, chitosan, DBM, chitosan and propolis (chitosan-propolis), and DBM and propolis (DBM-propolis). The bone repairing capability was characterized using radiography at 28th, 42nd and 56th postoperative days. Gross morphologic, histopathologic, histomorphometric and biomechanical examinations were performed following euthanasia at the 56th post-operative day. ResultsThe DBM-propolis group, showed better structural and biomechanical properties compared to the untreated, DBM, chitosan and chitosan-propolis groups. The defect site in the chitosan and untreated groups were mainly restored by fibrous connective tissue while the lesions in the autograft group were mostly filled by cartilage and a lesser amount of woven bone. The woven bone, and the hyaline cartilage were the main constituents of the newly formed tissues in the DBM-propolis group, at the 56th day after injury. ConclusionThe results of this study showed that percutaneous injection of diluted aqueous propolis extract in the bone defect (25 mg/defect) can improve bone formation in the critical radial bone defect in rat. Since there was no significant difference between the autograft and DBM-propolis group, probably this therapeutic strategy has high potential in augmentation of autologous bone grafting.

Mechanism of tissue-engineered bone recruiting endogenous mesenchymal stem cells towards bone regeneration

Objective To investigate the mechanism of implanted tissue-engineered bone (TEB) recruiting endogenous mesenchymal stem cells (BMSCs) towards bone regeneration after traumatic bone defect. Methods In vivo experiments: 2 mm of diaphysis and periosteum were removed from the middle of the femoral shaft in 8 week old FVB/N mice to form a large segment of bone defect. Demineralized bone matrix (DBM) and TEB were implanted into the defect area and fixated. All mice were randomly divided into DBM group (n=18) and TEB group (n=18). The results were observed 24 hours after implantation: (1) flow cytometry was used to evaluate the number of mobilized host BMSCs into the blood; (2) non-invasive bioluminescent imaging was used to observe the ability of two groups in recruiting mouse bone marrow derived mesenchymal stem cells (mBMSCs) in peripheral blood to the defect area; (3) ELISA was used to evaluate the stromal cell-derived factor 1 (SDF-1) content in peripheral blood of two groups. In vitro experiments: (1) transwell assay was conducted to evaluate the ability of SDF-1 (100 ng/ml) in promoting the migration of human bone marrow derived mesenchymal stem cells (hBMSCs). SDF-1/C-X-C motif chemokine receptor-4 (CXCR4) pathway was blocked by the selective CXCR4 antagonist Plerixafor (AMD3100). The experimental groups were divided into control group, SDF-1 group, and SDF-1+ AMD3100 group. (2) The co-culture system of human umbilical vein endothelial cells (hUVECs) and hBMSCs was established, and cells were stimulated by SDF-1. The experimental groups were divided into hBMSCs group, hBMSCs+ hUVECs group, and hBMSCs+ hUVECs (AMD3100 pretreatment) group. Transwell assays were used to compare the migration of hBMSCs in each group. ELISA was used to detect the concentration of hepatocyte growth factor (HGF) in the co-culture supernatant. (3) In vitro cultured hUVECs were stimulated by SDF-1 and SDF-1/CXCR4 pathway was antagonized by AMD3100. The experimental groups were divided into control group, SDF-1 group, and SDF-1+ AMD3100 group. Quantitative real-time polymerase chain reaction (qRT PCR) was used to evaluate the expression of HGF in each group. Results In vivo experiments: 24 h after transplantation, the number of BMSCs and SDF-1 concentration in the TEB group were significantly higher than those in the DBM group (P 0.05); (3) qRT-PCR showed that the expression of HGF was significantly increased in the SDF-1 group compared with the control group (P<0.05). After antagonizing SDF-1/CXCR4, HGF expression in the SDF-1+ AMD3100 group was significantly lower than that in the SDF-1 group. Conclusions TEB transplantation in traumatic bone defect can significantly increase the concentration of chemokine SDF-1 in vivo and effectively promote the mobilization of endogenous MSCs and recruitment of circulating MSCs. SDF-1 not only directly promotes the migration of hBMSCs through SDF-1/CXCR4 pathway, but also up-regulates the expression and secretion of HGF in vascular cells to further amplify the chemotactic effect of SDF-1 on hBMSCs. Key words: Tissue engineering; Mesenchymal stem cells; Stromal cell-derived factor-1

An effective delivery vehicle of demineralized bone matrix incorporated with engineered collagen-binding human bone morphogenetic protein-2 to accelerate spinal fusion at low dose.

The aim of this study was to investigate the feasibility and efficacy of a new delivery matrix using demineralized bone matrix (DBM) incorporated with collagen-binding bone morphogenetic protein-2 (CBD-BMP-2) in the rat inter-transverse spinal fusion model. Sixty rats undergoing posterolateral (inter-transverse) spinal fusion were divided into 3 groups according to the fusion materials containing different components (n = 20 per group). Group A were implanted with DBM, Group B with combination of DBM and BMP-2 and Group C with combination of DBM and CBD-BMP-2. After surgery, the spinal fusion of all the rats was assessed by plain radiography, CT + 3D reconstruction, manual palpation and histological evaluation. Significant difference was found in terms of solid fusion rate among the three groups, with 95% in Group C, 65% in Group B and 0% in Group A (P < 0.001). Compared with Groups B and A, new bone formation was observed earlier and was obvious larger, trabecular bone microarchitecture assessment was better and bone mineral density was statistically larger in Group C. In addition, more newly woven bone and osteocytes were shown by histological evaluation in Group C at 4 weeks post-operation. The present study showed CBD domain could help BMP-2 to improve the efficiency of posterolateral spinal fusion. DBM scaffold activated by collagen-binding BMP-2 was a feasible and promising bone repair vehicle. The present study showed better results in terms of plain radiography, CT + 3D reconstruction, manual palpation and histological evaluation in the rat inter-transverse spinal fusion model using DBM+CBD-BMP-2, compared with DBM+BMP-2 and DBM alone, indicating DBM scaffold activated by collagen-binding BMP-2 was a feasible and promising bone repair vehicle.

Abstract: A Comparative Analysis of rhBMP-2/Dbm Vs. Icbg for Secondary Alveolar Bone Grafts in Patients with Cleft Lip and Palate: Review of 501 Cases

INTRODUCTION: Alveolar cleft reconstruction using iliac crest bone graft (ICBG) is considered standard of care for children with complete cleft lip and palate at the time of mixed dentition. Harvesting bone may result in donor site morbidity, additional operating time and length of hospitalization. Recombinant human bone morphogenetic protein (rhBMP)-2 with a demineralized bone matrix (DBM) was used as an alternative bone source for alveolar cleft reconstruction. We investigate the outcomes of rhBMP-2/DBM versus ICBG for alveolar cleft reconstruction by reviewing postoperative surgical complications and cleft closure. METHODS: A retrospective chart review was conducted for 258 rhBMP-2/DBM and 243 ICBG procedures on 414 patients over a 12-year period with a mean follow-up of 2.9 years (rhBMP-2/DBM) and 4.1 years (ICBG). We compared the complications, canine eruption and alveolar cleft closure between the two groups. RESULTS: In the rhBMP-2/DBM group, one patient required prolonged intubation due to intraoperative airway swelling not thought to be caused by rhBMP-2, 36 reported facial swelling and one required outpatient steroids as treatment, 12 had dehiscence; however, half of these complications resolved without intervention. 23/228 of the rhBMP-2/DBM and 28/242 of the ICBG groups required repeat surgery for alveolar cleft repair. The findings of canine tooth eruption into the cleft site through the graft were similar between the two groups. CONCLUSION: rhBMP-2/DBM appears to be an acceptable alternative for alveolar cleft repair. We found no increase in serious adverse events with the use of this material. Local complications, such as swelling and minor wound dehiscence predominantly improved without intervention.