Synthesis and in Vitro Toxicity Assessment of Different Nano-Calcium Phosphate Nanoparticles

Abstract Nanoscale biomaterials are commonly used in a wide range of biomedical applications such as bone graft substitutes, gene delivery systems, and biologically active agents. On the other hand, the cytotoxic potential of these particles hasn't yet been studied comprehensively to understand whether or not they exert any negative impact on the cellular structures. Here, we undertook the synthesis of beta-tricalcium phosphate (ß-TCP) and biphasic tricalcium phosphate (BCP) nanoparticles (NPs) and determine their concentration-dependent toxic effects in human fetal osteoblastic (hFOB 1.19) cell line. Firstly, BCP and β-TCP were synthesized using a water-based precipitation technique and characterized by X-Ray Diffraction (XRD), Raman Spectroscopy, and Transmission Electron Microscopy (TEM). The cytological effects of β-TCP and BCP at different concentrations (0-640 ppm) were evaluated by using 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. The total oxidative status (TOS) parameter was used for investigating oxidative stress potentials of the NPs. In addition, the study assessed the DNA damage product 8-hydroxy-2′-deoxyguanosine (8-Oxo-dG) level in hFOB 1.19 cell cultures. The results indicated that the β-TCP (above 320 ppm) and BCP (above 80 ppm) NPs exhibited cytotoxicity effects on high concentrations. It was also observed that the oxidative stress increased relatively as the concentrations of NPs increased, aligning with the cytotoxicity results. However, the NPs concentrations of 160 ppm and above increased the level of 8-OH-dG. Consequently, there is a need for more systematic in vivo and in vitro approaches to the toxic effects of both nanoparticles.

Biphasic calcium phosphate loaded with advanced platelet rich fibrin can promote the activity of rabbit bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND: Adding growth factor to scaffold material can promote the proliferation and osteogenic differentiation of cultured stem cells in vitro and promote bone tissue regeneration. Advanced platelet rich fibrin (A-PRF) contains a variety of growth factors, which can promote the proliferation activity of a variety of cells and the expression of related functional proteins. OBJECTIVE: To observe the effects of the sole and combined usage regarding A-PRF and biphasic calcium phosphate (BCP) on the growth of bone marrow mesenchymal stem cells. METHODS: The third generation of rabbit bone marrow mesenchymal stem cells was cultured in four groups, including basic medium (blank group), A-PRF condition medium (A-PRF group), BCP (BCP group), A-PRF condition medium and BCP (A-PRF+BCP group). Cell proliferation activity was detected by CCK-8 assay. Cell adhesion was observed based on methylrhodamine-phalloidin fluorescence staining. Intracellular alkaline phosphatase expression and mineralized nodules were quantitatively measured. RESULTS AND CONCLUSION: (1) The absorbance value of proliferation of the A-PRF+BCP group was higher than that of the other three groups at 3, 5, 7, 11 and 14 days after culture. The absorbance value of proliferation of cells cultured in the A-PRF group was higher than that of the BCP group and the blank group at 1, 3 and 5 days after culture. The absorbance value of proliferation of BCP group was higher than that of the A-PRF group and the blank group at 7, 11 and 14 days after culture. (2) Methylrhodamine-phalloidin fluorescence staining showed that bone marrow mesenchymal stem cells in the BCP group and the A-PRF+BCP group adhered to the surface of BCP and the number of cells and microfilaments in the A-PRF+BCP group was higher than that in BCP group. (3) The synthesis of mineralized nodules was A-PRF+BCP group > BCP group > A-PRF group > blank group at 1, 21 and 28 days after surgery. (4) The expression of alkaline phosphatase was A-PRF+BCP group > BCP group > A-PRF group > blank group at 5, 7 and 9 days. There was significant difference between the two groups (P < 0.05). (5) The results showed that BCP exerted a weak influence on promoting cell proliferation in the early stage, but its effect of scaffold was apparent. A-PRF had a significant effect on promoting cell proliferation with considerable influence on promoting cell proliferation and differentiation when combined BCP.

Eight-week healing of grafted calvarial bone defects with hyperbaric oxygen therapy in rats

PURPOSE: The purpose of this study was to evaluate the synergistic effect of adjunctive hyperbaric oxygen (HBO) therapy on new bone formation and angiogenesis after 8 weeks of healing. METHODS: Sprague-Dawley rats (n=28) were split into 2 groups according to the application of adjunctive HBO therapy: a group that received HBO therapy (HBO group [n=14]) and another group that did not receive HBO therapy (NHBO group [n=14]). Each group was divided into 2 subgroups according to the type of bone graft material: a biphasic calcium phosphate (BCP) subgroup and an Escherichia coli-derived recombinant human bone morphogenetic protein-2-/epigallocatechin-3-gallate-coated BCP (mBCP) subgroup. Two identical circular defects with a 6-mm diameter were made in the right and left parietal bones of each rat. One defect was grafted with bone graft material (BCP or mBCP). The other defect was not grafted. The HBO group received 2 weeks of adjunctive HBO therapy (1 hour, 5 times a week). The rats were euthanized 8 weeks after surgery. The specimens were prepared for histologic analysis. RESULTS: New bone (%) was higher in the NHBO-mBCP group than in the NHBO-BCP and control groups (P<0.05). Blood vessel count (%) and vascular endothelial growth factor staining (%) were higher in the HBO-mBCP group than in the NHBO-mBCP group (P<0.05). CONCLUSIONS: HBO therapy did not have a positive influence on bone formation irrespective of the type of bone graft material applied after 8 weeks of healing. HBO therapy had a positive effect on angiogenic activity.

Improvement of the osteogenic potential of ErhBMP-2-/EGCG-coated biphasic calcium phosphate bone substitute: in vitro and in vivo activity

PURPOSE: The aim of this study was to evaluate the enhancement of osteogenic potential of biphasic calcium phosphate (BCP) bone substitute coated with Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) and epigallocatechin-3-gallate (EGCG). METHODS: The cell viability, differentiation, and mineralization of osteoblasts was tested with ErhBMP-2-/EGCG solution. Coated BCP surfaces were also investigated. Standardized, 6-mm diameter defects were created bilaterally on the maxillary sinus of 10 male New Zealand white rabbits. After removal of the bony windows and elevation of sinus membranes, ErhBMP-2-/EGCG-coated BCP was applied on one defect in the test group. BCP was applied on the other defect to form the control group. The animals were sacrificed at 4 or 8 weeks after surgery. Histologic and histometric analyses of the augmented graft and surrounding tissue were performed. RESULTS: The 4-week and 8-week test groups showed more new bone (%) than the corresponding control groups (P<0.05). The 8-week test group showed more new bone (%) than the 4-week test group (P<0.05). CONCLUSIONS: ErhBMP-2-/EGCG-coated BCP was effective as a bone graft material, showing enhanced osteogenic potential and minimal side effects in a rabbit sinus augmentation model.

Adjunctive hyperbaric oxygen therapy for irradiated rat calvarial defects

PURPOSE: The aim of this study was to conduct a histologic evaluation of irradiated calvarial defects in rats 4 weeks after applying fibroblast growth factor-2 (FGF-2) with hyaluronan or biphasic calcium phosphate (BCP) block in the presence or absence of adjunctive hyperbaric oxygen (HBO) therapy. METHODS: Twenty rats were divided into HBO and non-HBO (NHBO) groups, each of which was divided into FGF-2 and BCP-block subgroups according to the grafted material. Localized radiation with a single 12-Gy dose was applied to the calvaria of rats to simulate radiotherapy. Four weeks after applying this radiation, 2 symmetrical circular defects with a diameter of 6 mm were created in the parietal bones of each animal. The right-side defect was filled with the materials mentioned above and the left-side defect was not filled (as a control). All defects were covered with a resorbable barrier membrane. During 4 weeks of healing, 1 hour of HBO therapy was applied to the rats in the HBO groups 5 times a week. The rats were then killed, and the calvarial specimens were harvested for radiographic and histologic analyses. RESULTS: New bone formation was greatest in the FGF-2 subgroup, and improvement was not found in the BCP subgroup. HBO seemed to have a minimal effect on new bone formation. There was tendency for more angiogenesis in the HBO groups than the NHBO groups, but the group with HBO and FGF-2 did not show significantly better outcomes than the HBO-only group or the NHBO group with FGF-2. CONCLUSIONS: HBO exerted beneficial effects on angiogenesis in calvarial defects of irradiated rats over a 4-week healing period, but it appeared to have minimal effects on bone regeneration. FGF-2 seemed to enhance new bone formation and angiogenesis, but its efficacy appeared to be reduced when HBO was applied.

Preparation of polydopamine coated 3D printed biphasic calcium phosphate tissue engineering scaffold and its evaluation / 吉林大学学报(医学版)

Objective: To coat polydopamine (PDA) on the surface of biphasic calcium phosphate (BCP) scaffold prepared by 3D printing and construct a novel bone tissue engineering scaffold with high osteogenic activity, and to conduct a preliminary evaluation on its application potential.Methods:BCP bioceramic scaffolds were prepared by 3D printing technology, and then they were immersed in dopamine solution for a certain period to form a nanoscale PDA film structure on the surface.The PDA-free scaffolds were named 3DBCP group, and the PDA-coated scaffolds were named PDA-3DBCP group. Scanning electron microscope (SEM) was used to observe the surface topography of the scaffolds in each group; the hydrophilicity of the material was characterized by measuring the water contact angle of the scaffold surface; the scaffold porosity was determined by the specific gravity method, and the mechanical strength was tested by the universal testing machine; CCK-8 assay was adopted to detect the cell proliferation activity on the scaffold.Results:Compared with 3DBCP group, the surface water contact angle of the the scaffolds in PDA-3DBCP group was significantly reduced (t=5.06,P0.05;t=0.002,P>0.05).The cells were inoculated into the scaffolds and cultured for 1, 3 and 5 d;the CCK-8 assay results showed that the proliferation activities of the cells in two groups were gradually increased with the prolongation of the culture time. Furthermore, compared with 3DBCP group, the cell proliferation activity of the cells in PDA-3DBCP group on the 5th day was significantly increased (t=39.3,P<0.05).Conclusion: The PDA-coated 3D printed BCP porous scaffold has the advantages in characterization,it can improve the cell proliferation ability, which shows the potential as bone tissue engineering scaffolds.

Bone remodeling function of orthodontic tooth movement in beagle dogs with periodontal defect regeneration under action of biphasic calcium phosphate / 吉林大学学报(医学版)

Objective: To observe the orthodontic tooth movement after regeneration of Beagl dog' s periodontal tissue defect with biphasic calcium phosphate (BCP), and to elucidate the mechanism of BCP as a scaffold material for periodontal regeneration. Methods: Six adult male Beagle dogs were selected; the right upper quardrant (B) and the left lower quardrant (D) regions of each dog were used as blank control group, and the left upper quardrant (A) and the right lower quardrant (D) regions were used to establish the dog models of periodontal tissue defect of bilateral incisors. BCP was implanted into the defect to regenerate the defect. After 12 weeks of BCP implantation into the defect for defect tissue regeneration, the orthodontic tooth movement models were established (experimental group). Stress stimulation was applied in experimental group and control group, respectively. Two Beagle dogs were randomly executed at 1, 2 and 4 weeks after loading. The specimens were stained, the histological changes of regenerated periodontal tissue and the expression of core binding factor al (Cbfal) regulating osteogenesis under stress were observed; the changes in normal periodontal tissue under the same stress were observed. Results: The Masson staining results showed that the periodontal ligament of the dogs in experimental group and control group became narrower and denser at 1 week after stress stimulation; the alveolar bone of the dogs in dogs in experimental group was mainly blue; the alveolar bone of the dogs in control group was generally red except for the compression area of the periodontal ligament. At 4 weeks after stress stimulation, the alveolar bone of the dogs in experimental group was red-blue, while the alveolar bone of the dogs in control group was red; the blood vessels in periodontal ligament of the dogs in two groups were rounded. One week after stress stimulation, the alveolar bone surface of the dogs in experimental group and control group was covered with bone resorption lacunae containing the multinucleated osteoclasts, the cytoplasmic Cbfal staining was positive, and the compressed and deformed periodontal ligament cells were arranged disorderly. Four weeks after stress stimulation, the osteoclasts disappeared in experimental group, and the bone resorption lacunae was filled by osteoblasts, and the osteoblasts on the other side of the trabecula were also active; the expression of Cbfal was still found in the bone marrow mesenchymal cells and the marginal osteoblasts of alveolar bone. The expression of Cbfal was weak in control group. Conclusion: The periodontal tissue regenerated by BCP has reached the normal periodontal tissue. Under the action of orthodontic force, it has normal osteogenesis function and can complete the bone remodeling process of orthodontic tooth movement.

Fibrin biopolymer as scaffold candidate to treat bone defects in rats

Bone tissue repair remains a challenge in tissue engineering. Currently, new materials are being applied and often integrated with live cells and biological scaffolds. The fibrin biopolymer (FBP) proposed in this study has hemostatic, sealant, adhesive, scaffolding and drug-delivery properties. The regenerative potential of an association of FBP, biphasic calcium phosphate (BCP) and mesenchymal stem cells (MSCs) was evaluated in defects of rat femurs. Methods: Adult male Wistar rats were submitted to a 5-mm defect in the femur. This was filled with the following materials and/or associations: BPC; FBP and BCP; FBP and MSCs; and BCP, FBP and MSCs. Bone defect without filling was defined as the control group. Thirty and sixty days after the procedure, animals were euthanatized and subjected to computed tomography, scanning electron microscopy and qualitative and quantitative histological analysis. Results: It was shown that FBP is a suitable scaffold for bone defects due to the formation of a stable clot that facilitates the handling and optimizes the surgical procedures, allowing also cell adhesion and proliferation. The association between the materials was biocompatible. Progressive deposition of bone matrix was higher in the group treated with FBP and MSCs. Differentiation of mesenchymal stem cells into osteogenic lineage was not necessary to stimulate bone formation. Conclusions: FBP proved to be an excellent scaffold candidate for bone repair therapies due to application ease and biocompatibility with synthetic calcium-based materials. The satisfactory results obtained by the association of FBP with MSCs may provide a more effective and less costly new approach for bone tissue engineering.(AU)

The Influences of Different Ratios of Biphasic Calcium Phosphate and Collagen Augmentation on Posterior Lumbar Spinal Fusion in Rat Model

PURPOSE: To determine the influence of different ratios of hydroxyapatite (HA)/beta tricalcium phosphate (β-TCP) and collagen augmentation for posterior lumbar fusion in a rat model. MATERIALS AND METHODS: We generated a posterior lumbar fusion model in 50 rats and divided it into five groups of equal number as follows; 1) autologous bone graft as group A, 2) 70% HA+30% β-TCP as group B, 3) 70% HA+30% β-TCP+collagen as group C, 4) 30% HA+70% β-TCP as group D, and 5) 30% HA+70% β-TCP+collagen as group E. Rats were euthanized at 12 weeks after surgery and fusion was assessed by manual palpation, quantitative analysis using microCT and histology. RESULTS: The score of manual palpation was significantly higher in group C than group E (3.1±1.1 vs. 1.8±0.8, p=0.033). However, in terms of microCT analysis, group D showed significantly higher scores than group B (5.5±0.8 vs. 3.1±1.1, p=0.021). According to quantitative volumetric analysis, 30% HA+70% β-TCP groups (group D and E) showed significantly reduced fusion mass at 12 weeks after surgery (123±14.2, 117±46.3 vs. 151±27.3, p=0.008, 0.003, respectively). Collagen augmentation groups revealed superior results in terms of both microCT score and histologic grade. CONCLUSION: A 7:3 HA/β-TCP ratio with collagen augmentation rather than a 3:7 HA/β-TCP ratio could be a more favorable graft substitute for lumbar spinal fusion. There was positive role of collagen as an adjunct for spinal bone fusion process.

Avaliação microtomográfica e histomorfométrica do processo de reparo de defeitos ósseos em calvária de coelhos tratados com diferentes materiais de enxerto / Microtomographic and histomorphometric evaluation of bone repair in rabbit cranial defects treated with different graft materials

Um dos grandes desafios para o tratamento de defeitos ósseos extensos na região bucomaxilofacial têm sido o desenvolvimento de um biomaterial substituto ósseo ao enxerto autógeno. No presente trabalho avaliou-se a formação óssea e a biodegrabilidade do osso desproteinizado bovino Bio-Oss® e do seu similar GenOx Inorg® e da cerâmica bifásica GenPhos® XP no processo de reparo de defeitos ósseos cranianos em coelhos, comparativamente ao osso autógeno (controle positivo) e coágulo sanguíneo (controle negativo). Foram realizados cirurgicamente defeitos bilaterais de 8-mm de diâmetro nos ossos parietais de 39 coelhos. A seguir os defeitos foram preenchidos aleatoriamente com 0,1cm3 de material ou coágulo conforme cada grupo de tratamento. Após os períodos de 4, 8 e 24 semanas os crânios foram coletados, analisados no microtomógrafo e processados histologicamente. O percentual de volume do defeito ocupado pelo material e osso neoformado foi avaliado pela microtomografia e histomorfometria, enquanto que, para a medula óssea, tegumento e tecido conjuntivo, apenas pela análise histomorfométrica. Os resultados quantitativos obtidos foram comparados estatisticamente pela ANOVA a dois critérios (período e tratamento) e teste de Tukey com p<0,05. A intensidade da associação linear dos dados microtomográficos e histomorfométricos avaliada pelo coeficiente de correlação de Pearson, mostraram correlação moderada a forte. Nos períodos iniciais de reparo (30 e 60 dias), os defeitos tratados com Bio-Oss®, GenOx® Inorg e GenPhos® XP apresentaram manutenção do volume do material enxertado (Vvi médio de 34% ) e formação óssea menor e mais imatura em relação grupo autógeno (Vvi = 22% vs. 32% no grupo autógeno). No período mais tardio (180 dias) a quantidade de formação óssea foi estatisticamente similar nos grupos Bio-Oss® (Vvi = 27%), GenOx® Inorg (Vvi = 26%) e GenPhos® XP (Vvi = 20%) porém, o GenOx® Inorg promoveu a formação de um tecido ósseo mais organizado e com maior acúmulo de biomaterial+osso+medula óssea (Vvi = 67,9%) comparado ao GenPhos® XP (Vvi =58,9%) e Bio Oss (Vvi = 55,6%) mas, inferior ao do enxerto autógeno (Vvi = 78%). Os resultados aqui obtidos permitem concluir que o osso autógeno promove rápida formação e maturação óssea, porém não consegue promover o reestabelecimento completo da díploe removida cirurgicamente. Os materiais BioOss, GenOx® Inorg e GenPhos® XP são excelentes materiais osteocondutores levando a formação óssea em toda extensão do defeito, sendo o GenOx® Inorg o que apresenta menor grau de reabsorção e maior e melhor preenchimento do defeito.(AU)

One major challenge for treatment of critical size defects in maxillofacial region has been the development of a substitute biomaterial to the autogenous bone grafts. In present study we evaluated the bone formation and biodegradability of deproteinized bovine bone Bio-Oss® and GenOx® Inorg, and biphasic calcium phosphate GenPhos XP® during bone repair process in rabbits cranial defects compared to autogenous bone (positive control) and blood clot (negative control). In parietal bone of 39 rabbits were made bilateral 8-mm diameter defects, which were filled randomly with 0,1cm3 material or clot as each treatment group. After periods of 4, 8 and 24 weeks skulls of animals were collected, analyzed the MicroCT scanner and histologically processed. The percentage of defect volume occupied by biomaterial and new-formed bone were assessed by histomorphometry and microtomography, while the bone marrow, connective tissue and tegument only by first analysis. The quantitative data were compared by two-way ANOVA analysis (time and treatment) and Tukey's test at p <0.05. The intensity of the linear association of MicroCT and morphometric data evaluated by the Pearson correlation coefficient, showed moderate to strong correlation. In the early repair periods (30 and 60 days), the defects treated with Bio- Oss, GenOx® Inorg and GenPhos® XP showed maintenance of the graft material volume (average Vvi of 34%) and lower and more immature bone compared autograft group (Vvi = 22% vs. 32% in the autograft group). In the later period (180 days) the amount of bone formation was statistically similar to the groups Bio-Oss® (Vvi = 27 %), GenOx® Inorg (Vvi = 26%) and GenPhos® XP (Vvi = 20%) however, the bone formation in GenOx® Inorg was more organized and with greater accumulation of particles + bone tissue + bone marrow (Vvi = 67.9%), when compared to GenPhos® XP (Vvi = 58.9%) and Bio-Oss® (Vvi = 55.6%) but lower than the autograft (Vvi = 78%). It was concluded that the autogenous bone promotes rapid bone formation and maturation, but cannot promote the complete reestablishment of diploe surgically removed. The Bio-Oss®, GenOx® Inorg and GenPhos® XP are excellent osteoconductive materials leading to bone formation in the full extent of the defects, and the GenOx® Inorg showing less absorption promotes more and better defect filling.(AU)

Late-term healing in an augmented sinus with different ratios of biphasic calcium phosphate: a pilot study using a rabbit sinus model

PURPOSE: The aim of this pilot study was to determine the osteoconductivity and dimensional stability of augmented sinuses using different ratios of biphasic calcium phosphate (BCP) in a rabbit sinus model. METHODS: Each sinus of New Zealand white rabbits (2.5-3.5 kg) was assigned to one of two groups: BCP with a hydroxyapatite to beta-tricalcium phosphate (HA:beta-TCP) ratio of 70:30 (group TCP30) and BCP with an HA:beta-TCP ratio of 30:70 (group TCP70). After preparing a window in the antral wall of a sinus, the Schneiderian membrane was elevated, and the applicable material was grafted. A fluorochrome calcein green was injected five days before euthanizing the animals at four months post-surgery. The specimens were analyzed histologically, histomorphometrically, and by using micro-computed tomography (micro-CT). RESULTS: Micro-CT analysis revealed that the total augmented volume and the new bone volume did not differ significantly between the two groups whereas the resorption of materials was greater in the TCP70 group. The trabecular thickness, number, and separation also did not differ significantly between the two groups. Histomorphometrically, the areas of total augmentation, new bone, and residual material, as well as the ratio of new-bone-material contact did not differ significantly between the groups. Histologically, the residual particles were more scattered in the TCP70 group than in the TCP30 group. The fluorescence of the calcein green did not differ notably between the two groups. CONCLUSIONS: The osteoconductivity and dimensional stability of the two BCPs with different ratios tested in this study were comparable after four months of healing. Therefore, we conclude that both BCPs show promise as a bone substitute for sinus augmentation.

Four-week histologic evaluation of grafted calvarial defects with adjunctive hyperbaric oxygen therapy in rats

PURPOSE: The aim of this study was to characterize the healing in the grafted calvarial defects of rats after adjunctive hyperbaric oxygen therapy. METHODS: Twenty-eight male Sprague-Dawley rats (body weight, 250–300 g) were randomly divided into two treatment groups: with hyperbaric oxygen therapy (HBO; n=14) and without HBO (NHBO; n=14). Each group was further subdivided according to the bone substitute applied: biphasic calcium phosphate (BCP; n=7) and surface-modified BCP (mBCP; n=7). The mBCP comprised BCP coated with Escherichia-coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) and epigallocatechin-3-gallate (EGCG). Two symmetrical circular defects (6-mm diameter) were created in the right and left parietal bones of each animal. One defect was assigned as a control defect and received no bone substitute, while the other defect was filled with either BCP or mBCP. The animals were allowed to heal for 4 weeks, during which those in the HBO group underwent 5 sessions of HBO. At 4 weeks, the animals were sacrificed, and the defects were harvested for histologic and histomorphometric analysis. RESULTS: Well-maintained space was found in the grafted groups. Woven bone connected to and away from the defect margin was formed. More angiogenesis was found with HBO and EGCG/BMP-2 (P<0.05). None of the defects achieved complete defect closure. Increased new bone formation with HBO or EGCG/BMP-2 was evident in histologic evaluation, but it did not reach statistical significance in histometric analysis. A synergic effect between HBO and EGCG/BMP-2 was not found. CONCLUSIONS: Within the limitations of this study, the present findings indicate that adjunctive HBO and EGCG/BMP-2 could be beneficial for new bone formation in rat calvarial defects.

Union Rates of Autologous Bone Marrow, Local Autobone and Biphasic Calcium Phosphate Mixed Graft in Lumbar Posterolateral Fusion

STUDY DESIGN: A retrospective study. OBJECTIVES: We examined union rates and clinical outcomes to evaluate the efficacy of using autologous bone marrow along with a local autobone and biphasic calcium phosphate mixed graft with posterolateral fusion in spinal stenosis and spondylolisthesis. SUMMARY OF LITERATURE REVIEW: In lumbar posterolateral fusion, union rates of biphasic calcium phosphate and local autobone mixed graft are low compared to union rates of autogenous iliac bone graft. MATERIALS AND METHODS: Among the patients who had lumbar posterolateral fusion with autologous bone marrow along with local autobone and biphasic calcium phosphate mixed graft between February 2013 and January 2014, we analyzed 40 patients who were available for at least one year of follow-up. There were 22 cases with spinal stenosis and 18 cases with spondylolisthesis. Bone fusion was determined along with the fusion rates based on Lenke's criteria (citation). All patients were evaluated postoperatively at one year, using 3D CT. and the clinical outcomes were assessed using Kim's method (citation). RESULTS: In spinal stenosis, bone union was observed in 19 cases out of 22 (86.4%), and in case of spondylolisthesis, bone union was observed in 16 cases out of 18 (88.9%). In spinal stenosis, the clinical outcomes were: 2 excellent, 16 good, 3 fair, and 1 poor; in other words 18 cases (81.8%) displayed good or excellent outcomes. In spondylolisthesis, 2 excellent, 12 good, 4 fair and 0 poor; in other words, 14 cases (77.8%) showed good or superior outcomes. CONCLUSIONS: Posterolateral fusion using autologous bone marrow along with a local autobone and biphasic calcium phosphate mixed graft showed similar bone fusion rates to using autogenous iliac bone graft. Therefore, this method could serve as an alternative to using autogenous iliac bone graft in posterior lumbar fusion.

Biphasic Calcium Phosphate and Local Autobone Mixed Graft in Lumbar Posterolateral Fusion

STUDY DESIGN: Retroprospective study. OBJECTIVES: To evaluate the efficacy of biphasic calcium phosphate and local autobone mixed graft in cases of spinal stenosis and spondylolisthesis in posterolateral fusion by examining radiologic union rates and clinical outcomes. SUMMARY OF LITERATURE REVIEW: It can be a practical alternative to the use of tricalcium phosphate in hydroxyapatite as a graft aid since using hydroxyapatite mixture in lumbar spine fusion has been reported to lead to a high rate of bone union. MATERIALS AND METHODS: From July 2011 to February 2013, we followed up 107 patients who had lumbar posterolateral fusion using biphasic calcium phosphate composed of HA/TCP (60:40) and local autobone mixed graft. Of these patients, 64 had spinal stenosis and 43 had spondylolisthesis. The bone fusion rate was determined using Lenke's criteria and clinical outcomes were evaluated using Kim's method. RESULTS: In spinal stenosis, bone union was presented in 53 patients (of 64; 82.8%) and in spondylolisthesis, 35 patients (of 43; 81.4%). In spinal stenosis, the clinical outcomes resulted in 20 excellent, 34 good, 9 fair and 1 poor. (84.4%, excellent or good) In spondylolisthesis, the clinical outcomes resulted in 10 excellent, 25 good, 7 fair and 1 poor. (81.4%, excellent or good). CONCLUSION: Posterolateral fusion using biphasic calcium phosphate and local autobone mixed graft showed high rates of bone union and acceptable clinical outcomes, and is considered a satisfactory bone graft aid.

Ectopic bone formation in adipose-derived mesenchymal stem cell-seeded osteoinductive calcium phosphate scaffolds / 中国组织工程研究

BACKGROUND:The phenomenon of osteoinduction by biomaterials has been proven in animal experiments. OBJECTIVE:To investigate whether the ability of a biomaterial to initiate bone formation in ectopic implantation sites improves the performance of osteoinductive biomaterial as a scaffold for tissue-engineered bone. METHODS:We compared ectopic bone formation by combining autologous adipose-derived stromal cells with an osteoinductive and a nonosteoinductive biphasic calcium phosphate ceramic to create a tissue engineering construction in the muscle of dogs. Al implants were implanted in the back muscle of 10 adult dogs for 8 weeks and 12 weeks, including osteoinductive biphasic calcium phosphate ceramic+adipose-derived stromal cells (osteoinductive complex group), osteoinductive biphasic calcium phosphate ceramic (osteoinductive broup), nonosteoinductive biphasic calcium phosphate ceramic+adipose-derived stromal cells (nonosteoinductive complex group), and nonosteoinductive biphasic calcium phosphate ceramic (nonosteoinductive group). Micro-CT analysis and histomorphometry were performed to evaluate and quantify ectopic bone formation. RESULTS AND CONCLUSION:Ectopic bone formation was visible in the osteoinductive complex group and osteoinductive group, and the former group was superior to the latter one in quality of new bone (P<0.05). However, there was no ectopic bone formation in the other two groups. Micro-CT results were consistent with the histomorphological detection. These findings indicate that osteoinductive biphasic calcium phosphate ceramic, as a kind of bone tissue engineering scaffold material, has a better osteogenic capacity, while adipose-derived mesenchymal stem cells serve as seed cells to promote the ectopic bone formation.

Histomorphometric evaluation of bone healing with fully interconnected microporous biphasic calcium phosphate ceramics in rabbit calvarial defects / 대한치주과학회지

PURPOSE: The purpose of this study was to histomorphometrically evaluate the osteoconductivity of a new biphasic calcium phosphate ceramics with fully interconnected microporous structure. MATERIAL AND METHODS: Osseous defects created in the rabbit calvaria were filled with four different bone graft substitutes. Experimental sites were filled with a new fully interconnected microporous biphasic calcium phosphate with(BCP-2) or without(BCP-1) internal macropore of 400micrometer in diameter. MBCP(Biomatlante, France) and Bio-Oss(Geistlich Pharma, Switzerland) were used as controls in this study. Histomorphometric evaluation was performed at 4 and 8 weeks after surgery. RESULT: In histologic evaluation, new bone formation and direct bony contact with the graft particles were observed in all four groups. At 4 weeks, BCP-1(15.5%) and BCP-2(15.5%) groups showed greater amount of newly formed mineralized bone area(NB%) compared to BO(11.4%) and MBCP(10.3%) groups. The amounts of NB% at 8 weeks were greater than those of 4 weeks in all four groups, but there was no statistically significant differences in NB% between the groups. CONCLUSION: These results indicate that new bone substitutes, BCP with interconnected microporous structure and with or without internal macroporous structures, have the osteoconductivity comparable to those of commercially available bone substitutes, MBCP and Bio-Oss.

Histometrical evaluation of biphasic calcium phosphate in surgically created 1-wall periodontal intrabony defects in dogs / 대한치주과학회지

PURPOSE: The aim of this study was to evaluated biphasic calcium phosphate applied in surgically created 1-wall periodontal intrabony defects in dogs by histometrical analysis. MATERIAL AND METHOD: Critical sized(4 mm x 4 mm), one wall periodontal intrabony defects were surgically produced at the proximal aspect of mandibular premolars in either right and left jaw quadrants in four canines. The control group was treated with debridement alone, and experimental group was treated with debridement and biphasic calcium phosphate application. The healing processes were histologically and histometrically observed after 8 weeks. RESULTS: In biphasic calcium phosphate group, more new bone and cementum formation, less epithelium and connective tissue attachment were observed compared to other groups. But there was no statistical significance. CONCLUSION: Though the statistically significant difference could not be found, it seemed that there was more new bone and cementum formation with applying biphasic calcium phosphate in 1 wall intrabony defects in dogs by preventing junctional epithelium migration.

rhBMP-2 using biphasic calcium phosphate block as a carrier induces new bone formation in a rat subcutaneous tissue / 대한치주과학회지

PURPOSE: The carrier for the delivery of bone morphogenetic proteins(BMPs) should also serve as a scaffold for new bone growth. In addition, predictable bone formation in terms of the volume and shape should be guaranteed. This study evaluated the ectopic bone formation of recombinant human BMP-2(rhBMP-2) using a micro macroporous biphasic calcium phosphate (MBCP: mixture of betaTCP and HA) block as a carrier in a rat subcutaneous assay model. MATERIALS AND METHODS: Subcutaneous pockets were created on the back of 40 male Sprague-Dawley rats. In the pockets, rhBMP-2/MBCP and MBCP alone were implanted. The blocks were evaluated by histological and histometric parameters after a healing interval of 2 weeks (each 10 rats; MBCP and rhBMP-2/MBCP) or 8 weeks (each 10 rats; MBCP and rhBMP-2/MBCP). RESULTS: The shape and volume of the block was maintained stable over the healing period. No histological bone forming activity was observed in the MBCP alone sites after 2 weeks and there was minimal new bone formation at 8 weeks. In the rhBMP-2/MBCP sites, new bone formation was evident in the macropores of the block. The new bone area at 8 weeks was greater than at 2 weeks. There was a further increase in the quantity of new bone with the more advanced stage of remodeling. CONCLUSIONS: A MBCP block could serve as a carrier system for predictable bone tissue engineering using rhBMPs.

The Effect of Recombinant Human Bone Morphogenetic Protein-2/Macroporous Biphasic Calcium Phosphate Block system on Bone Formation in Rat Calvarial Defects / 대한치주과학회지

No abstract available.

Histologic evaluation of macroporous biphasic calcium phosphate(MBCP(R)) and flouorohydrxyapatite(Algipore(R)) in surgically created 1-wall periodontal intrabony defects of minipigs / 대한치주과학회지

Periodontal regenerative therapy and tissue engineering on defects destructed by severe periodontitis need maintaining of space, which provides the environment for cell migration, proliferation and differentiation. Application of bone grafts may offer this environment in periodontal defects. This study evaluated bone graft materials, MBCP(R) and Algipore(R), in surgically created 1-wall periodontal intrabony defects of minipigs by histological analysis. Critical sized(4mmX4mm), one wall periodontal intrabony defects were surgically produced at the proximal aspect of mandibular premolars in either right and left jaw quadrants in four minipigs. The control group was treated with debridement alone, and experimental group was treated with debridement and MBCP(R) and Algipore(R) application. The healing processes were histologically observed after 8 weeks and the results were as follows. 1. In the control group, limited new bone formation was observed. 2. In MBCP group, more new bone formation was observed compared to other groups. 3. Histologically, dispersed mixture of new bone, biomaterial particles and connective tissue were shown and osteoblasts, osteoclasts and new vessels were present in this area. 4. Defects with Algipore showed limited new bone formation and biomaterial particles capsulated by connective tissue. 5. Histologically, lots of osteoclasts were observed around the biomaterial but relatively small numbers of osteblasts were shown. Within the limitation to this study protocol, MBCP(R) application in 1-wall intrabony defect enhanced new bone formation rather than Algipore(R) application.