In Vivo Effects of an Osteogenic Bone Extract on Cartilage of the Chick Embryo

1991 ◽  
Vol 252 ◽  
Author(s):  
Sally R. Frenkel ◽  
Ann B. Prewett ◽  
Richard D. Finkelman
Keyword(s):  
Growth Factors ◽  
Chick Embryo ◽  
Guanidine Hydrochloride ◽  
Bone Matrix ◽  
Water Soluble ◽  
Synthetic Activity ◽  
Animal Cells ◽  
Noncollagenous Proteins ◽  
In Vivo Effects

Growth and differentiation of animal cells are influenced by a number of interacting local and circulating protein factors. Several such growth factors, or morphogenetic proteins, that affect hard tissue regeneration and repair have been isolated from bone [1–3]. Bone matrix is a complex milieu consisting of serum, cell, and hydroxyapatite binding proteins, bioactive agents, and other proteins whose functions are not yet known. Most of the growth factors can be dissociated from the decalcified collagen matrix only by using chaotropic solvents such as guanidine hydrochloride or urea [4].This extraction removes virtually all noncollagenous proteins from the matrix, producing a nonselective portfolio of proteins, of which growth factors are only a small percentage. A series of chromatographic separations are then required to isolate the morphogenetic proteins from the mixture [5]. Recently, a process has been developed that permits selective extraction of certain growth factors from demineralized bone and produces a water-soluble extract of collagenous and noncollagenous proteins. When placed in an orthotopic site in the rat, the extract exhibits pronounced osteogenic activity and has a surface-adherent property that may be exploited in the coating of allograft bone or osteoprosthetic implants to facilitate osseointegration. The objective of this study is to observe the in vivo effects of this extract on proliferation and synthetic activity of cartilage cells of the chick embryo.

In Vitro and In Vivo Evaluation of a Calcium Phosphate and Demineralized Bone Matrix Composite Biomaterial

2010 ◽  
Vol 5 ◽  
pp. 1-12 ◽  
Author(s):  
A. Rosenberg ◽  
Aliassghar Tofighi ◽  
N. Camacho ◽  
J. Chang
Keyword(s):  
Calcium Phosphate ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Negative Control ◽  
Water Soluble ◽  
Dense Area ◽  
Viscosity Modifier ◽  
Demineralized Bone

A new class of osteoconductive and osteoinductive combination biomaterials composed of calcium phosphate cement (CPC), demineralized bone matrix (DBM) and a water-soluble viscosity modifier were prepared and characterized in-vitro and in-vivo. In previous studies, a range of combinations formulations were tested in order to compare their performance characteristic. In-vitro characterization results show that the mechanical strength is decreased when the amount of DBM increases. However, DBM does not affect the CPC’s ability to set hard and convert to nanocrystalline apatitic calcium phosphate, which shares the chemical structure of natural bone as seen in x-ray diffraction. It is known that the DBM alone is osteoinductive. In-vivo osteoinductivity testing of the formulations in an intramuscular, athymic rat model demonstrated that the combination material is also osteoinductive. Two formulations were chosen for in-vivo efficacy testing based on the results of in-vitro and in-vivo characterization. These formulations were studied using rabbit critical-sized femoral core defect model. The formulations were composed of DBM with particle sizes of 250 to 710 μm, carboxymethyl-cellulose (CMC) as the viscosity modifier and weight percent compositions of 50% DBM/ 45% CPC/ 5% CMC and 60% DBM/ 30% CPC/ 10% CMC. Bone integration and healing was graded at 6, 12, and 24 weeks. The two formulations were compared to the gold standard autograft at 12 weeks and to an empty defect as the negative control at 24 weeks. Based on micro-computed topography (μCT), both formulations allowed for continuity of bone throughout the defect region at all time points. No differences in dense area fraction were seen between two formulations at 6 weeks (p = 0.8661). There was no significant statistical difference between the two formulations and autograft at 12 weeks (p = 0.2467). At 24 weeks, both formulations had significantly higher dense area fractions than empty controls (p = 0.0001). Histologically, the biology of the treatment areas appeared to have returned to normal by 24 weeks with CPC appearing to be the principal osteogenic inducer. In conclusion, these combinations of CPC and DBM offers significant advantages (handling, mechanical properties and osteoinductivity) over current DBM products and can be an effective alternative to autograft in healing of bone defects.

scholarly journals In vivo transdifferentiation, osteoconductive and osteoinductive properties of experimental water-soluble organo-biomaterials – A Pilot Study

2021 ◽  
Vol 10 (5) ◽  
pp. e45310515017
Author(s):  
Viviane Rozeira Crivellaro ◽  
Gilvan Spada ◽  
Cláudia Salete Judachesci ◽  
Paula Porto Spada ◽  
Luiza Rodrigues Saling ◽  
...  
Keyword(s):  
Bone Matrix ◽  
Negative Control ◽  
Water Soluble ◽  
Bovine Bone ◽  
Longitudinal Effects ◽  
Variance Homogeneity ◽  
Immunohistochemical Analyses ◽  
Control Sham

Inorganic bovine bone matrix (IBBM) is a biomaterial with proven osteoconductive functionalities. The objective of this study was to assess the in vivo bone regeneration functionalities of IBBM modified or not by an experimental MOE in sheep. MOE synthesis was performed by suspending nacre particles (0.05 g, diameters < 0.01 mm) in anhydrous acetic acid (pH 7, 5 mL, 25°C, 72 hours) using magnetic stirring. Polyethylene carriers (d= 5.0 mm, l= 10.0 mm, open ends) of negative control (sham) or experimental groups (IBBM or MOE-modified IBBM) were placed (n=3 conditions /animal; intramuscularly) adjacent to the lower spine of adult sheep (8 animals, » 45 Kg, 2 years old). Tissues were harvested (at 3 or 6 months) after implantation in preparation for histological (H), morphometrical (MM) and immunohistochemical analyses (IH; Wnt-3a, CD34, Vimentin and PREF-1). MM data were tested for normality and variance homogeneity using the Shapiro-Wilk and Levene tests, and Mann Whitney and Kruskal-Wallis, respectively. IM data were analyzed using two-way ANOVA and Tukey tests. Differences (p < 0.05) were observed between experimental groups (IBBM and IBBM+MOE at both 3 and 6 months) and controls (sham) for total area; Differences were not found for presence of remnant particles among experimental groups. The highest formation of bone was observed with IBBM+MOE (6-months). No differences (p > 0.05) were found on IM analysis (CD34, Vimentin, PREF-1, Wnt3a). Results indicated that experimental materials (IBBM+MOE) display promising functionalities. Additional studies are necessary to define biomaterials’ longitudinal effects and long-term biocompatibility properties.

scholarly journals Preclinical analysis of cytokine therapy in the SCID-hu mouse

Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1479-1488 ◽  
Author(s):  
S Kyoizumi ◽  
LJ Murray ◽  
R Namikawa
Keyword(s):  
Growth Factors ◽  
Synergistic Effects ◽  
Small Animal ◽  
Human Neutrophils ◽  
Inhibitory Effects ◽  
Hematopoietic Growth Factors ◽  
In Vivo Effects ◽  
Dose Dependent ◽  
Stimulating Factor

A severe combined immunodeficient (SCID)-hu mouse model implanted with human fetal bone was used to assess the effects of various recombinant human (rh) hematopoietic growth factors, administered either alone or in combination, on human hematopoiesis in vivo. Treatment with rh granulocyte colony-stimulating factor (G-CSF) elicited the expansion of mature neutrophilic granulocyte populations in human marrow. Administration of rh interleukin-3 (IL-3) induced significant increases of eosinophilic granulocyte and burst-forming unit, erythrocyte (BFU-E) activity. The rhIL-6 did not cause significant changes in the subpopulations of human hematopoietic cells within the grafts, but did increase the number of colony-forming unit, granulocyte-macrophage and BFU-E. Pretreatment with rhIL-3 followed by rh erythropoietin (Epo) administration enhanced Epo-induced human erythropoiesis significantly. No synergistic effects on myelopoiesis were observed using sequential treatment with rhIL-3 followed by rhG-CSF. Instead, these factors seemed to work independently, with rhG-CSF increasing the percentage of neutrophils and rhIL-3 increasing the percentage of eosinophils. When administered simultaneously with rhEpo, rhIL-6 showed dose-dependent inhibitory effects on in vivo Epo-induced human erythropoiesis. The rhIL-6 also caused a reduction in the percentage of human neutrophils induced by rhG-CSF. These results suggest that the SCID-hu mouse provides a useful small animal model to assess the in vivo effects of hematopoietic growth factors on human hematopoiesis.

A Statistical Model to Allow the Phasing Out of the Animal Testing of Demineralised Bone Matrix Products

2007 ◽  
Vol 35 (4) ◽  
pp. 405-409 ◽  
Author(s):  
Samuel S. Murray ◽  
Elsa J. Brochmann ◽  
Judith O. Harker ◽  
Edward King ◽  
Ryan J. Lollis ◽  
...  
Keyword(s):  
Growth Factors ◽  
Statistical Model ◽  
Gold Standard ◽  
Interactive Effect ◽  
Bone Matrix ◽  
In Vivo Model ◽  
Demineralised Bone Matrix ◽  
In Vivo Assay ◽  
Demineralised Bone

Demineralised bone matrix (DBM) products are complex mixtures of proteins known to influence bone growth, turnover, and repair. They are used extensively in orthopaedic surgery, and are bioassayed in vivo prior to being used in clinical applications. Many factors contribute to the osteogenic potency of DBM, but the relative contributions of these factors, as well as the possibility of interactive effects, are not completely defined. The “gold standard” measure of the therapeutic value of DBM, the in vivo assay for ectopic bone formation, is costly, time-consuming, and involves the use of numerous animal subjects. We have measured the levels of five growth factors released by the collagenase digestion of DBM, and statistically related these levels with osteogenic potency as determined by a standard in vivo model, in order to determine which value or combination of values of growth factors best predict osteogenic activity. We conclude that the level of BMP-2 is the best single predictor of osteogenic potency, and that adding the values of other growth factors only minimally increases the predictive power of the BMP-2 measurement. A small, but significant, interactive effect between BMP-2 and BMP-7 was demonstrated. We present a statistical model based on growth factor (e.g. BMP-2) analysis that best predicts the in vivo assay score for DBM. This model allows the investigator to predict which lots of DBM are likely to exhibit in vivo bioactivity and which are not, thus reducing the need to conduct in vivo testing of insufficiently active lots of DBM. This model uses cut-point analysis to allow the user to assign an estimate of acceptable uncertainty with respect to the “gold standard” test. This procedure will significantly reduce the number of animal subjects used to test DBM products.

scholarly journals Preclinical analysis of cytokine therapy in the SCID-hu mouse

Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1479-1488 ◽  
Author(s):  
S Kyoizumi ◽  
LJ Murray ◽  
R Namikawa
Keyword(s):  
Growth Factors ◽  
Synergistic Effects ◽  
Small Animal ◽  
Human Neutrophils ◽  
Inhibitory Effects ◽  
Hematopoietic Growth Factors ◽  
In Vivo Effects ◽  
Dose Dependent ◽  
Stimulating Factor

Abstract A severe combined immunodeficient (SCID)-hu mouse model implanted with human fetal bone was used to assess the effects of various recombinant human (rh) hematopoietic growth factors, administered either alone or in combination, on human hematopoiesis in vivo. Treatment with rh granulocyte colony-stimulating factor (G-CSF) elicited the expansion of mature neutrophilic granulocyte populations in human marrow. Administration of rh interleukin-3 (IL-3) induced significant increases of eosinophilic granulocyte and burst-forming unit, erythrocyte (BFU-E) activity. The rhIL-6 did not cause significant changes in the subpopulations of human hematopoietic cells within the grafts, but did increase the number of colony-forming unit, granulocyte-macrophage and BFU-E. Pretreatment with rhIL-3 followed by rh erythropoietin (Epo) administration enhanced Epo-induced human erythropoiesis significantly. No synergistic effects on myelopoiesis were observed using sequential treatment with rhIL-3 followed by rhG-CSF. Instead, these factors seemed to work independently, with rhG-CSF increasing the percentage of neutrophils and rhIL-3 increasing the percentage of eosinophils. When administered simultaneously with rhEpo, rhIL-6 showed dose-dependent inhibitory effects on in vivo Epo-induced human erythropoiesis. The rhIL-6 also caused a reduction in the percentage of human neutrophils induced by rhG-CSF. These results suggest that the SCID-hu mouse provides a useful small animal model to assess the in vivo effects of hematopoietic growth factors on human hematopoiesis.

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