scholarly journals Collagen-Based Matrices for Osteoconduction: A Preclinical In Vivo Study

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 143
Author(s):  
Hiroki Katagiri ◽  
Yacine El Tawil ◽  
Niklaus P. Lang ◽  
Jean-Claude Imber ◽  
Anton Sculean ◽  
...  
Keyword(s):  
Bone Density ◽  
Central Area ◽  
Collagen Membrane ◽  
Lamellar Bone ◽  
Tissue Samples ◽  
Critical Size Defects ◽  
New Zealand White Rabbits ◽  
Calvarial Defects ◽  
Bone Height

The aim of this study was to evaluate the influence of additional hydroxyapatite (HA) in collagen-based matrices (CM) and membrane placement on bone formation in calvarial defects. Critical size defects in the calvaria of 16 New Zealand White Rabbits were randomly treated with CM or mineralized collagen-based matrices (mCM). Half of the sites were covered with a collagen membrane. Animals were euthanized after 12 weeks of healing. The samples were studied by micro-CT and histology. Newly formed lamellar bone was observed in all samples at the periphery of the defect. In the central areas, however, new bone composed of both woven and lamellar bone was embedded in the soft tissue. Samples treated with mCM showed more residual biomaterial and induced more small bony islands in the central areas of the defects than samples with CM. Nevertheless, a complete defect closure was not observed in any of the samples at 12 weeks. Membrane placement resulted in a decrease in bone density and height. Significant differences between the groups were revealed only between CM groups with and without membrane coverage for bone height in the central area of the defect. Neither mineralization of CM nor membrane placement improved the osteogenic capacity in this particular defect. Nevertheless, mineralisation influenced bone density without a membrane placement and bone volume underneath a membrane. CM may be used as a scaffold in bone regeneration procedures, without the need of a membrane coverage. Further preclinical studies are warrant to optimise the potential of mCM.

Effect of sex steroids on peak bone density of growing rabbits

1988 ◽  
Vol 255 (4) ◽  
pp. E416-E421 ◽  
Author(s):  
V. Gilsanz ◽  
T. F. Roe ◽  
D. T. Gibbens ◽  
E. E. Schulz ◽  
M. E. Carlson ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Neutron Activation Analysis ◽  
Bone Density ◽  
Sex Steroids ◽  
Skeletal Maturity ◽  
Quantitative Computed Tomography ◽  
Peak Bone Density ◽  
New Zealand White Rabbits

To determine the effect of sex hormones on bone density (BD) during growth, longitudinal quantitative computed tomography (QCT) measurements were obtained in growing, castrated New Zealand White rabbits following administration of normal saline, testosterone, or estrogen from 6 wk of age until the time of skeletal maturity. Vertebral QCT densities increased during growth, were highest at the time of epiphyseal closure, and were significantly greater (P less than 0.001) in hormone-treated animals. In vivo QCT measurements in 12 vertebraes correlated strongly (r = 0.92) with percentage of calcium per weight assessed in vitro by neutron activation analysis.

scholarly journals Histomorphometric and Radiographic Analysis of Biological Responses Following the Use of Pure Hydroxyapatite and Hydroxyapatite with Collagen

2020 ◽  
pp. 1-8
Author(s):  
Juliana Larocca de Geus ◽  
Sandra Regina Masetto Antunes ◽  
Edson Durval Menezes Alves ◽  
Eduardo Bauml Campagnoli ◽  
Érika de Lara ◽  
...  
Keyword(s):  
Critical Size ◽  
Collagen Membrane ◽  
Critical Size Defects ◽  
Group 4 ◽  
Biological Responses ◽  
Synthetic Hydroxyapatite ◽  
Group 3 ◽  
Group 2 ◽  
Source Of Information

Background and Objectives: The objective of this study was to evaluate in vivo two new biomaterials for bone substitution aiming to determining their ability to enable bone neoformation in critical-size defects in rats’ calvaria. Methods: Synthetic hydroxyapatite were developed – Pure hydroxyapatite (HaP) and Hydroxyapatite with collagen (HCol). The third synthetic hydroxyapatite used as a comparing element was the commercial hydroxyapatite Alobone® (HaAl). Sixty Wistar rats divided randomly into four groups (Group 1, HaP; Group 2, HaCol; Group 3, HaAl and Group 4, Control). Critical size defects of 8mm were performed in the calvaria, and the three biomaterials were implanted. All groups also received a collagen membrane. Results: On day 30, the inflammatory response on the defect was practically absent in all groups, mainly when compared to the period of 7 days. Some areas of bone neoformation were seen. There was predominance of osteoblasts, osteocytes, and macrophages in lower amounts. Regarding the radiographic aspect, after 30 days, a marked biodegradation of the hydroxyapatite and signs of bone neoformation were observed. Conclusions: It was concluded that the results of our study in vivo can be used as a preliminary source of information about biocompatibility, biodegradability, and bone neoformation from the implant of new biomaterials in vivo.

scholarly journals The effect of synthetic bone graft substitutes on bone formation in rabbit calvarial defects

2021 ◽  
Vol 32 (1) ◽  
Author(s):  
Nikola Saulacic ◽  
Masako Fujioka-Kobayashi ◽  
Yasushi Kimura ◽  
Ava Insa Bracher ◽  
Claudio Zihlmann ◽  
...  
Keyword(s):  
Bone Formation ◽  
Collagen Membrane ◽  
Bony Tissue ◽  
Critical Size Defects ◽  
Woven Bone ◽  
Ha Coating ◽  
Healing Period ◽  
Calvarial Defects ◽  
Bone Graft Substitutes ◽  
Biomimetic Hydroxyapatite

AbstractThe aim of this study was to evaluate the influence of the intensity of the biomimetic hydroxyapatite (HA) coating of α-tricalcium phosphate (α-TCP) on biomaterial degradation and bone formation. Twenty-four female NZW rabbits of approximately 12 weeks of age were used. Critical size defects were randomly treated with 3%:97% HA:α-TCP (BBCP1), 12%:88% HA:α-TCP (BBCP2), and 23%:77% HA:α-TCP (BBCP3), respectively or sham. All defects were covered with a resorbable collagen membrane. Animals were euthanized after 3 and 12 weeks of healing and samples were investigated by micro-CT and histologic analysis. Ingrowth of newly formed woven bone from the original bone at 3-week healing period was observed in all samples. At the 12-week healing period, the new bone in the peripheral area was mainly lamellar and in the central region composed of both woven and lamellar bone. New bony tissue was found on the surface of all three types of granules and at the interior of the BBCP1 granules. Samples with 3% HA showed significantly less residual biomaterial in comparison to the other two groups. Furthermore, BBCP1 significantly promoted new bone area as compared to other three groups and more bone volume as compared to the control. Within its limitations, this study indicated the highest degradation rate in case of BBCP1 concomitant with the highest rate of bone formation. Hence, formation of new bone can be affected by the level of biomimetic HA coating of α-TCP.

Biomedical applications: Pitfalls in the practice

1994 ◽  
Vol 52 ◽  
pp. 378-379
Author(s):  
J. D. Shelburne ◽  
Peter Ingram ◽  
Victor L. Roggli ◽  
Ann LeFurgey
Keyword(s):  
Operating Room ◽  
Liquid Nitrogen ◽  
Lung Tissue ◽  
Biomedical Applications ◽  
Microprobe Analysis ◽  
Tissue Sample ◽  
Cellular Level ◽  
Tissue Samples ◽  
Asbestos Fibers

At present most medical microprobe analysis is conducted on insoluble particulates such as asbestos fibers in lung tissue. Cryotechniques are not necessary for this type of specimen. Insoluble particulates can be processed conventionally. Nevertheless, it is important to emphasize that conventional processing is unacceptable for specimens in which electrolyte distributions in tissues are sought. It is necessary to flash-freeze in order to preserve the integrity of electrolyte distributions at the subcellular and cellular level. Ideally, biopsies should be flash-frozen in the operating room rather than being frozen several minutes later in a histology laboratory. Electrolytes will move during such a long delay. While flammable cryogens such as propane obviously cannot be used in an operating room, liquid nitrogen-cooled slam-freezing devices or guns may be permitted, and are the best way to achieve an artifact-free, accurate tissue sample which truly reflects the in vivo state. Unfortunately, the importance of cryofixation is often not understood. Investigators bring tissue samples fixed in glutaraldehyde to a microprobe laboratory with a request for microprobe analysis for electrolytes.

Scintigraphic Detection of Experimental Myocardial Infarction with 99mTc-2,3-Dimercaptosuccinic Acid

1984 ◽  
Vol 23 (06) ◽  
pp. 317-319
Author(s):  
J. Novák ◽  
Y. Mazurová ◽  
J. Kubíček ◽  
J. Yižd’a ◽  
P. Kafka ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Intravenous Administration ◽  
Experimental Myocardial Infarction ◽  
Myocardial Infarctions ◽  
Clinical Use ◽  
Scintigraphic Imaging ◽  
Tissue Samples ◽  
Scintigraphic Finding

SummaryAcute myocardial infarctions were produced by ligature of the left frontal descending coronary artery in 9 dogs. The possibility of scintigraphic imaging with 99mTc-DMSA 4 hrs after intravenous administration was studied. The infarctions were 4, 24 and 48 hrs old. The in vivo scan was positive in only one dog with a 4-hr old infarction. The in vivo scans were confirmed by the analysis of the radioactivity in tissue samples. The accumulation of the radiopharmaceutical increased slightly in 48-hr old lesions; however, this increase was not sufficient for a positive scintigraphic finding. Thus, we do not recommend 99mTc-DMSA for clinical use in acute lesions.

In vivo Experiments of Natural Products Protection of Antagonistic Effects of Lead on Iron

2018 ◽  
Vol 68 (12) ◽  
pp. 2747-2751
Author(s):  
Marioara Nicula ◽  
Nicolae Pacala ◽  
Lavinia Stef ◽  
Ioan Pet ◽  
Dorel Dronca ◽  
...  
Keyword(s):  
Aquatic Environment ◽  
Iron Homeostasis ◽  
Iron Concentration ◽  
Antagonistic Effect ◽  
Tissue Samples ◽  
Antagonistic Effects ◽  
In Vivo Experiments ◽  
Living Organisms ◽  
Toxic Potential

Living organisms take nutrients from the environment, and together with them, substances with toxic potential � such as heavy metals. Lead is one common metal pollutant especially in aquatic environment, from where the fish can be intoxicated very easily. Bioavailability, distribution, toxic action, synergistic and antagonistic effects are characteristics which can alter the fish health. Our experimental study followed the effects of lead overload in water on iron distribution, in different tissues sample Carassius gibelio Bloch fish. We performed the experiment in four different fish groups: control C; lead � Pb (administration of lead in water 0.075mg/mL of water, as Pb(NO3)2 x � H2O); lead (the same dose) and 2% of freeze-dry garlic incorporated into fishes� food � Pb+garlic; lead (the same dose) and 2% chlorella incorporated into fishes� food � Pb+chlorella, for 21 consecutive days. The iron concentration was analysed with AAS (Atomic Absorption Spectroscopy) from gills, muscle, skin (and scales), intestine, liver, heart, brain, ovary, testicles, and kidney. The obtained data presented a significantly decrease of iron content in all tested tissue samples that demonstrated, alteration of iron homeostasis, explained by a strong antagonistic effect of lead on iron. Our experiment showed that biologic active principles from garlic and chlorella act like natural protectors, and potentiate the iron deficiency even in the case of lead overload in aquatic environment, for fish.

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