Mechanical Properties of a Biodegradable Bone Regeneration Scaffold

2000 ◽  
Vol 122 (3) ◽  
pp. 286-288 ◽  
Author(s):  
B. D. Porter, ◽  
J. B. Oldham, ◽  
S.-L. He, and ◽  
M. E. Zobitz ◽  
R. G. Payne ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Regeneration ◽  
Trabecular Bone ◽  
Biodegradable Polymer ◽  
Modulus Of Elasticity ◽  
Mechanical Stability ◽  
Circular Cylinders ◽  
Order Of Magnitude ◽  
The Mean

Poly (Propylene Fumarate) (PPF), a novel, bulk erosion, biodegradable polymer, has been shown to have osteoconductive effects in vivo when used as a bone regeneration scaffold (Peter, S. J., Suggs, L. J., Yaszemski, M. J., Engel, P. S., and Mikos, A. J., 1999, J. Biomater. Sci. Polym. Ed., 10, pp. 363–373). The material properties of the polymer allow it to be injected into irregularly shaped voids in vivo and provide mechanical stability as well as function as a bone regeneration scaffold. We fabricated a series of biomaterial composites, comprised of varying quantities of PPF, NaCl and β-tricalcium phosphate (β-TCP), into the shape of right circular cylinders and tested the mechanical properties in four-point bending and compression. The mean modulus of elasticity in compression Ec was 1204.2 MPa (SD 32.2) and the mean modulus of elasticity in bending Eb was 1274.7 MPa (SD 125.7). All of the moduli were on the order of magnitude of trabecular bone. Changing the level of NaCl from 20 to 40 percent, by mass, did not decrease Ec and Eb significantly, but did decrease bending and compressive strength significantly. Increasing the β-TCP from 0.25 g/g PPF to 0.5 g/g PPF increased all of the measured mechanical properties of PPF/NVP composites. These results indicate that this biodegradable polymer composite is an attractive candidate for use as a replacement scaffold for trabecular bone. [S0148-0731(00)01203-6]

scholarly journals Properties of a bovine collagen type I membrane for guided bone regeneration applications

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 210-221
Author(s):  
Igor S. Brum ◽  
Carlos N. Elias ◽  
Jorge J. de Carvalho ◽  
Jorge L. S. Pires ◽  
Mario J. S. Pereira ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Collagen Type ◽  
Mechanical Stability ◽  
Collagen Type I ◽  
Guided Bone Regeneration ◽  
Bone Volume ◽  
Male Rats ◽  
Toxicity Tests ◽  
Type I

Abstract Dental implant treatment requires an available bone volume in the implantation site to ensure the implant’s mechanical stability. When the bone volume is insufficient, one must resort to surgical means such as guided bone regeneration (GBR). In GBR surgery, bone grafts and membranes are used. The objective of this work is to manufacture and characterize the in vitro and in vivo properties of resorbable collagen type I membranes (Green Membrane®) for GBR. Membrane surface morphology was characterized by SEM and roughness was measured using an interferometric noncontact 3D system. In vivo skin sensitization and toxicity tests have been performed on Wistar rats. Bone defects were prepared in 24 adult male rats, filled with biomaterials (Blue Bone® and Bio Oss®) and covered with collagen membranes to maintain the mechanical stability of the site for bone regeneration. The incisions were closed with simple stitches; and 60 days after the surgery, the animals were euthanized. Results showed that the analyzed membrane was homogeneous, with collagen fiber webs and open pores. It had no sign of cytotoxicity and the cells at the insertion site showed no bone morphological changes. There was no tissue reaction and no statistical difference between Blue Bone® and Bio Oss® groups. The proposed membrane has no cytotoxicity and displays a biocompatibility profile that makes it suitable for GBR.

scholarly journals Zn-Containing Membranes for Guided Bone Regeneration in Dentistry

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1797
Author(s):  
Manuel Toledano ◽  
Marta Vallecillo-Rivas ◽  
María T. Osorio ◽  
Esther Muñoz-Soto ◽  
Manuel Toledano-Osorio ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Regeneration ◽  
Bone Healing ◽  
Bone Repair ◽  
Complex Modulus ◽  
Bacterial Colonization ◽  
Guided Bone Regeneration ◽  
M2 Macrophage

Barrier membranes are employed in guided bone regeneration (GBR) to facilitate bone in-growth. A bioactive and biomimetic Zn-doped membrane with the ability to participate in bone healing and regeneration is necessary. The aim of the present study is to state the effect of doping the membranes for GBR with zinc compounds in the improvement of bone regeneration. A literature search was conducted using electronic databases, such as PubMed, MEDLINE, DIMDI, Embase, Scopus and Web of Science. A narrative exploratory review was undertaken, focusing on the antibacterial effects, physicochemical and biological properties of Zn-loaded membranes. Bioactivity, bone formation and cytotoxicity were analyzed. Microstructure and mechanical properties of these membranes were also determined. Zn-doped membranes have inhibited in vivo and in vitro bacterial colonization. Zn-alloy and Zn-doped membranes attained good biocompatibility and were found to be non-toxic to cells. The Zn-doped matrices showed feasible mechanical properties, such as flexibility, strength, complex modulus and tan delta. Zn incorporation in polymeric membranes provided the highest regenerative efficiency for bone healing in experimental animals, potentiating osteogenesis, angiogenesis, biological activity and a balanced remodeling. Zn-loaded membranes doped with SiO2 nanoparticles have performed as bioactive modulators provoking an M2 macrophage increase and are a potential biomaterial for promoting bone repair. Zn-doped membranes have promoted pro-healing phenotypes.

scholarly journals Longitudinal variation in mechanical competence of bone along the avian humerus.

1995 ◽  
Vol 198 (1) ◽  
pp. 209-212
Author(s):  
R H Bonser
Keyword(s):  
Mechanical Properties ◽  
Trabecular Bone ◽  
Cortical Bone ◽  
Vickers Microhardness ◽  
Bird Species ◽  
Longitudinal Variation ◽  
The Mean ◽  
Compressive Tests

Vickers microhardness tests were used to gauge the mechanical "competence" (ability to resist bending and failure) of cortical and trabecular bone along the humeri of three bird species. Hardness was greatest at the mid-length portion of the shaft. The mean hardness of trabeculae, where present, was between 78.7 and 90.9% of that of the adjacent cortical bone. The possible causes of this are briefly discussed. Microhardness tests offer the opportunity to gauge differences in mechanical properties over small distances and might usefully be applied to test the homogeneity of mechanical properties within specimens for tensile or compressive tests.

scholarly journals Method for Calibration of Left Ventricle Material Properties Using Three-Dimensional Echocardiography Endocardial Strains

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Yaghoub Dabiri ◽  
Kevin L. Sack ◽  
Nuno Rebelo ◽  
Peter Wang ◽  
Yunjie Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Left Ventricle ◽  
Diffusion Tensor ◽  
Diastolic Pressure ◽  
Three Dimensional ◽  
Heart Association ◽  
Mean Difference ◽  
Imaging Data ◽  
The Mean

We sought to calibrate mechanical properties of left ventricle (LV) based on three-dimensional (3D) speckle tracking echocardiographic imaging data recorded from 16 segments defined by American Heart Association (AHA). The in vivo data were used to create finite element (FE) LV and biventricular (BV) models. The orientation of the fibers in the LV model was rule based, but diffusion tensor magnetic resonance imaging (MRI) data were used for the fiber directions in the BV model. A nonlinear fiber-reinforced constitutive equation was used to describe the passive behavior of the myocardium, whereas the active tension was described by a model based on tissue contraction (Tmax). isight was used for optimization, which used abaqus as the forward solver (Simulia, Providence, RI). The calibration of passive properties based on the end diastolic pressure volume relation (EDPVR) curve resulted in relatively good agreement (mean error = −0.04 ml). The difference between the experimental and computational strains decreased after segmental strain metrics, rather than global metrics, were used for calibration: for the LV model, the mean difference reduced from 0.129 to 0.046 (circumferential) and from 0.076 to 0.059 (longitudinal); for the BV model, the mean difference nearly did not change in the circumferential direction (0.061) but reduced in the longitudinal direction from 0.076 to 0.055. The calibration of mechanical properties for myocardium can be improved using segmental strain metrics. The importance of realistic fiber orientation and geometry for modeling of the LV was shown.

How effective is KRM-1648 in treatment of disseminated Mycobacterium avium complex infections in beige mice?

1996 ◽  
Vol 40 (2) ◽  
pp. 437-442 ◽  
Author(s):  
B Ji ◽  
N Lounis ◽  
C Truffot-Pernot ◽  
J Grosset
Keyword(s):  
Mycobacterium Avium ◽  
Mycobacterium Avium Complex ◽  
Antimicrobial Effect ◽  
Bacteriostatic Effect ◽  
Dose Selection ◽  
Order Of Magnitude ◽  
The Mean ◽  
Resistant Mutants ◽  
Selection Of

Although the MICs of 3'-hydroxy-5'-(4-isobutyl-1-piperazinyl)benzoxazinorifamycin, or KRM-1648 (KRM), for Mycobacterium avium complex (MAC) were significantly lower than those of other drugs, its in vivo activity was very weak. Beginning 28 days after inoculation, beige mice that had been infected intravenously with 1.87 x 10(7) CFU of MAC 101 were administered KRM alone, clarithromycin (CLARI) alone, or CLARI plus KRM six times weekly for 16 weeks. In contrast to the mice treated with CLARI-containing regimens, the mortality and the mean spleen weights of mice treated with KRM alone (either 10 or 20 mg/kg of body weight per dose) did not differ significantly from those of untreated mice, their numbers of CFU were very much greater than pretreatment values, and multiplication of MAC was only slightly inhibited. Although monotherapy by KRM selected KRM-resistant mutants, the selection was very weak; the mean number of CFU and the frequency of KRM-resistant mutants increased by no more than 1 order of magnitude after 16 weeks of treatment with KRM at 20 mg/kg per dose. Selection of CLARI-resistant mutants was inhibited but not completely prevented by treatment of the mice with CLARI plus KRM. These results indicate that KRM displayed only a weak bacteriostatic effect against the isolate tested in the beige mouse model; its ability to enhance the antimicrobial effect of CLARI or to prevent emergence of CLARI-resistant mutants was very limited.

scholarly journals Bone Regeneration in Peri-Implant Defect Using Autogenous Tooth Biomaterial Enriched with Platelet-Rich Fibrin in Animal Model

2020 ◽  
Vol 10 (6) ◽  
pp. 1939 ◽  
Author(s):  
Moon Hwan Jung ◽  
Jeong Hun Lee ◽  
Puneet Wadhwa ◽  
Heng Bo Jiang ◽  
Hyon Seok Jang ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Regeneration Capacity ◽  
Histomorphometric Analysis ◽  
Implant Stability ◽  
Micro Computed Tomography ◽  
Platelet Rich Fibrin ◽  
New Zealand White Rabbits ◽  
Bone To Implant Contact ◽  
The Mean

Tooth biomaterial may be useful in bone regeneration for restoring peri-implant defects in vivo. The aim of this study was to compare bone regeneration capacity in peri-implant defects augmented with autogenous tooth biomaterial combined with platelet-rich fibrin (PRF), tooth biomaterial alone, or PRF alone. Two monocortical defects were generated on each tibia of 10 New Zealand white rabbits (n = 10 per group) with a trephine bur, and the dental implant was installed into the defects. In experimental groups 1, 2, and 3, the peri-implant defects were filled with tooth biomaterial and platelet-rich fibrin (PRF), tooth biomaterial only, and PRF only, respectively and the control was left empty. Micro computed tomography (CT), implant stability, and histomorphometric analysis were conducted eight weeks after operation. The mean regenerated bone areas were 53.87 ± 7.60%, 51.56 ± 6.45%, and 18.45 ± 1.34% in experimental groups 1, 2, and 3, respectively, and 11.57 ± 1.12% in the control. Mean bone-to-implant contact values were 43.67 ± 2.50%, 41.07 ± 2.59%, and 21.45 ± 1.25% in experimental groups 1, 2, and 3, respectively, and 16.57 ± 2.83% in the control. Tooth biomaterial enriched with platelet-rich fibrin (PRF) and tooth biomaterial alone showed more enhanced regeneration than PRF alone in our study.

scholarly journals Variations in Physico-Mechanical Properties of Lonchocarpus sericeus (Poir), a Lesser-Used Species in West Africa

2021 ◽  
Vol 71 (3) ◽  
pp. 252-261
Author(s):  
Lawrence Olanipekun Aguda ◽  
Babatola Olufemi ◽  
Babatunde Ajayi ◽  
Olajide Rasaq Adejoba ◽  
Adedeji Robert Ojo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
High Strength ◽  
Modulus Of Rupture ◽  
Wood Age ◽  
Lonchocarpus Sericeus ◽  
The Mean ◽  
End Use

Abstract This study investigates the properties of Lonchocarpus sericeus to determine its potential use for timber. Three matured trees of L. sericeus were selected from a forest located in Longe Village, Oluyole Local Government Area in Oyo State, Nigeria. Discs from the harvested trees were collected at the base (10%), middle (50%), and top (90%) and further partitioned into inner wood, center wood, and outer wood. An investigation was carried out to characterize the wood age, density, shrinkage, impact strength, modulus of elasticity, modulus of rupture, compressive, and shear strength. The ages were 28, 29 and 32 years. The mean wood density at 12 percent moisture content was 836.63 kg/m3, which shows that it belongs to the high-density wood category. The mean shrinkage values in the radial, tangential, and longitudinal directions were 2.50, 3.99, and 0.78 percent respectively; the volumetric shrinkage was 6.36 percent. These shrinkage values were indicative of good dimensional stability. The mean impact bending strength, modulus of rupture, modulus of elasticity, maximum shear strength parallel to grain, and maximum compression strength parallel to the grain were 24.14, 114.18, 11,276, 12.76, and 47.16 N/mm2, respectively. End-use assessments suggest that the wood species can be used in similar applications as well-known timbers. The study found L. sericeus to be very dense with high strength in comparison to well-known timbers. It was observed that the mechanical properties of the species decrease from the base to the top and also increase from the outer wood to the core wood.

In Vivo Assessment of Architecture and Micro-Finite Element Analysis Derived Indices of Mechanical Properties of Trabecular Bone in the Radius

2002 ◽  
Vol 13 (1) ◽  
pp. 6-17 ◽  
Author(s):  
B. van Rietbergen ◽  
G. von Ingersleben ◽  
C. Chesnut ◽  
B. MacDonald ◽  
H. K. Genant ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Trabecular Bone ◽  
Element Analysis ◽  
In Vivo Assessment

Membrane instability in late-stage erythropoiesis

Blood ◽  
2001 ◽  
Vol 97 (6) ◽  
pp. 1869-1875 ◽  
Author(s):  
Richard E. Waugh ◽  
Athanassios Mantalaris ◽  
Richard G. Bauserman ◽  
William C. Hwang ◽  
J. H. David Wu
Keyword(s):  
Mechanical Properties ◽  
Blood Cell ◽  
Structural Organization ◽  
Time Course ◽  
Mononuclear Cells ◽  
Mechanical Stability ◽  
Adhesive Contact ◽  
Cytoskeletal Proteins ◽  
Mature Cell ◽  
The Mean

During maturation of the red blood cell (RBC) from the nucleated normoblast stage to the mature biconcave discocyte, both the structure and mechanical properties of the cell undergo radical changes. The development of the mechanical stability of the membrane reflects underlying changes in the organization of membrane-associated cytoskeletal proteins, and so provides an assessment of the time course of the development of membrane structural organization. Membrane stability in maturing erythrocytes was assessed by measuring forces required to form thin, tubular, lipid strands (tethers) from the surfaces of mononuclear cells obtained from fresh human marrow samples, marrow reticulocytes, circulating reticulocytes, and mature erythrocytes. Cells were biotinylated and manipulated with a micropipette to form an adhesive contact with a glass microcantilever, which gave a measure of the tethering force. The cell was withdrawn at controlled velocity and aspiration pressure to form a tether from the cell surface. The mean force required to form tethers from marrow reticulocytes and normoblasts was 27 ± 9 pN, compared to 54 ± 14 pN for mature cells. The energy of dissociation of the bilayer from the underlying skeleton increases 4-fold between the marrow reticulocyte stage and the mature cell, demonstrating that the mechanical stability of the membrane is not completely established until the very last stages of RBC maturation.

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