scholarly journals Biocompatibility, degradability, bioactivity and osteogenesis of mesoporous/macroporous scaffolds of mesoporous diopside/poly( l -lactide) composite

2015 ◽  
Vol 12 (111) ◽  
pp. 20150507 ◽  
Author(s):  
Zhulin Liu ◽  
Jiajin Ji ◽  
Songchao Tang ◽  
Jun Qian ◽  
Yonggang Yan ◽  
...  
Keyword(s):  
Degradation Products ◽  
Immunohistochemical Analysis ◽  
Solution Casting ◽  
Macroporous Structure ◽  
New Bone Formation ◽  
Composite Scaffolds ◽  
Good Biocompatibility ◽  
Particulate Leaching ◽  
Acidic Degradation

Bioactive mesoporous diopside (m-DP) and poly( l -lactide) (PLLA) composite scaffolds with mesoporous/macroporous structure were prepared by the solution-casting and particulate-leaching method. The results demonstrated that the degradability and bioactivity of the mesoporous/macroporous scaffolds were significantly improved by incorporating m-DP into PLLA, and that the improvement was m-DP content-dependent. In addition, the scaffolds containing m-DP showed the ability to neutralize acidic degradation products and prevent the pH from dropping in the solution during the soaking period. Moreover, the scaffolds containing m-DP enhanced attachment, proliferation and alkaline phosphatase activity of MC3T3-E1 cells, which were also m-DP content-dependent. Furthermore, the histological and immunohistochemical analysis results showed that the scaffolds with m-DP significantly promoted new bone formation and improved the materials degraded in vivo , indicating good biocompatibility. The results suggested that the mesoporous/macroporous scaffolds of the m-DP/PLLA composite with osteogenesis had a potential for bone regeneration.

scholarly journals Coatings Based on Organic/Non-Organic Composites on Bioinert Ceramics by Using Biomimetic Co-Precipitation

Ceramics ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 260-270 ◽  
Author(s):  
Tomasz Engelmann ◽  
Gaëlle Desante ◽  
Norina Labude ◽  
Stephan Rütten ◽  
Rainer Telle ◽  
...  
Keyword(s):  
Immunohistochemical Analysis ◽  
Sem Images ◽  
Soaking Time ◽  
Chemical Inertness ◽  
Good Biocompatibility ◽  
Co Precipitation ◽  
Substrate Surfaces ◽  
Bioinert Ceramics ◽  
Standard Protein

Bioinert ceramics have been commonly used in the field of orthopedic and dentistry due to their excellent mechanical properties, esthetic look, good biocompatibility and chemical inertness. However, an activation of its bioinert surface could bring additional advantages for better implant-integration in vivo. Therefore, we introduce an innovative biomimetic co-precipitation technique by using modified simulated body fluid (SBF) to obtain a composite coating made of organic/non-organic components. The zirconia samples were soaked in SBF containing different concentrations of protein (0.01, 0.1, 1, 10 and 100 g/l). Bovine serum albumin (BSA) was applied as a standard protein. During the soaking time, a precipitation of calcium phosphate took place on the substrate surfaces. The proteins were incorporated into the coating during precipitation. Morphology changes of precipitated hydroxyapatite (HAp) due to the presence of proteins were observed on SEM-images. The presence of proteins within the coating was proven by using SEM/energy dispersive X-ray spectroscopy (EDX) and immunohistochemical analysis. We conclude that it is possible to co-precipitate the organic/non-organic composite on inert ceramic by using the wet-chemistry method. In future studies, BSA could be replaced by targeted proteins appropriate to the application area. This method could create new biomaterials, the surfaces of which could be tailored according to the desires and requirements of their use.

Cotton-Wool-Like Resorbable Bone Void Fillers Containing β-TCP and Calcium Carbonate Particles

2018 ◽  
Vol 782 ◽  
pp. 53-58 ◽  
Author(s):  
Naoki Osada ◽  
Masashi Makita ◽  
Yasutoshi Nishikawa ◽  
Toshihiro Kasuga
Keyword(s):  
Distal Femur ◽  
Cotton Wool ◽  
Micro Ct ◽  
New Bone Formation ◽  
Defect Sites ◽  
Electrospinning Method ◽  
New Zealand White Rabbits ◽  
Good Biocompatibility ◽  
Bone Void

Cotton-wool-like bioresorbable bone void fillers consisting of β-tricalcium phosphate (β-TCP), siloxane-containing vaterite (SiV) and poly (L-lactic acid) (PLLA) was prepared by an electrospinning method. The fibers, which were 50 ~ 150 μm-width with 10 ~ 30 μm-thickness, were entwined. The resulting cotton-wool-like material showed mechanical flexibility and excellent shapability; it showed easy, excellent mechanical-fixation in defects. The in vivo performance of this material was examined in the distal femur in New Zealand white rabbits. It was evaluated using micro CT and histologic analyses at time points of 6 and 12 weeks. These analyses of the defect sites verified normal healing response and new bone formation. The in vivo testing with rabbits showed good biocompatibility and excellent osteogenic ability.

Biocompatibility and Osteogenesis of Calcium Phosphate Cement Scaffolds for Bone Tissue Engineering

2008 ◽  
Vol 47-50 ◽  
pp. 1383-1386 ◽  
Author(s):  
Han Guo ◽  
Jie Wei ◽  
Hang Kong ◽  
Chang Sheng Liu ◽  
Ke Feng Pan
Keyword(s):  
Stem Cells ◽  
Calcium Phosphate ◽  
Calcium Phosphate Cement ◽  
New Bone Formation ◽  
Negative Effects ◽  
Osteoblastic Phenotype ◽  
Proliferation And Differentiation ◽  
Good Biocompatibility

Porous calcium phosphate cement (CPC) scaffolds were successfully fabricated utilizing particle-leaching method. Mesenchymal stem cells (MSCs) were cultured, expanded and seeded on the scaffolds and the proliferation and differentiation of MSCs into osteoblastic phenotype were determined using MTT assay, ALP activity and ESEM. The results revealed that the CPC scaffolds were biocompatible and had no negative effects on the MSCs in vitro. The in vivo biocompatibility and osteogenicity of the scaffolds were investigated. Both pure scaffolds and MSCs/scaffold constructs were implanted in rabbit mandibles and studied histologically. The results showed that CPC scaffolds exhibited good biocompatibility and osteoconductivity. Moreover, the introduction of MSCs into the scaffolds dramatically enhanced the efficiency of new bone formation initially.

Plasma-Sprayed Wollastonite Coatings for Biomedical Application

2005 ◽  
Vol 486-487 ◽  
pp. 201-204 ◽  
Author(s):  
Wei Chang Xue ◽  
Xuan Yong Liu ◽  
Xue Bin Zheng ◽  
Chuan Xian Ding
Keyword(s):  
Mechanical Properties ◽  
Body Fluid ◽  
Biomedical Application ◽  
Fibrous Tissue ◽  
New Bone Formation ◽  
Living Bone ◽  
Good Biocompatibility ◽  
Plasma Sprayed

A new bioceramic coating based on wollastonite was prepared by plasma spraying. The coatings exhibited good mechanical properties. The bond strength of the coating on substrate was about 40 MPa, which is higher than that of HA coatings used in orthopedics and dentistry. The bioactivity of wollastonite coatings was evaluated in vitro and in vivo. After immersed in simulated body fluid, a bone-like apatite layer was formed on the surface of wollastonite coatings. Osteoblast could survive and proliferate on the surface of coatings. After implanted in dog’s cortical bone, histological observation demonstrated that bone tissue could extend and grow along the surface of wollastonite coatings. The coating bonded directly to bone without any fibrous tissue, indicating good biocompatibility and bone conductivity. The wollastonite coatings also showed good bone inductivity property, inducing new-bone formation on their surface after implanted in marrow. The results obtained indicated that the plasma-sprayed wollastonite coatings possessed good mechanical properties and excellent bioactivity in vitro and in vivo. It appears that a wollastonite coating may be suitable for the repair and replacement of living bone, especially for load-bearing situations.

In Vivo Behavior of Calcium Phosphate Glasses with Controlled Solubility

2005 ◽  
Vol 284-286 ◽  
pp. 893-896 ◽  
Author(s):  
Melba Navarro ◽  
E.S. Sanzana ◽  
Josep A. Planell ◽  
M.P. Ginebra ◽  
P.A. Torres
Keyword(s):  
Calcium Phosphate ◽  
Biological Response ◽  
Phosphate Glasses ◽  
New Bone Formation ◽  
Tissue Engineering Scaffolds ◽  
Bone Fixation ◽  
Vitreous System ◽  
Fixation Devices ◽  
Good Biocompatibility

Resorbable calcium phosphate glasses offer interesting solutions in the biomedical field, as bone cavity fillers, drug delivery systems, biodegradable reinforcing phase in the case of composites for bone fixation devices and tissue engineering scaffolds. In this work, two different glass formulations in the systems 44.5CaO-44.5P2O5-(11-X)Na2O-XTiO2 (X=0or 5) have been elaborated. It is known that the incorporation or TiO2 into the vitreous system reduces considerably the solubility of the glasses. To study the material solubility effect on the in vivo response, glass particles of the two formulations were implanted in rabbits. Results showed that both glasses elicited a similar biological response and good biocompatibility. The percentage of new bone formation in the glasses was comparable to that obtained for the autologous bone (control) after 12 weeks of implantation. The materials showed to have an osteoconductive potential. Finally, this study showed that in spite of the solubility difference of the studied glasses, there were no significant differences in the in vivo response.

The Inhibition of Platelet Aggregation by an Aorta Intima Extract

1974 ◽  
Vol 32 (02/03) ◽  
pp. 417-431 ◽  
Author(s):  
A. du P Heyns ◽  
D. J van den Berg ◽  
G. M Potgieter ◽  
F. P Retief
Keyword(s):  
Platelet Aggregation ◽  
Degradation Products ◽  
Adenosine Diphosphate ◽  
Inhibitory Effect ◽  
Protective Role ◽  
Vascular Trauma ◽  
Wear And Tear ◽  
Sequential Addition ◽  
Aggregation Activity

SummaryThe platelet aggregating activity of extracts of different layers of the arterial wall was compared to that of Achilles tendon. Arterial media and tendon extracts, adjusted to equivalent protein content as an index of concentration, aggregated platelets to the same extent but an arterial intima extract did not aggregate platelets. Platelet aggregation induced by collagen could be inhibited by mixing with intima extract, but only to a maximum of about 80%. Pre-mixing adenosine diphosphate (ADP) with intima extracts diminished the platelet aggregation activity of the ADP. Depending on the relationship between ADP and intima extract concentrations aggregating activity could either be completely inhibited or inhibition abolished. Incubation of ADP with intima extract and subsequent separation of degradation products by paper chromatography, demonstrated a time-dependent breakdown of ADP with AMP, adenosine, inosine and hypoxanthine as metabolic products; ADP removal was complete. Collagen, thrombin and adrenaline aggregate platelets mainly by endogenous ADP of the release reaction. Results of experiments comparing inhibition of aggregation caused by premixing aggregating agent with intima extract, before exposure to platelets, and the sequential addition of first the intima extract and then aggregating agent to platelets, suggest that the inhibitory effect of intima extract results from ADP breakdown. It is suggested that this ADP degradation by intima extract may play a protective role in vivo by limiting the size of platelet aggregates forming at the site of minimal “wear and tear” vascular trauma.

Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse
Keyword(s):  
High Purity ◽  
Time Course ◽  
Prothrombin Complex Concentrate ◽  
Degradation Products ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

Accumulation of Macromolecular Particles in the Reticuloendothelial System (RES) Mediated by Platelet Aggregation and Disaggregation

1969 ◽  
Vol 22 (03) ◽  
pp. 496-507 ◽  
Author(s):  
W.G van Aken ◽  
J Vreeken
Keyword(s):  
Platelet Aggregation ◽  
Degradation Products ◽  
Reticuloendothelial System ◽  
Caproic Acid ◽  
Carbon Particles ◽  
Carbon Clearance ◽  
Aggregation And Disaggregation ◽  
Platelet Aggregates

SummaryCarbon particles cause platelet aggregation in vitro and in vivo. Prior studies established that substances which modify thrombocyte aggregation also influence the rate at which carbon is cleared from the blood.This study was performed in order to elucidate the mechanism by which the carbon-platelet aggregates specifically accumulate in the RES.Activation of fibrinolysis by urokinase or streptokinase reduced the carbon clearance rate, probably due to generated fibrinogen degradation products (FDP). Isolated FDP decreased the carbon clearance and caused disaggregation of platelets and particles in vitro. Inhibition of fibrinolysis by epsilon-amino-caproic acid (EACA), initially accelerated the disappearance of carbon and caused particle accumulation outside the RES, predominantly in the lungs. It is supposed that platelet aggregation and locally activated fibrinolysis act together in the clearance of particles. In the normal situation the RES with its well known low fibrinolytic activity, becomes the receptor of the particles.

The Effects of Brinolase (Fibrinolytic Enzyme from Aspergillus Oryzae) on Platelet Aggregation of Dog and Man

1972 ◽  
Vol 28 (01) ◽  
pp. 031-048 ◽  
Author(s):  
W. H. E Roschlau ◽  
R Gage
Keyword(s):  
Platelet Aggregation ◽  
Aspergillus Oryzae ◽  
Degradation Products ◽  
Blood Platelet ◽  
Human Platelets ◽  
Fibrinolytic Enzyme ◽  
Inhibitory Effects ◽  
Blood Platelet Aggregation

SummaryInhibition of blood platelet aggregation by brinolase (fibrinolytic enzyme from Aspergillus oryzae) has been demonstrated with human platelets in vitro and with dog platelets in vivo and in vitro, using both ADP and collagen as aggregating stimuli. It is suggested that the optimal inhibitory effects of brinolase occur indirectly through the generation of plasma fibrinogen degradation products, without compromising platelet viability, rather than by direct proteolysis of platelet structures.

Turnover of Human Extrinsic (Tissue-Type) Plasminogen Activator in Rabbits

1981 ◽  
Vol 46 (03) ◽  
pp. 658-661 ◽  
Author(s):  
C Korninger ◽  
J M Stassen ◽  
D Collen
Keyword(s):  
Plasminogen Activator ◽  
Intravenous Injection ◽  
Active Site ◽  
Half Life ◽  
Degradation Products ◽  
Gel Filtration ◽  
Tissue Type ◽  
Organ Distribution ◽  
Small Rise

SummaryThe turnover of highly purified human extrinsic plasminogen activator (EPA) (one- and two-chain form) was studied in rabbits. Following intravenous injection, EPA-activity declined rapidly. The disappearance rate of EPA from the plasma could adequately be described by a single exponential term with a t ½ of approximately 2 min for both the one-chain and two-chain forms of EPA.The clearance and organ distribution of EPA was studied by using 125I-labeled preparations. Following intravenous injection of 125I-1abeled EPA the radioactivity disappeared rapidly from the plasma also with a t ½ of approximately 2 min down to a level of 15 to 20 percent, followed by a small rise of blood radioactivity. Gel filtration of serial samples revealed that the secondary increase of the radioactivity was due to the reappearance of radioactive breakdown products in the blood. Measurement of the organ distribution of 125I at different time intervals revealed that EPA was rapidly accumulated in the liver, followed by a release of degradation products in the blood.Experimental hepatectomy markedly prolonged the half-life of EPA in the blood. Blocking the active site histidine of EPA had no effect on the half-life of EPA in blood nor on the gel filtration patterns of 125I in serial plasma samples.It is concluded that human EPA is rapidly removed from the blood of rabbits by clearance and degradation in the liver. Recognition by the liver does not require a functional active site in the enzyme. Neutralization in plasma by protease inhibitors does not represent a significant pathway of EPA inactivation in vivo.

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