scholarly journals In vitro and in vivo assessment of biomedical Mg–Ca alloys for bone implant applications

2018 ◽  
Vol 16 (3) ◽  
pp. 126-136 ◽  
Author(s):  
Preeti Makkar ◽  
Swapan Kumar Sarkar ◽  
Andrew R. Padalhin ◽  
Byoung-Gi Moon ◽  
Young Seon Lee ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Bone Formation ◽  
Femoral Condyle ◽  
Immersion Test ◽  
Hydrogen Gas ◽  
In Vivo Studies ◽  
Biodegradable Implant ◽  
In Vitro Degradation

Background: Magnesium (Mg)-based alloys are considered to be promising materials for implant application due to their excellent biocompatibility, biodegradability, and mechanical properties close to bone. However, low corrosion resistance and fast degradation are limiting their application. Mg–Ca alloys have huge potential owing to a similar density to bone, good corrosion resistance, and as Mg is essential for Ca incorporation into bone. The objective of the present work is to determine the in vitro degradation and in vivo performance of binary Mg– xCa alloy ( x = 0.5 or 5.0 wt%) to assess its usability for degradable implant applications. Methods: Microstructural evolutions for Mg– xCa alloys were characterized by optical, SEM, EDX, and XRD. In vitro degradation tests were conducted via immersion test in phosphate buffer saline solution. In vivo performance in terms of interface, biocompatibility, and biodegradability of Mg– xCa alloys was examined by implanting samples into rabbit femoral condyle for 2 and 4 weeks. Results: Microstructural results showed the enhancement in intermetallic Mg2Ca phase with increase in Ca content. Immersion tests revealed that the dissolution rate varies linearly, with Ca content exhibiting more hydrogen gas evolution, increased pH, and higher degradation for Mg–5.0Ca alloy. In vivo studies showed good biocompatibility with enhanced bone formation for Mg–0.5Ca after 4 weeks of implantation compared with Mg–5.0Ca alloy. Higher initial corrosion rate with prolonged inflammation and rapid degradation was noticed in Mg–5.0Ca compared with Mg–0.5Ca alloy. Conclusions: The results suggest that Mg–0.5Ca alloy could be used as a temporary biodegradable implant material for clinical applications owing to its controlled in vivo degradation, reduced inflammation, and high bone-formation capability.

scholarly journals Low Intensity Pulsed Ultrasound for Bone Tissue Engineering

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1488
Author(s):  
Colleen McCarthy ◽  
Gulden Camci-Unal
Keyword(s):  
Bone Formation ◽  
Bone Tissue ◽  
Mechanical Stimulation ◽  
Synergistic Effects ◽  
In Vivo Studies ◽  
Pulsed Ultrasound ◽  
Low Intensity Pulsed Ultrasound ◽  
Low Intensity

As explained by Wolff’s law and the mechanostat hypothesis, mechanical stimulation can be used to promote bone formation. Low intensity pulsed ultrasound (LIPUS) is a source of mechanical stimulation that can activate the integrin/phosphatidylinositol 3-OH kinase/Akt pathway and upregulate osteogenic proteins through the production of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). This paper analyzes the results of in vitro and in vivo studies that have evaluated the effects of LIPUS on cell behavior within three-dimensional (3D) titanium, ceramic, and hydrogel scaffolds. We focus specifically on cell morphology and attachment, cell proliferation and viability, osteogenic differentiation, mineralization, bone volume, and osseointegration. As shown by upregulated levels of alkaline phosphatase and osteocalcin, increased mineral deposition, improved cell ingrowth, greater scaffold pore occupancy by bone tissue, and superior vascularization, LIPUS generally has a positive effect and promotes bone formation within engineered scaffolds. Additionally, LIPUS can have synergistic effects by producing the piezoelectric effect and enhancing the benefits of 3D hydrogel encapsulation, growth factor delivery, and scaffold modification. Additional research should be conducted to optimize the ultrasound parameters and evaluate the effects of LIPUS with other types of scaffold materials and cell types.

scholarly journals Biodegradable Zn–Sr alloy for bone regeneration in rat femoral condyle defect model: In vitro and in vivo studies

2021 ◽  
Vol 6 (6) ◽  
pp. 1588-1604
Author(s):  
Bo Jia ◽  
Hongtao Yang ◽  
Zechuan Zhang ◽  
Xinhua Qu ◽  
Xiufeng Jia ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Femoral Condyle ◽  
In Vivo Studies ◽  
Defect Model

scholarly journals In vivo and in vitro degradation of peptide YY3–36 to inactive peptide YY3–34 in humans

2016 ◽  
Vol 310 (9) ◽  
pp. R866-R874 ◽  
Author(s):  
Signe Toräng ◽  
Kirstine Nyvold Bojsen-Møller ◽  
Maria Saur Svane ◽  
Bolette Hartmann ◽  
Mette Marie Rosenkilde ◽  
...  
Keyword(s):  
Half Life ◽  
Peptide Yy ◽  
Degradation Products ◽  
In Vivo Studies ◽  
Metabolic Clearance ◽  
In Vitro Degradation ◽  
Healthy Men ◽  
Amino Acid Peptide

Peptide YY (PYY) is a 36-amino-acid peptide released from enteroendocrine cells upon food intake. The NH2 terminally truncated metabolite, PYY3–36, exerts anorexic effects and has received considerable attention as a possible antiobesity drug target. The kinetics and degradation products of PYY metabolism are not well described. A related peptide, neuropeptide Y, may be degraded from the COOH terminus, and in vivo studies in pigs revealed significant COOH-terminal degradation of PYY. We therefore investigated PYY metabolism in vitro after incubation in human blood and plasma and in vivo after infusion of PYY1–36 and PYY3–36 in eight young, healthy men. A metabolite, corresponding to PYY3–34, was formed after incubation in plasma and blood and during the infusion of PYY. PYY3–34 exhibited no agonistic or antagonistic effects on the Y2 receptor. PYY1–36 infused with and without coadministration of sitagliptin was eliminated with half-lives of 10.1 ± 0.5 and 9.4 ± 0.8 min (means ± SE) and metabolic clearance rates of 15.7 ± 1.5 and 14.1 ± 1.1 ml·kg−1·min−1 after infusion, whereas PYY3–36 was eliminated with a significantly longer half-life of 14.9 ± 1.3 min and a metabolic clearance rate of 9.4 ± 0.6 ml·kg−1·min−1. We conclude that, upon intravenous infusion in healthy men, PYY is inactivated by cleavage of the two COOH-terminal amino acids. In healthy men, PYY3–36 has a longer half-life than PYY1–36.

Effect of Fluoride Conversion Coating on Corrosion of Behavior of Mg-Ca-Zn Alloy

2013 ◽  
Vol 712-715 ◽  
pp. 3-6
Author(s):  
Shahram Ghaedi Faramoushjani ◽  
Farhad Chinaei ◽  
Hamid Reza Bakhsheshi-Rad ◽  
Mohd Hasbullah Idris
Keyword(s):  
Corrosion Resistance ◽  
Protective Layer ◽  
Corrosion Current ◽  
Immersion Test ◽  
Conversion Coating ◽  
Average Weight ◽  
In Vitro Degradation ◽  
Degradable Biomaterials ◽  
Zn Alloy

Magnesium and its alloys have been received huge attention as new kind of degradable biomaterials. However its application hindered by poor carrion resistance fluoride conversion coating was performed due to improve the corrosion resistance of Mg-Ca-Zn alloy. In the present work ccorrosion of behaviour and degradation bahaviour of fluoride treated Mg-Ca-Zn alloy were investigated. Microstructural evolutions were characterized by scanning electron microscopy and energy dispersive x-ray spectroscopy. The corrosion resistance was examined in vitro by potentiodynamic polarization and immersion test in Kokubo solution at room temperature. The coating characterization indicated that the dense and uniform film with 6 μm thickness consists of MgO and MgF2formed on the alloy. Polarization tests recorded a significant reduction in the corrosion current density from 188 μAcm-2in bare Mg-Ca-Zn to 6.11 μAcm-2in fluoride treated alloy as a result of formation MgF2protective layer. The in vitro degradation tests showed that the average weight loss of the untreated specimens significantly higher than that of fluoride treated Mg-Ca-Zn alloy. The results revealed that the fluoride conversion coating noticeably improve the corrosion resistance of Mg-Ca-Zn alloy resistance of Mg in Kokubo solution.

scholarly journals In vitro and in vivo studies of surface-structured implants for bone formation

2012 ◽  
pp. 4873 ◽  
Author(s):  
Lu Xia ◽  
Bo Feng ◽  
Peizhi Wang ◽  
Siyang Ding ◽  
Zhiyuan Liu ◽  
...  
Keyword(s):  
Bone Formation ◽  
In Vivo Studies

scholarly journals Osteoconductive and electroactive carbon nanofibers/hydroxyapatite nanocomposite tailored for bone tissue engineering: in vitro and in vivo studies

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hadi Samadian ◽  
Hamid Mobasheri ◽  
Mahmoud Azami ◽  
Reza Faridi-Majidi
Keyword(s):  
Tissue Engineering ◽  
Bone Formation ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Carbon Nanofibers ◽  
In Vivo Studies ◽  
Histological Evaluation ◽  
Control Group

Abstract In this study, we aimed to fabricate osteoconductive electrospun carbon nanofibers (CNFs) decorated with hydroxyapatite (HA) crystal to be used as the bone tissue engineering scaffold in the animal model. CNFs were derived from electrospun polyacrylonitrile (PAN) nanofibers via heat treatment and the carbonized nanofibers were mineralized by a biomimetic approach. The growth of HA crystals was confirmed using XRD, FTIR, and EDAX analysis techniques. The mineralization process turned the hydrophobic CNFs (WCA: 133.5° ± 0.6°) to hydrophilic CNFs/HA nanocomposite (WCA 15.3° ± 1°). The in vitro assessments revealed that the fabricated 24M-CNFs nanocomposite was biocompatible. The osteoconductive characteristics of CNFs/HA nanocomposite promoted in vivo bone formation in the rat’s femur defect site, significantly, observed by computed tomography (CT) scan images and histological evaluation. Moreover, the histomorphometric analysis showed the highest new bone formation (61.3 ± 4.2%) in the M-CNFs treated group, which was significantly higher than the negative control group (the defect without treatment) (< 0.05). To sum up, the results implied that the fabricated CNFs/HA nanocomposite could be considered as the promising bone healing material.

Hydrothermal Synthesis of Bioinert Oxide Film on Pure Ti: In Vitro and In Vivo Studies

2012 ◽  
Vol 1418 ◽  
Author(s):  
Masato Ueda ◽  
Masahiko Ikeda ◽  
Richard Langford ◽  
Jeremy Skepper ◽  
Ruth E. Cameron ◽  
...  
Keyword(s):  
Citric Acid ◽  
Bone Conduction ◽  
Immersion Test ◽  
In Vivo Studies ◽  
Contact Ratio ◽  
Bone Implant ◽  
Surface Product ◽  
Hank’S Solution

ABSTRACTTitanium and its alloys have been employed in bone plates/screws, and these are often designed to be removed after recovery. Bone is known to bond to the surface of Ti alloys. This can lead to re-fracture of newly repaired bone during operations to remove the implants, however bone does not bond to Zr-based alloys. The inhibition of bone conduction on the surface of Zr-based alloys is thought to be due to the presence of a thin layer of zirconia (ZrO2) on the surface. The purpose of the present study was to synthesize bioinert films, including ZrO2 on pure Ti surfaces. In vitro apatite (HAp) formation and in vivo bone conduction in the tibiae of rats on the films were also investigated.Commercial purity Ti was chemically treated with aqueous H2O2/HNO3 at 353 K for 20 min. The disks were hydrothermally treated with aqueous ZrOCl2/NH3/C6H8O7 (citric acid) in an autoclave at 453 K for 12 h. Simulated body fluid (SBF) immersion test and implantation into tibiae of rats were carried out.In the hydrothermal treatment with aqueous ZrOCl2/NH3, the surface product was anatase-type TiO2. On the other hand, when citric acid was added the surface of Ti was covered homogeneously with a TiO2–ZrO2 composite film though the amount of ZrO2 was very small. HAp began to form on the non-modified Ti and TiO2 surfaces after 6 days and 4 days immersion in Hank’s solution, respectively. On the surfaces of TiO2–ZrO2, the presence of precipitates was confirmed after 6-8 days. The HAp formation was suppressed on the surfaces of TiO2–ZrO2.The present TiO2-ZrO2 surface also showed significantly lower bone-implant contact ratio in cortical bone compared with TiO2.

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