scholarly journals In vitro and in vivo degradation of poly(D, L-lactide-co-glycolide)/amorphous calcium phosphate copolymer coated on metal stents

2011 ◽  
Vol 96A (4) ◽  
pp. 632-638 ◽  
Author(s):  
Xiaodong Ma ◽  
Shizu Oyamada ◽  
Tim Wu ◽  
Michael P. Robich ◽  
Hao Wu ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Metal Stents ◽  
In Vivo Degradation

scholarly journals Phosphoserine Functionalized Cements Preserve Metastable Phases, and Reprecipitate Octacalcium Phosphate, Hydroxyapatite, Dicalcium Phosphate, and Amorphous Calcium Phosphate, during Degradation, In Vitro

2019 ◽  
Vol 10 (4) ◽  
pp. 54 ◽  
Author(s):  
Joseph Lazraq Bystrom ◽  
Michael Pujari-Palmer
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Octacalcium Phosphate ◽  
Ionic Concentration ◽  
Strong Adhesion ◽  
Acidic Conditions ◽  
Rapid Transformation ◽  
Comparable Mass

Phosphoserine modified cements (PMC) exhibit unique properties, including strong adhesion to tissues and biomaterials. While TTCP-PMCs remodel into bone in vivo, little is known regarding the bioactivity and physiochemical changes that occur during resorption. In the present study, changes in the mechanical strength and composition were evaluated for 28 days, for three formulations of αTCP based PMCs. PMCs were significantly stronger than unmodified cement (38–49 MPa vs. 10 MPa). Inclusion of wollastonite in PMCs appeared to accelerate the conversion to hydroxyapatite, coincident with slight decrease in strength. In non-wollastonite PMCs the initial compressive strength did not change after 28 days in PBS (p > 0.99). Dissolution/degradation of PMC was evaluated in acidic (pH 2.7, pH 4.0), and supersaturated fluids (simulated body fluid (SBF)). PMCs exhibited comparable mass loss (<15%) after 14 days, regardless of pH and ionic concentration. Electron microscopy, infrared spectroscopy, and X-ray analysis revealed that significant amounts of brushite, octacalcium phosphate, and hydroxyapatite reprecipitated, following dissolution in acidic conditions (pH 2.7), while amorphous calcium phosphate formed in SBF. In conclusion, PMC surfaces remodel into metastable precursors to hydroxyapatite, in both acidic and neutral environments. By tuning the composition of PMCs, durable strength in fluids, and rapid transformation can be obtained.

scholarly journals Amorphous calcium phosphate nanoparticles using adenosine triphosphate as an organic phosphorus source for promoting tendon–bone healing

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Haoran Liao ◽  
Han-Ping Yu ◽  
Wei Song ◽  
Guangcheng Zhang ◽  
Bingqiang Lu ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Rotator Cuff ◽  
Adenosine Triphosphate ◽  
Bone Healing ◽  
Amorphous Calcium Phosphate ◽  
Organic Phosphorus ◽  
Biological Activities ◽  
Phosphorus Source

Abstract Background Rotator cuff tear (RCT) is a common problem of the musculoskeletal system. With the advantage of promoting bone formation, calcium phosphate materials have been widely used to augment tendon-bone healing. However, only enhancing bone regeneration may be not enough for improving tendon–bone healing. Angiogenesis is another fundamental factor required for tendon–bone healing. Therefore, it’s necessary to develop a convenient and reliable method to promote osteogenesis and angiogenesis simultaneously, thereby effectively promoting tendon–bone healing. Methods The amorphous calcium phosphate (ACP) nanoparticles with dual biological activities of osteogenesis and angiogenesis were prepared by a simple low-temperature aqueous solution method using adenosine triphosphate (ATP) as an organic phosphorus source. The activities of osteogenesis and angiogenesis and the effect on the tendon–bone healing of ACP nanoparticles were tested in vitro and in a rat model of acute RCT. Results The ACP nanoparticles with a diameter of tens of nanometers were rich in bioactive adenosine. In vitro, we confirmed that ACP nanoparticles could enhance osteogenesis and angiogenesis. In vivo, radiological and histological evaluations demonstrated that ACP nanoparticles could enhance bone and blood vessels formation at the tendon–bone junction. Biomechanical testing showed that ACP nanoparticles improved the biomechanical strength of the tendon–bone junction and ultimately promoted tendon–bone healing of rotator cuff. Conclusions We successfully confirmed that ACP nanoparticles could promote tendon–bone healing. ACP nanoparticles are a promising biological nanomaterial in augmenting tendon–bone healing. Graphic abstract

Biomimetic Organic-Inorganic Nanocomposite Coatings for Titanium Implants. II. Biological "In Vitro" and "In Vivo" Characterization

2007 ◽  
Vol 330-332 ◽  
pp. 401-404 ◽  
Author(s):  
M. Dutour Sikirić ◽  
Rene Elkaim ◽  
S. Lamolle ◽  
H.J. Ronold ◽  
S.P. Lyngstadass ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Organic Matrix ◽  
Titanium Implants ◽  
Nanocomposite Coatings ◽  
In Vivo Testing ◽  
In Vivo Characterization

Biological mineralization proceeds within an organic matrix and is induced and controlled by extracellular, highly acidic matrix macromolecules. Our group has recently prepared organic-inorganic nanocomposite coatings by a strategy that closely mimics these processes. The strategy involves depositing a matrix of polyelectrolyte multilayers (PE MLs), alternating with layers of amorphous calcium phosphate (ACP) particles, then "in situ" growing nanosized apatite crystals within that matrix [1, 2]. Here we describe the results of biological "in vitro" and "in vivo" testing of these materials.

scholarly journals In Vitro and In Vivo Biosafety Analysis of Resorbable Polyglycolic Acid-Polylactic Acid Block Copolymer Composites for Spinal Fixation

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 29
Author(s):  
Seung Kyun Yoon ◽  
Jin Ho Yang ◽  
Hyun Tae Lim ◽  
Young-Wook Chang ◽  
Muhammad Ayyoob ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Animal Experiments ◽  
Polymeric Materials ◽  
Polyglycolic Acid ◽  
Poly Lactic Acid ◽  
Skin Sensitization ◽  
Spinal Fixation ◽  
In Vivo Degradation

Herein, spinal fixation implants were constructed using degradable polymeric materials such as PGA–PLA block copolymers (poly(glycolic acid-b-lactic acid)). These materials were reinforced by blending with HA-g-PLA (hydroxyapatite-graft-poly lactic acid) and PGA fiber before being tested to confirm its biocompatibility via in vitro (MTT assay) and in vivo animal experiments (i.e., skin sensitization, intradermal intracutaneous reaction, and in vivo degradation tests). Every specimen exhibited suitable biocompatibility and biodegradability for use as resorbable spinal fixation materials.

In vitro and in vivo degradation of silk fibers degummed with various sodium carbonate concentrations

2021 ◽  
Vol 27 ◽  
pp. 102369
Author(s):  
Shijun Lu ◽  
Xiaochen Tang ◽  
Qingqing Lu ◽  
Jiwei Huang ◽  
Xinran You ◽  
...  
Keyword(s):  
Sodium Carbonate ◽  
Silk Fibers ◽  
In Vivo Degradation

Porous-conductive chitosan scaffolds for tissue engineering II. in vitro and in vivo degradation

2005 ◽  
Vol 16 (11) ◽  
pp. 1017-1028 ◽  
Author(s):  
Ying Wan ◽  
Aixi Yu ◽  
Hua Wu ◽  
Zhaoxu Wang ◽  
Dijiang Wen
Keyword(s):  
Tissue Engineering ◽  
Chitosan Scaffolds ◽  
In Vivo Degradation

A Comprehensive Study of Osteogenic Calcium Phosphate Silicate Cement: Material Characterization and In Vitro/In Vivo Testing

2015 ◽  
Vol 5 (4) ◽  
pp. 457-466 ◽  
Author(s):  
Tianxing Gong ◽  
Zhiqin Wang ◽  
Yixi Zhang ◽  
Yubiao Zhang ◽  
Mingxiao Hou ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Material Characterization ◽  
Cement Material ◽  
Phosphate Silicate ◽  
In Vivo Testing ◽  
Comprehensive Study

Calcium Phosphate Coating on Blast-Treated Titanium Implants by RF Magnetron Sputtering

2009 ◽  
Vol 631-632 ◽  
pp. 211-216 ◽  
Author(s):  
Kyosuke Ueda ◽  
Takayuki Narushima ◽  
Takashi Goto ◽  
T. Katsube ◽  
Hironobu Nakagawa ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Magnetron Sputtering ◽  
Bonding Strength ◽  
Rf Magnetron Sputtering ◽  
Titanium Implants ◽  
Calcium Phosphate Coating ◽  
Phosphate Coating ◽  
Coating Films

Calcium phosphate coating films were fabricated on Ti-6Al-4V plates and screw-type implants with a blast-treated surface using radiofrequency (RF) magnetron sputtering and were evaluated in vitro and in vivo. Amorphous calcium phosphate (ACP) and oxyapatite (OAp) films obtained in this study could cover the blast-treated substrate very efficiently, maintaining the surface roughness. For the in vitro evaluations of the calcium phosphate coating films, bonding strength and alkaline phosphatase (ALP) activity were examined. The bonding strength of the coating films to a blast-treated substrate exceeded 60 MPa, independent of film phases except for the film after post-heat-treatment in silica ampoule. When compared with an uncoated substrate, the increase in the ALP activity of osteoblastic SaOS-2 cells on a calcium phosphate coated substrate was confirmed by a cell culture test. The removal torque of screw-type Ti-6Al-4V implants with a blast-treated surface from the femur of Japanese white rabbit increased with the duration of implantation and it was statistically improved by coating an ACP film 2 weeks after implantation. The in vitro and in vivo studies suggested that the application of the sputtered ACP film as a coating on titanium implants was effective in improving their biocompatibility with bones.

scholarly journals Mechanisms of in Vivo Degradation and Resorption of Calcium Phosphate Based Biomaterials

Materials ◽  
2015 ◽  
Vol 8 (11) ◽  
pp. 7913-7925 ◽  
Author(s):  
Zeeshan Sheikh ◽  
Mohamed-Nur Abdallah ◽  
Ahmed Hanafi ◽  
Syed Misbahuddin ◽  
Haroon Rashid ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
In Vivo Degradation
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