scholarly journals Effects of calcium phosphates incorporation on structural, thermal and drug-delivery properties of collagen:chitosan scaffolds

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Mirella Romanelli Vicente Bertolo ◽  
Virginia Conceição Amaro Martins ◽  
Ana Maria De Guzzi Plepis
Keyword(s):  
Drug Delivery ◽  
Calcium Phosphate ◽  
Calcium Phosphates ◽  
Great Influence ◽  
Collagen Gel ◽  
Dry Mass ◽  
Ex Situ ◽  
Porous Scaffolds ◽  
Drug Delivery Vehicles

In this study, we evaluated how different procedures of calcium phosphate synthesis and its incorporation in collagen:chitosan scaffolds could affect their structural and thermal properties, aiming the obtention of homogeneous scaffolds which can act as drug delivery vehicles in bone tissue engineering. Therefore, three different scaffold preparation procedures were developed, changing the order of addition of the components: in CC-CNPM1 and CC-CNPM2, calcium phosphate synthesis was performed in situ in the chitosan gel (1%, w/w) followed by mixture with collagen (1%, w/w), with changes in the reagents used for calcium phosphate formation; in CC-CNPM3 procedure, calcium phosphate was synthesized ex situ and then incorporated into the collagen gel, in which chitosan in powder was mixed. In all procedures, 5% (in dry mass) of ciprofloxacin was incorporated. FTIR analysis confirmed the presence of calcium phosphate in all scaffolds. DSC curves showed that collagen denaturation temperature (Td) increased with calcium incorporation. SEM photomicrographs of scaffolds cross-section revealed porous scaffolds with calcium phosphate grains internally distributed in the polymeric matrix. XRD diffractograms indicated that the calcium phosphates obtained are hydroxyapatite. The pore size distribution was more homogeneous for CC-CNPM3, which also stood out for its smaller porosity and lower absorption in PBS. These results indicate that the in situ or ex situ phosphate incorporation in the scaffolds had a great influence on its structural properties, which also had consequences for ciprofloxacin release. CC-CNPM3 released a smaller amount of antibiotic (30%), but its release profile was better described by all the tested models.

In Situ Precipitation of Amorphous Calcium Phosphate and Ciprofloxacin Crystals during the Formation of Chitosan Hydrogels and Its Application for Drug Delivery Purposes

Langmuir ◽  
2012 ◽  
Vol 28 (45) ◽  
pp. 15937-15946 ◽  
Author(s):  
Stefania Nardecchia ◽  
María C. Gutiérrez ◽  
M. Concepción Serrano ◽  
Mariella Dentini ◽  
Andrea Barbetta ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Chitosan Hydrogels

Carboxymethylchitosan/Calcium Phosphate Hybrid Materials Prepared by an Innovative Auto-Catalytic Co-Precipitation Method

2005 ◽  
Vol 284-286 ◽  
pp. 701-704 ◽  
Author(s):  
S.A. Costa ◽  
J. Miguel Oliveira ◽  
Isabel B. Leonor ◽  
Rui L. Reis
Keyword(s):  
Calcium Phosphate ◽  
Calcium Phosphates ◽  
Precipitation Method ◽  
Porous Scaffolds ◽  
X Ray Diffraction ◽  
Polymer Precipitation ◽  
Acid Bath ◽  
The Fourier Transform ◽  
Xrd Patterns ◽  
Co Precipitation

In this study, it is shown that it is possible to prepare carboxymethyl-chitosan/Ca-P hybrids using an innovative “auto-catalytic” co-precipitation method, namely by using an acid and an oxidant bath. The X-ray diffraction (XRD) patterns evidenced the formation of crystalline calcium-phosphate precipitates when using an acid bath, while amorphous ones were obtained for those produced in the oxidant bath. The Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM/EDS) studies revealed that the extent of the polymer precipitation and formation of calcium-phosphates is directly dependent on the pH and composition of the baths. Furthermore, by conducting bioactivity tests in a simulated body fluid (SBF) followed by the SEM/EDS analysis it was possible to detect the formation of an apatite layer with a cauliflower-like morphology on the surface of hybrids prepared by the acid bath, after 7 days of immersion. These results are quite promising because they can allow for the production of bioactive and biodegradable 3D porous scaffolds to be used in bone tissue engineering applications.

Efficient drug delivery system for bone repair by tuning the surface of hydroxyapatite particles

RSC Advances ◽  
2016 ◽  
Vol 6 (107) ◽  
pp. 104969-104978 ◽  
Author(s):  
Sobia Tabassum ◽  
Saba Zahid ◽  
Faiza Zarif ◽  
Mazhar Amjad Gilani ◽  
Faisal Manzoor ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Surface Properties ◽  
Functional Groups ◽  
Bone Repair ◽  
Precipitation Method ◽  
Drug Delivery Vehicles ◽  
Delivery Vehicles ◽  
Co Precipitation

Efficient drug delivery vehicles, hydroxyapatite modified by carboxylic acids, were prepared by an in situ co-precipitation method. The presence of functional groups and subsequent surface properties of modified HA improved ibuprofen loading and release efficiency.

scholarly journals In situ luminescence analysis: a new light on monitoring calcium phosphate phase transitions

2017 ◽  
Vol 4 (7) ◽  
pp. 1157-1165 ◽  
Author(s):  
H. Terraschke ◽  
M. Rothe ◽  
A.-M. Tsirigoni ◽  
P. Lindenberg ◽  
L. Ruiz Arana ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Calcium Phosphate ◽  
Synchrotron Radiation ◽  
Calcium Phosphates ◽  
High Sensitivity ◽  
Luminescence Analysis ◽  
Biologically Relevant ◽  
Phosphate Phase ◽  
Calcium Phosphate Phase

In situ luminescence measurements allow monitoring the phase transitions of biologically relevant calcium phosphates with high sensitivity, independent of synchrotron radiation.

scholarly journals Preparation of Calcium Phosphate/Polyurethane Composite Porous Scaffolds for Bone Repair by in situ Self-foaming Method

2016 ◽  
Vol 31 (7) ◽  
pp. 719 ◽  
Author(s):  
LI Gen ◽  
LI Jiong-Jiong ◽  
LI Li-Mei ◽  
JIANG Jia-Xing ◽  
LI Yu-Bao ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Bone Repair ◽  
Porous Scaffolds ◽  
Polyurethane Composite

Facile one-pot synthesis of carbon/calcium phosphate/Fe3O4 composite nanoparticles for simultaneous imaging and pH/NIR-responsive drug delivery

2016 ◽  
Vol 52 (74) ◽  
pp. 11068-11071 ◽  
Author(s):  
Mingyu Gou ◽  
Shengnan Li ◽  
Lingyu Zhang ◽  
Lu Li ◽  
Chungang Wang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Calcium Phosphate ◽  
Photothermal Therapy ◽  
Composite Nanoparticles ◽  
One Pot ◽  
Drug Delivery Vehicles ◽  
Simultaneous Imaging ◽  
One Pot Synthesis ◽  
Delivery Vehicles

We report herein a facile one-pot synthesis of carbon/calcium phosphate/Fe3O4 composite nanoparticles, which were employed as pH/NIR-responsive drug delivery vehicles for simultaneous MRI and chemo-photothermal therapy.

scholarly journals Determination of Quantity and Localization of Liquid in the Semi-Solid State Using both 3D X-Ray Microtomography and 2D Techniques for Steel Thixoforming

2012 ◽  
Vol 192-193 ◽  
pp. 191-196
Author(s):  
Guo Chao Gu ◽  
Raphaël Pesci ◽  
Eric Becker ◽  
Laurent Langlois ◽  
Régis Bigot
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Solid State ◽  
Room Temperature ◽  
Great Influence ◽  
Ex Situ ◽  
X Ray ◽  
Semi Solid

The distribution of liquid at the semi solid state is one of the most important parameters for steel thixoforging. It has a great influence on the viscosity of the material, on the flows and finally on the final shape and mechanical properties of the thixoforged parts. Both ex situ and in situ 3D X-ray microtomography characterizations have been carried out to determine the quantity and localization of liquid at high temperature of M2 steel slugs. Microtomography was first performed ex situ at room temperature on samples heated and quenched from semi-solid state. The specimens were also scanned in situ directly at high temperature. The obtained results have been compared to 2D observations using EDS technique in SEM on heated and quenched specimens. They showed a good correlation making both approaches very efficient for the study of the liquid zones at the semi-solid state

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