scholarly journals 3D multiphasic porous scaffolds of calcium phosphates doping with silicon and magnesium

2021 ◽  
Author(s):  
Nayarit A. Mata ◽  
Patricia Ros-Tárraga ◽  
Pablo Velasquez ◽  
Angel Murciano ◽  
Piedad N. De Aza
Keyword(s):  
Calcium Phosphates ◽  
Porous Scaffolds ◽  
Doping With Silicon

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.

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.

Fabrication of Porous Ceramic Scaffolds via Polymeric Sponge Method Using Sol-Gel Derived Strontium Doped Hydroxyapatite

2011 ◽  
Vol 117-119 ◽  
pp. 829-832 ◽  
Author(s):  
I. Sopyan ◽  
C.M. Mardziah ◽  
Ramesh Singh
Keyword(s):  
Cell Attachment ◽  
Calcium Phosphates ◽  
Porous Ceramic ◽  
Sol Gel ◽  
Ambient Air ◽  
Porous Scaffolds ◽  
High Porosity ◽  
Sintering Process ◽  
Morphological Evaluation ◽  
Dispersing Agent

Recently, development of porous calcium phosphates ceramics has raised considerable interest. A porous structure promotes cell attachment, proliferation and provides pathways for biofluids. Therefore, a high porosity with interconnected pore structure generally favors tissue regeneration. In this work, replication of 0, 2, 5, 10 and 15% SrHA (strontium-doped hydroxyapatite) porous scaffolds via polymeric sponge method has been employed using the sol-gel derived SrHA powders. To prepare the porous samples, the synthesized SrHA powders were mixed with distilled water and dispersing agent followed by drying in the ambient air and specific sintering process. Morphological evaluation by FESEM measurement revealed that the SrHA scaffolds were characterized by macro-micro interconnected porosity, which replicates the morphology of the cancellous bone. Compression test on the porous scaffolds revealed that doping 10 mol% of strontium in HA has increased the compressive strength by a factor of two compared to the undoped HA with 1.81±0.26 MPa at 41% porosity.

scholarly journals Three Dimensional Macroporous Calcium Phosphates Scaffolds for Bone Tissue Engineering

2009 ◽  
Vol 15 (S3) ◽  
pp. 61-62 ◽  
Author(s):  
S. Teixeira ◽  
M. P. Ferraz ◽  
F. J. Monteiro
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Bone Marrow Cells ◽  
Calcium Phosphates ◽  
Three Dimensional ◽  
Porous Scaffolds ◽  
Replication Method ◽  
Ceramic Slurry ◽  
Promising Area

AbstractBone tissue engineering is a promising area that aims at developing implants capable of repairing and/ or substituting damaged or lost bone tissue. Ceramics are widely used for bone tissue engineering purposes and in this study, hydroxyapatite porous scaffolds were produced using the polymer replication method. With this method, it was possible to obtain scaffolds with specific demands adequate to tissue engineering purposes namely: macroporosity, microporosity and interconnected porosity. Polyurethane sponges were used as templates and impregnated with a ceramic slurry at different ratios being afterwards sintered following a specific thermal cycle. The characteristics of the hydroxyapatite porous scaffolds were investigated by using scanning electron microscopy and micro computer tomography (μ-CT). Human bone marrow cells (HBMC) were isolated and cultured on the scaffolds for 28 days and SEM was used as a tool to assess cell morphology and distribution.

Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov
Keyword(s):  
Phase Composition ◽  
Calcium Phosphates ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impurity Phases ◽  
Position Sensitive ◽  
Diffraction Peaks ◽  
Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

A differentiated approach to the dental caries prevention in children with different levels of caries risk

2020 ◽  
Vol 20 (3) ◽  
pp. 211-215
Author(s):  
T. N. Tserakhava ◽  
N. V. Shakavets ◽  
E. I. Melnikava ◽  
M. I. Klenovskaya ◽  
D. N. Naumovich ◽  
...  
Keyword(s):  
Oral Hygiene ◽  
Calcium Phosphates ◽  
Clinical Effectiveness ◽  
Control Group ◽  
Caries Risk ◽  
Health Group ◽  
High Caries Risk ◽  
Permanent Molars ◽  
Different Levels ◽  
First Permanent Molars

Relevance. Prevention of caries of the first permanent molars is one of the most relevant problems in pediatricdentistry.Purpose – to develop an algorithm for prevention of first permanent molars caries in children with differentlevels of caries risk.Materials and methods. The article presents the results of the implementation of the algorithm for prevention of first permanent molars caries in children with different levels of caries risk. This algorithm includes a comprehensive assessment of the values of indices dmft, DMFT, OHI-S, and the patient's health group is also taken into account. The study involved 253 children aged 6-7 years divided into 4 groups: 3 groups of children depending on the health group and the control group. 3 subgroups were identified in each group – with a low, medium, and high caries risk. We developed preventive measures schemes were for children of each group including training in oral hygiene; controlled and home toothbrushing using fluoride-containing toothpastes; applications of varnishes containing fluoride, calcium, phosphates from 2 to 3 times a year; fissure sealing of the first permanent molars. We carried out these activities were for 24 months, and then evaluated theirs effectiveness. Children in the control group were trained in oral hygiene. The clinical effectiveness of medical prophylaxis was evaluated by changes in the above clinical indicators.Results. In group of children with medium caries risk the increase in caries was 0.09, and the reduction in caries was 89.65%. In children with a low and high caries risk no increase in caries was observed; the reduction in the intensity of caries was 100%. A significant decrease in OHI-S oral hygiene index values was noted in all groups (p < 0.05). We noted high preventive efficacy of fissures sealing in the first permanent molars. No occlusal surface caries developed in sealed fissures.Conclusions. The application of the proposed preventive schemes in patients demonstrates high efficacy of fluoride and calcium-containing varnishes and sealing the fissures of the first permanent molars. 

Recent Patents on Nano Calcium Phosphates

2008 ◽  
Vol 1 (3) ◽  
pp. 209-216 ◽  
Author(s):  
Yurong Cai ◽  
Peng Liu ◽  
Ruikang Tang
Keyword(s):  
Calcium Phosphates

scholarly journals Bioresorbable Magnesium-Based Alloys as Novel Biomaterials in Oral Bone Regeneration: General Review and Clinical Perspectives

2021 ◽  
Vol 10 (9) ◽  
pp. 1842
Author(s):  
Valentin Herber ◽  
Begüm Okutan ◽  
Georgios Antonoglou ◽  
Nicole G. Sommer ◽  
Michael Payer
Keyword(s):  
Additive Manufacturing ◽  
Bone Regeneration ◽  
Modulus Of Elasticity ◽  
Bone Repair ◽  
Clinical Results ◽  
Porous Scaffolds ◽  
General Review ◽  
Synthetic Materials ◽  
Bone Preservation

Bone preservation and primary regeneration is a daily challenge in the field of dental medicine. In recent years, bioresorbable metals based on magnesium (Mg) have been widely investigated due to their bone-like modulus of elasticity, their high biocompatibility, antimicrobial, and osteoconductive properties. Synthetic Mg-based biomaterials are promising candidates for bone regeneration in comparison with other currently available pure synthetic materials. Different alloys based on Mg were developed to fit clinical requirements. In parallel, advances in additive manufacturing offer the possibility to fabricate experimentally bioresorbable metallic porous scaffolds. This review describes the promising clinical results of resorbable Mg-based biomaterials for bone repair in osteosynthetic application and discusses the perspectives of use in oral bone regeneration.

scholarly journals Porous scaffolds with the structure of an interpenetrating polymer network made by gelatin methacrylated nanoparticle-stabilized high internal phase emulsion polymerization targeted for tissue engineering

RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 22544-22555
Author(s):  
Atefeh Safaei-Yaraziz ◽  
Shiva Akbari-Birgani ◽  
Nasser Nikfarjam
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Cell Growth ◽  
Polymer Network ◽  
Synthetic Polymers ◽  
Tissue Scaffolds ◽  
Interpenetrating Polymer Network ◽  
Porous Scaffolds ◽  
Promising Strategy ◽  
Internal Phase

The interlacing of biopolymers and synthetic polymers is a promising strategy to fabricate hydrogel-based tissue scaffolds to biomimic a natural extracellular matrix for cell growth.

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