Formation of Calcium Phosphate-Ellagic Acid Composites by Layer by Layer Assembly for Cellular Attachment to Osteoblasts

2012 ◽  
Vol 13 ◽  
pp. 1-17
Author(s):  
Ipsita A. Banerjee ◽  
Karl R. Fath ◽  
Nako Nakatsuka ◽  
Nazmul H. Sarker ◽  
Ipsita A. Banerjee
Keyword(s):  
Calcium Phosphate ◽  
Ellagic Acid ◽  
Liquid Crystalline ◽  
Average Pore Size ◽  
Layer By Layer ◽  
Average Pore ◽  
Assembly Method ◽  
Cellular Attachment ◽  
New Strategy

The quest for new biomaterials to serve as cell scaffolds for applications in tissue engineering is of prime importance. In this work, we investigated microfiber assemblies of Ellagic Acid (EA), a plant polyphenol to serve as scaffolds for attachment and proliferation of osteoblasts. The advantage of Ellagic Acid self-assembling system is its intrinsic ability to order into multiple layers due to its capability to form liquid crystalline assemblies. We prepared ellagic acid-microfiber composites by the layer-by-layer (LBL) assembly method, where collagen (COL), poly-Arginine (poly-R), and calcium phosphate nanocrystals were coated on the surface of ellagic acid microfibers. The attachment of the various layers was confirmed by various spectroscopic and microscopic methods. The samples were found to be porous with an average pore size of 600 nm. The formed microconjugates were biodegradable and supported the growth of human fetal osteoblast (hFOB) cells in vitro. Our findings suggest that this system not only promotes initial cell adhesion but also can be utilized to deliver the vital biological molecule ellagic acid to cells at the scaffold interface and displays a new strategy for the design of biomaterials.

Evaluation of 5% Na2O-Incorporated Calcium Metaphosphate as a Scaffold for Tissue-Engineered Bone Regeneration

2006 ◽  
Vol 309-311 ◽  
pp. 985-988 ◽  
Author(s):  
J.H. Yoon ◽  
J.T. Kim ◽  
Eui Kyun Park ◽  
Shin Yoon Kim ◽  
Chang Kuk You ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Bone Regeneration ◽  
Average Pore Size ◽  
Ectopic Bone Formation ◽  
Cellular Reaction ◽  
Average Pore ◽  
Cellular Attachment ◽  
Ectopic Bone ◽  
Osteogenic Effect

As a part of the effort to develop a suitable scaffold for tissue-engineered bone regeneration, we modified calcium metaphosphate (CMP) ceramic with Na20 and evaluated its efficiency as a scaffold. We incorporate 5% Na20 into pure CMP and prepare for an average pore size of 250 or 450 µm average pore sizes. The incorporation of 5% Na2O caused reduced compressive strength and there was no change in biodegradability. The in vitro cellular attachment and proliferation rate, however, were slightly improved. The 5% Na2O-incorporated macroporous CMP ceramic-cell constructs treated with Emdogain induced ectopic bone formation more effectively than those without Emdogain treatment. These results suggest that the incorporation of 5% Na2O into pure CMP is not effective for improving the physical characteristics of pure CMP but it is positive for improving the cellular reaction and osteogenic effect with the addition of Emdogain.

scholarly journals On the Morphological Characterization Procedures of Multilayer Hydrophobic Ceramic Membranes for Membrane Distillation Operations

Membranes ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 125 ◽  
Author(s):  
Mohamed K. Fawzy ◽  
Felipe Varela-Corredor ◽  
Serena Bandini
Keyword(s):  
Average Pore Size ◽  
Ceramic Membranes ◽  
Membrane Resistance ◽  
Morphological Characterization ◽  
Membrane Distillation ◽  
Gas Permeation ◽  
Layer By Layer ◽  
Morphological Parameters ◽  
Average Pore ◽  
Layer Membrane

The paper introduces some aspects of the characterization of hydrophobized multilayer ceramic membranes intended for use in membrane distillation (MD) operations. Four-layer hydrophobic carbon-based titania membranes, manufactured by the Fraunhofer Institute for Ceramic Technologies and Systems (IKTS, Hermsdorf, Germany), were tested according to the gas permeation technique. Gas permeance data were elaborated following the premises of the dusty gas model, to calculate the average pore size and the porosity-tortuosity ratio of each layer. Membrane testing was the opportunity to discuss which characterization method is more appropriate to obtain the membrane parameters necessary for the simulation of membranes in MD processes. In the case of multilayer membranes, the calculation of the morphological parameters should be performed for each layer. The “layer-by-layer gas permeation” method, previously introduced by other authors and completed in this work, is more appropriate for obtaining representative parameters of the membrane. Conversely, the calculation of morphological parameters, averaged over the entire membrane, might lead to heavy underestimations of the total membrane resistance and then to a heavy error on the transmembrane flux simulation.

Fabrication and Characterization of Mechanically Reinforced Collagen Sponge

2005 ◽  
Vol 288-289 ◽  
pp. 385-388
Author(s):  
Yosuke Hiraoka ◽  
Ueda Hiroki ◽  
Yu Kimura ◽  
Yasuhiko Tabata
Keyword(s):  
Cell Attachment ◽  
Average Pore Size ◽  
Collagen Sponge ◽  
Average Pore ◽  
Culture Studies ◽  
Collagen Solution ◽  
Freeze Dried ◽  
Interconnected Pore

This study describes an investigation of collagen sponge mechanically reinforced through the incorporation of poly(glycolic acid)(PGA) fiber. A collagen solution with PGA fiber homogeneously dispersed was freeze-dried, followed by dehydrothermal cross-linking to obtain collagen sponges incorporating PGA fiber. A collagen sponge without PGA fiber was prepared similarly by using the collagen solution. By scanning electron observation, the collagen sponges exhibited isotropic and interconnected pore structures with an average pore size of 180 µm, irrespective of PGA fiber incorporation. As expected, PGA fiber incorporation enabled the collagen sponge to significantly enhance the compression strength. In vitro cell culture studies revealed that the number of L929 fibroblasts initially attached was significantly greater for the collagen sponge incorporating PGA fiber than for the collagen sponge. In vitro cell proliferation studies revealed that the proliferation of cell was higher for the collagen sponge incorporating PGA fiber, by day 21, than the collagen sponge without PGA fiber. It is possible that shrinkage suppression results in the superior cell attachment and proliferation of sponge incorporating PGA fiber. After subcutaneous implantation into the backs of mice, the residual volume of collagen sponge incorporating PGA fiber was significantly large compared with that of collagen sponge. We concluded that the incorporation of PGA fiber is a simple way to reinforce collagen sponge without impairing the biocompatibility.

scholarly journals Preparation and Evaluation of Bioactivity of Porous Bioglass Tablets for Bone Tissue Regeneration

2019 ◽  
Vol 1 (3) ◽  
pp. 112-123
Author(s):  
Rohith Kumar R. ◽  
Sangeetha Ashok Kumar ◽  
K. Periyasami Bhuvana
Keyword(s):  
Surface Characterization ◽  
Mechanical Stability ◽  
Average Pore Size ◽  
High Surface ◽  
Bone Tissue Regeneration ◽  
Average Pore ◽  
Hydroxy Apatite ◽  
Sbf Solution

The present study endeavors in the preparation and characterization of semi crystalline 45S5 bioglass (BG) (SiO2-CaO-P2O5) through sol gel process. Dry press mold technique was used in the preparation porous BG tablets to examine the bioactivity through invitro studies. The synthesized BG powder was subjected to structural, morphological and mechanical characterization and the bioactivity was examined in vitro by immersing the BG tablet in the Simulated Body Fluid (SBF) solution. XRD pattern and the SEM micrographs revealed the semi crystalline nature of BG with spherical morphology. The elemental analysis confirms the presence of vital constituents required for Bone regeneration (Calcium, Phosphorous, Silica, and Sodium). The surface characterization of BG tablet reveals the pores structure of average pore size of 240nm which contributed to the high surface activity resulting in formation of carbonated hydroxy apatite (HCAP) when immersed in SBF. The disintegration studies denoted the stabilization period was after 48 of immersion of BG tablets in SBF solution. The compressive strength measurement of the tablet also reveals the higher mechanical stability.

scholarly journals The Effect of Pore Directionality of Collagen Scaffolds on Cell Differentiation and In Vivo Osteogenesis

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3187
Author(s):  
Miguelangel Moncayo-Donoso ◽  
Gustavo A. Rico-Llanos ◽  
Diego A. Garzón-Alvarado ◽  
José Becerra ◽  
Rick Visser ◽  
...  
Keyword(s):  
Bone Growth ◽  
Cell Attachment ◽  
Average Pore Size ◽  
Bone Matrix ◽  
Osteoblastic Differentiation ◽  
Collagen Scaffolds ◽  
Average Pore ◽  
Native Bone

Although many bone substitutes have been designed and produced, the development of bone tissue engineering products that mimic the microstructural characteristics of native bone remains challenging. It has been shown that pore orientation within collagen scaffolds influences bone matrix formation by the endochondral route. In addition, that the unidirectional orientation of the scaffolds can limit the growth of blood vessels. However, a comparison between the amount of bone that can be formed in scaffolds with different pore orientations in addition to analyzing the effect of loading osteogenic and proangiogenic factors is still required. In this work we fabricated uni- and multidirectional collagen sponges and evaluated their microstructural, physicochemical, mechanical and biological characteristics. Although the porosity and average pore size of the uni- and multidirectional scaffolds was similar (94.5% vs. 97.1% and 260 µm vs. 269 µm, respectively) the unidirectional sponges had a higher tensile strength, Young’s modulus and capacity to uptake liquids than the multidirectional ones (0.271 MPa vs. 0.478 MPa, 9.623 MPa vs. 3.426 MPa and 8000% mass gain vs. 4000%, respectively). Culturing of rat bone marrow mesenchymal stem cells demonstrated that these scaffolds support cell growth and osteoblastic differentiation in the presence of BMP-2 in vitro, although the pore orientation somehow affected cell attachment and differentiation. The evaluation of the ability of the scaffolds to support bone growth when loaded with BMP-2 or BMP-2 + VEGF in an ectopic rat model showed that they both supported bone formation. Histological analysis and quantification of mineralized matrix revealed that the pore orientation of the collagen scaffolds influenced the osteogenic process.

scholarly journals INFLUENCE OF SYNTHESIS TECHNO-CHEMICAL PARAMETERS ON PHYSICOCHEMICAL CHARACTERISTICS OF BIOMIMETIC CALCIUM-PHOSPHATE NANOCOMPOSITE DOPED BY SILICATE AND CARBONATE ANIONS

2020 ◽  
Vol 5 (10) ◽  
pp. 47-56
Author(s):  
M. Troubitsin ◽  
Viet Hung Hoang ◽  
L. Furda
Keyword(s):  
Calcium Phosphate ◽  
Specific Surface ◽  
Crystallite Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Average Pore Size ◽  
Average Crystallite Size ◽  
Average Pore ◽  
The Impact

The object of our investigation is a biomimetic calcium-phosphate nanocomposite doped by silicate and carbonate anions (BMHAP) synthesized by chemical deposition from aqueous solutions. The obtained samples are investigated using X-ray phase analysis (XRD), FTIR spectroscopy, and low-temperature nitrogen adsorption (BET method). The influence of the techno chemical synthesis parameters on the products characteristics (including phase composition, crystal lattice parameters, average crystallite size, specific surface area) is evaluated. The study on the effect of the synthesis temperature shows that with increasing in temperature from 22°C to 80°C, reveals a slight increase in the parameters of unit cells a and c, which leads to an increase in its volume. There is also a tendency towards a decrease in the average size of coherent scattering regions of crystallites (from 7,52 to 4,65 nm) and specific surface area (from 192,51 to 74,72 m2/g), but the pore volume and average pore diameter of the synthesized powders increases. The effect of the aging time of the sediment in the mother liquor is studied from 0,5 to 24 hours. It is found that with an increase in the maturation time of the sediment, the percent crystallinity of the powders improves by 1,7 times, an increase in the specific surface area from 163,43 to 192,51 m2/g and a slight decrease in the pore volume and average pore size of the samples are observed. The impact of the stirring rate of the reagents is investigated. An increase in speed from 300 to 1300 rpm has been shown to decrease the average crystallite size from 8,80 to 6,41 nm, and as a result, to increase the specific surface area of the synthesized samples from 178,58 to 192,51 m2/g, respectively.

scholarly journals In Vitro Performance and Chemical Stability of Lipid-Based Formulations Encapsulated in a Mesoporous Magnesium Carbonate Carrier

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 426
Author(s):  
Caroline Alvebratt ◽  
Tahnee J. Dening ◽  
Michelle Åhlén ◽  
Ocean Cheung ◽  
Maria Strømme ◽  
...  
Keyword(s):  
Chemical Stability ◽  
Oral Absorption ◽  
Physical Adsorption ◽  
Average Pore Size ◽  
In Vitro Digestion ◽  
Magnesium Carbonate ◽  
Resonance Spectroscopy ◽  
Average Pore ◽  
In Vitro Performance

Lipid-based formulations can circumvent the low aqueous solubility of problematic drug compounds and increase their oral absorption. As these formulations are often physically unstable and costly to manufacture, solidification has been suggested as a way to minimize these issues. This study evaluated the physicochemical stability and in vitro performance of lipid-loaded mesoporous magnesium carbonate (MMC) particles with an average pore size of 20 nm. A medium chain lipid was loaded onto the MMC carrier via physical adsorption. A modified in vitro lipolysis setup was then used to study lipid release and digestion with 1H nuclear magnetic resonance spectroscopy. The lipid loading efficiency with different solidification techniques was also evaluated. The MMC, unlike more commonly used porous silicate carriers, dissolved during the lipolysis assay, providing a rapid release of encapsulated lipids into solution. The digestion of the dispersed lipid-loaded MMC therefore resembled that of a coarse dispersion of the lipid. The stability data demonstrated minor degradation of the lipid within the pores of the MMC particles, but storage for three months did not reveal extensive degradation. To conclude, lipids can be adsorbed onto MMC, creating a solid powder from which the lipid is readily released into the solution during in vitro digestion. The chemical stability of the formulation does however merit further attention.

scholarly journals Synthesis of Thermal Polymerizable Alginate-GMA Hydrogel for Cell Encapsulation

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaokun Wang ◽  
Tong Hao ◽  
Jing Qu ◽  
Changyong Wang ◽  
Haifeng Chen
Keyword(s):  
Umbilical Vein ◽  
Average Pore Size ◽  
Three Dimensional ◽  
Cell Encapsulation ◽  
Myocardial Repair ◽  
Average Pore ◽  
Umbilical Vein Endothelial Cells

Alginate is a negative ionic polysaccharide that is found abundantly in nature. Calcium is usually used as a cross-linker for alginate. However, calcium cross-linked alginate is used only forin vitroculture. In the present work, alginate was modified with glycidyl methacrylate (GMA) to produce a thermal polymerizable alginate-GMA (AA-GMA) macromonomer. The molecular structure and methacrylation (%DM) of the macromonomer were determined by1H NMR. After mixing with the correct amount of initiator, the AA-GMA aqueous solution can be polymerized at physiological temperature. The AA-GMA hydrogels exhibited a three-dimensional porous structure with an average pore size ranging from 50 to 200 μm, directly depending on the macromonomer concentration. Biocompatibility of the AA-GMA hydrogel was determined byin vivomuscle injection and cell encapsulation. Muscle injectionin vivoshowed that the AA-GMA solution mixed with initiator could form a hydrogelin situand had a mild inflammatory effect. Human umbilical vein endothelial cells (HUVECs) were encapsulated in the AA-GMA hydrogelsin situat 37°C. Cell viability and proliferation were unaffected by macromonomer concentrations, which suggests that AA-GMA has a potential application in the field of tissue engineering, especially for myocardial repair.

scholarly journals Pulsed Microfluid Force-Based On-Chip Modular Fabrication for Liver Lobule-Like 3D Cellular Models

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
J. Cui ◽  
H. P. Wang ◽  
Q. Shi ◽  
T. Sun
Keyword(s):  
3D Structure ◽  
Perfusion Culture ◽  
Layer By Layer ◽  
Cell Distribution ◽  
Liver Lobule ◽  
Cellular Models ◽  
Assembly Method ◽  
On Chip

In vitro three-dimensional (3D) cellular models with native tissue-like architectures and functions have potential as alternatives to human tissues in regenerative medicine and drug discovery. However, it is difficult to replicate liver constructs that mimic in vivo microenvironments using current approaches in tissue engineering because of the vessel-embedded 3D structure and complex cell distribution of the liver. This paper reports a pulsed microflow-based on-chip 3D assembly method to construct 3D liver lobule-like models that replicate the spatial structure and functions of the liver lobule. The heterogeneous cell-laden assembly units with hierarchical cell distribution are fabricated through multistep photopatterning of different cell-laden hydrogels. Through fluid force interaction by pulsed microflow, the hierarchical assembly units are driven to a stack, layer by layer, and thus spatially assemble into 3D cellular models in the closed liquid chamber of the assembly chip. The 3D models with liver lobule-like hexagonal morphology and radial cell distribution allow the dynamic perfusion culture to maintain high cell viability and functional expression during long-term culture in vitro. These results demonstrate that the fabricated 3D liver lobule-like models are promising for drug testing and the study of individual diagnoses and treatments.

scholarly journals Characterisation of Calcium Phosphate Cement-Derived Hydroxyapatite Scaffolds with a PLGA-Bioactive Glass Composite Coating

2008 ◽  
Vol 1 ◽  
pp. 99-107 ◽  
Author(s):  
D.M.F. Tan ◽  
X. Miao ◽  
J. Li ◽  
Yin Xiao ◽  
Ross Crawford
Keyword(s):  
Calcium Phosphate ◽  
Bioactive Glass ◽  
Composite Coating ◽  
Calcium Phosphate Cement ◽  
Average Pore Size ◽  
Total Porosity ◽  
Fibroblast Cells ◽  
Glass Composite ◽  
Average Pore ◽  
Materials Used

The limitations of autogenic, allogenic and xenogenic grafting methods have led to the development of synthetic grafts as an alternative. The aim of this study was to manufacture highly porous and well interconnected hydroxyapatite scaffolds and modify them with a poly(lactic-co-glycolic acid) (PLGA)-bioactive glass composite coating to achieve mechanical properties close to those of natural cancellous bones. In this study, hydroxyapatite scaffolds were prepared from a calcium phosphate cement (CPC) powder and cell culture using fibroblast cells was done to examine the cytotoxicity of the materials used for the scaffolds. The average pore size of the scaffolds was found to be 650μm and the total porosity was about 80%. The hydroxyapatite scaffolds without the coating had a mean compressive strength and a mean compressive modulus of 0.74 MPa and 20.46 MPa, respectively, which were in contrast to those of the scaffolds coated with the PLGA-bioacitve glass composite material (1.36 MPa and 24.58 MPa, respectively). The fibroblast cells were observed to proliferate well on the PLGA-bioactive glass coated scaffolds. The cells had also penetrated into the scaffold to a depth of approximately 2mm. Thus the scaffolds fabricated in this study exhibited a favourable porous structure and good cell response which are desirable for bone tissue engineering.

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