scholarly journals Bioactive and bioresorbable cellular cubic-composite scaffolds for use in bone reconstruction

2006 ◽  
Vol 3 (11) ◽  
pp. 805-821 ◽  
Author(s):  
Yasuo Shikinami ◽  
Kenshi Okazaki ◽  
Makoto Saito ◽  
Masaki Okuno ◽  
Shin Hasegawa ◽  
...  
Keyword(s):  
Cancellous Bone ◽  
Tricalcium Phosphate ◽  
Three Dimensional ◽  
Octacalcium Phosphate ◽  
Dicalcium Phosphate ◽  
Precipitation Method ◽  
Bone Reconstruction ◽  
Alkaline Phosphatase Assay ◽  
A Cell

We used a novel composite fibre-precipitation method to create bioactive and bioresorbable cellular cubic composites containing calcium phosphate (CaP) particles (unsintered and uncalcined hydroxyapatite (u-HA), α-tricalcium phosphate, β-tricalcium phosphate, tetracalcium phosphate, dicalcium phosphate dihydrate, dicalcium phosphate anhydrate or octacalcium phosphate) in a poly- d / l -lactide matrix. The CaP particles occupied greater than or equal to 70 wt% (greater than or equal to 50 vol%) fractions within the composites. The porosities of the cellular cubic composites were greater than or equal to 70% and interconnective pores accounted for greater than or equal to 70% of these values. In vitro changes in the cellular geometries and physical properties of the composites were evaluated over time. The Alamar Blue assay was used to measure osteoblast proliferation, while the alkaline phosphatase assay was used to measure osteoblast differentiation. Cellular cubic C-u-HA70, which contained 70 wt% u-HA particles in a 30 wt% poly- d / l -lactide matrix, showed the greatest three-dimensional cell affinity among the materials tested. This composite had similar compressive strength and cellular geometry to cancellous bone, could be modified intraoperatively (by trimming or heating) and was able to form cortico-cancellous bone-like hybrids. The osteoinductivity of C-u-HA70, independent of biological growth factors, was confirmed by implantation into the back muscles of beagles. Our results demonstrated that C-u-HA70 has the potential as a cell scaffold or temporary hard-tissue substitute for clinical use in bone reconstruction.

Proliferation and Migration of Human Osteoblasts on Porous Three Dimensional Scaffolds

2010 ◽  
Vol 638-642 ◽  
pp. 506-511 ◽  
Author(s):  
Claudia Bergemann ◽  
Ernst Dieter Klinkenberg ◽  
Frank Lüthen ◽  
Arne Weidmann ◽  
Regina Lange ◽  
...  
Keyword(s):  
Cell Culture ◽  
Morphological Changes ◽  
Three Dimensional ◽  
3D Cell Culture ◽  
Porous Tantalum ◽  
Human Osteoblasts ◽  
A Cell ◽  
And Migration ◽  
Migration Of Cells

Porous tantalum (Ta) biomaterial is designed to function as a scaffold for osseous ingrowths and has found applications in orthopedics. Integration of this Ta foam into the neighboring bone requires that osteoprogenitor cells attach to the implant, grow into the scaffold, proliferate and differentiate to osteoblasts. The aim of the present study was to create an in vitro 3D model system to investigate the interaction of human osteoblasts with porous Ta in the depth of the corpus. To explore active migration of osteoblasts into the Ta scaffold two porous Ta discs (Zimmer, Poland) were horizontally fixed within a clamping ring. Thereby a 3D Ta module with 4 levels is generated, which is placed into a cell culture well with the appropriate medium. Osteoblast-like cells were seeded apical onto the Ta module and cultured for 7 days in humidified atmosphere. Active migration of cells into the scaffold was monitored by field emission scanning electron microscopy (FESEM) imaging of the apical, medial and basal layers. A problem in 3D cell culture is the nutrition of cells inside of the scaffold. Therefore morphological changes and differentiation of the cells in distinct layers were analyzed.

scholarly journals Cortical Spheroid Model for Studying the Effects of Ischemic Brain Injury

2021 ◽  
Author(s):  
Rachel M McLaughlin ◽  
Amanda Laguna ◽  
Ilayda Top ◽  
Christien Hernadez ◽  
Liane L Livi ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Three Dimensional ◽  
Cost Effective ◽  
Glucose Deprivation ◽  
In Vitro Models ◽  
3D Architecture ◽  
A Cell ◽  
Antioxidant Agent

Stroke is a devastating neurological disorder and a leading cause of death and long-term disability. Despite many decades of research, there are still very few therapeutic options for patients suffering from stroke or its consequences. This is partially due to the limitations of current research models, including traditional in vitro models which lack the three-dimensional (3D) architecture and cellular make-up of the in vivo brain. 3D spheroids derived from primary postnatal rat cortex provide an in vivo-relevant model containing a similar cellular composition to the native cortex and a cell-synthesized extracellular matrix. These spheroids are cost-effective, highly reproducible, and can be produced in a high-throughput manner, making this model an ideal candidate for screening potential therapeutics. To study the cellular and molecular mechanisms of stroke in this model, spheroids were deprived of glucose, oxygen, or both oxygen and glucose for 24 hours. Both oxygen and oxygen-glucose deprived spheroids demonstrated many of the hallmarks of stroke, including a decrease in metabolism, an increase in neural dysfunction, and an increase in reactive astrocytes. Pretreatment of spheroids with the antioxidant agent N-acetylcysteine (NAC) mitigated the decrease in ATP seen after 24 hours of oxygen-glucose deprivation. Together, these results show the utility of our 3D cortical spheroid model for studying ischemic injury and its potential for screening stroke therapeutics.

scholarly journals In Vitro Properties of Manganese-Substituted Tricalcium Phosphate Coatings for Titanium Biomedical Implants Deposited by Arc Plasma

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4411 ◽  
Author(s):  
Inna V. Fadeeva ◽  
Vasilii I. Kalita ◽  
Dmitry I. Komlev ◽  
Alexei A. Radiuk ◽  
Alexander S. Fomin ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Plasma Deposition ◽  
L929 Cell ◽  
Octacalcium Phosphate ◽  
Ceramic Coatings ◽  
Physiological Solution ◽  
Human Tooth ◽  
Arc Plasma ◽  
X Ray

Bioactive manganese (Mn)-doped ceramic coatings for intraosseous titanium (Ti) implants are developed. Arc plasma deposition procedure is used for coatings preparation. X-ray Diffraction, Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy, and Electron Paramagnetic Resonance (EPR) methods are applied for coatings characterization. The coatings are homogeneous, composed of the main phase α-tricalcium phosphate (α-TCP) (about 67%) and the minor phase hydroxyapatite (about 33%), and the Mn content is 2.3 wt%. EPR spectroscopy demonstrates that the Mn ions are incorporated in the TCP structure and are present in the coating in Mn2+ and Mn3+ oxidation states, being aggregated in clusters. The wetting contact angle of the deposited coatings is suitable for cells’ adhesion and proliferation. In vitro soaking in physiological solution for 90 days leads to a drastic change in phase composition; the transformation into calcium carbonate and octacalcium phosphate takes place, and no more Mn is present. The absence of antibacterial activity against Escherichia coli, Enterococcus faecalis, and Pseudomonas aeruginosa bacteria strains is observed. A study of the metabolic activity of mouse fibroblasts of the NCTC L929 cell line on the coatings using the MTT (dye compound 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test demonstrates that there is no toxic effect on the cell culture. Moreover, the coating material supports the adhesion and proliferation of the cells. A good adhesion, spreading, and proliferative activity of the human tooth postnatal dental pulp stem cells (DPSC) is demonstrated. The developed coatings are promising for implant application in orthopedics and dentistry.

In Vitro Evaluation of Porous Biphasic Scaffolds

2007 ◽  
Vol 330-332 ◽  
pp. 935-938
Author(s):  
Silvia R. A. Santos ◽  
Antonella M. Rossi ◽  
L.R. Andrade ◽  
Marcelo Henrique Prado da Silva
Keyword(s):  
Stem Cells ◽  
Tricalcium Phosphate ◽  
Three Dimensional ◽  
Adipose Stem Cells ◽  
In Vitro Evaluation ◽  
Bioactive Ceramics ◽  
Biphasic Scaffolds

In the present study, two methods for the production of three-dimensional scaffolds made of bioactive ceramics are presented. Depending on the method, the final product can be composed by pure hydroxyapatite or biphasic: hydroxiapatite + tricalcium phosphate. Bioactivity tests showed that all scaffolds are bioactive. Preliminary studies with adipose stem cells indicated biocompatibility of both scaffolds.

scholarly journals Extensive transcriptional and chromatin changes underlie astrocyte maturation in vivo and in culture

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael Lattke ◽  
Robert Goldstone ◽  
James K. Ellis ◽  
Stefan Boeing ◽  
Jerónimo Jurado-Arjona ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Cell Culture Model ◽  
Functional Maturation ◽  
Culture Model ◽  
Mature Astrocyte ◽  
Transcriptional Changes ◽  
A Cell ◽  
Brain Homeostasis

AbstractAstrocytes have essential functions in brain homeostasis that are established late in differentiation, but the mechanisms underlying the functional maturation of astrocytes are not well understood. Here we identify extensive transcriptional changes that occur during murine astrocyte maturation in vivo that are accompanied by chromatin remodelling at enhancer elements. Investigating astrocyte maturation in a cell culture model revealed that in vitro-differentiated astrocytes lack expression of many mature astrocyte-specific genes, including genes for the transcription factors Rorb, Dbx2, Lhx2 and Fezf2. Forced expression of these factors in vitro induces distinct sets of mature astrocyte-specific transcripts. Culturing astrocytes in a three-dimensional matrix containing FGF2 induces expression of Rorb, Dbx2 and Lhx2 and improves astrocyte maturity based on transcriptional and chromatin profiles. Therefore, extrinsic signals orchestrate the expression of multiple intrinsic regulators, which in turn induce in a modular manner the transcriptional and chromatin changes underlying astrocyte maturation.

scholarly journals Amine Plasma-Polymerization of 3D Polycaprolactone/β-Tricalcium Phosphate Scaffold to Improving Osteogenic Differentiation In Vitro

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 366
Author(s):  
Hee-Yeon Kim ◽  
Byung-Hoon Kim ◽  
Myung-Sun Kim
Keyword(s):  
Osteogenic Differentiation ◽  
Focal Adhesion ◽  
Tricalcium Phosphate ◽  
Plasma Polymerization ◽  
Surface Characterization ◽  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Alizarin Red ◽  
Fused Deposition

This study aims to investigate the surface characterization and pre-osteoblast biological behaviors on the three-dimensional (3D) poly(ε-caprolactone)/β-tricalcium phosphate (β-TCP) scaffold modified by amine plasma-polymerization. The 3D PCL scaffolds were fabricated using fused deposition modeling (FDM) 3D printing. To improve the pre-osteoblast bioactivity, the 3D PCL scaffold was modified by adding β-TCP nanoparticles, and then scaffold surfaces were modified by amine plasma-polymerization using monomer allylamine (AA) and 1,2-diaminocyclohexane (DACH). After the plasma-polymerization of PCL/β-TCP, surface characterizations such as contact angle, AFM, XRD, and FTIR were evaluated. In addition, mechanical strength was measured by UTM. The pre-osteoblast bioactivities were evaluated by focal adhesion and cell proliferation. Osteogenic differentiation was investigated by ALP activity, Alizarin red staining, and Western blot. Plasma-polymerization induced the increase in hydrophilicity of the surface of the 3D PCL/β-TCP scaffold due to the deposition of amine polymeric thin film on the scaffold surface. Focal adhesion and proliferation of pre-osteoblast improved, and osteogenic differentiation was increased. These results indicated that 3D PCL/β-TCP scaffolds treated with DACH plasma-polymerization showed the highest bioactivity compared to the other samples. We suggest that 3D PCL/β-TCP scaffolds treated with DACH and AA plasma-polymerization can be used as a promising candidate for osteoblast differentiation of pre-osteoblast.

scholarly journals Extensive transcriptional and chromatin changes underlie astrocyte maturation in vivo and in culture

2020 ◽  
Author(s):  
Michael Lattke ◽  
Robert Goldstone ◽  
Francois Guillemot
Keyword(s):  
Three Dimensional ◽  
Cell Culture Model ◽  
Culture Model ◽  
Mature Astrocyte ◽  
Transcriptional Changes ◽  
A Cell ◽  
Late Stages ◽  
Brain Homeostasis

SummaryAstrocytes have diverse functions in brain homeostasis. Many of these functions are acquired during late stages of differentiation when astrocytes become fully mature. The mechanisms underlying astrocyte maturation are not well understood. Here we identified extensive transcriptional changes that occur during astrocyte maturation and are accompanied by chromatin remodelling at enhancer elements. Investigating astrocyte maturation in a cell culture model revealed that in vitro-differentiated astrocytes lacked expression of many mature astrocyte-specific genes, including genes for the transcription factors Rorb, Dbx2, Lhx2 and Fezf2. Forced expression of these factors in vitro induced distinct sets of mature astrocytes-specific transcripts. Culturing astrocytes with FGF2 in a three-dimensional gel induced expression of Rorb, Dbx2 and Lhx2 and improved their maturity based on transcriptional and chromatin profiles. Therefore extrinsic signals orchestrate the expression of multiple intrinsic regulators, which in turn induce in a modular manner the transcriptional and chromatin changes underlying astrocyte maturation.

Octacalcium Phosphate as a Precursor in Biomineral Formation

1987 ◽  
Vol 1 (2) ◽  
pp. 306-313 ◽  
Author(s):  
W.E. Brown ◽  
N. Eidelman ◽  
B. Tomazic
Keyword(s):  
Thermogravimetric Analysis ◽  
Calcium Phosphates ◽  
Three Dimensional ◽  
Octacalcium Phosphate ◽  
Basic Form ◽  
Vacancy Defects ◽  
Impurity Ions

What are biominerals and how are they formed? It is usually assumed: (i) that the prototype for most apatitic biominerals is hydroxyapatite (OHAp), Ca5(PO4) 3OH; and (ii) that the OHAp structure has been modified by the presence of impurity ions and vacancy defects in specific OHAp lattice sites. The usual answer, at least implicitly, to the second question is that the apatitic mineral is formed directly by the precipitation of ions from the surrounding solution. Our answers are: (i) that apatitic biominerals are formed through a precursor mechanism in which octacalcium phosphate (OCP), Ca8H 2(PO4)6·5H2O, precipitates first and then hydrolyzes ireversibly in situ to a transition product intermediate to OCP and OHAp; and (ii) that this product, "octacalcium phosphate hydrolyzate" (OCPH), may contain (a) OHAp-like and OCP-like domains in varying amounts, (b) vacancy defects and impurity ions in lattice sites in these domains, and (c) various kinds of one-, two-, and three-dimensional defects which are not present in either the OHAp or the OCP lattice, these defects being formed during the in situ hydrolysis step. A calcification model of this type was first proposed in 1957, but full acceptance was delayed because most of the evidence was circumstantial and in vitro in nature. The situation has changed radically because of three unrelated studies that are in vivo in nature but lead to the same conclusion: I. 32P-pyrolysis studies of rat enamel: The results clearly demonstrated that an acidic calcium phosphate precursor was involved. II. Precipitation of calcium phosphates in serum. Ultrafiltered serum was equilibrated with brushite. Subsequent changes in the ionic concentrations revealed that OCP was formed at first and then hydrolyzed to a more basic form, OCPH, but never reached the solubility of OHAp. III. Physicochemical properties of cardiovascular biominerals: We recently characterized biominerals in cardiovascular deposits in an encompassing variety of ways. As an overall conclusion, OCPH was the prototype most compatible with the data [including indices of refraction, solubility, P2O74- formation on pyrolysis, thermogravimetric analysis (TGA) measurements, presence of water, and incorporation of CO32-, Na+, and Mg2+]. This calcification model has important consequences relative to all kinds of calcification and decalcification processes, including those of enamel.

scholarly journals In Vitro Production of Human Ballooned Hepatocytes in a Cell Sheet-based Three-dimensional Model

2020 ◽  
Vol 26 (1-2) ◽  
pp. 93-101 ◽  
Author(s):  
Botao Gao ◽  
Katsuhisa Sakaguchi ◽  
Katsuhisa Matsuura ◽  
Tetsuya Ogawa ◽  
Yuki Kagawa ◽  
...  
Keyword(s):  
Cell Sheet ◽  
Three Dimensional ◽  
Dimensional Model ◽  
In Vitro Production ◽  
Three Dimensional Model ◽  
A Cell ◽  
Vitro Production
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