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.

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 Platelet-Rich Fibrin Used in Regenerative Endodontics and Dentistry: Current Uses, Limitations, and Future Recommendations for Application

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Sohaib Arshad ◽  
Fatima Tehreem ◽  
Muhammad Rehab khan ◽  
Fatima Ahmed ◽  
Anand Marya ◽  
...  
Keyword(s):  
Bone Growth ◽  
Cell Attachment ◽  
Platelet Rich Plasma ◽  
Blood Clot ◽  
Permanent Teeth ◽  
Clinical Practices ◽  
Platelet Rich Fibrin ◽  
Regenerative Endodontics

Regenerative endodontics has introduced numerous procedures such as pulp implantation, revascularization, and postnatal stem cell therapy. Revascularization has been successfully implemented clinically nowadays, thus providing dentists with outrageous results. Platelet-rich fibrin (PRF) used either alone or along with bone graft promotes bone growth and vascularization. This matrix promotes migration, cell attachment, and proliferation of osteoblast that leads to bone formation. PRF consists of a packed fibrin complex consisting of leukocytes, cytokines, and glycoproteins such as thrombospondin. The usage of PRF has reported high success rates in surgical cases such as sinus lift procedures, healing of extraction sockets, and management of periapical abscesses. Compared to platelet-rich plasma, PRF is more economical, easy to prepare, and feasible to use in daily clinical practices. Revascularization compromised the induction of a blood clot into the root canal space, which emerged as a clinical triumph. This further led to platelet concentrates as an autologous scaffold on which revascularization could occur. The applications of PRF in regenerative endodontics are numerous, such as an agent for repairing iatrogenic perforation of the pulpal floor and for the revascularization of immature permanent teeth with necrotic pulps. It acts as a matrix for tissue ingrowth. Evidence of progressive thickening of dentinal walls, root lengthening, regression in the periapical lesion, and apical closure was reported. Further studies are needed to clarify the precise mechanism of action of PRF for dental pulp regeneration both in vitro and in vivo. The current review aims at the present uses of PRF in regenerative endodontics dentistry and its application with future recommendations and limitations.

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.

Porous calcium aluminate ceramics for bone-graft applications

2002 ◽  
Vol 17 (12) ◽  
pp. 3042-3049 ◽  
Author(s):  
S. J. Kalita ◽  
S. Bose ◽  
A. Bandyopadhyay ◽  
H. L. Hosick
Keyword(s):  
Bone Graft ◽  
Calcium Aluminate ◽  
Volume Fraction ◽  
Cell Attachment ◽  
Average Pore Size ◽  
Average Pore ◽  
Fused Deposition ◽  
Osteoblast Cell Line ◽  
Controlled Porosity

Calcium aluminate scaffolds with controlled porosity were processed for bone-graft applications. Indirect fused deposition process was used to fabricate these structures. Phase analyses were done using x-ray diffraction technique on powdered samples of calcium aluminates at different compositions. Hg porosimetry was used to determine the pore sizes and the pore volumes present in these controlled porosity structures at different calcium aluminate compositions. Cylindrical samples were tested under uniaxial compressive loading as a function of composition and volume fraction porosity (VFP). Samples of 29% and 44% VFP (designed) with average pore size of 300 μm showed compressive strength between 2 and 24 MPa. Cytotoxicity and cell proliferation studies were conducted with a modified human osteoblast cell line (HOB). These materials showed good cell attachment and a steady cell growth behavior with HOB cells during the first three weeks of in vitro analyses.

scholarly journals Osteoprotective Effects of Loganic Acid on Osteoblastic and Osteoclastic Cells and Osteoporosis-Induced Mice

2020 ◽  
Vol 22 (1) ◽  
pp. 233
Author(s):  
Eunkuk Park ◽  
Chang Gun Lee ◽  
Eunguk Lim ◽  
Seokjin Hwang ◽  
Seung Hee Yun ◽  
...  
Keyword(s):  
Osteoclast Differentiation ◽  
Osteoblastic Differentiation ◽  
Common Disease ◽  
Root Extract ◽  
Mouse Bone Marrow ◽  
Mineral Density ◽  
Bone Mineral Density Loss ◽  
In Vivo Experiments

Osteoporosis is a common disease caused by an imbalance of processes between bone resorption by osteoclasts and bone formation by osteoblasts in postmenopausal women. The roots of Gentiana lutea L. (GL) are reported to have beneficial effects on various human diseases related to liver functions and gastrointestinal motility, as well as on arthritis. Here, we fractionated and isolated bioactive constituent(s) responsible for anti-osteoporotic effects of GL root extract. A single phytochemical compound, loganic acid, was identified as a candidate osteoprotective agent. Its anti-osteoporotic effects were examined in vitro and in vivo. Treatment with loganic acid significantly increased osteoblastic differentiation in preosteoblast MC3T3-E1 cells by promoting alkaline phosphatase activity and increasing mRNA expression levels of bone metabolic markers such as Alpl, Bglap, and Sp7. However, loganic acid inhibited osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. For in vivo experiments, the effect of loganic acid on ovariectomized (OVX) mice was examined for 12 weeks. Loganic acid prevented OVX-induced bone mineral density loss and improved bone structural properties in osteoporotic model mice. These results suggest that loganic acid may be a potential therapeutic candidate for treatment of osteoporosis.

scholarly journals The Novel Role of PGC1α in Bone Metabolism

2021 ◽  
Vol 22 (9) ◽  
pp. 4670
Author(s):  
Cinzia Buccoliero ◽  
Manuela Dicarlo ◽  
Patrizia Pignataro ◽  
Francesco Gaccione ◽  
Silvia Colucci ◽  
...  
Keyword(s):  
Bone Metabolism ◽  
Osteoblastic Differentiation ◽  
In Vivo Studies ◽  
Peroxisome Proliferator ◽  
Sirtuin 3 ◽  
Peroxisome Proliferator Activated Receptor ◽  
Increased Risk

Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) is a protein that promotes transcription of numerous genes, particularly those responsible for the regulation of mitochondrial biogenesis. Evidence for a key role of PGC1α in bone metabolism is very recent. In vivo studies showed that PGC1α deletion negatively affects cortical thickness, trabecular organization and resistance to flexion, resulting in increased risk of fracture. Furthermore, in a mouse model of bone disease, PGC1α activation stimulates osteoblastic gene expression and inhibits atrogene transcription. PGC1α overexpression positively affects the activity of Sirtuin 3, a mitochondrial nicotinammide adenina dinucleotide (NAD)-dependent deacetylase, on osteoblastic differentiation. In vitro, PGC1α overexpression prevents the reduction of mitochondrial density, membrane potential and alkaline phosphatase activity caused by Sirtuin 3 knockdown in osteoblasts. Moreover, PGC1α influences the commitment of skeletal stem cells towards an osteogenic lineage, while negatively affects marrow adipose tissue accumulation. In this review, we will focus on recent findings about PGC1α action on bone metabolism, in vivo and in vitro, and in pathologies that cause bone loss, such as osteoporosis and type 2 diabetes.

Candida Albicans — Platelet Interaction: Evidence for, in Vivo and in Vitro, Cell to Cell Attachment

1991 ◽  
pp. 131-135 ◽  
Author(s):  
C. Mahaza ◽  
R. Robert ◽  
M. Miègeville ◽  
G. Tronchin ◽  
J. M. Senet
Keyword(s):  
Candida Albicans ◽  
Cell Attachment

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.

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