PLGA-Hydroxyapatite Composite Scaffolds for Osteoblastic-Like Cells

2008 ◽  
Vol 396-398 ◽  
pp. 461-464 ◽  
Author(s):  
André Dutra Messias ◽  
Aguedo Aragones ◽  
Eliana Aparecida de Rezende Duek
Keyword(s):  
Cell Adhesion ◽  
Collagen Synthesis ◽  
Colorimetric Method ◽  
Cellular Responses ◽  
Osteoblastic Cells ◽  
Adhesion Assay ◽  
Polymer Scaffolds ◽  
Composite Scaffolds ◽  
Hydroxyapatite Composite ◽  
Sirius Red

The aim of this work was to investigate the behaviour of rat calvarial osteoblastics cells on porous PLGA/HA composite scaffolds. Cells were submitted to cytotoxicity and cell adhesion assay. In addition, the cells morphology were observed by SEM, and the collagen synthesis measured by Sirius Red colorimetric method. The results showed that the material was not cytotoxic and hydroxyapatite improved cell adhesion. Osteoblastic cells could adhere and spread on the scaffolds as observed. After 14 days the presence of hydroxyapatite increased the synthesis of collagen. This study demonstrates that composite scaffolds presented better cellular responses compared to polymer scaffolds.

Evaluation of Stemness Maintenance Properties of the Recombinant Human Laminin α2 LG1-3 Domains in Human Mesenchymal Stem Cells

2019 ◽  
Vol 26 (10) ◽  
pp. 785-791
Author(s):  
Ji-Eun Kim ◽  
Hye-Jin Seo ◽  
SuJin Lee ◽  
Jun-Hyeog Jang
Keyword(s):  
Escherichia Coli ◽  
Stem Cells ◽  
Molecular Weight ◽  
Mesenchymal Stem Cells ◽  
Cell Adhesion ◽  
Human Mesenchymal Stem Cells ◽  
Adhesion Assay ◽  
Proliferation Assay ◽  
Undifferentiated State ◽  
Laminin Α2

Background: Laminin, a member of the Extracellular Matrix (ECM), is a glycoprotein that is used as a factor that affects cell adhesion, proliferation, survival, and differentiation. Of these, five globular domains (LG domains) of the alpha chain play an important role in influencing the cell by binding to the integrin. Objective: This study aimed to evaluate the ability of globular domains 1-3 of laminin alpha2 (rhLAMA2LG1-3) in maintaining the pluripotency of human Mesenchymal Stem Cells (hMSCs), which are widely used in regenerative medicine. Methods: hMSCs were grown in the medium supplemented with rhLAMA2LG1-3, then the effect of the protein on hMSCs were confirmed through cell adhesion assay, proliferation assay and RTPCR. Results: rhLAMA2LG1-3 expressed in Escherichia coli has a molecular weight of 70 kDa, at 1 µg/ml concentration of rhLAMA2LG1-3, the attachment and proliferation of hMSCs were approximately 3.18-fold and 1.67-fold, respectively, more efficient than those of untreated controls. In addition, the undifferentiated state and degree of stemness of hMSCs were measured, on the basis of CD90 and CD105 levels. In the rhLAMA2LG1-3-treated hMSCs, the expression levels of CD90 and CD105 increased by 2.83-fold and 1.62-fold, respectively, compared to those in untreated controls. Conclusion: rhLAMA2LG1-3 can be potentially used in stem cell therapy to improve the viability and maintain the undifferentiated state of hMSCs.

scholarly journals Differences in a Single Extracellular Residue Underlie Adhesive Functions of Two Zebrafish Aqp0s

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2005
Author(s):  
Irene Vorontsova ◽  
James E. Hall ◽  
Thomas F. Schilling ◽  
Noriaki Nagai ◽  
Yosuke Nakazawa
Keyword(s):  
Cell Adhesion ◽  
Single Amino Acid ◽  
Amino Acid Difference ◽  
Adhesion Assay ◽  
Loss Of Function ◽  
Adhesive Properties ◽  
The Difference ◽  
In Vitro Adhesion ◽  
Cell To Cell Adhesion

Aquaporin 0 (AQP0) is the most abundant lens membrane protein, and loss of function in human and animal models leads to cataract formation. AQP0 has several functions in the lens including water transport and adhesion. Since lens optics rely on strict tissue architecture achieved by compact cell-to-cell adhesion between lens fiber cells, understanding how AQP0 contributes to adhesion would shed light on normal lens physiology and pathophysiology. We show in an in vitro adhesion assay that one of two closely related zebrafish Aqp0s, Aqp0b, has strong auto-adhesive properties while Aqp0a does not. The difference appears to be largely due to a single amino acid difference at residue 110 in the extracellular C-loop, which is T in Aqp0a and N in Aqp0b. Similarly, P110 is the key residue required for adhesion in mammalian AQP0, highlighting the importance of residue 110 in AQP0 cell-to-cell adhesion in vertebrate lenses as well as the divergence of adhesive and water permeability functions in zebrafish duplicates.

Structure and Properties of Poly(α-hydroxyl acids)/Nano Hydroxyapatite Composite Scaffolds

2002 ◽  
Vol 735 ◽  
Author(s):  
Guobao Wei ◽  
Peter X. Ma
Keyword(s):  
Tissue Engineering ◽  
Pore Structure ◽  
The Body ◽  
Polymer Scaffolds ◽  
Composite Scaffolds ◽  
Average Pore ◽  
Thermally Induced ◽  
Tissue Engineering Approach ◽  
Biodegradable Poly ◽  
Organ Failures

ABSTRACTTissue losses and organ failures resulting from injuries or diseases remain frequent and serious health problems despite great advances in medical technologies. Transplantation and reconstructive surgeries are seriously challenged by donor tissue shortage. We take a tissue engineering approach to design 3D scaffolds for cells to grow and synthesize new tissues. The scaffolds are biodegradable and will be absorbed after fulfilling the purpose as 3D templates, leaving nothing foreign in the body. To better mimic natural bone structurally, mechanically and biologically, nano-sized hydroxyapatite particles (N-HAP) were formulated with biodegradable poly(α-hydroxyl acids) to form composite scaffolds with well-controlled pore structures using thermally induced phase separation (TIPS) in this work. The pore structure and mechanical properties of the scaffolds were optimized by the use of multiple solvent systems, different quenching rates and quenching depths. The fabricated scaffolds possessed porosities higher than 90% and average pore sizes ranging from 50 to 500 μm. The scaffolds containing N-HAP maintained open and regular 3D pore structure similar to those of plain polymer scaffolds, implying that N-HAP particles were dispersed within the polymer pore walls of the scaffolds. The addition of N-HAP increased the compressive modulus by 20∼80% over that of plain polymer scaffolds. These results indicate that poly(α-hydroxyl acids)/N-HAP scaffolds may provide excellent 3D substrates for bone tissue engineering.

Screening for novel cell adhesive regions in bovine Achilles tendon collagen peptides

2014 ◽  
Vol 92 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pradipta Banerjee ◽  
Alka Mehta ◽  
C. Shanthi
Keyword(s):  
Cell Adhesion ◽  
Docking Studies ◽  
Exchange Chromatography ◽  
Adhesion Assay ◽  
Structural Protein ◽  
Cell Adherence ◽  
Collagen Peptides ◽  
Adhesion Ability ◽  
A Cell ◽  
Hydrophilic Residues

Collagen, a major structural protein of the ECM, is known for its high cell adherence capacity. This study was conducted to identify regions in collagen that harbour such bioactivity. Collagen from tendon was hydrolysed and the peptides fractionated using ion-exchange chromatography (IEC). Isolated peptide fractions were coated onto disposable dishes and screened for cell adherence and proliferative abilities. Active IEC fractions were further purified by chromatography, and two peptides, C2 and E1 with cell adhesion ability, were isolated. A cell adhesion assay done with different amounts of C2 coated onto disposable dishes revealed the maximum adhesion to be 94.6%, compared with 80% for collagen coated dishes and an optimum peptide coating density of 0.507 nmoles per cm2 area of the dish. Growth of cells on C2, collagen, and E1 revealed a similar pattern and a reduction in the doubling time compared with cells grown on uncoated dishes. C2 had a mass of 2.046 kDa with 22 residues, and sequence analysis revealed a higher percentage occurrence of hydrophilic residues compared with other regions in collagen. Docking studies revealed GDDGEA in C2 as the probable site of interaction with integrins α2β1 and α1β1, and stability studies proved C2 to be mostly protease-resistant.

scholarly journals Changes in E-cadherin rigidity sensing regulate cell adhesion

2017 ◽  
Vol 114 (29) ◽  
pp. E5835-E5844 ◽  
Author(s):  
Caitlin Collins ◽  
Aleksandra K. Denisin ◽  
Beth L. Pruitt ◽  
W. James Nelson
Keyword(s):  
Cell Adhesion ◽  
Signaling Molecules ◽  
Membrane Dynamics ◽  
Cell Contact ◽  
Adhesion Assay ◽  
Cell Periphery ◽  
Actin Organization ◽  
Rigidity Sensing ◽  
E Cadherin ◽  
Cell Cell

Mechanical cues are sensed and transduced by cell adhesion complexes to regulate diverse cell behaviors. Extracellular matrix (ECM) rigidity sensing by integrin adhesions has been well studied, but rigidity sensing by cadherins during cell adhesion is largely unexplored. Using mechanically tunable polyacrylamide (PA) gels functionalized with the extracellular domain of E-cadherin (Ecad-Fc), we showed that E-cadherin–dependent epithelial cell adhesion was sensitive to changes in PA gel elastic modulus that produced striking differences in cell morphology, actin organization, and membrane dynamics. Traction force microscopy (TFM) revealed that cells produced the greatest tractions at the cell periphery, where distinct types of actin-based membrane protrusions formed. Cells responded to substrate rigidity by reorganizing the distribution and size of high-traction-stress regions at the cell periphery. Differences in adhesion and protrusion dynamics were mediated by balancing the activities of specific signaling molecules. Cell adhesion to a 30-kPa Ecad-Fc PA gel required Cdc42- and formin-dependent filopodia formation, whereas adhesion to a 60-kPa Ecad-Fc PA gel induced Arp2/3-dependent lamellipodial protrusions. A quantitative 3D cell–cell adhesion assay and live cell imaging of cell–cell contact formation revealed that inhibition of Cdc42, formin, and Arp2/3 activities blocked the initiation, but not the maintenance of established cell–cell adhesions. These results indicate that the same signaling molecules activated by E-cadherin rigidity sensing on PA gels contribute to actin organization and membrane dynamics during cell–cell adhesion. We hypothesize that a transition in the stiffness of E-cadherin homotypic interactions regulates actin and membrane dynamics during initial stages of cell–cell adhesion.

Cellular responses to novel, micropatterned biomaterials

2008 ◽  
Vol 80 (11) ◽  
pp. 2479-2487 ◽  
Author(s):  
Marga C. Lensen ◽  
Vera A. Schulte ◽  
Jochen Salber ◽  
Mar Diez ◽  
Fabian Menges ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cellular Responses ◽  
Poly Ethylene Glycol ◽  
Uv Curable ◽  
Cellular Behavior ◽  
Remarkable Effect ◽  
Support Cell ◽  
Poly Ethylene ◽  
Line Patterns ◽  
Perfluorinated Polyether

Two UV-curable polymers, i.e., a star-shaped poly(ethylene glycol) (PEG) and a linear perfluorinated polyether (PFPE), are investigated as novel biomaterials in a systematic study of the cellular responses to surface chemistry, topography, and elasticity. Based on the wettability it was expected that the two novel biomaterials were too hydrophilic or -phobic, respectively, to support cell adhesion. Indeed, no cell adhesion was observed on the smooth, unstructured elastomers, whereas the materials showed no cytotoxicity. However, when the materials bear defined, topographic patterns (prepared by UV-based imprinting), cells do react strongly to the surfaces; they adhere, spread, and change their shape depending on the geometry of the features. Typically, cells were found to align along line patterns and "float" on pillar structures. It should be noted that the chemistry of the surface is not altered by the imprinting process, hence, there are no biofunctional molecules present at the surface to aid the cell adhesion. Finally, a remarkable effect of elasticity on the cellular behavior was discovered. Thus, the three parameters of chemistry, topography, and elasticity were investigated in- and interdependently, and it was found that the biomaterials may lose their resistance to protein adsorption and cell adhesion depending on the surface topography.

Sign in / Sign up

Export Citation Format

Share Document