scholarly journals Effects of magnesium silicate on the mechanical properties, biocompatibility, bioactivity, degradability, and osteogenesis of poly(butylene succinate)-based composite scaffolds for bone repair

2016 ◽  
Vol 4 (48) ◽  
pp. 7974-7988 ◽  
Author(s):  
Zhaoying Wu ◽  
Kai Zheng ◽  
Jue Zhang ◽  
Tingting Tang ◽  
Han Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Repair ◽  
Magnesium Silicate ◽  
Hierarchical Porous Structure ◽  
Composite Scaffolds ◽  
Butylene Succinate ◽  
Promote Cell Proliferation ◽  
Hierarchical Porous

The m-MS/PBSu scaffolds, with a hierarchical porous structure, could promote cell proliferation in vitro and bone regeneration in vivo.

scholarly journals Zn-Containing Membranes for Guided Bone Regeneration in Dentistry

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1797
Author(s):  
Manuel Toledano ◽  
Marta Vallecillo-Rivas ◽  
María T. Osorio ◽  
Esther Muñoz-Soto ◽  
Manuel Toledano-Osorio ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Regeneration ◽  
Bone Healing ◽  
Bone Repair ◽  
Complex Modulus ◽  
Bacterial Colonization ◽  
Guided Bone Regeneration ◽  
M2 Macrophage

Barrier membranes are employed in guided bone regeneration (GBR) to facilitate bone in-growth. A bioactive and biomimetic Zn-doped membrane with the ability to participate in bone healing and regeneration is necessary. The aim of the present study is to state the effect of doping the membranes for GBR with zinc compounds in the improvement of bone regeneration. A literature search was conducted using electronic databases, such as PubMed, MEDLINE, DIMDI, Embase, Scopus and Web of Science. A narrative exploratory review was undertaken, focusing on the antibacterial effects, physicochemical and biological properties of Zn-loaded membranes. Bioactivity, bone formation and cytotoxicity were analyzed. Microstructure and mechanical properties of these membranes were also determined. Zn-doped membranes have inhibited in vivo and in vitro bacterial colonization. Zn-alloy and Zn-doped membranes attained good biocompatibility and were found to be non-toxic to cells. The Zn-doped matrices showed feasible mechanical properties, such as flexibility, strength, complex modulus and tan delta. Zn incorporation in polymeric membranes provided the highest regenerative efficiency for bone healing in experimental animals, potentiating osteogenesis, angiogenesis, biological activity and a balanced remodeling. Zn-loaded membranes doped with SiO2 nanoparticles have performed as bioactive modulators provoking an M2 macrophage increase and are a potential biomaterial for promoting bone repair. Zn-doped membranes have promoted pro-healing phenotypes.

Preparation and Characterization of Polylactide-co-glycolide/Carbonate Apatite (PLGA/CHA) Composite Scaffolds

2011 ◽  
Vol 493-494 ◽  
pp. 572-576
Author(s):  
Heather Elizabeth Stone ◽  
Helen Lu ◽  
Racquel Z. LeGeros
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Elastic Modulus ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Bone Repair ◽  
Carbonate Apatite ◽  
Composite Scaffolds ◽  
Physico Chemical

Both natural and synthetic materials have been utilized to provide three dimensional scaffold environments ideal for bone repair. The biomechanical and biocompatibility characteristics of these scaffolds play a vital role in successful tissue engineering constructs. Polymer/carbonate apatite (CHA) composites have shown to improve cell adhesion and proliferation on the scaffold as well as increase elastic modulus, toughness and strength. The aim of this study is to prepare CHA- polylactic-co-glycolide (PLGA) composites in the form of microsphere, scaffold and disc and evaluate their physico-chemical properties, mechanical properties and in vitro bioactivity. 3-D porous cylindrical composite scaffolds were prepared using PLGA/CHA composites with varying PLGA/CHA ratios (30:70 and 50:50). The CHA was prepared by hydrolysis method and characterized using x-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). The physico-chemical and mechanical properties of the composite scaffolds were evaluated using scanning electron microscopy (SEM), micro-computed tomography (μCT), XRD, FTIR, and thermogravimetry (TGA). Flexural strength was determined using Instron. In vitro bioactivity was determined by the formation of apatite on composite disc surfaces after immersion in simulated body fluid (SBF). SEM and μCT analyses showed high porosity and interconnectivity between microspheres in the composite scaffolds. In vitro bioactivity was observed by the development of an apatite layer on the surfaces of the composite scaffolds after immersion in simulated body fluid. The mechanical strength of the scaffolds was to be dependent on the PLGA-CHA ratio. The elastic modulus, toughness and strength values obtained for the composites were similar to those of reported bone substituted materials. Results from this study provided information on the fabrication of PLGA-CHA scaffolds and their properties that may be useful for their potential application in bone repair and as scaffolds in tissue engineering for bone regeneration.

scholarly journals Injectable non-leaching tissue-mimetic bottlebrush elastomers as an advanced platform for reconstructive surgery

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Erfan Dashtimoghadam ◽  
Farahnaz Fahimipour ◽  
Andrew N. Keith ◽  
Foad Vashahi ◽  
Pavel Popryadukhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reconstructive Surgery ◽  
Biomedical Applications ◽  
The Body ◽  
Surrounding Tissue ◽  
Curing Time ◽  
Materials Used ◽  
Significant Health

AbstractCurrent materials used in biomedical devices do not match tissue’s mechanical properties and leach various chemicals into the body. These deficiencies pose significant health risks that are further exacerbated by invasive implantation procedures. Herein, we leverage the brush-like polymer architecture to design and administer minimally invasive injectable elastomers that cure in vivo into leachable-free implants with mechanical properties matching the surrounding tissue. This strategy allows tuning curing time from minutes to hours, which empowers a broad range of biomedical applications from rapid wound sealing to time-intensive reconstructive surgery. These injectable elastomers support in vitro cell proliferation, while also demonstrating in vivo implant integrity with a mild inflammatory response and minimal fibrotic encapsulation.

scholarly journals A composite scaffold of Wharton’s jelly and chondroitin sulphate loaded with human umbilical cord mesenchymal stem cells repairs articular cartilage defects in rat knee

2021 ◽  
Vol 32 (4) ◽  
Author(s):  
Zhong Li ◽  
Yikang Bi ◽  
Qi Wu ◽  
Chao Chen ◽  
Lu Zhou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Articular Cartilage ◽  
Composite Scaffold ◽  
Biomechanical Properties ◽  
Cartilage Defects ◽  
Human Umbilical Cord ◽  
Composite Scaffolds ◽  
Articular Cartilage Defects

AbstractTo evaluate the performance of a composite scaffold of Wharton’s jelly (WJ) and chondroitin sulfate (CS) and the effect of the composite scaffold loaded with human umbilical cord mesenchymal stem cells (hUCMSCs) in repairing articular cartilage defects, two experiments were carried out. The in vitro experiments involved identification of the hUCMSCs, construction of the biomimetic composite scaffolds by the physical and chemical crosslinking of WJ and CS, and testing of the biomechanical properties of both the composite scaffold and the WJ scaffold. In the in vivo experiments, composite scaffolds loaded with hUCMSCs and WJ scaffolds loaded with hUCMSCs were applied to repair articular cartilage defects in the rat knee. Moreover, their repair effects were evaluated by the unaided eye, histological observations, and the immunogenicity of scaffolds and hUCMSCs. We found that in vitro, the Young’s modulus of the composite scaffold (WJ-CS) was higher than that of the WJ scaffold. In vivo, the composite scaffold loaded with hUCMSCs repaired rat cartilage defects better than did the WJ scaffold loaded with hUCMSCs. Both the scaffold and hUCMSCs showed low immunogenicity. These results demonstrate that the in vitro construction of a human-derived WJ-CS composite scaffold enhances the biomechanical properties of WJ and that the repair of knee cartilage defects in rats is better with the composite scaffold than with the single WJ scaffold if the scaffold is loaded with hUCMSCs.

scholarly journals Fibronectin Adsorption on Electrospun Synthetic Vascular Grafts Attracts Endothelial Progenitor Cells and Promotes Endothelialization in Dynamic In Vitro Culture

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 778 ◽  
Author(s):  
Ruben Daum ◽  
Dmitri Visser ◽  
Constanze Wild ◽  
Larysa Kutuzova ◽  
Maria Schneider ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Activation ◽  
Vascular Endothelial Cells ◽  
Endothelial Progenitor ◽  
Advanced Therapy Medicinal Product ◽  
Endothelial Colony Forming Cells ◽  
Advanced Therapy ◽  
Custom Made

Appropriate mechanical properties and fast endothelialization of synthetic grafts are key to ensure long-term functionality of implants. We used a newly developed biostable polyurethane elastomer (TPCU) to engineer electrospun vascular scaffolds with promising mechanical properties (E-modulus: 4.8 ± 0.6 MPa, burst pressure: 3326 ± 78 mmHg), which were biofunctionalized with fibronectin (FN) and decorin (DCN). Neither uncoated nor biofunctionalized TPCU scaffolds induced major adverse immune responses except for minor signs of polymorph nuclear cell activation. The in vivo endothelial progenitor cell homing potential of the biofunctionalized scaffolds was simulated in vitro by attracting endothelial colony-forming cells (ECFCs). Although DCN coating did attract ECFCs in combination with FN (FN + DCN), DCN-coated TPCU scaffolds showed a cell-repellent effect in the absence of FN. In a tissue-engineering approach, the electrospun and biofunctionalized tubular grafts were cultured with primary-isolated vascular endothelial cells in a custom-made bioreactor under dynamic conditions with the aim to engineer an advanced therapy medicinal product. Both FN and FN + DCN functionalization supported the formation of a confluent and functional endothelial layer.

In Vitro and In Vivo Degradation, Mechanical Properties, and Histocompatibility of Weft-Knitted Silk Mesh-Like Grafts

2022 ◽  
Vol 12 (2) ◽  
pp. 411-416
Author(s):  
Liang Tang ◽  
Si-Yu Zhao ◽  
Ya-Dong Yang ◽  
Geng Yang ◽  
Wen-Yuan Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Degradation Rate ◽  
Maximum Load ◽  
Artificial Ligament ◽  
In Vivo Degradation

To investigate the degradation, mechanical properties, and histocompatibility of weft-knitted silk mesh-like grafts, we carried out the In Vitro and In Vivo silk grafts degradation assay. The In Vitro degradation experiment was performed by immersing the silk grafts in simulated body fluid for 1 year, and the results showed that the degradation rate of the silk mesh-like grafts was very slow, and there were few changes in the mechanical properties and quality of the silk mesh-like graft. In Vivo degradation assay was taken by implantation of the silk mesh-like grafts into the subcutaneous muscles of rabbits. At 3, 6, and 12 months postoperation, the rate of mass loss was 19.36%, 31.84%, and 58.77%, respectively, and the maximum load was 63.85%, 34.63%, and 10.76%, respectively of that prior to degradation. The results showed that the degradation rate of the silk graft and the loss of mechanical properties In Vivo were faster than the results obtained in the In Vitro experiments. In addition, there were no significant differences in secretion of serum IL-6 and TNF-α between the experimental and normal rabbits (P >0.05), suggesting no obvious inflammatory reaction. The findings suggest that the weft-knitted silk mesh-like grafts have good mechanical properties, histocompatibility, and In Vivo degradation rate, and therefore represent a candidate material for artificial ligament

scholarly journals HPV-18 E6 Oncoprotein and Its Spliced Isoform E6*I Regulate the Wnt/β-Catenin Cell Signaling Pathway through the TCF-4 Transcriptional Factor

2018 ◽  
Vol 19 (10) ◽  
pp. 3153 ◽  
Author(s):  
J. Muñoz-Bello ◽  
Leslie Olmedo-Nieva ◽  
Leonardo Castro-Muñoz ◽  
Joaquín Manzo-Merino ◽  
Adriana Contreras-Paredes ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Promote Cell Proliferation ◽  
E6 And E7 ◽  
Hpv 18

The Wnt/β-catenin signaling pathway regulates cell proliferation and differentiation and its aberrant activation in cervical cancer has been described. Persistent infection with high risk human papillomavirus (HR-HPV) is the most important factor for the development of this neoplasia, since E6 and E7 viral oncoproteins alter cellular processes, promoting cervical cancer development. A role of HPV-16 E6 in Wnt/β-catenin signaling has been proposed, although the participation of HPV-18 E6 has not been previously studied. The aim of this work was to investigate the participation of HPV-18 E6 and E6*I, in the regulation of the Wnt/β-catenin signaling pathway. Here, we show that E6 proteins up-regulate TCF-4 transcriptional activity and promote overexpression of Wnt target genes. In addition, it was demonstrated that E6 and E6*I bind to the TCF-4 (T cell factor 4) and β-catenin, impacting TCF-4 stabilization. We found that both E6 and E6*I proteins interact with the promoter of Sp5, in vitro and in vivo. Moreover, although differences in TCF-4 transcriptional activation were found among E6 intratype variants, no changes were observed in the levels of regulated genes. Furthermore, our data support that E6 proteins cooperate with β-catenin to promote cell proliferation.

Effects of Cyclic Stress on the Mechanical Properties of Cultured Collagen Fascicles from the Rabbit Patellar Tendon

2003 ◽  
Vol 125 (6) ◽  
pp. 893-901 ◽  
Author(s):  
Ei Yamamoto ◽  
Susumu Tokura ◽  
Kozaburo Hayashi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Patellar Tendon ◽  
Control Level ◽  
Quadratic Function ◽  
Peak Stress ◽  
Cyclic Stress ◽  
Original Strength

Effects of cyclic stress on the mechanical properties of collagen fascicles were studied by in vitro tissue culture experiments. Collagen fascicles (approximately 300 μm in diameter) obtained from the rabbit patellar tendon were applied cyclic load at 4 Hz for one hour per day during culture period for one or two weeks, and then their mechanical properties were determined using a micro-tensile tester. There was a statistically significant correlation between tensile strength and applied peak stress in the range of 0 to 5 MPa, and the relation was expressed by a quadratic function. The maximum strength (19.4 MPa) was obtained at the applied peak stress of 1.8 MPa. The tensile strength of fascicles were within a range of control values, if they were cultured under peak stresses between 1.1 and 2.6 MPa. Similar results were also observed in the tangent modulus, which was maintained at control level under applied peak stresses between 0.9 and 2.8 MPa. The stress of 0.9 to 1.1 MPa is equivalent to approximately 40% of the in vivo peak stress which is developed in the intact rabbit patellar tendon by running, whereas that of 2.6 to 2.8 MPa corresponds to approximately 120% of the in vivo peak stress. Therefore, the fascicles cultured under applied peak stresses of lower than 40% and higher than 120% of the in vivo peak stress do not keep the original strength and modulus. These results indicate that the mechanical properties of cultured collagen fascicles strongly depend upon the magnitude of the stress applied during culture, which are similar to our previous results observed in stress-shielded and overstressed patellar tendons in vivo.

scholarly journals Injectable Non-leaching Tissue-mimetic Bottlebrush Elastomers: A New Platform for Advancing Reconstructive Surgery

2020 ◽  
Author(s):  
Erfan Dashtimoghadam ◽  
Farahnaz Fahimipour ◽  
Andrew Keith ◽  
Foad Vashahi ◽  
Pavel Popryadukhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reconstructive Surgery ◽  
Biomedical Applications ◽  
The Body ◽  
Surrounding Tissue ◽  
Curing Time ◽  
Materials Used ◽  
Significant Health

Abstract Current materials used in biomedical devices do not match tissue’s mechanical properties and leach various chemicals into the body. These deficiencies pose significant health risks that are further exacerbated by invasive implantation procedures. Herein, we leverage the brush-like polymer architecture to design and administer minimally invasive injectable elastomers that cure in vivo into leachable-free implants with mechanical properties matching the surrounding tissue. This strategy allows tuning curing time from minutes to hours, which empowers a broad range of biomedical applications from rapid wound sealing to time-intensive reconstructive surgery. These injectable elastomers support in vitro cell proliferation, while also demonstrating in vivo implant integrity with a mild inflammatory response and minimal fibrotic encapsulation.

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