scholarly journals The influence of supercritical foaming conditions on properties of polymer scaffolds for tissue engineering

2017 ◽  
Vol 38 (4) ◽  
pp. 535-541 ◽  
Author(s):  
Katarzyna Kosowska ◽  
Marek Henczka
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Process Parameters ◽  
Three Dimensional ◽  
Experimental Investigations ◽  
Porous Structures ◽  
Static Compression ◽  
Precise Control ◽  
Foaming Process ◽  
Supercritical Foaming

Abstract The results of experimental investigations into foaming process of poly(ε-caprolactone) using supercritical CO2 are presented. The objective of the study was to explore the aspects of fabrication of biodegradable and biocompatible scaffolds that can be applied as a temporary three-dimensional extracellular matrix analog for cells to grow into a new tissue. The influence of foaming process parameters, which have been proven previously to affect significantly scaffold bioactivity, such as pressure (8-18 MPa), temperature (323-373 K) and time of saturation (1-6 h) on microstructure and mechanical properties of produced polymer porous structures is presented. The morphology and mechanical properties of considered materials were analyzed using a scanning electron microscope (SEM), x-ray microtomography (μ-CT) and a static compression test. A precise control over porosity and morphology of obtained polymer porous structures by adjusting the foaming process parameters has been proved. The obtained poly(ε-caprolactone) solid foams prepared using scCO2 have demonstrated sufficient mechanical strength to be applied as scaffolds in tissue engineering.

scholarly journals Is Dialdehyde Chitosan a Good Substance to Modify Physicochemical Properties of Biopolymeric Materials?

2021 ◽  
Vol 22 (7) ◽  
pp. 3391
Author(s):  
Sylwia Grabska-Zielińska ◽  
Alina Sionkowska ◽  
Ewa Olewnik-Kruszkowska ◽  
Katarzyna Reczyńska ◽  
Elżbieta Pamuła
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Physicochemical Properties ◽  
Silk Fibroin ◽  
Three Dimensional ◽  
Microscopy Imaging ◽  
Maximum Deformation ◽  
One Step ◽  
Chitosan Blends ◽  
Fourier Transfer Infrared Spectroscopy

The aim of this work was to compare physicochemical properties of three dimensional scaffolds based on silk fibroin, collagen and chitosan blends, cross-linked with dialdehyde starch (DAS) and dialdehyde chitosan (DAC). DAS was commercially available, while DAC was obtained by one-step synthesis. Structure and physicochemical properties of the materials were characterized using Fourier transfer infrared spectroscopy with attenuated total reflectance device (FTIR-ATR), swelling behavior and water content measurements, porosity and density observations, scanning electron microscopy imaging (SEM), mechanical properties evaluation and thermogravimetric analysis. Metabolic activity with AlamarBlue assay and live/dead fluorescence staining were performed to evaluate the cytocompatibility of the obtained materials with MG-63 osteoblast-like cells. The results showed that the properties of the scaffolds based on silk fibroin, collagen and chitosan can be modified by chemical cross-linking with DAS and DAC. It was found that DAS and DAC have different influence on the properties of biopolymeric scaffolds. Materials cross-linked with DAS were characterized by higher swelling ability (~4000% for DAS cross-linked materials; ~2500% for DAC cross-linked materials), they had lower density (Coll/CTS/30SF scaffold cross-linked with DAS: 21.8 ± 2.4 g/cm3; cross-linked with DAC: 14.6 ± 0.7 g/cm3) and lower mechanical properties (maximum deformation for DAC cross-linked scaffolds was about 69%; for DAS cross-linked scaffolds it was in the range of 12.67 ± 1.51% and 19.83 ± 1.30%) in comparison to materials cross-linked with DAC. Additionally, scaffolds cross-linked with DAS exhibited higher biocompatibility than those cross-linked with DAC. However, the obtained results showed that both types of scaffolds can provide the support required in regenerative medicine and tissue engineering. The scaffolds presented in the present work can be potentially used in bone tissue engineering to facilitate healing of small bone defects.

Application of Microbial Polyesters-Polyhydroxyalkanoates as Tissue Engineering Materials

2005 ◽  
Vol 288-289 ◽  
pp. 437-440 ◽  
Author(s):  
Guo Qiang Chen ◽  
Qiong Wu ◽  
Ya Wu Wang ◽  
Zhong Zheng
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Surface Treatment ◽  
Surface Properties ◽  
Three Dimensional ◽  
Material Surface ◽  
New Class ◽  
Molecular Studies ◽  
Cartilage Cells ◽  
Engineering Materials

Poly(hydroxybutyrate-co-hydroxyhexanoate) (PHBHHx) has improved mechanical properties over the existing PHA and our results have shown that PHBHHx has better biocompatibility over polyhydroxybutyrate (PHB) and polylactic acid (PLA). Surface treatment with lipases dramatically changed the material surface properties and increased the biocompatibility of the PHBHHx. PHBHHx and its PHB blends had been used to make three dimensional structures and it has been found that cartilage, osteoblast, and fibroblasts all showed strong growth on the PHBHHx scaffolds. The growth was much better compared with PLA. The molecular studies also showed that mRNA encoding cartilages were strongly expressed when cartilage cells were grown on the PHBHHx. As PHBHHx has strong mechanical properties, easily processible and biodegradable, this material can be used to develop a new class of tissue engineering materials.

scholarly journals Biomimicry in Bio-Manufacturing: Developments in Melt Electrospinning Writing Technology Towards Hybrid Biomanufacturing

2019 ◽  
Vol 9 (17) ◽  
pp. 3540 ◽  
Author(s):  
Ferdows Afghah ◽  
Caner Dikyol ◽  
Mine Altunbek ◽  
Bahattin Koc
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Cell Attachment ◽  
Three Dimensional ◽  
Future Perspective ◽  
Melt Electrospinning ◽  
Wide Range ◽  
Challenges And Opportunities ◽  
Potential Applications ◽  
Homogeneous Cell

Melt electrospinning writing has been emerged as a promising technique in the field of tissue engineering, with the capability of fabricating controllable and highly ordered complex three-dimensional geometries from a wide range of polymers. This three-dimensional (3D) printing method can be used to fabricate scaffolds biomimicking extracellular matrix of replaced tissue with the required mechanical properties. However, controlled and homogeneous cell attachment on melt electrospun fibers is a challenge. The combination of melt electrospinning writing with other tissue engineering approaches, called hybrid biomanufacturing, has introduced new perspectives and increased its potential applications in tissue engineering. In this review, principles and key parameters, challenges, and opportunities of melt electrospinning writing, and particularly, recent approaches and materials in this field are introduced. Subsequently, hybrid biomanufacturing strategies are presented for improved biological and mechanical properties of the manufactured porous structures. An overview of the possible hybrid setups and applications, future perspective of hybrid processes, guidelines, and opportunities in different areas of tissue/organ engineering are also highlighted.

Experimental investigations into ultrasonic-assisted double-disk magnetic abrasive finishing of two paramagnetic materials

2015 ◽  
Vol 231 (6) ◽  
pp. 1021-1038 ◽  
Author(s):  
Prateek Kala ◽  
Pulak M Pandey
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Experimental Investigations ◽  
Magnetic Abrasive Finishing ◽  
Force Microscopy ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Ultrasonic Assisted ◽  
Paramagnetic Materials ◽  
Pulse On Time

This article evaluates the finishing performance of ultrasonic-assisted double-disk magnetic abrasive finishing process on two paramagnetic materials (copper alloy and stainless steel) with different mechanical properties such as flow stress, hardness, shear modulus, and so on. The finishing experiments were performed based on response surface methodology. The results obtained after finishing have been analyzed to determine the effect of different process parameters such as working gap, rotational speed, and pulse-on time of ultrasonic vibration for both work materials and to study various interaction effects that may significantly affect the finishing performance by the process. The outcome of analysis for the two different work materials has been critically compared to understand the effect of the considered process parameters on the finishing performance of the process based on mechanical properties of the workpiece such as hardness. Furthermore, the scanning electron microscopy and atomic force microscopy were carried on the workpiece surface to understand the possible mechanism of material removal and the surface morphology produced after the finishing process.

Combined Effects of Scaffold Material and Mechanical Stimulation on the Formation of Tissue Engineered Constructs Using Tendon and Ligament Progenitor Cells

2013 ◽  
Author(s):  
Andrew P. Breidenbach ◽  
Nathaniel A. Dyment ◽  
Yinhui Lu ◽  
Jason T. Shearn ◽  
David W. Rowe ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Progenitor Cells ◽  
Three Dimensional ◽  
Musculoskeletal Injuries ◽  
Combined Effects ◽  
Joint Movement ◽  
Scaffold Material ◽  
Ligament Injuries ◽  
Promising Alternative

Tendon and ligament injuries account for one-third of all musculoskeletal injuries [1]. Collagen fibrils in these mechanosensitive tissues transmit forces to mobilize and stabilize joint movement. Donor tissues used to repair these tissues often lack the mechanical properties of the tissue they are replacing. One promising alternative using tissue engineering combines stem/progenitor cells in three-dimensional tissue engineered constructs (TECs).

scholarly journals Alginate/Gelatin Hydrogels Reinforced with TiO2 and β-TCP Fabricated by Microextrusion-based Printing for Tissue Regeneration

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 457 ◽  
Author(s):  
Rodrigo Urruela-Barrios ◽  
Erick Ramírez-Cedillo ◽  
A. Díaz de León ◽  
Alejandro Alvarez ◽  
Wendy Ortega-Lara
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Tissue Regeneration ◽  
Average Pore Size ◽  
Three Dimensional ◽  
Engineering Applications ◽  
Average Pore ◽  
Viscous Deformation ◽  
Freeze Dried ◽  
3D Printed

Three-dimensional (3D) printing technologies have become an attractive manufacturing process to fabricate scaffolds in tissue engineering. Recent research has focused on the fabrication of alginate complex shaped structures that closely mimic biological organs or tissues. Alginates can be effectively manufactured into porous three-dimensional networks for tissue engineering applications. However, the structure, mechanical properties, and shape fidelity of 3D-printed alginate hydrogels used for preparing tissue-engineered scaffolds is difficult to control. In this work, the use of alginate/gelatin hydrogels reinforced with TiO2 and β-tricalcium phosphate was studied to tailor the mechanical properties of 3D-printed hydrogels. The hydrogels reinforced with TiO2 and β-TCP showed enhanced mechanical properties up to 20 MPa of elastic modulus. Furthermore, the pores of the crosslinked printed structures were measured with an average pore size of 200 μm. Additionally, it was found that as more layers of the design were printed, there was an increase of the line width of the bottom layers due to its viscous deformation. Shrinkage of the design when the hydrogel is crosslinked and freeze dried was also measured and found to be up to 27% from the printed design. Overall, the proposed approach enabled fabrication of 3D-printed alginate scaffolds with adequate physical properties for tissue engineering applications.

scholarly journals Review on globularization of titanium alloy with lamellar colony

2020 ◽  
Vol 7 ◽  
pp. 18 ◽  
Author(s):  
Jian Zhang ◽  
Hongwei Li ◽  
Mei Zhan
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Prediction Models ◽  
Three Dimensional ◽  
Beta Phase ◽  
Hot Working ◽  
Homogeneous Microstructure ◽  
Precise Control ◽  
Microstructure Parameters ◽  
Working Parameters

The globularization of titanium alloy with lamellar colony during hot working is an important way to obtain fine and homogeneous microstructure which has excellent mechanical properties. Because of its great technological importance, globularization has captured wide attention and much research. This paper conducts a systematic study on state of art on globularization of titanium alloy, which mainly includes globularization mechanism, prediction model and the effects of hot-working parameters and microstructure parameters. Firstly, the shortcomings of the well-known globularization mechanisms (dynamic recrystallization, boundary splitting, shearing mechanism and termination migration) were summarized. Moreover, the comparison and analysis of prediction models were accomplished through tabular form. In addition, the effects of hot-working parameters (strain, strain rate, temperature) and microstructure parameters (alpha/beta interface, geometry necessary dislocation and high temperature parent beta phase) were systematically summarized and analyzed. Meanwhile, this study also explores those difficulties and challenges faced by precise control on globularization. Finally, an outlook and development tendency of globularization of titanium alloy are also provided, which includes microstructure evolution of three-dimensional lamellar alpha, the relationship between lamellar colony and mechanical properties and the effect of severe plastic deformation on globularization.

Porous and strong three-dimensional carbon nanotube coated ceramic scaffolds for tissue engineering

2015 ◽  
Vol 3 (42) ◽  
pp. 8337-8347 ◽  
Author(s):  
P. Newman ◽  
Z. Lu ◽  
S. I. Roohani-Esfahani ◽  
T. L. Church ◽  
M. Biro ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Tissue Engineering ◽  
Carbon Nanotube ◽  
Three Dimensional ◽  
Biological Properties ◽  
Porous Structures ◽  
High Quality

A method to coat high-quality uniform coatings of carbon nanotubes throughout 3D porous structures is developed. Testing of their physical and biological properties demonstrate their potential for application in tissue engineering.

Experimental Investigations on the Influence Factors of Paperboard Deep Drawing

2012 ◽  
Vol 200 ◽  
pp. 511-515
Author(s):  
Ya Jie Li ◽  
Zhong Ji ◽  
Ren Liu ◽  
Yi Guo Luan ◽  
Chao Zheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Surface Quality ◽  
Process Parameters ◽  
Deep Drawing ◽  
Influence Factors ◽  
Experimental Investigations ◽  
Blank Shape ◽  
Shape And Size

Experiments were conducted to study which type of paperboard and process parameters are suitable for deep drawing of paperboard into trays. The tray is a shallow rectangle box with round corners, wavy bottom and indented walls. Paperboard used in this paper is anisotropic, and its mechanical properties include tensile strength and elongation. Results show that paperboard with the basis weight of 260g/m2 is the suitable type. Proper moisture can improve the tensile strength and ensure the surface quality. Improper blank shape and size can result in wrinkling and cracking.

Reinforcing of Porous Hydroxyapatite Ceramics with Hydroxyapatite Fibres for Enhanced Bone Tissue Engineering

2011 ◽  
Vol 10 ◽  
pp. 67-73 ◽  
Author(s):  
Lie Feng Liang ◽  
Xiao Yi Han ◽  
Xiao Cai Yan ◽  
Jie Weng
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Test Machine ◽  
Porous Structures ◽  
X Ray Diffraction ◽  
Porous Hydroxyapatite ◽  
Hydroxyapatite Ceramics ◽  
Ceramic Implants

Porous hydroxyapatite (HA) ceramic implants have attracted attention in bone tissue engineering due to their excellent bioactivity and biocompatibility due to their chemical similarity with the mineral component of natural bone. Unfortunately, HA when is formed into porous structures exhibits very low compression strength. In this study, fabrication of porous HA ceramic scaffolds containing HA fibers is presented. The primary aim of the study is to improve mechanical properties of the scaffold by introducing the fiber with uniform component relative to the scaffold. Scanning electron microscopy was used to observe the surface morphology and pore size of the scaffold. X-ray diffraction (XRD) was used to detect the phase composition and crystallinity of the scaffold. The compressive strength was determined using a universal material test machine. The results and the characterizations demonstrate the addition of HA fiber could enhance the uniformity of mechanical properties among samples and also the strength for a given open porosity.

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