scholarly journals PEDOT:PSS-Containing Nanohydroxyapatite/Chitosan Conductive Bionanocomposite Scaffold: Fabrication and Evaluation

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Alireza Lari ◽  
Tao Sun ◽  
Naznin Sultana
Keyword(s):  
Cell Attachment ◽  
Three Dimensional ◽  
Mouse Fibroblast ◽  
Cytotoxicity Test ◽  
X Ray ◽  
Chitosan Matrix ◽  
Conductive Properties ◽  
Electron Microscope Image ◽  
Highly Porous

Conductive poly(3,4-ethylenedioxythiophene)-poly(4-styrene sulfonate) (PEDOT:PSS) was incorporated into nanohydroxyapatite/chitosan (nHA/CS) composite scaffolds through a freezing and lyophilization technique. The bionanocomposite conductive scaffold was then characterized using several techniques. A scanning electron microscope image showed that the nHA and PEDOT:PSS were dispersed homogeneously in the chitosan matrix, which was also confirmed by energy-dispersive X-ray (EDX) analysis. The conductive properties were measured using a digital multimeter. The weight loss and water-uptake properties of the bionanocomposite scaffolds were studiedin vitro. Anin vitrocell cytotoxicity test was carried out using mouse fibroblast (L929) cells cultured onto the scaffolds. Using a freezing and lyophilization technique, it was possible to fabricate three-dimensional, highly porous, and interconnected PEDOT:PSS/nHA/CS scaffolds with good handling properties. The porosity was 74% and the scaffold’s conductivity was9.72±0.78 μS. The surface roughness was increased with the incorporation of nHA and PEDOT:PSS into the CS scaffold. The compressive mechanical properties increased significantly with the incorporation of nHA but did not change significantly with the incorporation of PEDOT:PSS. The PEDOT:PSS-containing nHA/CS scaffold exhibited significantly higher cell attachment. The PEDOT:PSS/nHA/CS scaffold could be a potential bionanocomposite conductive scaffold for tissue engineering.

scholarly journals Engineering of Chitosan-Hydroxyapatite-Magnetite Hierarchical Scaffolds for Guided Bone Growth

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2321 ◽  
Author(s):  
Pistone ◽  
Celesti ◽  
Piperopoulos ◽  
Ashok ◽  
Cembran ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bone Growth ◽  
Cell Attachment ◽  
X Ray Diffraction ◽  
Culture Studies ◽  
X Ray ◽  
Support Cell ◽  
Chitosan Matrix

Bioabsorbable materials have received increasing attention as innovative systems for the development of osteoconductive biomaterials for bone tissue engineering. In this paper, chitosan-based composites were synthesized adding hydroxyapatite and/or magnetite in a chitosan matrix by in situ precipitation technique. Composites were characterized by optical and electron microscopy, thermogravimetric analyses (TGA), x-ray diffraction (XRD), and in vitro cell culture studies. Hydroxyapatite and magnetite were found to be homogeneously dispersed in the chitosan matrix and the composites showed superior biocompatibility and the ability to support cell attachment and proliferation; in particular, the chitosan/hydroxyapatite/magnetite composite (CS/HA/MGN) demonstrated superior bioactivity with respect to pure chitosan (CS) and to the chitosan/hydroxyapatite (CS/HA) scaffolds

scholarly journals X-Ray Microtomography Studies of Tannin-Derived Organic and Carbon Foams

2009 ◽  
Vol 15 (5) ◽  
pp. 384-394 ◽  
Author(s):  
G. Tondi ◽  
S. Blacher ◽  
A. Léonard ◽  
A. Pizzi ◽  
V. Fierro ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Mathematical Treatment ◽  
Independent Data ◽  
Scanning Electron Microscope Image ◽  
X Ray ◽  
Carbon Foams ◽  
First Time ◽  
Electron Microscope Image ◽  
Highly Porous ◽  
Porosity Fraction

AbstractTannin-based rigid foams of different bulk densities and their carbonized counterparts were investigated for the first time by X-ray microtomography. This method allowed acquisition of three-dimensional pictures of such highly porous materials. Through mathematical treatment of the images, extremely useful physical characteristics such as porosity, fraction of open cells, connectivity, tortuosity, and pore-size distribution were determined as a function of the foam's density. The obtained information was compared with independent data derived from pycnometry measurements and scanning electron microscope image analysis. The agreement was shown to be acceptable in the limit of the accuracy of the laboratory microtomograph (4 μm). Moreover, recalculating properties like permeability were shown to be quite possible based on the results of standard microtomography data.

scholarly journals Osteogenic Properties of 3D-Printed Silica-Carbon-Calcite Composite Scaffolds: Novel Approach for Personalized Bone Tissue Regeneration

2021 ◽  
Vol 22 (2) ◽  
pp. 475
Author(s):  
Parastoo Memarian ◽  
Francesco Sartor ◽  
Enrico Bernardo ◽  
Hamada Elsayed ◽  
Batur Ercan ◽  
...  
Keyword(s):  
Osteogenic Differentiation ◽  
Bone Tissue ◽  
Cell Attachment ◽  
Three Dimensional ◽  
Bone Tissue Regeneration ◽  
Hemolysis Assay ◽  
Novel Approach ◽  
Related Transcription Factor ◽  
Diphenyl Tetrazolium Bromide

Carbon enriched bioceramic (C-Bio) scaffolds have recently shown exceptional results in terms of their biological and mechanical properties. The present study aims at assessing the ability of the C-Bio scaffolds to affect the commitment of canine adipose-derived mesenchymal stem cells (cAD-MSCs) and investigating the influence of carbon on cell proliferation and osteogenic differentiation of cAD-MSCs in vitro. The commitment of cAD-MSCs to an osteoblastic phenotype has been evaluated by expression of several osteogenic markers using real-time PCR. Biocompatibility analyses through 3-(4,5-dimethyl- thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), lactate dehydrogenase (LDH) activity, hemolysis assay, and Ames test demonstrated excellent biocompatibility of both materials. A significant increase in the extracellular alkaline phosphatase (ALP) activity and expression of runt-related transcription factor (RUNX), ALP, osterix (OSX), and receptor activator of nuclear factor kappa-Β ligand (RANKL) genes was observed in C-Bio scaffolds compared to those without carbon (Bio). Scanning electron microscopy (SEM) demonstrated excellent cell attachment on both material surfaces; however, the cellular layer on C-Bio fibers exhibited an apparent secretome activity. Based on our findings, graphene can improve cell adhesion, growth, and osteogenic differentiation of cAD-MSCs in vitro. This study proposed carbon as an additive for a novel three-dimensional (3D)-printable biocompatible scaffold which could become the key structural material for bone tissue reconstruction.

scholarly journals Improved Bioactivity of 3D Printed Porous Titanium Alloy Scaffold with Chitosan/Magnesium-Calcium Silicate Composite for Orthopaedic Applications

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 203 ◽  
Author(s):  
Chun-Hao Tsai ◽  
Chih-Hung Hung ◽  
Che-Nan Kuo ◽  
Cheng-Yu Chen ◽  
Yu-Ning Peng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Silicate ◽  
Cell Attachment ◽  
Three Dimensional ◽  
Bone Defects ◽  
Metal Alloys ◽  
Potential Candidate ◽  
Natural Bone

Recently, cases of bone defects have been increasing incrementally. Thus, repair or replacement of bone defects is gradually becoming a huge problem for orthopaedic surgeons. Three-dimensional (3D) scaffolds have since emerged as a potential candidate for bone replacement, of which titanium (Ti) alloys are one of the most promising candidates among the metal alloys due to their low cytotoxicity and mechanical properties. However, bioactivity remains a problem for metal alloys, which can be enhanced using simple immersion techniques to coat bioactive compounds onto the surface of Ti–6Al–4V scaffolds. In our study, we fabricated magnesium-calcium silicate (Mg–CS) and chitosan (CH) compounds onto Ti–6Al–4V scaffolds. Characterization of these surface-modified scaffolds involved an assessment of physicochemical properties as well as mechanical testing. Adhesion, proliferation, and growth of human Wharton’s Jelly mesenchymal stem cells (WJMSCs) were assessed in vitro. In addition, the cell attachment morphology was examined using scanning electron microscopy to assess adhesion qualities. Osteogenic and mineralization assays were conducted to assess osteogenic expression. In conclusion, the Mg–CS/CH coated Ti–6Al–4V scaffolds were able to exhibit and retain pore sizes and their original morphologies and architectures, which significantly affected subsequent hard tissue regeneration. In addition, the surface was shown to be hydrophilic after modification and showed mechanical strength comparable to natural bone. Not only were our modified scaffolds able to match the mechanical properties of natural bone, it was also found that such modifications enhanced cellular behavior such as adhesion, proliferation, and differentiation, which led to enhanced osteogenesis and mineralization downstream. In vivo results indicated that Mg–CS/CH coated Ti–6Al–4V enhances the bone regeneration and ingrowth at the critical size bone defects of rabbits. These results indicated that the proposed Mg–CS/CH coated Ti–6Al–4V scaffolds exhibited a favorable, inducive micro-environment that could serve as a promising modification for future bone tissue engineering scaffolds.

scholarly journals Gradient Chitosan Hydrogels Modified with Graphene Derivatives and Hydroxyapatite: Physiochemical Properties and Initial Cytocompatibility Evaluation

2020 ◽  
Vol 21 (14) ◽  
pp. 4888
Author(s):  
Karolina Kosowska ◽  
Patrycja Domalik-Pyzik ◽  
Małgorzata Sekuła-Stryjewska ◽  
Sylwia Noga ◽  
Joanna Jagiełło ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Mechanical Analysis ◽  
Biological Properties ◽  
Human Umbilical Cord ◽  
Tissue Engineering Scaffolds ◽  
X Ray ◽  
Chitosan Matrix ◽  
Graphene Derivatives

In this study, we investigated preparation of gradient chitosan-matrix hydrogels through a novel freezing–gelling–thawing method. The influence of three types of graphene family materials (GFM), i.e., graphene oxide (GO), reduced graphene oxide (rGO), and poly(ethylene glycol) grafted graphene oxide (GO-PEG), as well as hydroxyapatite (HAp) on the physicochemical and biological properties of the composite hydrogels was examined in view of their potential applicability as tissue engineering scaffolds. The substrates and the hydrogel samples were thoroughly characterized by X-ray photoelectron spectroscopy, X-ray diffractometry, infrared spectroscopy, digital and scanning electron microscopy, rheological and mechanical analysis, in vitro chemical stability and bioactivity assays, as well as initial cytocompatibility evaluation with human umbilical cord Wharton’s jelly mesenchymal stem cells (hUC-MSCs). We followed the green-chemistry approach and avoided toxic cross-linking agents, using instead specific interactions of our polymer matrix with tannic acid, non-toxic physical cross-linker, and graphene derivatives. It was shown that the most promising are the gradient hydrogels modified with GO-PEG and HAp.

scholarly journals The biological seal of the implant–soft tissue interface evaluated in a tissue-engineered oral mucosal model

2012 ◽  
Vol 9 (77) ◽  
pp. 3528-3538 ◽  
Author(s):  
Wen L. Chai ◽  
Ian M. Brook ◽  
Anders Palmquist ◽  
Richard van Noort ◽  
Keyvan Moharamzadeh
Keyword(s):  
Soft Tissue ◽  
Cell Attachment ◽  
Tritiated Water ◽  
Three Dimensional ◽  
Permeability Test ◽  
Significant Difference ◽  
Surface Topographies ◽  
Tissue Interface

For dental implants, it is vital that an initial soft tissue seal is achieved as this helps to stabilize and preserve the peri-implant tissues during the restorative stages following placement. The study of the implant–soft tissue interface is usually undertaken in animal models. We have developed an in vitro three-dimensional tissue-engineered oral mucosal model (3D OMM), which lends itself to the study of the implant–soft tissue interface as it has been shown that cells from the three-dimensional OMM attach onto titanium (Ti) surfaces forming a biological seal (BS). This study compares the quality of the BS achieved using the three-dimensional OMM for four types of Ti surfaces: polished, machined, sandblasted and anodized (TiUnite). The BS was evaluated quantitatively by permeability and cell attachment tests. Tritiated water (HTO) was used as the tracing agent for the permeability test. At the end of the permeability test, the Ti discs were removed from the three-dimensional OMM and an Alamar Blue assay was used for the measurement of residual cells attached to the Ti discs. The penetration of the HTO through the BS for the four types of Ti surfaces was not significantly different, and there was no significant difference in the viability of residual cells that attached to the Ti surfaces. The BS of the tissue-engineered oral mucosa around the four types of Ti surface topographies was not significantly different.

Requirements for the Manufacturing of Scaffold Biomaterial With Features at Multiple Scales

2005 ◽  
Author(s):  
I. M. Sebastine ◽  
D. J. Williams
Keyword(s):  
Tissue Engineering ◽  
Multiple Scales ◽  
Cell Attachment ◽  
Structural Parameters ◽  
Complex Function ◽  
Three Dimensional ◽  
Cell Orientation ◽  
Length Scales

Tissue engineering aims to restore the complex function of diseased tissue using cells and scaffold materials. Tissue engineering scaffolds are three-dimensional (3D) structures that assist in the tissue engineering process by providing a site for cells to attach, proliferate, differentiate and secrete an extra-cellular matrix, eventually leading cells to form a neo-tissue of predetermined, three-dimensional shape and size. For a scaffold to function effectively, it must possess the optimum structural parameters conducive to the cellular activities that lead to tissue formation; these include cell penetration and migration into the scaffold, cell attachment onto the scaffold substrate, cell spreading and proliferation and cell orientation. In vivo, cells are organized in functional tissue units that repeat on the order of 100 μm. Fine scaffold features have been shown to provide control over attachment, migration and differentiation of cells. In order to design such 3D featured constructs effectively understanding the biological response of cells across length scales from nanometer to millimeter range is crucial. Scaffold biomaterials may need to be tailored at three different length scales: nanostructure (<1μm), microstructure (<20–100μm), and macrostructure (>100μm) to produce biocompatible and biofunctional scaffolds that closely resemble the extracellular matrix (ECM) of the natural tissue environment and promote cell adhesion, attachment, spreading, orientation, rate of movement, and activation. Identification of suitable fabrication techniques for manufacturing scaffolds with the required features at multiple scales is a significant challenge. This review highlights the effect and importance of the features of scaffolds that can influence the behaviour of cells/tissue at different length scales in vitro to increase our understanding of the requirements for the manufacture of functional 3D tissue constructs.

scholarly journals Complete In Vitro Assembly of the Reovirus Outer Capsid Produces Highly Infectious Particles Suitable for Genetic Studies of the Receptor-Binding Protein

2001 ◽  
Vol 75 (11) ◽  
pp. 5335-5342 ◽  
Author(s):  
Kartik Chandran ◽  
Xing Zhang ◽  
Norman H. Olson ◽  
Stephen B. Walker ◽  
James D. Chappell ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Cell Attachment ◽  
Molecular Genetic ◽  
Three Dimensional ◽  
Host Cells ◽  
Dimensional Structure ◽  
Dependent Manner ◽  
Viral Attachment ◽  
Structure Assembly

ABSTRACT Mammalian reoviruses, prototype members of theReoviridae family of nonenveloped double-stranded RNA viruses, use at least three proteins—ς1, μ1, and ς3—to enter host cells. ς1, a major determinant of cell tropism, mediates viral attachment to cellular receptors. Studies of ς1 functions in reovirus entry have been restricted by the lack of methodologies to produce infectious virions containing engineered mutations in viral proteins. To mitigate this problem, we produced virion-like particles by “recoating” genome-containing core particles that lacked ς1, μ1, and ς3 with recombinant forms of these proteins in vitro. Image reconstructions from cryoelectron micrographs of the recoated particles revealed that they closely resembled native virions in three-dimensional structure, including features attributable to ς1. The recoated particles bound to and infected cultured cells in a ς1-dependent manner and were approximately 1 million times as infectious as cores and 0.5 times as infectious as native virions. Experiments with recoated particles containing recombinant ς1 from either of two different reovirus strains confirmed that differences in cell attachment and infectivity previously observed between those strains are determined by the ς1 protein. Additional experiments showed that recoated particles containing ς1 proteins with engineered mutations can be used to analyze the effects of such mutations on the roles of particle-bound ς1 in infection. The results demonstrate a powerful new system for molecular genetic dissections of ς1 with respect to its structure, assembly into particles, and roles in entry.

Cytocompatibility Comparative Study of Hydroxyapatite Coating on Titanium Alloy Treated with Two Chemical Routes

2013 ◽  
Vol 658 ◽  
pp. 61-66
Author(s):  
Qing Zong Si ◽  
Xiao Li An ◽  
Yang Li ◽  
Bin Liu ◽  
Jin Qing Wang
Keyword(s):  
Titanium Alloy ◽  
In Vitro Cytotoxicity ◽  
Combination Method ◽  
Cytotoxicity Test ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Ha Coating ◽  
Cell Adhesion And Proliferation

In order to prepare bioactive hydroxyapatite (Ca10 (PO4)6(OH) 2, HA) coating with ideal biocompatibility, the surface of titanium alloy was treated with the two kinds of chemical methods, which are the acid-alkali-combination method and Self-polymerization-adhesion of dopamine. After pretreatment, the treated titanium alloy plates were immersed in simulated body fluid (SBF) to form HA coating on their surface. The chemical composition of the coating was analyzed by an X-ray diffraction (XRD) and the morphology was observed by a scanning electron microscope (SEM). After that, the plates were training in vitro cytotoxicity test with MC3T3-E1 osteoblasts. Compared with the results of cell culture, the method of Self- polymerization -adhesion of dopamine showed better cell adhesion and proliferation..

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